A DICTIONARY OF ARTS, MANUFACTURES AND MINES; CONTAINING. CLEAR EXPOSITION OF THEIR PRINCIPLES AND PRACTICE BY ANDREW URE, M.D., F.R.S. M.G.S. M.A.S. LOND.; M. ACAD. N.S. PHILAD.; It. PH. SOC. N. GERM. HANOV.; MULII. ETC. ETC.,LLUSTRATED WITH NEARLY SIXTEEN'HUNDRED ENGRAVINGS ON WOOD. REPRINTED ENTIRE FROM THE LAST CORRECTED AND GREATLY ENLARGED ENGLISI EDITION. IN TWO VOLUMES.-VOL. I. NEW YORK: D. APPLETON & CO., 90, 92 & 94 GRAND STREET. 1870. L.= PREFACE. IT is the business of operative industry to produce, transform, and distribute all such material objects as are suited to satisfy the wants of man kind. The primary production of these objects is assigned to the husbandman, the fisherman, and the miner; their transformation to the manufacturer and artisan; and their distribution to the engineer, shipwright, and sailor.* The unworked or raw materials are derived,-1 from the organic processes of vegetables and animals, conducted either without or with the fostering care of man; 2. from the boundless stores of mineral and metallic wealth, arranged upon or within the surface of the earth by the benignant Parsnt of our being, in the fittest condition to exercise our physical and intellectual powers in turning them to the uses of life. The task which I have undertaken in the present work, is to describe and explain the transformations of these primary materials, by mechanical and chemical agencies, into general objects of exchangeable value, leaving, on the one hand, to the mechanical engineer, that of investigating the motive powers of transformation and transport; and, on the other hand, to the handicraftsman, that of tracing their modifications into objects of special or local demand. Contemplated in this view, an art or manufacture may be defined to be that species of industry which effects a certain change in a substance, to suit it for the general market, by combining its parts in a new order and form, through mechanical or chemical means. Iron will serve the purpose of illustrating the nature of the distinctions here laid down, between mechanical engineering; arts and manufactures; and handicraft trades. The engineer perforates the ground with a shaft, or a drift, to the level of the ore, erects the pumps for drainage, the ventilating, and hoisting apparatus, along with the requisite steam or water power; he constructs the roads, the bridges, canals, railways, harbors, docks, cranes, &c., subservient to the transport of the ore and metal; he mounts the steam or water-power, and bellows for working the blast-furnaces, the forges, and the cupolas; his principal end and aim on all occasions being to overcome the forces of inertia, gravity, and cohesion The ores extracted and sorted *For correct and copious information upon agricultural production, I nave great pleasure in referring my readers to Mr. Loudon's elaborate Encyclopedias of agriculture, Gardening, and Plants; and for mercantile production and distribution, to Mr. M'Cul. och's excellent Dictionary of Commerce and Commercial Navgathon. iv PREFACE. by the miner, and transported by the engineer to the smelting station, are there skilfully blended by. the iron-master (manufacturer), who treats -lhen in a furnace appropriately constructed, along with their due proportions of flux and fuel, whereby he reduces them to cast iron of certain quality, which he runs off at the right periods into rough pigs or regular moulds; he then transforms this crude metal, by mechanical and chemical agencies, into bar and plate iron of various sizes and shapes, fit for the general market; he finally converts the best of the bars into steel, by the cementation furnace, the forge, and the tilt-hammer, or the best of the plates into tin-plate. When farther worked by definite and nearly uniform processes into objects of very general demand in all civilized countries, these iron and steel bars still belong to the domain of manufactures; as, for example, when made into anchors, chain-cables, files, nails, needles, wire, &c.; but when the iron is fashioned, into ever varying and capricious forms, they belong either to the general business of the founder and cutler; or to the particular calling of some handicraft, as the locksmith, gratesmith, coachsmith, gunsmith, tinman, &c. Such are the principles which have served to guide me in selecting aitlcles for the present volume. By them, as a clew, I have endeavored to hold a steady course through the vast and otherwise perplexing labyrinth of arts, manufactures, and mines; avoiding alike engineering and mechanical arts, which cause no change in the texture or constitution of matter,and handicraft operations, which are multiform, capricious, and hardly susceptible of scientific investigation. In fact, had such topics been introduced into the volume, it would have presented a miscellaneous farrago of incongruous articles, too numerous to allow of their being expounded in a man-. ner either interesting or instructive to the manufacturer and the metallurgist. I readily acknowledge, however, that I have not been able to adhere always so rigorously as I could have wished to the above rule of selection; having been constrained by intelligent and influential friends to introduce a few articles which I would gladly have left to the mechanical engineer. Of these Printing is one, which, having had no provision made for it in my original plan, was too hastily compiled to admit of my describing, with suitable figures, the flat-printing automatic machine of Mr. Spottiswoode, wherewith the pages of this volume were worked off; a mechanism which I regard as the most elegant, precise, and productive, hitherto employed to execute the best style of letter press. I- have imbodied in this work the results of my long experience as a Professor of Practical Science. Since the year 1805, when I entered at an early age upon the arduous task of conducting the schools of chemistry and manufactures in the Andersonian Institution, up to the present day, I have been assiduously engaged in the study and improvement of most of the chemical and many of the mechanical arts. Consulted professionally by proprietors of factories, workshops, and mines of various descriptions, both in this country and abroad, concerning derangements in their operations, or defects in their products, I have enjoyed peculiar opportunities of becoming familiar with their minutest details, and have frequently had the good fortune to rectify what was amiss, or to supply what was wanting. Of the stores of information thus acquired, I have availed myself on the present occasion; careful, meanwhile, to neglect no means of knowledge which my extensive intercourse with foreign nations affords. I therefore humbly hope that this work will prove a valuable contribution.o the literature of science, serving - In the first place, to instruct the Manufacturer, Metallurgist, and Tradesman, in the principles of their respective processes, so as to render them in PREFACE. v realhty, the masters of their business, and to emancipate them from a state of bondage to such as are too commonly the slaves of blind prejudice and vicious routine. Secondly, to afford to Merchants, Brokers, Drysalters, Druggists, and Officers of the Revenue, characteristic descriptions of the commodities which pass through their hands. Thirdly, by exhibiting some of the finest developments of chemistry and physics, to lay open an excellent practical school to students of these kindred sciences. Fourthly, to teach Capitalists, who may be desirous of placing their funds in some productive bank of industry, to select judiciously among plausible claimants. Fifthly, to enable Gentlemen of the Law to become well acquainted with the nature of those patent schemes which are so apt to give rise to litigation. Sixthly, to present to our Legislators such a clear exposition of our staple manufactures, as may dissuade them from enacting laws which obstruct industry, or cherish one branch of it to the injury of many others: and, Lastly, to give the General Reader, intent chiefly on intellectual cultivation, a view of many of the noblest achievements of science, in effecting those grand transformations of matter to which Great Britain owes her paramount wealth, rank, and power among the kingdoms. The latest statistics of every important object of manufacture is given from the best, and, usually, from official authority, at the end of each article.* The following summary of our manufactures is extracted from Mr. Macqueen's General Statistics of the British Empire, published in 1836. It shows the amount of capital embarked in the various departments of manufacturing industry, and of the returns of that capital: Capital. Produce. ~ ~ Cotton manufactures - - - 40973,872 52,513,586 Woollen ditto.. - 36,000,000 44,250,000 Silk ditto -.. 8,000,000 10,000,000 Linen ditto -- - -12,000,000 15,421,186 Leather ditto - - - - - 13,000,000 16,000,000 Iron ditto, to making pig iron - - - 10,000,000 7,098,000 Iron, hardware, cutlery, &c. - - - - 25,000,000 31,072,600 Copper and brass ditto -- 3,600,000 4,673,186 China, glass, &c. - 8,600,000 10,892,794 Paper, furniture, books, &c. - - - - 10,000,000 14,000,000 Spirits (British), ales, soap, &c. - - 37,600,000 47,163,847 Sundries additional - - - -- 9,000,000 Totals - - 201,773,872 262,085,199 Although I am conscious of having used much diligence for many years in collecting information for this work, from every quarter within my reach, the utmost pains in preparing it for publication, and incessant vigilance during its passage through the press, yet I am fully aware that it must contain several errors and defects. These I have studied to rectify in the text of this fourth edition. Since this book is not a Methodical Treatise, but a Dictionary, one exten. sive subject may be necessarily dispersed through many articles. Thus, for * The statistics of agriculture, trade, and manufactures, are ably and fairly discussed in Mr. McCulloch's Dictionary already referred to. vl PREFACE. example, information upon the manufacture of Colors will be found undei azure; black pigment; bone-black; bronze; brown dye; calico-printing; carmine; carthamus; chromium; cochineal; crayons; dyeing; enamels; gold; gilding; gamboge; gray dye; green dye; green paints; indigo; kermes; lac dye; lakes; madder; massicot; mercury, periodide of; Naples yellow; orange dye; orpiment; paints, grinding of; ochres; paper-hangings; pastes; pearl white; Persian berries; pottery pigments; Prussian blue; purple of Cassius; red lead; rouge; Scheele's green; Schweinfurth green; stained glass; terra di Sienna; ultramarine; umber; verditer; vermilion; vitrifiable colors, weld, white lead; woad, yellow king's. A casual consulter of the Dictionary, who did not advert to this distribution, might surmise it to be most deficient, where it is in reality most copious. The elaborate and costly Encyclopedias and Dictionaries of Arts, which have appeared from time to time in this country and abroad, have, for the most part, treated of the mechanical manufactures more fully and correctly than of the chemical. The operations of the former are, in fact, tolerably obvious and accessible to the inspection of the curious; nor are they difficult to transfer into a book, with the aid of a draughtsman, even by a person but moderately versed in their principles. But those of the latter are not unfrequently involved in complicated manipulations, and depend, for their success, upon a delicate play of affinities, not to be understood without an operative familiarity with the processes themselves. Having enjoyed the best opportunities of studying the chemical arts upon the greatest scale, in this kingdom and on the Continent, I may venture, without the imputation of arrogance, to claim for my work, in this respect, more precision and copiousness than its predecessors possess. I have gone as far in describing several curious processes hitherto veiled in mystery, as I felt warranted, without breach of confidence, to go; regarding it as a sacred duty never to publish any secret whatever, without the consent of its proprietor. During my numerous tours through the factory districts of Great Britain, France, Belgium, Germany, and Switzerland, many suggestions, however, have been presented to my mind, which I am quite at liberty to communicate in private, or carry into execution, in other districts too remote to excite injurious competition against the original inventors. I am also possessed of many plans of constructing manufactories, of which the limits of these volumes did not permit me to avail myself, but which I am ready to furnish, upon moderate terms, to proper applicants. May I venture to point attention to the very insecure tenure by which patents for chemical or chemico-mechanical inventions are held; of which there is hardly one on record which may not be readily invaded by a person skilled in the resources of practical chemistry, or which could stand the ordeal of a court of law, directed by an experienced chemist. The specifications of such patents stand in need of a thorough reform; being for the most part not only discreditable and delusive to the patentees, but calculated to involve them in one of the greatest of evils-a chancery suit. While I gratefully acknowledge the indulgence with which this work has been received, may I be permitted to advert very briefly to some of my present endeavours to render it less undeserving of public favor, though, after all my efforts, it will by no means realize either my own wishes and intentions, or the expectations of all my readers? To investigate thoroughly any single branch of art, we should examine it in its origin, objects, connexion with kindred arts, its progressive advancement, latest improved state, and theoretical perfection. The general princioles on which it is founded, whether belonging to the mechanical, the physical, PREFACE. n! the chemical sciences, or to natural history, should be fully expounded, arid tested by an application to its practical working on the great scale. The max. imum effect of the machinery which it employs, and the maximum product of the chemical mixtures and operations which it involves, should in every case be calculated and compared with the actual results. Such have been my motives in the numerous consultations I have hac with manufacturers relatively to the establishment or amelioration of their factories; and when they are kept steadily in view, they seldom fail to disclose whatever is erroneous or defective, and thereby lead to improvement. It will not be denied by any one conversant with the productive arts, that very few of them have been either cultivated or described in this spirit. It is to be hoped, however, that the period is not remote, under the intellectual excite ment and emulation now so prevalent in a peaceful world, when manufactories will be erected, and conducted upon the most rational and economical principles, for the common benefit of mankind. Meanwhile it is the duty of every professor of practical science to contribute his mite towards this desirable consummation. It is under a sense of this responsibility that I have written the leading articles of this edition, having enjoyed some peculiar advantages in my profession for making the requisite researches and comparisons. I trust that not many of them deserve to be regarded as trite compilations or as frivolous novelties, with the exception of a few of the notices of recent patents, which I have intentionally exhibited as beacons to deter from the treacherous quicksands, not as lights to friendly havens. I have sought sincerely to make them all conducive, more or less, to utility; being either new contributions to the old stock of knowledge, or additions and corrections to the present double volume. Manufacture is a word which, in the vicissitude of language, has come to signify the reverse of its literal intrinsic meaning; for it now denotes every extensive product of art which is made by machinery, with little or no aid of the human hand; so that the most perfect manufacture is that which dispenses entirely with manual labor. In every well-governed state of continental Europe there exists a Board of Health, or Conseil de Salubrite composed of eminent physicians, chemists, and engineers, appointed to watch over whatever may affect injuriously the public health and comfort. In France, this commission consists, for the capital, of seven members, who have the surveillance, in this respect, of markets, factories, places of public amusement, bakeries, shambles, secret medicines, &c. This tribunal has discharged its functions to the entire satisfaction of their fellow citizens, as appears from the following authentic report: —" Non settlement une foule de causes d'insalubrite disparurent, mais beaucoup de moyens, de procedes nouveaux furent proposes pour assainir les Arts et les Metiers, qui jusque la avaient part inseparables de ces causes d'insalubrit; la plupart de ces mayens eurent un plein succes. II n'y a pas d'exemple que les membres du Conseil appelles, a donner leur avis sur les plaintes formees contre des fabriques, aient jamais repondu qu'il fallait les supprimer sans avoir cherche eux-memes a aplanir les difficulties, que presentait aux fabricants, l'assainissement de leur art, et presque toujours ils sont parvenu a re. soudre le probleme. Le Conseil de Salubrite, que l'on ne saurait trop signaler a la reconnaissance du publique, est une institution que les nations etranPeres admirent, et s'efforceront d'imiter sans doute." From this confident hope of emulation by other nations, the author of these excellent observations would have excepted tie United Kingdom, had he known how little paternal care is felt by the government for the general interests of the people. In Germany, indeed, where the fatherland feeling is viii PREFACE. strong in the breasts even of those rulers whom we are apt to consider despots, similar boards of health are universally established, whereas our legislative oligarchy frames laws chiefly for the benefit of its own class and dependents; as happened in the old time, when there was no king in Israel to regard alike the interests of the poor and the rich. The Prussian municipal law (Allyemeine Landrecht) contains the following enactments with regard to the sale of spoiled or adulterated victuals. Th. II. Tit. 20.; Abschnitt 11, ~~ 722 to 725. " No person shall knowingly sell or communicate to other persons for their use, articles of food or drink which possess properties prejudicial to health under a penalty of fine or bodily punishment. Whosoever adulterates any such victuals in any manner prejudicial to health, or mixes them with unwholesome materials, especially by adding any preparation of lead to liquors, shall, according to the circumstances of the case, and the degree of danger to health, be liable to imprisomnent in a correction house, or in a fortress, during a period varying from one to three years. Besides this punishment, those who are found guilty of knowingly selling victuals which are damaged or spoiled (verdorbener), or mixed with deleterious additions, shall be rendered incapable for ever of carrying on the same branch of business. The articles in question shall be destroyed if incorrigibly bad, but if otherwise, they are to be improved as far as possible at the cost of the culprit, and then confiscated for the benefit of the poor. Further, whosoever mixes victuals or other goods with foreign materials, for the purpose of increasing their weight or bulk, or their seeming good qualities, in a deceitful manner, shall be punished as a swindler." It is singular how, amid the law-making mania which has actuated oui senators for many sessions, that not even one bill has been framed for the protection of the people from spoiled and adulterated foods and drinks."* Many novelties of an interesting and useful nature, first displayed in the late Grand Exhibition of the Industry of all Nations, which had not been noticed in the alphabetical places as patent or other inventions, are here described with merited commendation; though at the hazard, sometimes, of a little repetition. This valuable portion of the Dictionary was accomplished with the aid of the able abstracts made by the ingenious authors of a series of articles inserted in successive numbers of "Newton's London Journal of Science." The candid critic will take into view the number of original disertations now introduced, and treated at considerable length. On comparing these with the usual staple with which similar books are made up, he will recognize my diligence at least, and make allowance for a few oversights. He will see, that having fully availed myself of the facilities offered by the alphabetical distribution of the subjects, I have been able to amend, under an equivalent title, what seemed amiss under the main head. Thus, for example, the elegant new art, for which we are indebted to Daguerre, may be considered in connection with his name, as also under the title Photography, or better perhaps under that of Heliography, or Sun-painting; since the solar rays are the preferable excitant. As it has been also termed Calotype, under this name Sun-painting has been briefly noticed. In the mechanical department of the Dictionary, I have received valuable contributions from the two distinguished engineers, Mr. William and Mr. Peter Fairbairn, brothers. The first is generally recognized all over the factory world as eminent for the originality, grandeur, and justness of his inventions. It has been my good fortune to be conversant with his magnificent workshops, in Manchester and Millwall, during very many years, and I have * See the article " novisioxs, PRESERVED." PREFACE. ix always regarded them as the best mechanical schools in the kingdom. Mr Fairbairn commenced his brilliant career as a factory millwright, by discarding the heavy and clumsy square shafts and drums of Arkwright and his compeers, and replacing them by slender rods of wrought-iron, and cast-iron pulleys; causing these to revolve with such a velocity as fully compensated for their diminished weight, according to the true principles of dynamics. He thus effected an immense and most beneficial revolution in factory-construction, in cotton, corn, flax and silk mills; enabling the machinery to be.driven with far less power and greater precision. His next important step was a general improvement in mill architecture; the construction of fire-proof buildings; as also mounting the fly-wheels of steam-engines, with teeth on their periphery, into first motions. This change was condemned by some millwrights at the time, but has since become general. The investigation of the strength of cast-iron beams, and a greatly improved style of building, by the introduction of pilasters at the corners, completed his system of fire-proof spinning works. This plan has been since copied in all the textile factories. The experiments referred to, and the construction of several iron steamboats, led him to the extensive use of iron as as a material for shipbuilding. Though Mr. Fairbairn was not the first to build iron boats, yet he and his then partner, Mr. Lillie, were the first to show how this material should be best applied. The system of working steam-engines expansively, by means of revolving discs, which is also very extensively used, with the saving of one half of the fuel, was contrived by Mr. Fairbairn about this time. We have now arrived at the grand consummation of his mechanical genius-the tubular bridges and tubular cranes. His bridges across the Conway river and the sea straits of Menai are such stupendous and marvellous creations of engineering enterprize, as to have cast all former mechanical exploits into the shade, and to have led to the notion that nothing of a like description was ever undertaken or executed by him. Hence, perhaps, I may be blamed for using the expression Fairbairn's Tubular Bridges. Fifty-two tubular bridges have been already erected in this and other countries by this unparalleled Pontifex. Maximus. In fact, Mr. Fairbairn's title to the honor of inventing the genuine rectangular tubular bridge, not the spurious cylindrical or elliptic form, is as clear as that of Sir Isaac Newton to the invention of the binomial theorem, or Sir H. Davy to that of the miners' safety lamp. I am indebted, with my readers, to Peter Fairbairn, Esq., of Leeds, undoubtedly the great and the best manufacturer of flax machinery and flax mills, for the article FLAX. He has been ably assisted by the engineers of his princely establishment, and especially by Mr. Robert Busk. Many most ingenious and instructive disquisitions are due to my worthy chemical friend, Mr. Lewis Thompson, and that particularly under the head COAL, in the body of the work; anl in the following few remarks. That there is nothing personal in the language is clear from this, that it is an exact transcript of the original Government Report. Few persons at all alive to the enormous importance of the question at issue will consider it possible to be too critical in a matter so notoriously associated with our national power, welfare, and prosperity. After all, however, the remarks must speak for themselves. Nevertheless, lest their merits should be called in question, it becomes necessary to demonstrate, not only that they are correct and just, but that even the gentlemen engaged in this coal investigation themselves bear evidence to the scientific accuracy of those x.~~ P~PREFACE. very remarks, and have actually modified their subsequent reports in accordance with the principles there first developed. But over and beyond all tllis, it will now be shown, from practical results obtained during many years by the most impartial experimentalists, that the views there displayed respecting the calorific power of fuel are strictly in accordance with facts of the most ob. vious and certain nature, and should lead to a vast economy in steam navigation. Without needlessly dilating therefore upon the value of the evidence now about to be given, I shall at once proceed to offer the evidence itself, and leave the public to draw an unbiassed conclusion. In the first Admiralty Report it was attempted to be proved " that the evaporative value of a bituminous coal is expressed by the evaporative value of its coke, the heat of combustion of its volatile products proving in practice little more than that necessary to volatilize them." And this foregone conclusion was found to be verified by column B. of Table VI., which proved "that, notwithstanding several striking exceptions which might have been expected, the experiments on the whole show the work capable of being performed by the coke alone is actually GREATER than that obtained by experiments with the original coal." Again, as regards the nitrogen contained in coal, it was asserted, that the whole system of manufacturing coke is at present very defective; that "an immense quantity of ammonia is lost by been thrown into the atmosphere;" and that "by a construction of the most simple kind, the coke ovens now in use might be made to economize much of the nitrogen which invariably escapes in the form of ammonia."' And accordingly a column of Table VI. was set apart for the purpose of rousing the dormant energies of coke makers by showing " the amount of sulphate of ammonia " which, " by a construction of the most simple kind," they could get from the coals. Again, it was laid down, that it is easy from analysis to examine whether the duty performed by the coal is to be attributed to its fixed ingredients (ingredient?) or coke;" and hence a column in Table VI. was given to show the theoretical " number of lbs. of water convertible into steam by the coke left by the coal." Again, in the First Report, " the area of the damper open " was for the most part kept uniform in different trials with the same coal; as, for example, with the Penterfelin, the Duffryn, Wards Fiery vein, the Binea, the Llangenneck, the Mynydd Newydd, the Graigola, &c. &c. &c., a change in the area being the exception. Now in all these respects the Reports No. 2. and 3. differ entirely from Report No. 1., as also in respect to certain proximate analyses which were contained in No. 1. Report. The "theoretical lbs. of water convertible into steam by the coke" have disappeared; the ammonia and sulphate of ammonia to be got by "a construction of the most simple kind" have disappeared; the proximate analyses have disappeared; the foregone conclusion respecting the coke of bituminous coal has not only disappeared, but met with a direct negative answer upon practical trial; " the area of the damper open " has been never twice alike with the Same coal, nay the very litharge experiments have been arranged so as to compensale for the errors arising from iron pyrites; and lastly, we find that it is not only not " easy from the analysis to examine," &c., but even the calorific coke theory is abandoned in Report No. 3., for it there appears that the analyses show generally that, although the " quantities of carbon and hydrogen regulate materially the economic values of the coals," yet in spite of these analyses " the inquiry would have been far from sufficient, had we not elicited'he economic values of the coals by actual trial under the boilers,"-a result PREFACE. xi not varying much from our former dictum, that "a good stoker was of more importance than a scientific chemist for such an investigation." And how in fact can it be otherwise, when we find that the analyses were made on such a scale that "more accurate results were obtained by operating upon three or four grains than upon a larger quantity! " The great principle contended for in our previous remarks was that the volatile constituents of a bituminous coal, so far from being worthless in a calorific point of view, were on the contrary of the greatest importance. Now this, though in direct opposition to the deductions of Report No. 1, can be proved to demonstration from the results of Report No. 2.; and hence no doubt the reason why we find in Report No. 3 that the quantities of carbon and hydrogen regulate materially, &c. At page 45 of Report No. 2, a comparative experiment is recorded for the purpose of determining whether the coke of a bituminous coal or the coal itself possessed the greatest evaporative power; for as we have seen in Report No. 1, the "work capable of being performed by the coke alone was actually greater than that obtained with the original coal." The coal employed in this experiment was the Tanfield, and it yielded 65 per cent. of coke; the coke was made from the same coal by Messrs. Cory & Son, of New Barge House, Lambeth, names too well known for the excellence of their manufacture to require comment here. The experiments were carried on for 34 consecutive hours with each material, and the total amount of water evaporated was 33,170 lbs. or about 15 tons. So far, however, from finding that " the evaporative value of a coal is expressed by the evaporative value of its coke," which in this case was 65 per cent. only, lo! the experiments prove that the evaporative power of the coal was 20-1 per cent. greater, weight for weight, than that of the coke, or about 50 per cent.! greater than its own amount of coke!-thus showing that the 35 per cent. of volatile ingredients were absolutely equal in heating power to the whole of the coke!.! And strange to say, this is borne out exactly by the results obtained in the manufacture of gas, in which, as is quite notorious, each gallon of tar, weighing from 10~ to 11 lbs. is found to have a calorific power equal to half a bushel of coke weighing from 21 to 23 lbs. There is not a gas engineer in Great Britain ignorant of this important fact, nor the secretary of a gas works, who, with coke at 4d. per bushel, estimates coal tar as fuel at less than 2Id. per gallon; and we happen to have now before us a series of actual workings extending over very long periods of time since the year 1831, and made by the engineer of the largest gas works in the world, for the express purpose of ascertaining the practical details connected with the relative economy of coal tar, coal and coke, and from which we have deduced the following, as the average values of these combustibles expressed in pounds of coal carbonized or distilled by the same weight of each:Tar equal 5 lbs Newcastle coal equal - - 4j lbs. Coke from do. equal - - - 3i lbs. the " breeze " employed with the tar being deducted and estimated as equal to Jths of its weight of coke. In point of fact, however, the relative value of coal and coke may be more decidedly determined by examining the heating power of the whole of the products of a ton of coal, and deducting therefrom the fuel employed in the distillation. For example, a ton of Newcastle coal may be distilled practically by 11 bushels of its own coke, and it will then yield about 36 bushels of coke, 4 bushels of breeze, 10 gallons of tar, and 9500 cubic feet of gas of specific gravity'400. Consequently th- heating power of the tar and gas - -- - -------------------------------------------------— l~~~~~~~~~~~ xll PREFACE. taken together ought, upon the hypothesis assumed in the Admiralty Repor No. 1, to be equal only to that of 11 bushels of coke, " the heat of the volatile products, &c., being only sufficient to volatilize them." Now it has been demon strated over and over again, that every cubic foot of the aforesaid gas will practically boil off 2950 grs. of water, therefore 9500 cubic feet will boil oft 4000 lbs. of water. But since the 11 bushels of coke employed in carbonizing the coal weigh only about 460 lbs., and the evaporative value even of the best oven coke, according to the Admiralty Coals Report, is only 7'91 for every lb. (vide page 46, Report No. 2), it follows that the 11 bushels in question would only evaporate 3538 lbs. of water, or less by 462 lbs. than. the gas alone, without taking into account the evaporative power of the 10 gallons of tar, and which cannot be assumed at less than 2000 lbs. upon the lowest computation. Consequently our facts, and the hypothesis contained in the First Admiralty Report stand as under: Hypothesis. Practical Facts. One ton of coals carbonized by the One ton of coal carbonized by 11 bushels heat of its volatile constituents affords 40 of coke affords 9500 cubic feet of gas, 10 bushels or 1680 lbs. of coke, equal to the gallons of tar, and 40 bushels of coke, evaporation of 13,378 lbs. of water. from which latter 11 are to be deducted. Thus leaving as the total heating power: lbs. of water. 29 bushels, or 1218 lbs. of coke equal to - - - 9634 9500 cubic feet of gas equal to - 4000 10 gallons of tar equal at least to 2000 Total lbs. 15,634 or nearly 20 per cent. more than the coke, a result which not only agrees with the practical experiments made with the Admiralty boiler, but also with the statements of Mr. Clegg, who indeed makes the difference greater, that is, 21 per cent. in favor of coal. Mr. Clegg, in the second edition of his practical treatise on Coal Gas, just published, gives the following as the relative amounts of coal, coke, or coal tar required to distil one chaldron of coals: Coal Tar from 24 to 27 gallons, or from 264 to 297 lbs. Coal from 5 to 58 cwt., or from 560 to 616 lbs. Coke from 16 to 18 bushels, or from 672 to 756 lbs. He also estimates coal tar at 3d. per gallon. If arguments of this kind do not conclusively establish the validity of our first remarks, we can scarcely hope to demonstrate any truth whatever; for these conclusions are drawn from actual data, the result of many years of labor undertaken by several different individuals, in different localities, having discordant interests in all respects but one, and that one the discovery of the simple truth with a view to practical economy in fuel, in establishments where the fuel accounts annually reach many thousands of pounds sterling. If it be demanded how it happens that these results differ so materially from the great bulk of those arrived at by the Admiralty boiler, we might very properly refer the question to the fabricators of the three Admiralty Reports; but the causes of that difference are too obvious to escape the most superficial observer; and therefore, without wearying the reader by a tedious recapitulation, we will merely collate a few instances from these Reports, which prave, beyond the possibility of contradiction that the boiler experi PREFACE. xii ments were totally inconclusive even upon the assumptions of the experi menters themselves. We have before called attention to the want of varied adjustment in t[ open area of the damper in most of the experiments in Report No. 1; this objection is seen very forcibly in Reports Nos. 2 and 3, where it not unfrequently happens that between 112 inches of area and 56 inches, the value of the same coal is found to vary as much as 20 per cent. Such being the case, it is but reasonable to conclude that where a coal has gone on durmg three experiments increasing in value as the open area of the damper was increased, that the value of that coal has not been developed simply because the proper extent of the open area has not been reached in any of the experiments. As examples where the area has been too small, we may cite the following:Area Area Area. Blackbrook Rushy 112 56 84 Park coals 112 Result 8-62 lbs.'755 Ibs.'7 89 lbs. Area Area. Area Blackbrook 112 56 84 Little Delf 5 8 Result 8 57 lbs. 8'13 lbs. 8'17 lbs. AeArea. Area. Area Johnson and Wir- thington's Rushy 112 56 85 Park Result 8'59 lbs.'783 lbs. 7-62 lbs. Area. Area. Area. Lynvi coal 112 56 84 Result 9'61 lbs. 8-89 lbR 908 lbs. Area Area. Area. Balcarras five? 112 56 84 feet nine 56 84 Result'779 lbs. 6-60 Abs.'723 lbs. Area. Area. Area. Hastings Hartley 112 56 84 Result 8-18 lbs.'765 lbs.'-49 lba. And in precisely the same condition are the Balcarras Arley, Carr's Hartley, Hedley's Hartley, Bate's West Hartley, Davison's West Hartley, Cowpen and Sidney Hartley, Hill's Plymouth Coals, the Willington Coal, the Wigan Four Foot Seam, and a host of others, in Report No. 3, all of which would no doubt have given a better result with an increased opening in the damper. Conversely, we find many others with too large an opening, as for example: Area Area. Area North Percy 112 56 8 Hartley 112 56 84 Result'7-43 lbs.'7 74 lbs. 754 lbs. Area. Area. Area. Balcarras Haigh 112 56 84 Yard mine 112 56 Result 6'79 lbs. 8-65 lbs. 8-26 lbs. And about a dozen more throughout Reports 2 and 3, in which the greatest effect has been produced by the minimum of area, leading therefore to the inference that a more restricted opening would have increased the value of the fuel. Taken as a whole, the only honest inference that can be K1W PREFACE. drawn from the three Reports is, that the question sought to be solved by the Admiralty coal investigation remains exactly where it was for all practical purposes; the analyses, whether proximate,'ultimate, or lithargic, together with the boiler experiments, being in all senses of the expression null, void, and of no effect or value whatever. And as a proof of the little care taken to insure accuracy to the whole performance, we find at page 10, Report No. 3, that even the simplest rules of arithmetic have been violated in a Table purporting to show the average composition of the coals from Wales, Newcastle, Lancashire, Scotland, and Derbyshire. This table gives, or ought to give, the composition of the respective coals in 100 parts, and strange to say, the results do not amount to 100 in ny single instance: the Welsh coal is more, and the others less thar. 100, though the oxygen was calculated from the loss. LONDON, 18 Upper Seymour-strec4 lotAh J, 1858. A DICTIONARY OF ARTS, MANUFACTURES, AND MINES. AB1ETINE. A pale yellow, transparent, viscid exudat cn from the Abies pectinata, a species of fir, growing in the neighborhood of Stiasburg, and hence called Strasburg turpentine. It contains 35 per cent. of a volatile oil of an agreeable smell, combined with a resin, and a small quantity of the acid of ember, as well as the peculiar body called abietin, a resin of an acid kind, styled therefore by some abietic acid. If the indifferent resin be removed by absolute alcohol, and the remainder digested with carbonate of potash, an abietate of potash is obtained. It dissolves in petroleum, and crystallizes out of it. It resembles Canadian balsam, and is used for attaching microscopic objects to glass slips. ACETAL, is the subacetate of ether; having for its chemical symbol 3 Ac O -+- Ac Os. It is a light colorless ethereous liquid. ACETATE. (Acetate, Fr.; Essigsaure, Germ.) Any saline compound of which the acetic is the acid constituent; as acetate of soda, of iron, of copper, &c. ACETATE OF ALUMINA, see RED LIQUOR and MORDANT; of COPPER, see COPPER; of IRON, see IRON; of LEAD, see LEAD; of LIME, see PYROLIGNOUS ACID. ACETIC ACID, or, according to the new nomenclature of organic chemistry, acetylic acid hydrate, being a compound of the radical acetyl (Ac C4 118 ) and oxygen (03), with water (H O), for it cannot be bought in the dry state. It is formed out of alcohol in the acetous fermentation, or by its oxygenation with air; it is produced in the dry distillation of most non-volatile organic compounds, as of wood, gum, starch, &c., in the spontaneous decomposition of the watery solutions of citric and tartaric acids, as also by the boiling of several organic substances with sulphuric acid. It exists ready formed in several vegetable and animal juices. See GERlARDT. Alcohol is a compound which, even diluted with water and exposed to the air, is not liable to spontaneous change; but if in this state it is mixed with yeast, at a temperature of from 60~ to 90~ Fahr., it absorbs oxygen, and passes into acetic acid. The oxygen forms first water, with 2 atoms of the hydrogen of the ethyl, whereby acetyl is generated; therefore ethyloxide-hydrate (alcohol) becomes acetyloxide hydrate, (aldehyde), which by absorption of two more atoms of oxygen, constitutes hydrated acetic acid. 1 Atom Alcohol C 4 Hs 0 - II 0 - 2 Atoms Hydrogen = II2 Aldehyde C4 H3 0O +-H O + 2 Atoms Oxygen 02 - Acetic Acid Hyd. C4 H3 0s + 1-I O. Its atomic weight on the hydrogen scale is therefore 60 in the state of hydrate, and 51 dry. Albumen, gluten, and vegetable matters which contain these substances, such as the juice of beet-roots, operate also the oxidation of alcohol, and that the more rapidly, the more ample the exposure of the mixture to the air. While sugar is transmuted into carbonic acid, and alcohol only through the intervention of gluten, alcohol suf. fers that change by contact with finely divided platinum. It is hence probable, that to what is called acetous fermentation, the vital action of the particles of yeast is not indispensable, and that it belongs rather to the category of chemical combustion; to the contact action of Liebig, the catalysis bf Berz-lius, or the polar combination of Loviig. In the vinegar of wine, malt, or that in which organic matter has been infused, there appears a peculiar mould-plant, belonging to the genus 2lycoderma Pers.; which s usually called vit:egar mother. As the plant grows, it decomposes the acid, and 2 2 ACETIC ACID. leaves eventually nothing but water. It contains proteine, and consequently azote, but leaves no ashes when burned. The same circumstances which govern the conversion of alcohol into vinegar pre. side over that of wood spirit into formic acid (acid of ants), fusel oil (oil of grain) into valerianic acid; and probably butyric acid has some such organ. With regard to the formation of vinegar, M. Dumas observes that every fermentation has for its effect to dissociate a compound into a more simple state; but the so-called acetous fermentation unites alcohol or aldehyde with the oxygen of the air; being the only case in which fermentation represents a true combination. He admits, notwithstanding, that this fermentation, in a certain point of view, possesses the character of the other fermentive actions, namely, the concourse of an organized substance, and of an organic matter; the one being a ferment (the mother), and the other fermentable. The conversion of alcohol into vinegar never happens in common cases, without the aid of an albuminous substance, and of circumstances favorable to all fermentations, such as the presence of air, not only at its commencement, but during its entire course. The lactic fermentation has however been sometimes mistaken for the acetous; but it may be distinguished by its requiring no alcohol, but only starchy or saccharine matters; and after it begins, exposure.: air is not needed. It has been supposed that acetification is analogous to nitrification, as to the utility of porous bodies which divide the liquid and the air; thus ammonia passed along with air through platinum sponge, gently ignited in a tube, produces nitric acid; and pumicestone, in like circumstances, combines sulphurous acid and oxygen into the sulphuric; and so we have seen that a mixture of alcohol vapor and air under the influence of the same sponge is converted by a true oxidation of the ether (of the alcohol), first into aldehyde, and afterwards into acetic acid. A like oxidation takes place in the wine or beer, which being purposely left in casks partially filled, rises by capillarity on the wood above the liquid level, and is there subjected to the porous influence. The vinegar is much more rapidly generated, however, by the various artificial methods of multiplication of points of contact with the air, presently to be described. Vinegars may be arranged under four heads: 1. Malt or sugar vinegar; 2. Wine and fruit vinegar; 3. Alcohol vinegar; 4. Wood vinegar. 1. Malt vinegar is manufactured most extensively in the United Kingdom, chiefly in England, to the amount of fully 8,000,000 of gallons, on which an excise duty of 2d. per gallon is levied, and for the license to manufacture it, 51. annually must be paid. The total number of vinegar manufactories in this country is about fifty, of which five of the principal ones are in London, and these carry on at the same time the manufacture of British wines, now happily emancipated from the trammels of the Excise. From 6 bushels of malt, properly crushed, 100 gallons of wort in whole may be extracted by du.a.ashing, the first water of infusion being of the temperature of 160~ Fahr., and the next two progressively hotter, for exhausting the soluble saccharine matter. When the wort is cooled to 750, from 3 to 4 gallons of good yeast are stirred into it in the fermenting tun, and when it has been in brisk fermentation for about 40 hours, it is racked off into used vinegar casks, laid upon their sides in a room heated with a stove for quick work; or otherwise, during summer, in the open air, under exposure to the sun. The casks should be only about 4 filled, and left unclosed, or loosely covered from the rain at their bung holes, to favor the free acidifying action of the atmosphere. In the air, the acetic fermentation may not be completed till after the lapse of three months; but in stove-rooms in much shorter time, according to the temperature. The sour liquor is then transferred from the several casks by means of a flexible pipe, anld pumped into the stove-vat, whence it is run into the clarifying and flavoring casks, called "rapes," being here made to filter slowly and repeatedly through condensed heaps of the stalks and skins of raisins, called rape, which is the refuse of the British wine manufacture. Vinegar thus made contains always a considerable qt.antity of gluten, and is therefore liable to become mouldy and to putrify; to counteract which, a certain portion of sullhuric acid may be legally, and is always, mixed with British-made vinegar; but that portion is too often overpassed through aval ice, and is certainly injurious to health. I have found by analysis in a sample of vinegar, made by one of the most eminent London manufacturers, with which he supplies the public, no less than 175 grains of the strongest oil of vitriol per gallon, added to vinegar containing only 3'6 per cent. of real acetic acid; giving it an apparent strength after all of only 4 per cent.; whereas standard commercial vinegar is rated at 5 per cent. It is a remarkable fact, that the people of this country have had their vinegar palate so depraved, that they prefer the vitriolized vinegar to the pure; and that all attempts at introducing a better article into general sale has proved abortive,-a fact discreditable to our nation, of which several instances have come before me. The complete acidification of nialt wort by the above process being very slow, has given rise to many projects, more or less successful, for accelerating it. So long ago as the year 1824, Mr. Ham, of Norwich, obtained a patent for exposing w)rts to the ACETIC ACID. I atmospheric a.r upon a most extensive surface, by means of a revolving pump, which caused a constant sh,wer of it to fall upon and through a bundle of birch twigs supported in the middle of a large tun. The air had free access to the twigs. The wash, being kept at a temperature of from 90~ to 10t)~ Fahr., by steam pipes at the bottom of the tun, and continually repumped, became moderately acetified in 48 hours, and was finished into good vinegar, either by that process, or preferably by racking off into casks, and exposing it in them to a temperature'of 85~ Fahr. for 15 or 20 days. lIe also found that a wort made with 1 part of malt mixed with 6 of raw barley, properly mashed, afforded by this means an excellent vinegar. A wort of sp. gr.'060 (6i excise gravity) will yield a vinegar of revenue proof, or of 5 per cent. of real acetic acid. This quick process belongs rather to the combustion class of chemical transformations than to that of the fermentative, as yeast is not essential, though it is found to prove serviceable, as in the corresponding formation of acetic acid from the oxygenation of alcohol some stale vinegar is used as a ferment, or as a contact agent. Under Messrs. Hala's instructions four considerable manufactories of vinegar have been established, with the products of two of which I am practically conversant, and I am warranted by experimental proofs in declaring th;t the vinegar made by Messrs. Hill, Evans, and Williams, of Worcester, and Messrs. Hills and Underwood, of Norwich and Eastcheap, London, are perfect specimens of acetic acid for family use, and also for manufacturing purposes. The latter company liberally displayed, in the South Gallery of the loyal Exhibition, at No. 7. Class 3. substances used as food, a model of their acetifying apparatus, as mounted in their works. An excellent vinegar may be made for domestic puirposes by adding to a syrup consisting of one pound and a quarter of sugar for every gallon of water, a quarter of a pint of good yeast. The liquor being maintained at a heat of from 75~ to 80~ Fahr., acetification will proceed so well that in 2 or 3 days it may be racked off from the sediment into the ripenin cask, where it is to be mixed with 1 oz. of cream of tartar, and 1 oz. of crushed raisins. When completely fieed fiom the sweet taste, it should be drawn off clear into bottles, and closely corked up. The juices of currants, gooseberries, and many other indigenous fruits, may be acetified either alone, or in combination with syrup. Vinegar made by the above process fiom sugar should have fully the revenue strength. It will keep much better than malt vinegar, on account of the absence of gluten, and at the present low price of sugar will not cost more, when fi6ed upon beech chips, than Is. per gallon. 2. Wine vinegar is made of the best quality, and on the greatest scale, at Orleans in France, out of wines which have become more or less acidulous, and are, therefore, of inferior value. When the vinegar is made from well-flavoured wines, it is preferable to every other for the use of the table. The old method pursued in the vinaigreries consists merely in partially filling a series of large casks placed in 3 or 4 ranges over each other in a cellar warmed with a stove to the temperature of 85~ Fahr., with the wine mixed with a certain proportion of ready-made vinegar as a ferment. More wine is added in successive small portions as fast as the first has become acetified, taking care that a free ventilation be maintained, in order to replace the carbonic acid produced by fresh atmospheric oxygen. In summer, under a favorable exposure of the windows and walls of the fermenting room to the sun, artificial heat is not needed. Each cask is of about 60 gallons capacity, and the whole set is filled up 3 with vinegal, to which 2 galls. of wine are added, and weekly afterwards 2 galls. more. About 8 gallons are drawn off at the end of four weeks as vinegar, and then successive additions of wine are made as before to the casks. These are laid horizontally in rows upon their gawntrees, and are pierced at the upper surface of the front end with two holes: one, called the eye, is two inches in diameter, and serves'or pouring in the charges through a tunnel; the other is a'small air-hole alongside. The casks should never be more than I frll, otherwise a sufficient body of air is not present in them for favouring rapid acetification. At the end of a certafn period, tile deposit of tartar and lees becomes so great, that the casks must be cleared out. This renovation usually takes place every ten years; but the casks, when made of well-seasoned oak and bound with iron hoops, will last 25 years. The wine as well as the vinegar produced should be clarified by being slowly filtered through beech chips closely packed in a large open tun. When wines are new, and somewhat saccharine, or too alcoholic, they acetify reluctantly, and need the addition of a little yeast or even water to the mixture; and when they are too weak, they should be enriched by the addition of some sugar or stronger wine, so as to bring them to a uniform state for producing vinegar of normal strength. To favour the renewal of fresh air into the upper part of the hogsheads, it would be advisable to pierce a two-inch hole near to the upper level ot the liquid when the cask is fullest, by which means the heavy carbonic acid would fall out, and be replaced by the atmospheric air at the superior apertures. I have had occasion to examine professionally the best wine vinegars imported inft ~{(~~ ~ACETIC ACID. this country from Orleans, and I found their Qpecific gravity to be about 1 01 9, and tlleil percentage of acetic acid hydrate (crystalline acid) to be from 6 to nearly 7. One or tSwc samples were supposed to contain acetified cider. This adulteration may be tested by neutralizing the vinegar with ammonia, and then adding solution of acetate of lime. Tartrate of lime is of course precipitated from the wine vinegar, while the pearly malio acid of the cider affords no precipitate with the lime, but may be detected by ace tate of lead, by the glistening pearly scales of malate of lead, hardly soluble in the cold. 3. Alcohol Vinegar.-This species has been hitherto manufactured chiefly in Germany, having commenced soon after D6bereiner's fine discovery of the combustion of alcohol into acetic by the agency of platinum mohr. Under a large glass bell, he placed on shelves, an inch or two apart, several saucers, containing spirits of wine, with slips of blotting paper so suspended as that their lower edges dipped in the spirits. Over and alongside of these saucers, other smaller ones were set, containing the black platinum powder moistened with the spirits. The apparatus being exposed to the sunshine, or even put into an apartment moderately warm, a copious formation of vapours takes place, with a manifest increase of temperature, and streaks of condensed fluid run down the sides of the bell into the subjacent basin. This fluid is acetic acid, resulting from the acidification of the elements of the alcohol by the oxygen of the atmospherical air included. This interesting transformation ceases with the exhaustion of the oxygen, but it may be renewed from time to time by renovation of the air. One atom of alcohol = C4 H5 0 + H O = 46 parts; in which compound, two atoms of hydrogen being replaced by two of oxygen, we have 46 + 14=60 parts, or one atom of hydrated acetic acid. Hence we see that 46 parts of absolute alcohol afford 60 of radical vinegar; 100 parts therefore afford 130, and require for this conversion nearly 70 parts of oxygen, allowing two atoms of oxygen for the abstraction of the two atoms of hydrogen Since air in round numbers contains a little more than one fifth its volume of oxygen, then 1000 cubic inches wil contain upwards of 200 of oxygen, which will weigh fully 70 grains, being the quantity requisite for the transformation of 100 grains of alcohol into acetic acid in the above process. Two atoms of water are also formed, equal to 18 grains. In practice it is found that weak alcohol answers best. With a box of 12 cubic feet capacity, and with 7 or 8 ounces of platinum mohr properly distributed, 1 lb. of alcohol may in the course of a day be converted into pure vinegar, fit for every purpose of the kitchen or the chemist. I have examined the vinegar manufactured from spirits, and found it to be excellent, as it contains no gluten, and it is therefore not liable to change. It is not possible in this way to make a strong acetic acid, nor can it be made at all on the large scale in this country, on account of our revenue laws. In the sequel of Dobereiner's discovery, another German chemist, M. Schutzenbach, applied the principle of oxygenation to beers and other alcoholic liquors, for the purpose of converting them rapidly into vinegar; and about the same time M. Wagenmann contrived his graduator, or essigbilder, a simple apparatus for the quick vinegar manufacture. It consists of an oaken tub 52 feet high, 3S feet wide, and 3 feet at bottom, set upon a wooden frame about 14 inches from the floor. Fifteen inches above the bottom, the tub is pierced with a horizontal row of eight equidistant holes, one inch in diameter. Five inches beneath the mouth of the tub a strong beechwood hoop is fastened to the inner surface, in order to support a circular oaken shelf, the space round the edge of which is stuffed tight with hemp. This shelf is perforated with at least 400 gimlet holes of about k of an inch, through each of which a porous cotton wick is let down several inches, hanging by a knot in the top of the hole at its upper end. In the same circular shelf there are 4 holes, 1~ inch in diameter, and 18 inches apart, into each of which is fixed tight the middle of a stout glass tube about 4 inches long. These tubes favour the circulation of the air admittted by the circumferential holes. One inch above the bottom of the tub a hole is pierced for the reception of a syphon of discharge, the top curvature of which must stand about 1 inch below the holes in'the side of the tub, to prevent the liquor collected, to the depth of about 12 inches on the bottom, being spilled. Into the empty space over this liquor, the bulb of a thermometer is placed, while the stem and scale project to show the interior temperature. Beneath the lower outer leg of the syphon a reception cistern is set. The mouth of the tub has a wooden lid, with a funnel fixed in its middle for the introduction of the liquor to be acetified. The whole capacity of this tub from the bottom up to within 1 or 2 inches of the perforated shelf, is to be filled up with shavings of beech-wood (previously boiled in water), or with grap6 stalks, or birch-twigs, all well soaked with vinegar. This apparatus being placed in an apartment, heated to from 80~ to 100~ Fahr., is to have its uppermost compartment fill ed with liquor. This slowly filters down through the cotton wick threads, thence orel the surfaces of the chips or stalks, and finally into the subjacent receiver, having been exposed in its transit very freely to the air. The ordinary acetifying mixture consistA of 8 parts of proof spirits, 25 parts of river water, 15 parts of good vinegar, and 15 parts of clear beer or wine. The water should be heated to albout 150~ before the other ingredients are added to it, whereby the mixture acauires a genial temperature. Aftel ACETIC ACID. 5 this has Deen all transmitted through the apparatus, it will be found imperfectly aceti. fled, and therefore must be passed through once or twice more. And since the more alcohol that is present the slower is the process, it is advisable to keep back part of the spirits at first, and to add it in the subsequent transmissions. The wash-cistern, which contains the acetifying mixture, should be supported on a shelf near the ceiling of the stove-heated apartment, in order to be kept constantly warm. After the first operation is completed, the interior of the cask becomes so active an oxidizer, that the addition of vinegar to the mixture is no longer necessary; but care should always be taken to have it as well clarified as possible, in order to prevent the depositing of much gluten upon the beech-chips. Dr. Kastner prescribes the following manner of making a malt wine for the quick vinegar process:-Crush togetler 80lbs. of pale barley malt, and 40lbs. of pale wheat malt, and infuse them in 100 quarts of water of 122~ Fahr., and afterwards mash them properly with 300 quarts of hotter water. The wort thus made is to be cooled, drawn off from the grains, fermented with yeast for 3 days, then the beer is to be barrelled up for use. I have already adverted to the quick acetification of malt-wort by Mr. Ham's patent process. This has been mounted ul:on a large scale of late years, the air for oxygenating the alcohol of the wash, previously fermented with yeast, having been supplied from two gasometers, alternately moved by steam-engine power. Two circumstances attend this quick process; which are, that as the materials are not thoroughly acetified, the product must be left for some time to ripen in casks, and the resulting vinegar has not the flavor of that slowly made in the old way. I am informed that a vinegar, equiva lent not merely to 51 per cent. has been produced, but one five times stronger, by operating with an apparatus 13 feet high, 14 wide at bottom, and 15 at top, in which an adequate temperature was generated during the oxidation of the great mass of materials, without artificial warmth. 3. Chemicalprocess.-Acetic acid from the pure acetate of soda is formed as follows: -100 lbs. of the pulverized salt being put into a hard glazed stoneware receiver, or deep pan, from 35 to 36 lbs. of concentrated sulphuric acid are poured in one stream upon the powder, so as to flow under it. The mixture of the salt and acid is to be made very slowly, in order to moderate the action and the heat generated as much as possible. After the materials have been in intimate contact for a few hours, the decomposition is effected; sulphate of soda in crystalline grains will occupy the bottom of the vessel, and radical vinegar, or acetic acid (hydrate), the upper portion, partly liquid and partly in crystals. A small portion of pure acetate of lime, added to the acid, will free it from any remainder of sulphate of soda, leaving only a little acetate in its place; and though a small portion of sulphate of soda may still remain, it is unimportant, whereas the presence of any free sulphuric acid would be very injurious. This is easily detected by evaporating a little of the liquid, at a moderate heat, to dryness, when that mineral acid can be distinguished from the neutral soda sulphate. This plan of superseding a troublesome distillation, which is due to M. Mollerat, is one of the greatest improvements in this process, and depends upon the insolubility of the sulphate of soda in acetic acid. The sulphate of soda thus recovered, and well drained, serves anew to decompose acetate of lime; so that nothing but this cheap earth is consumed in carrying on the manufacture. To obtain absolutely pure acetic acid, the above acid has to be distilled in a glass retort. That acid, in its crystallizable state, boils at 230~ Fahr., or 1100 C., by my experiments made with a pure acid prepared by M. Lemire, of Paris: others have rated its boiling point 114~ and even 120~ C. The following table of the specific gravities of acetic acid, of successive strengths, is the result of a series of experiments made by me in Glasgow in May, 1819; the liquid crystallizable hydrate being reckoned 100:Acid. Sp. Gr. Acid. Sp. Gr. Acid. Sp. Gr. 100 1 0620 76 1 -0743 52 1 0617 98 1 0650 74 1 0740 50 1 0603 96 1 0680 72 1 0733 45 1 0558 94 1 0700 70 1 0725 40 1 0512 92 1 0715 68 1'0716 35 1 0459 90 1 0728 66 1 -0712 30 1 0405 88 1-0730 64 1 -0701 25 1 0342 86 1 0735 62 1 0687 20 1'0282 84 1 -0738 60 1 0675 15 1 0213 82 1 0740 58 1 -0665 I 10 1 0147 80 1 0750 56 1 -0647 5 1'0075 78 1'-0748 54 1 -06234 6~~8 ~ACETIC ACID. In Berzelius Jahres. berichte xvi. 192, the table of Van der Toom is given for the successive quantities of dry acetic acid, corresponding to successive densities. HTe rates the sp. gr. of the hydrate at 1'0570, being the acid which contains'8511 of dry acid. In my table, the equivalent hydrate is mnarked 1 062, a gravity ts low as is probably to be obtained by weighing a solution of the drained crystals. An acid of 1'0698 contains, according to hin, 51 of the dry; while an acid of 1'0675 corresponds, in my table, to 60 of the hydrate, or 51 of dry acid. In general his gravities are a little greater than mine at corresponding degrees of acid strength. The above numbers in my table are experimental, not interpolated from a few points, and may, I hope, be relied upon. The greatest density seems to be produced when two atoms of water 18 are mixed with one of the hydrate = 60, or 23 with 77, at which dilution the differences of density are very small, and minute errors may have occurred. When 6 atoms of water are added to one of the hydrate, making 7 atoms of water in all, then the acid acquires its primitive liquid density of about 1'062. A curious analogy exists in this respect with nitric acid, which suffers the greatest degree.of condensation, in the series of its dilutions, when one atom of the real acid is combined with 7 atoms of water. Pure acetic acid possesses a peculiar pungent, though not disagreeable smell, and a strongly acid taste. It crystallizes in needles and plates when coo!ed to 55~ Fahr., and melts when heated to 61~. The specific gravity of the crystals (taken by means of spirits of turpentine) I found to be 1'135 at 550 Fahr. The vapor of the boiling acid is highly combustible, and burns with a blue flame. Acetic acid hydrate dissolves camphor, gliadine, resins, the fibrine of blood, and several organic compounds. When its vapor is conducted through a slightly ignited porcelain tube, it is converted entirely into carbonic acid and aceton, an atom of the acid being resolved into an atom of each of the resultants. At a white heat, the vapor is converted into carbonic acid, carburetted hydrogen, and water. The acetates comport themselves at elevated temperatures differently, according to the strength of affinity between the acidsand the base. When this is weak the acid escapes unchanged, and the stronger it is, the more acid is converted into aceton. Acetate of barytes affords most of this spirituous liquor, and next to it the alkaline acetates and acetate of lead. Acetate of copper yields, at a heat of 400~ or 500~, a concentrated acetic acid, mixed with some aceton. This process was formerly employed for preparing radical vinegar, as also that of decomposing that of acetate of lead, by sulphuric acid; but both are now renounced for the process by acetate of soda above described. Acetic acid is a pretty stable compound, as is evinced by its compound with soda and potash, bearing the heat of 600~ Fahr. without decomposition. Acetate of potash and soda, dissolved in much water, readily mould and decompose; but acetate of ammonia is not liable to change in close vessels. When acetic acid is distilled along with peroxide of manganese and sulphuric acid, it is converted into formic acid. lodic acid has the same effect with precipitation of iodine: it reduces gold from its chloride without disengagement of carbonic acid; but it does not reduce mercury from its nitrate or sulphate, as formic acid does. The simplest reagent for purifying common vinegar is recently calcined wood char coal in fine powder; with which it may be digested, or, what is better, distilled, where. by a portion of the water comes over first, and may be got rid of, while the stronger vinegar is a later product. Attempts are often made to give wood vinegar the flavor of that made from wine, by adding acetic ether, wine, &c., but never with complete effect. The best disguise is obtained by mixing in some highly flavored Orleans vinegar. Malt vinegar prepared by very slow fermentation in the air, acquires a peculiar ethereous odor, which cannot be imitated artificially, and hence persons accustomed to the flavor of such vinegar, b itself or in pickles, do not relish the vinegar made by the quick oxidizement process, either from malt or spirits. Even subjecting this vinegar to the action of rape accomplishesimperfectly the object in view. Were vinegar pure, it would be valued by its specific gravity alone, which at all strengths under 50 per cent. gives exact indications; but this is seldom the case, for ordinary vinegar contains more or less gluten and other organic matter, such as caramel, or burnt sugar, to color and flavor it, besides sulphuric and possibly other acids. Hence the Excise have adopted the following plan of acetometry suggested by Messrs. Taylor. When pure vinegar is saturated with quicklime, the liquid takes a density double of that due to the acetic acid present. Thus, an acetate of lime of sp. gr. 1-018, corresponds to a pure vinegar of 1'009; but malt vinegar of that strength has its density raised to 1-014 by the gluten. When such vinegar is saturated with quicklime, the acetate acquires a specific gravity of 1'023, from which, if the five due to the gluten be deducted, the remainder, 1-018, will be double of the true density. Revenue proof vinegar, called No. 24, has, according to these gentlemen, the ACETIC ACID. 7 Sp. gr. 1'0085, and contains of real acid 5 in 100. Do. 1-0170 do. do. 10 do. Do. 1'0257 do. do. 15 do. Do. 1-0320 do. do. 20 do. Do. 1-0470 do. do. 30 do. Do. 1-0580 do. do. 40 do. The acid of this table is the anhydrous, being stronger by about 15 per cent. than that of my table given above. The chemical analysis of vinegar consists first in determining the presence and proportion of foreign matter. With this view 500 grains of it should be evaporated by the heat of a chlor-calcium bath, the residuum weighed and examined. If it be sour, sulphuric acid may be suspected, and its amount be ascer. tained by precipitation with nitrate of barytes, and weighing the washed and dried precipitate. Every 118 parts indicate 49 of oil of vitrol; but if saline sulphates be present, their amount may be ascertained by igniting the above residuum and weighing what remains. The loss in ignition will be due to organic matter, acetates, and sulphuric acid. If an alkaline acetate be present after ignition, the residuum may be an alkalirnc carbonate. Nitric acid is best detected by adding a few drops of a dilute sulphate of indigo to the vinegar, and by boiling the mixture; when the blue will pass into a dirty brown yellow if nitric acid be present. In common cases a ready mode of estimating the strength of the vinegar is wanted, and no reagent is better for the purpose than the bicarbonate of potash, two grains of which are equivalent to very nearly one of suhydrous acetic acid. To 100 or 1000 grs. of the vinegar in question we have only to add from a weighed parcel of pounded bicarbonate of potash, enough to produce neutralization by the test of litmus paper, and the half number of grains required denotes the number of grains of acetic acid in 100 or 1000 of the vinegar. Or a normal solution of the bicarbonate may be kept ready made, of which 1000 water grain measures contain 100 of the salt; then each 20 grain measures expended in neutralizing 1000 water grain measures of the vinegar denote one grain of real acetic acid. As the extrication of carbonic acid from the bicarbonate is apt, however, in common hands to cause fallacies, I prefer ammonia as a general acidimetrical test, of which 1000 water grain measures of specific gravity 0'992 neutralize exactly one atom of acetic acid; that is, 51 grains of the anhydrous, or 60 of the hydrate; therefore after adding that test ammonia to the vinegar faintly reddened with litmus, out of a graduated glass tube, till the neutral tint of color be hit, the number of water grain measures of test expended, being multiplied either by 51 or 60, will give for a product the per centage of anhydrous or hydrated acetic acid. This is the method I have pursued for very many years, and which gives results of perfect precision in a few minutes. Vinegar is so extensively employed as a condiment, that it should be of better quality than is commonly on sale in the United Kingdom, where it is almost always contaminated with oil of vitriol. All our pickles participate in the same noxious ingredient. The fumes of vinegar, and even its odor, as in the vinegar of the Three Thieves of Marseilles, were lono supposed to be counteractive of contagion in sick rooms; but they are rather injurious, by covering unwholesome smells from want of due cleanliness and ventilation, and should never be relied upon. In combination with alumina, and also with oxide of iron, it is extensively used in the dyeing and printing of cotton, under thi 3 names of red liquor and iron liquor, as mordants for bright and dark colors. According to Dobereiner and Liebig, in the conversion of alcohol into acetic acid no carbonic acid is formed. 100 lbs. of alcohol consisting of 52-6 carbon - 12'9 hydrogen -- 31-5 oxygen, absorb from the air, in the process of acetification, 35'2 lbs. of oxygen, which abstract 4'4 lbs. of hydrogen from the alcohol, and thus generate 39'6 lbs. of water, leaving the substance called aldehyde (dehydrogenated alcohol), which consists of 52'6 carbon + 8-5 hydrogen - 68'4 oxygen. In practice we cannot obtain so much acid as the above, but the theoretical maximum serves as a beacon, and the nearer we can approach to.it the better. About 3600 cubic feet of air contain 69 lbs. of oxygen, the quantity barely necessary for acetifying 100 lbs. of alcohol; but as the air is only partially stripped of that element, much more is needed, and this excessive current carries off some alcohol, aldehyde, and acetic acid, and so lessens the product. If, on the other hand, air be too sparingly supplied, volatile aldehyde is chiefly formed, which flies off, and leaves a mawkish putrefying liquor of no value. We rzay complete the preceding view of the production of acetic acid, by showing the relatiolns which subsist between it and sugar, and starch, through the medium of alcohol-four correlative compounds, 100 lbs. of cane sugar are convertible into 100 lbs, of starch sugar or grape sugar, by boiling it with sulphuric or tartaric acid, and abstract. ing the acid by means of chalk; and that weight of either kind of sugar is capable or 8 ACETIC ACID. yielding by fermentation, 53'7 lbs. of alcohol. 100 Ibs. of starch, if well saccharified should afford fully loo0 lbA. of starch sugar, and, therefore, 53'7 lbs. alcohol. These are the theoretical quantities, but they can never be realized in practice. A quarter of good malt, weighing 320 lbs., contains by my experiments 144 solid extract, which should yield, first, 691 alcohol; and next 100 lbs. of acetic acid hydrate, equivalent to 17 times that weight of revenue proof vinegar =- 170 gallons nearly. Before the process for pyroligneous acid, or wood vinegar, was known, there was cnly one method of obtaining strong vinegar practised by chemists; and it is still followed by some operators, to prepare what is called radical or aromatic vinegar. This consists in decomposing, by heat alone, the crystallized binacetate of copper, commonly, but improperly, called distilled verdigris. With this view, we take a stoneware retort (fig. 1), of.i size suited to the " i quantity we wish to operate upon; and coat it with a mixture of fire clay and r*^^^ ^r hl horsedung, to make it stand the heat better. JL...-, [>Pf~~ E J ^ When this coating is dry, U we introduce into the retort the crystallized ace. ^-]n G~ |.l_~ _I:t otate slightly bruised, but F*- --- - ig. 1. - -very dry; we fill it as far ~'i * as it will hold without spilling when the beak is considerably inclined. /e. then set it in a proper furnace. We attach to its neck an adopter pipe, and two or three globes with opposite tubulures, and a last globe with a vertical tubulure. The apparatus is terminated by a Welter's tube, with a double branch; the shorter issues from the last globe, and the other dips into a flask filled with distilled vinegar. Everything being thus arranged, we lute the joinings with a putty made of pipeclay and linseed oil, and cover them with glue paper. Each globe is placed in a separate basin of cold water, or the whole may be put into an oblong trough, through which a constant stream of cold water is made to flow. The tubes must be allowed a day to dry. Next day we proceed to the distillation, tempering the heat very nicely at the beginning, and increasing it by very slow degrees till we see the drops follow each other pretty rapidly from the neck of the retort, or the end of the adopter tube. The vapors which pass over are very hot, whence a series of globes are necessary to condense them. We should renew, from time to time, the water of the basins, and keep moist pieces of cloth upon the globes; but this demands great care, especially if the fire be a little too brisk, for the vessels become, in that case, so hot, that they would infallibly be broken, if touched suddenly with cold water. It is always easy for us to regulate this operation, according to the emission of gas from the extremity of the apparatus. When the air bubbles succeed each other with great rapidity, we must damp the fire. The liquor which passes in the first half hour is weakest; it proceeds, in some measure, from a little water sometimes left in the crystals, which when well made, however, ought to be anhydrous. A period arrives towards the middle of the process when we see the extremity of the beak of the retort, and of the adopter, covered with crystals of a larellar or needle shape, and of a pale green tint. By degrees these crystals are carried into the condensed liquid by the acid vapors, and give a color to the product. These crystals are merely some of the cupreous salt forced over by the heat. As the process approaches its conclusion, we find more difficulty in raising the vapors; and we must then augment the intensity of the heat, in order to continue their disengagement. Finally, we judge that the process is altogether finished, when the globes become cold, notwithstanding the furnace is at the hottest, and when no more vapors are evolved. The fire may then be allowed to go out, and the retort to cool. As the acid thus obtained is slightly tinged with copper, it must be rectified before bringing it into the market.'For this purpose we may make use of the same apparatus, only substituting for the stoneware retort a glass one, placed in a sand bath. All the globes ought to be perfectly clean and dry. The distillation is to be conducted in the usual way. If we divide the product into thirds, the first yields the feeblest acid, and the third the strongest. We should not push the process quite to dryness, because there remain in the last portions certain impurities, which would injure the flavor of the acid. The total acid thus obtained forms nearly one half of the weight of the acetate employed, and the residuum forms three tenths; so that about two tenths of the acid have been decomposed by the heat, and are lost. As the oxyde of copper is readily reduced to the metallic state, its oxygen goes to the elements of one part of the acid, and forms water, which mingles with the products of carbonic acid, carbureted hydrogen, and ACETIC ACID. 9:arbor ic oxyde gases which are disengaged: and there remains in the retort some chalcoil mixed with metallic copper. These two combustibles are in such a state of division. that the residuum is pyrophoric. Hence it often takes fire the moment of its being removed from the cold retort. The very considerable loss experienced in this operation has induced chemists to try different methods to obtain all the acid contained in the acetate. Thus, for example, a certain addition of suitlhuric acid has been prescribed; but, besides that the radical vinegar obtained in this way always contains sulphurous acid, from which it is difficult to free it, it is thereby deprived of that spirit called the pyroacetic, which tempers the sharpness of its smell, and gives an agreeable aroma. It is to be prestumed, therefore, that the preceding process will continue to be preferred for making aromatic vinegar. Its odor is often further modified by essential oils, such as those of rosemary, lavender, &e. 4. Pyroligneous Acid, or Wood Vinegar.-The process for making this acid is founded upon the general property of heat, to separate the elements of vegetable substances, and to unite them anew in another order, with the product on of compounds which did not exist in the bodies subjected to i'q action. The respective proportion of these products varies, not only in the different suLstances, but also in the same substance, according as the degree of heat has been greater or less, or conducted with more or less skill. When we distil a vegetable body in a close vessel, we obt-in at first the included water, or tnat of vegetation; there is next formed another portion a" water, at the expense of the oxygen and hydrogen of the body; a proportional quantity of charcoal is set free, and, with the successive increase of the heat, a small portion (,f charcoal combines with the oxygen and hydrogen to form acetic acid. This was considered, for some time, as a peculiar acid, and was accordingly called t'yroligi.eous acid. As the proportion of carbon becomes preponderant, it combines with the other principles, and then some empyreumatic oil is volatilized, of little color, but which becomes thicker, and of a darker tint, always getting more loaded with carbon. Several elastic fluids accompany these different products. Carbonic acid comes over, but in small quantity, much carburreled hydrogen, and, towards the end, a considerable proportion of carbonic oxyde. The remainder of the charcoal, which could not be carried of' in these several combinations, is found in the retort, and preserves, usually, the form of the vegetable body which furnished it. Since mankind have begun to reason on the dilferent operations of the arts, and to raise them to a level with scientific researches, they have introduced into several branches of manufacture a multitude of improvements, of which, formerly, they would hardly have deemed them susceptible. Thus, in pa ti, alar, the process for carbonizing wood has been singularly meliorated, and in reference to the preceding observations, advantage as been derived from several products that formerly were not even collected. The apparatus employed for obtaining crude vinegar from wood, by the agency of heat, Fig. 2. are large iron cylinders. In this country they are made of cast iron, and are laid horizontally in the furnace; in France, they are made of sheet iron riveted together, and they are set upright in the fire. Fig. 2 will give an acI ((. i -~ curate idea of the British plan, which is much the same as I N' l i j' ) ~ i that adopted for decomposing pit coal in gas works, only that'he clinders for the pyroligneous acid manufacture ire r ^^ \ l ( _: genera.y larger, being frequently 4 feet in diameter, and T bar^^ " ) \ 6 or 8 feet long, and built horizontally in brickwork, so that the flame of one furnace may play around two ot them. It would probably answer better, if their size were brought nearer the dimensions of the gas-light retorts, and if the whole system of worKing them were assimilated to ^^^^^^ ^ ~ that of coal gas. The foilowmg ariangement is adopted in an excellent establishment in Glasgow, where the above large cylinders are _- l |' - _ ~_ 6 feet long, and both ends of them project a very little beyond the brickwork. One end has a disc or round plate of cast iron, well fitted, and firmly bolted to it, from the centre of which disc an iron tube, about 6 inches diameter, proceeds and enters, at a right angle, the main tube of refrigeration. The diameter of this tube may be from 9 to 14 inches, according to the number of cylinders. The other end of the cylinder is called the mouth of the retort; this is closed by a disc of iron, smeared round its edge by clay lute, and secured in its place by fir wedges. The charge of wood for such a cylinder is about 8 cwt. The hard woods-oak, ash, birch, and beech-are alone used; fir does not answer. The heat is kept up during the day-time, and the furnace is allowed to cool during the night. Next morning the door is opened, the c larcoal removed, and a new charge of wood is introduced. The average product of crude vinegar called pyrolignrieus a.id, is 35 gallons. It is much contaminated with tar, is of a deep brown color, 10 ACETIC ACID. and has a sp. gr. of 1'025. Its total weight is therefore about 300. lbs., but the residuarv charcoal is found to weigh no more than one fifth of the wood employed; hence n arly nne half of the ponderable matter of the wood is dissipated in incondensable ga3es Count Rumford states, that the charcoal is equal in weight to more than four tenths of the Arood from which it is made. The count's error seems to have arisen from the slight heat of an oven to which his wood was exposed in a glass cylincer. The result now given, is the experience of an eminent manufacturing chemist. The crude pyroligneous acid is rectified by a second distillation in a copper still, in the body of which about twenty gallons of viscid tarry matter are left from every 100. It has no;v become a transparent brown vinegar, having a considerably empyreumatic smell, and a sp. gr. of 1'013. Its acid powers are superior to those of the best household vinegar, in the proportion of three to two. By redistillation, saturation with quicklime, evaporation of the liquid acetate to dryness, and conversion into acetate of soda by sulphate of soda, the empyreumatic matter is so completely dissipated, that on decomposing the pure acetate of soda by sulphuric acid, a perfectly colorless and grateful vine. gar rises in distillation. Its strength will be proportionable to the concentration of the decomposing acid. The acetic acid of the chemist may be prepared also in the following modes:-1. Two parts of fused acetate of potash, with one of the strongest oil of vitriol, yield, by slow distillation from a glass retort into a refrigerated receiver, concentrated acetic acid. A small portion of sulphurous acid, which contaminates it., may be removed by redistillation from a little acetate of lead. 2. Or four parts of good sugar of lead, with one part of sulphuric acid, treated in the same way, afford a slightly weaker acetic acid. 3. Gently calcined sulphate of iron, or green vitriol, mixed with sugar of lead, in the proportion of 1 of the former to 2. of the latter, or with acetate of copper, and carefully distilled from a porcelain retort into a cool receiver, may be also considered an economical process. But that with binacetate of copper above described, is preferable to any of these. The manufacture of pyroligneous acid is conducted in the following way in France. Into large cylindrical -Q_-; vessels (fig. 3) made of riveted sheet iron, and having Fig. 3S (. \at their top and side a small sheet iron cylinder, the wood * \\ l intended for making charcoal is introduced. To the upper part of this vessel a cover of sheet iron, B, is adapted, which is fixed with bolts. This vessel, thus closed, represents, as we see, a vast retort. When it is prepared, as we have said, it is lifted by means of a swing C/ \ crane, c, and placed in a furnace, D (fig. 4), of a form relative to that of the vessel, and the opening of the furnace is covered with a dome, E, made of masonry or brickwork. The whole being thus arranged, heat is applied in the furnace at the bottom. The moisture of the wood is first dissipated, but by degrees the liquor Weases to.e transparent, and becomes sooty. An adopter tube, A, is then fitted to the lateral cylinder. This adopter A^ I 1 ~ enters into another tube at the same degree of inclination 0 (4)Q d wlwhich commencesethe condensing apparatus. The means of condensation vary according to the localities. In certain works they cool by means of air, by making the vapor pass through a long series of cylinders, or sometimes, even, through a series of casks connected together; but most usually water is used for condensing, when it sA^-..can be easily procured in abundance. The most simple {-Fig. 4. L Ah apparatus employed for this;E p1 ig. *. ^ ~ purpose consists of two cy linders, F, F (fig. 4), the n one within the other, and.s.4.. _.l. which leave between them a sufficient space to allow 1A _ -_ _. --— A a considerable body of LXq1.^3^^-~- -_ --— ~ — - -=:= —M>) -':-L ^HU wwater to circulate along and cool the vapors. This - -'.- double cylinder is adapted.- --................ } to the distilling vessel, and.-. —---.....-....=........ distplaced at a certain inclina-' 7<~ - I)\ tion. To the first double rJ^cLI=;~i L >- -U -— r tube, F, F, a second, and ACETIC ACID. 11 sometimes a thild, entirely similar, are connected, which, to Fave space, return upon themselves in a zigzag fashion. The water is set in circulation by an ingenious means now adopted in many different manufactories. From the lower extremity, G, of the system of condensers, a pei endicular tube rises, whose length should be a little more.han the most elevated point of the system. The water, furnished by a reservoir, L, enters by means of the perpendicular tube through the lower part of the system, and fills the whole space between the double cylinders. When the apparatus is in action, the vapors, as they condense, rase the temperature of the water, which, by the column in L G, is pressed to the upper part of the cylinders, and runs over by the spout i. To this point a very short tube is attached, which is bent towards the ground, and serves as an overflow. The condensing apparatus is terminated by a conduit in bricks covered and sunk in the ground. At the extremity of this species of gutter is a bent tube, E, which discharges the liquid product into the first cistern. When it is full, it empties itseil, or means of an overflow pipe, int a great reservoir: the tube which terminates the gutte: plunges into the liquid, and thus intercepts communication with the inside of the apparatus. The disengaged gas is brought back by means of pipes M L, from one of the sides of the conduit to the under part of the ash pit of the furnace. These pipes are furnished with stopcocks M, at some distance in front of the furnace, for the purpose of regulating the jet of the gas, and interrupting, at pleasure, communication with the inside of the apparatus. The part of the pipes which terminates in the furnace rises perpendicularly several inches above the ground, and is expanded like the rose of a watering can, N. The gas, by means of this disposition, can distribute itself uniformly under the vessel, without suffering the pipe which conducts it to be obstructed by the fuel or the ashes. The temperature necessary to effect the carbonization is not considerable: however, at the last it is raised so high as to make the vessels red hot; and the duration' of the process is necessarily proportional to the quantity of wood carbonized. For a vessel which shall contain about 5 meters cube (nearly 6 cubic yds.), 8 hours of fire is sufficient. It is known that the carbonization is complete by the color of the flame of the gas: it is first of a yellowish red; it becomes afterwards blue, when more carbonic oxyde than carbonic hydrogen is evolved; and towards the end it becomes entirely white,- a circumstance owing, probably, to the furnace being more heated at this period, and the combustion being more complete. There is still another means of knowing the state of the process, to which recourse is more frequently had; that is the cooling of the first tubes, which are not surrounded with water: a few drops of this fluid are thrown upon their surface, and if they evaporate quietly, it is judged that the calcination is sufficient. The adopter tube is then unluted, and is slid into its junction pipe; the orifices are immediately stopped with plates of iron and plaster loam. The brick cover, E, of the furnace is first removed by means of the swing crane, then the cylinder itself is lifted out and replaced immediately by another one previously charged. When the cylinder which has been taken out of the furnace is entirely cooled, its cover is removed, and the charcoal is emptied. Five cubic meters of wood furnish about 7 chaldrons (voies) and a half of charcoal. (For modifications of the wood-vinegar apparatus, see CHARCOAL and PYROLIGNEOUS ACID.) The different qualities of wood employed in this operation give nearly similar pr). ducts in reference to the acid; but this is not the case with the charcoal, for it is better the harder the wood; and it has been remarked that wood long exposed to the air furnishes a charcoal of a worse quality than wood carbonized soon after it is cut. Having described the kind of apparatus employed to obtain pyroligneous acid, I shall now detail the best mode of purifying it. This acid has a reddish brown color; it holds in solution a portion of empyreumatic oil and of the tar which were formed at the same lime, another portion of these products is in the state of a simple mixture: the latter may be separated by repose alone. It is stated above, that the distilling apparatus terminates in a subterranean reservoir, where the products of all the vessels are mixed. A common pump communicates with the reservoir, and sinks to its very bottom, in order that it may draw off only the stratum of tar, which, according to its greater density, occupies the lower part. From time to time the pump is worked to remove the tar as it is deposited. The reservoir has at its top an overflow pipe, which discharges the clearest acid into a cistern, from which it is taken by means of a second pump. The pyroligneous acid thus separated from the undissolved tar is transferred from this cistern into large sheet iron boilers, where its saturation is effected either by quicklime or by chalk, the latter of which is preferable, as the lime is apt to take some of the atr into combination. The acid parts by saturation with a new portion of the tar, which is removed by skimmers. The neutral solution is then alloT ed to rest for a sufficient, time to let its clear parts be drawn off by decantation. The acetate of lime thus obtained indicates by the hydrometer, before being mixed with the waters of edulcoration, a degree corresponding to the acidimetric degree of the acid 12 ACETIC ACID. employed. This solution must be evaporated till it reaches a specific gravity of 1*114 (15~ Baum6), after which there is added to it a saturated solution of sulphate of soda. The acids exchange bases; sulphate of lime precipitates, and acetate of soda remains in solution. In some ilanufactures, instead of pursuing the above plan, the sulphate ol soda is dissolved in the hot pyroligneous acid, which is afterwards saturated with chalk ei lime. By -his means no water need be employed to dissolve the sulphate, and accordingly the liquor is obtained in a concentrated form without evaporation. In both modes the sulphate of lime is allowed to settle, and the solution of acetate of soda is decanted. The residuum is set aside to be edulcorated, and the last waters are employed for washing fresh portions. The acetate of soda which results from this double decomposition is afterwards evaporated till it attains to the density of 1-225 or 1-23, according to the season. This solution is poured into large crystallizing vessels, from which, at the end of 3 or 4 days, according to their capacity, the mother waters are decanted, and a first crystallization is oetained of rhomboidal prisms, which are highly colored and very bulky. Their facettes are finely polished, and their edges very sharp. The mother waters are submitted to successive evaporations and crystallizations till they refuse to crystallize, and they are then burnt to convert them into carbonate of soda. To avoid guesswork proportions, which are always injurious, by the loss of time which they occasion, and by the bad results to which they often lead, we should determine experimentally, beforehand, the quantities absolutely necessary for the reciprocal decomposition, especially when we change the acid or the sulphate. But it may be remarked that, notwithstanding all the precautions we can take, there is always a notable quantity of sulphate of soda and acetic acid, which disappear totally in this decomposition. This arises from the circumstance that sulphate of soda and acetate of lime do not completely decompose each other, as I have ascertained by experiments on a very considerable scale; and thus a portion of each of them is always lost with the mother waters. It might be supposed that by calcining the acetate of lime we could completely destroy its empy. reumatic oil; but, though I have made many experiments with this view, I never could abtain an acetate capable of affording a tolerable acid. Some manufacturers prefer to make the acetate of soda by direct saturation of the acid with the alkali, and think that the higher price of this substance is compensated by the economy of time and fuel which it produces.'Ihe acetate of soda is easily purified by crystallizations and torrefaction; the latter process, when well conducted, freeing it completely from every particle of tar. This torrefaction, to which the name of fusion may be given, requires great care and dexterity. It is usually done in shallow cast iron boilers of a hemispherical shape. During all the time that the heat of about 500~ Fahr. is applied, the fused mess must be diligently worked with rakes; an operation which continues about 24 hours for half a ton of materials. We must carefully avoid raising the temperature so high as to decompose the acetate; and be sure that the heat is equally distributed; for if any point of the mass enters into decomposition, it is propagated with such rapidity, as to be excessively difficult to stop its progress in destroying the whole. The heat should never be so great as to disengage any smoke, even when the whole acetate is liquefied. When there is no more frothing up, and the mass flows like oil, the operation is finished. It is now allowed to cool in a body, or it may be ladled out into moulds, which is preferable. When the acetate is dissolved in water, the charcoaly matter proceeding from the decomposition of the tar must be separated by filtration, or by boiling up the liquor to the specific gravity 1-114, when the carbonaceous matter falls to the bottom. On evaporating the clear liquor, we obtain an acetate perfectly fine, which yields beautiful crystals on cooling. In this state of purity it is decomposed by sulphuric acid, in order to separate its acetic acid. This last operation, however simple it appears, requires no little care and skill. The acetate of soda crystallized and ground is put into a copper, and the necessary quantity of sulphuric acid of 1-842 (about 35 per cent. of the salt) to decompose almost, but not all, the acetate, is poured on. The materials are left to act on each other; by degrees the acetic acid quits its combination, and swims upon the surface; the greater part of the resulting sulphate of soda falls in a pulverulent form, or in small granular crystals, to the bottom. Another portion remains dissolved in the liquid, which has a specific gravity of 1'08. By distillation we separate this remainder of the sulphate, and finally obtain acetic acid, having a specific gravity of 1-05, an agreeable taste and smell, though towards the end it becomes a little empyreumatic, and colored; for which reason, the last portions must be kept apart. The acid destined for table use ought to be distilled in an alembic whose capital and condensing worm are of silver; and to make it very fine, it may be afterwards infused over a little pure animal charcoalthe well-washed residuum of the Prussian-blue-works black. ACTINISM. 18 An excise duty of 2d. is levied on every gallon of the above proof vinegar. itl st'rngth is not, however, estimated directly by its specific gravity, but by the specific gravty which it assumes when saturated with quicklime. The decimal fract:a of the specii.c gravity of the calcareous acetate is very nearly the double of that of the pure vinegat; or, 1'009 in vinegar becomes 1P0i8 in acetate of lime. The vinegar of malt contains so much mucilage or gluten, that when it has only the same acid strength as the above, it has a density of 1.0014, but it becomes only 1'023 when converted into acetate of lime: indeed, 0-005 of its density is due to mucilaginous matter. This fact shows the fallacy of trusting to the hydrometer for determinil,, the strength of vinegars, which may be more or less loaded with vegetable gluten. The proper test of this, as of all other acids, is, the quantity of alkaline matter which a given weight or measure of it will saturate. For this purpose the bicarbonate of potash, commonly called, in the London shops, carbonate, may be employed very conveniently. As it is a very uniform substance, and its atomic weight, by the hydrogen radix, is 100'584, while the atomic weight of acetic acid, by the same radix, is 51'563, if we estimate 2 grains of the bicarbonate as equivalent to 1 of the real acid, we shall commit no appreciable error. Hence, a solution of the carbonate containing 200 grains in 100 measures, will form an aceti. meter of the most perfect and convenient kind; for the measures of test liquid expended in saturating any measure, —for instance, an ounce or 1000 grains of acid,-will indicale the number of grains of real acetic acid in that quantity. Thus, 1000 grains of the above proof, would require 5'0 measures of the acetimetrical alkaline solution, showing that it contains 50 grains of real acetic acid in 1000, or 5 per cent. It is common to add to purified wood vinegar, a little acetic ether, or caramelized (burnt) sugar to color it, also, in France, even wine, to flavor it. Its blanching effect upon red cabbage, which it has been employed to pickle, is owing to a little sulphurous acid. This may be removed by redistillation with peroxyde of manganese. Indeed, Stollze professes to purify the pyroligneous acid solely by distilling it with peroxyde of manganese, and then diaesting it with bruised wood charcoal; or by distilling it with a mixture of sulphuric acid and manganese. But much acid is lost in this case by the formation of acetate of that metal. Birch and beech afford most pyroligneous acid, and pine the least. It is exclusively employed in the arts, for most purposes of which it need not be very highly purified. It is much used in calico printing, for preparing acetate of iron called IRON LIQUOR, and acetate of alumina, called RED LIQUOR; which see. It serves also to make sugar of lead; yet when it contains its usual quantity, after rectification of tarry matter, the acetate of lead will hardly crystallize, but forms cauliflower concretions. This evil may be remedied, I believe, by boiling the saline solution with a very little nitric acid, which causes the precipitation of a brown granular substance, and gives the liquor a reddish tinge. The solution being afterwards treated with brAised charcoal, becomes colorless, and furnishes regular crystals of acetate or sugar of lead. Pyroligneous acid possesses, in a very eminent degree, anti-putrescent properties. Flesi steeped in it for a few hours may be afterwards dried in the air without corrupting; but it becomes hard, and somewhat leather-like: so that this mode of preservation does not answer well for butcher's meat. Fish are sometimes cured with it. See PYRO-ACET'IC SPIRIT; PYROXILIC ETHER; PYROXOLIC SPIRIT; PYROLIGNEOUS ACID and VINEGAR. In 1838, 2,628,978 gallons of vinegar paid duty in England; in 1839, 2,969,665; and in 1840, 3,021,130; upon which the gross amount of duty was, respectively, 21,9081. 3s.; 24,4481. 17s. 6d.; and 25,978/. 12s. 9d. In Scotland, in the same years, 15,626 gallons; 14,532; and 12,967; on which the duty charged was, respectively, 1301. 4s. 4d.; 121/. 2s..; and 1111. 19s. 7d. In Ireland, in the same years, 48,158 gallons; 50,508; and 56,812; on which the duty charged was 4011. 6s. 4s.; 4201. 18s.; and 4891. 12s. ACETIMETER. An apparatus for determining the strength of vinegar. See the preceding article for a description of my simple method of acetimetry. ACETONE. The new chemical name of pyro-acetic spirit. ACID OF ARSENIC. (Acide arsenique, Fr.; Arseniksaure, Germ.) See ARSENIC. ACIDS. A class of chemical substances characterized by the property of combining with and neutralizing the alkaline and other bases, and of thereby forming a peculiar class of bodies called salts. The acids which constitute objects of special manufacture for commercial purposes are the following:-acetic, arsenious, carbonic, chromic, citric, hydrocyanic, malic, muriatic, nitric, oxalic, phosphoric, sulphuric, tartaric, which see. ACII)IMETER. See ALKALIMETER. ACROSPIRE. (Plumule, Fr.; Blattkeim, Germ.) That part of a germinating seed which botanists call the plumula, or plumes. See BEER and MALT. ACTINISM. Some years ago, Mr. R. Hunt announced that he had discovered that, associated with the light and heat derived fiom the sun, there is another principle most active in producing changes in the organic and inorganic worlds, which he has called 14 ADIPOCIRE. A titismm, from the Greek for a ray of the sun. IIe has given the following striking evidences of the truth of his discovery, derived from the vegetable world. That the actinic principle was necessary to germination was shown by the fact, that seeds placed under the influence of the solar rays transmitted through yellow glass would not germinate, because yellow glass prevents the passage of the actinic principle. Accordingly; during spring the solar beam contained a larger amount of the actinic principle than at any other, because it was neceRsary at that season for the germination of seeds anl the development of buds. In summer, again, there was a large proportion of the light-giving principle necessary to the formation of the woody portions of plants; and towards autumn the calorific heat giving or ripening principle of the solar rays increased. It resulted from these principles that the recent use in greenhouses of white German sheet glass was most objectionable. Under this kind of glass, plants were subject to an injurious solar influence which they had not suffered under the old crown glass. It became therefore necessary to discover some method to cut off those parathermic rays, which, passing through the white glahs, scorched and browned particular portions of the leaves, without cutting off the other portions of the rays which were necessary to the growth of the plant. With tills view Mr. Hunt has devised and applied at the Kew observatory a green glass stained with oxide of copper, which effectually excludes the injurious parathermic rays, wl.ile it admits the other solar rays necessary for the plant, as freely as ordinary white glass. In the manufacture of this green glass it was essential that no manganese should be used, as was the case in white glass. If manganese were used, the glass would after a while assume a pinkish hile, which would more freely admit-the burning rays. ADDITIONS. Such articles as are added to the fermenting wash of the distiller are distinguished by this trivial name. ADIPOCIRE. Fr. (Fettwachs, Germ.) The fatty matter generated in dead bodies buried under peculiar circumstances. In 1786 and 1787, when the churchyard of the Innocents, at Paris, was cleaned out, and the bones transported to the catacombs, it was discovered that not a few of the cadavres were converted into a saponaceous white substance, more especially many of those which had been interred for fifteen years in one pit, to the amount of 1500, in coffins closely packed together. These bodies were flattened, in consequence of their mutual pressure; and, though they generally retained their shape, there was deposited round the bones of several a grayish white, somewhat soft, flexible substance. Fourcroy presented to the Academy of Sciences, in 1789, a comprehensive memoir upon this phenomenon, which appeared to prove that the fatty body was an ammoniacal soap, containing phosphate of lime; that the fat was similar to sper. maceti, as it assumed on slow cooling a foliated crystalline structure; as also to wax, as, when rapidly cooled, it became granular: hence he called it.ddivocire. Its melting point was 52'5~ C. (126-5~ Fahr.). He likewise compared this soap to the fat of gall-stones, and supposed it to be a natural product of the slow decomposition of all animal matter, except bones, nails, and hairs. This substance was again examined by Chevreul in 1812, and was found by him to contain margaric acid, oleic acid, combined with a yellow coloring, odorous matter, Jbesides ammonia, a little lime, potash, oxyde of iron, salts of lactic acid, an azotized substance; and was therefore considered as a combination of margaric and oleic acids, in variable proportions (whence arose its variable fusibility), but that it was not analogous with eithier spermaceti or cholesterine (gallstones). These fat acids are obviously generated by the reaction of the ammonia upon the margarine and oleine, though they eventually lose the greater part of that volatile alkali. According to the views of both Gay Lussac and Chevreul, this adipocire proceeds solely from the pre-existing fat of the dead body, and not from the flesh, tendons, or cartilages, as had been previously imagined; which had led to some expensive and abortive attempts, upon the great scale of manufacture, to convert the dead bodies of cattle into adipocire, for the purposes of the candle-maker or soap-boiler, by exposing them for some time to the action of moisture. Von Hartkol made experiments during 25 years upon this subject, from which 4e inferred, that there is no formation of adipocire in bodies buried in dry ground; that in moist earth the fat of the dead body does not increase, but changes into a fetid saponaceous substance, incapable of being worked into either soap or candles; that the dead bodies of mammalia immersed in running water, leave behind after 3 years a pure fat, which is more abundant from young than from old anmials; that the intestines aflbrd more fat than the muscles; that from this fat, without any purification; candles may be made, as void of smell, as hard, and as white, as from bleached wax; that from cadavers immersed for 3 years in stagnant water, more fat is procured than fiom those in running water, but that it needs to be purified before it can be made into soap or candles. The cause of the lifference between Hartkol's and Chevreul's results cannot be assigned, as the latter has not published his promised remarks upon the subject. At ALABASTER. 1t any rate, dea animal matter can be worked up more profitably tlan in making artificial adipocire. ADIT. The horizontal entrance of a mine. It is sometimes called the drift. See MINING and METALLURGY. ADULTERATION. The debasing any product of manufacture, especially chemical, by the introduction of cheap materials. The art of ascertaining the genuineness of the several products will be taught under the specific objects of manufacture. rETiIER. See ETHER. AFFINITY. The chemieal term denoting the peculiar,attractive force which produces the combination of dissimilar substances; such as of an alkali with an acid, or of sulphur with a metal. It is oftcn called elective attraction, to distinguish it from corpuscular or cohesive attraction, by which particles of like kinds of matter are combined; and because it displays the power of selecting its preferable associates. Its full discussion belongs to chemistry. AGARIC. A species of boletus or fungus, which grows in dunghills; with the salts of iron it affords a black dye. It is said to be convertible into a kind of china ink. AGATE. A silicious mineral which is cut into seals and other forms for the coarser kinds of jewellery. See GEM. AIR. See VENTILATION. A LABASTER, is a stone usually white, and soft enough to be scratched by iron,, There are two kinds of it: the gypseous, which is merely a natural semi-crystalline sulphate of lime; and the calcareous alabaster, which is a carbonate of lime. The oriental alabaster is always of the latter kind, and is most esteemed, because it is agreeably variegated with lively colors, and especially with zones of honey-yellow, yellow-brown, red, &c.; it is, moreover, susceptible of taking a marble polish. The fineness of the grain of' alabaster, the uniformity of its texture, the beauty of its polished surface, and its semi-transparency, are the qualities which render it valuable to the sculptor and to the manufacturer of ornamental toys. The limestone alabaster is frequently found as a yellowish-white deposite in certain fountains. The most celebrated spring of this kind is tkat of the baths of San Filippo, in Tuscany. The water, almost boiling hot, runs over an enormous mass of stalactites, which it has formed, and holds the carbonate of lime in solution by means of sulphureted hydrogen (according to M. Alexandre Brongniard), which escapes by contact of the atmosphere. Advantage has' been taken of this property to make basso relievos of considerable hardness, by placing moulds of sulphur very obliquely, or almost upright, in wooden tubs open at the bottom. These tubs are surmounted at the top with a large wooden cross. The water of the spring after having deposited in an external conduit or cistern the coarser sediment, is made to flow upon this wooden cross, where it is scattered into little streamlets, and thence lets fall, upon the sulphur casts, a precipitate so much the finer the more nearly vertical the mould. From one to four months are required for this operation, according to the thickness of the deposited crust. By analogous processes, the artists have succeeded in moulding vases, figures of animals, and other objects, in relief, of every different form, which require only to be trimmed a little, and afterwards polished. The common alabaster is composed of sulphuric acid and lime, though some kinds of it effervesce with acids, and therefore contain some carbonate of lime. This alabaster occurs in many different colors, and of very different degrees of hardness, but it is always softer than marble. It forms, usually, the lowest beds of the gypsum quarries. The sculptors prefer the hardest, the whitest, and those of a granular texture, like Carrara marble, and so like that they can only be distinguished by the hardness. The alabaster is worked with the same tools as marble; and as it is many degrees softer, it is so much the more easily cut; but it is more difficult to polish, from its little solidity. After it has been fashioned into the desired form, and smoothed down with pumice stone, it is polished with a pap-like mixture of chalk, soap, and milk; and, last of all, finished by friction with flannel. It is apt to acquire a yellowish tinge. Besides the harder kinds, employed for the sculpture of large figures, there is a softer alabaster, pure white and semi-transparent, from which small ornamental objects are made, such as boxes, vases, lamps, stands of time-pieces, &c. This branch of business is muac prosecuted in Florence, Leghorn, Milan, &c., and employs a great many turning lathes. Of all the alabasters, the Florentine merits the preference, on account of its beauty and uniformity, so that it may be fashioned into figures of considerable size: for which purpose there are large work-shops where it is cut with steel saws into blocks and mas. ses of various shapes. Other sorts of gypsum, such as that of Salzburg and Austria, contain sand veins, and hard nodules, and require to be quarried by cleaving and blasting 16 ALCOHOL. operations which are apt to crack it, and unfit it for all delicate objects of sculpture. It is besides of a gray shade, and often stained with darker colors. The alabaster best adapted for the fine arts is pretty white when newly broken, and becomes whiter on the surface by drying. It may be easily cut with the knife or chisel, anl formed into many pleasing shapes by suitable steel tools. It is worked either by the hand alone, or with the aid of a turning lathe. The turning tools should not be too thin, or sharp-edged; but such as are employed for ivory and brass are most suitable for alabaster, and are chiefly used to shave and to scratch the surface. The objects which cannot be turned may be fa-hioned by the rasping tools, or with minute files, such as variegated.foliage. Fine chisels and graving tools are also used for the better pieces of statuary. For polishing such works, a peculiar process is required; pumice stone, in fine powder, serves to smooth down the surfaces very well, but it soils the whiteness of the alabaster. To take away the unevenness and rolg-hness, dried shave-grass (equisetuin answers best. Frictions with this l)lant and water polish down the asperities left by the chisel: the fine streaks left by the grass may be removed by rubbing the pieces with slaked lime, finely pulverized and sifted, made into a paste or putty with water. The polish and satin-lustre of the surface are communicated by friction, first with soapwater and lime, and finally with powdered and elutriated talc or French chalk. Such articles as consist of several pieces are joined by a cement composed of quicklime and white of egg, or of well-calcined and well-sifted Paris plaster, mixed with the least possible quantity of water. Alabaster objects are liable to become yellow by keeping, an(d are especially injured by smoke, dust, &c. They may be in some measure restored by washing with soap and water, then with clear water, and again polished with shave-grass. Grease-spots may be removed either by rubbing with talc powder, or with oil of turpentine. The surface of alabaster may be etched by covering over the parts that are not to be touched with a solution of wax in oil of turpentine, thickened with white lead, and immersing the articles in pure water after the varnish has set. The action of the water is continued from 20 to 50 hours, more or less, according to the depth to which the etching is to be cut. After removing the varnish with oil of turpentine, the etched places, which are necessarily deprived of their polish, should be rubbed with a brush dipped in finely-powdered gypsum, which gives a kind of opacity, contrasting well with the rest of the surface. Alabaster may be stained either with metallic solutions, with spirituous tinctures of dyeing plants, or with colored oils, in the same way as marbles. This substance has been hardened, it is said, by exposing it to the heat of a baker's oven for 10 or 20 hours, after taking it out of the quarry, and giving it the figure, roughly, which it is intended to have. After this exposure, it must be dipped for two minutes in running water; when it is cold, it must be dipped a second time for the same period. On being exposed to the air for a few days, alabaster so treated acquires a marble-like hardness. I doubt the truth of this last statement. I believe a much better means of induration would be by soaking it in solution of alum. Alabaster is by the mineralogist considered as hydrous gypsum; and consists of one atom of sulphuric acid, one atom of lime, and two atoms of water. ALBATA. A white metal like silver; see COPPER, of which it is an alloy with nickel and zinc. ALBUM GRIECUM. The white dung of dogs, sometimes used to soften leather in the process of dressing it after the depilatory action of lime. It is essentially phosphate of lime and mucus. ALBUMINE, an animal product, like white of egg, which is diffused through the whole body, and is on account of the multifarious uses which it subserves in the vital economy called Proteine. It consists of carbon 550; hydrogen 7'07; oxygen 22-0; azote 15-92. ALCARAZZAS. A species of porous earthenware, made in Spain, for cooling liquors. Alcarazzas are made of a sandy marl, made up into a dough, with a solution of salt, and very little fired. M. Fourmy has mounted a factory of them in Paris under the Greek title of Hygroceramen. ALCOHOL. The well-known intoxicating liquor procured by distillation from various vegetable juices, and infusions of a saccharine nature, which have undergone the vinous fermentation. Common alcohol, or proof spirit,as it is called,contains about one-half its weight of water. It may be concentrated till its specific gravity becomes so low as 0'825, by simple redistillation at a steam or water-blth heat; but to make it stronger, we must mix with it, in the still or retort, dry carbonate of potash, chloride of calcium, dry lime, or some other substances strongly attractive of water. and then it may be ob. tained of a specific gravity so low as 07 91 at 160 Reaumur (68~ Fahr.), water being 1-000 ALCOHOL. 17 At 0-825, it contains, still, 11 per cent. of water; and in this state it is as volatile as absolute alcohol, on account of the inferior density of the aqueous vapor, compared to the alcoholic. Indeed, according to Yelin and Fuchs, the boiling point of anhydrous alcohol is higher than of that which contains 2 or 3 per cent. of water; hence, in the distillation of alcohol of 94 per cent., the first portions that come over are more aqueous than the following. Absolute alcohol.has its boiling point at 1681~ Fahr.; but when it holds more than 6 per cent. of water, the first portions that come over are richest in alcohol, and the temperature of the boiling point, or of the spirituous vapor, is always higher the longer the distillation continues. According to Grdning's researches, the following temperatures of the alcoholic vapors correspond to the accompanying contents of alcohol in per centage of volume, which are disengaged in the boiling of the spirituous liquid. K - _ _ _ _ _ _ _ - -. _ _ Alcoholic con- Alcoholic con- Alcoholic con- Alcoholic conTemperature. tent of.the tent of the boil Temperature. tent of the.ent of the boil. vapor. ig liquid. vapor. ing liquid. Fahr. 170 -0 93 92 Fahr. 189 8 71 20 171 8 92 90 192 0 68 18 172 91 85 164 66 15 172 8 90( 80 196 4 61 12 174 90 70 198 -6 55 19 174 -6 89 70 201 50 7 176 87 65 203 42 5 178 -3 85 50 205 -4 36 3 180 -8 82 40 207 -7 28 2 183 80 35 210 13 1 185 78 30 212 0 0 187 4 76' 25 Gr5ning undertook this investigation in order to employ the thermometer as an alcohol-meter in the distillation of spirits: for which purpose he thrust the bulb of the thermometer through a cork, inserted into a tube fixed in the capital of the still.'he state of the barometer ought also to be considered in making comparative experimenrts of this kind. Since, by this method, the alcoholic content may be compared with the temperature of the vapor that passes over at any time, so, also, the contents of the whole distillation may be found approximately; and the method serves as a convenient means of making continual observations on the progress of the distillation. The Abbe Vidal of Toulon constructed a few years ago an instrument which lh termed the Ebullition Alcoolmntre, for estimating the strength of alcohol from the temperature of its boiling point. It is an awkward apparatus, consisting of a large cylindrical glass bulb, like that of a wheel barometer, containing mercury, and a floating glass bead, with a thread attached; the other end of which pasued over a littlepulley, and was terminated by a counterweight. Concentric with this pulley a graduated flat ring of brass was fixed, on which an index traversed with the pulley, as it was moved b. the thread in its ascent by the mercury in its expansions by the heat of the alcohol, placed in a little cylinder into which the bulb was plunged. This cylinder was subjected to the flame of a little spirit lamp. I found the instrument, as thus made in France, difficult to manage, easily deranged by a loss of a drop of the mercury, and difficult to repair. I therefore substituted a simple thermometer, with a very narrow bore from 212~ to 184~ Fahr. and consequently a long range of scale between these two points. The scale was divided as follows: Temp. Fahr. Sp. Gr. Temp. Fahr. Sp. Gr. 178-60. 0-920 P. 185-6 0-9665 50 U. P. 179-75 0-9821 10 U. P. 189-0 0-9729 60 180-4 09420 20 191-8 0-9786 70 182-00 0'9516 30 196-4 0'9850 80 188-40 0'960 40 202-0 0-992 90 The above table is the mean of a great many experiments. P. means proof spirits of the British excise standard; U. P. denotes under proof. —n the Pharmaceutical Journal, vol. 7. p. 166., there is a dctaled account, with enLrravings, of the two instruments. Thle first of the followinr two tables of the boiling points of alcohol of different strengths may be compared with my short one given above. _ _ __ ____ _____________ 18 ALCOHOL. Groning. Yelin. Alcohol. Boiling Alcohol Boiling in 100. Point. in 100. Point. 5 96'3~ C. 94 76-97~ C. 10 92-9 95'7699 15 91-0 96'7692 20 89-1 97 76-85 25 87'5 98 76-85 30 86-2 99 76'90 35 85'0 100 77-02 40 84-1 45 83-4 50 83-1 55 82-2 60 81-9 65 81-5 70 80-9 75 80-3 80 79-7 85 79-4 90 79'0 95 78-4 Proof spirit of sp. gr. 0-92 at 60~ Fahr. consists of absolute alcohol of gravity 0'794, and of distilled water very near equal weights; but in volumes, of 126 of alcohol and 100 of water; therefore 100 measures of such spirits contain 55-75 of the alcohol (,26- By the table of Gay Lussac, spirits that'contain 55-75 of absolute aleohol have a specific gravity of 0-9218 instead of 0-9200; while spirits of 0-9200, according to Gay Lussac, contain 56-66 in 100 by volume. By the table of Tralles, spirits of 0-825 contain 92-43 of the said alcohol; and hence 100+5666 =-60 6 of Gilpin's 92-43 alcohol by Gay Lussac; whereas by Gilpin's table, spirits of 0-9200 contain 100 of alcohol of 0'825 +81-2 of water by weight: and 100 =121-2121 by volume. Again, 0'825 121-2121 +81-2-=202-2121; 121-2121 divided by 202-2121 gives a quotient of 59'88 as the alcohol of 0-825 in the 100 by volume. Now as 60-6 by Gay Lussac's table exceeds 59-88 by 0-72, there, must be an error; most probably on the side of the French chemist. The temperature, corresponding to a certain per centage of alcohol in vapor, suggests the employment of a convenient method for obtaining, at one process, a spirit as free from water as it can be made by mere distillation. We place over the top of the capital a water-bath, and lead up through it a spiral pipe from the still, which there passes obliquely downwards, and proceeds to the refrigeratory. If this bath be maintained, by a constant influx of cold water, at a certain temperature, only the alcoholic vapor corresponding to that temperature will pass over, and the rest will be recondensed and returned into the still. If we keep the temperature of the water at 174~, for example, the spirituous vapor which passes over will contain 90 per cent. of absolute alcohol, according to the preceding table. The skilful use of this principle constitutes the main improvement in modern distilleries. See DISTILLATION and STILL. Another method for concentrating alcohol is that discovered by Summering, founded upon the property of ox bladders to allow water to pass through and evaporate out of them, but not to permit alcohol to transpire, or only in a slight degree. Hence, if an ox's bladder is filled with spirit of wine, well tied at the mouth, and suspended in a warm lace, the water will continually exhale, and the alcohol will become nearly anhydrous; for in this way alcohol of 97 or 98 per cent. may be obtained. According to Summerinr, we should take for this purpose the bladder of an ox or a calf, soak it for some time in water, then inflate it and free it from the fat and the attached vessels; which is to be also done to the other surface, by turning it inside out. After it is again inflated and dried, we must smear over the outer side twice, and the inner side four imes, with a solution of isinglass, by which its texture is made closer, and the concen-.ration of the alcohol goes on better. A bladder so prepared may serve more than a ALCOIOL. 19 hundred times. It must be charged with the spirits to be concentrated, leaving a small space vacant, it is then to be tightly bound at the mouth, and suspended in a warm situation, at a temperature of 1220 Fahr., over a sand-bath, or in the neighborhood of an oven. The surface of the bladder remains moist with the water as long as the sp. gr. of the contained spirit is greater than 0.952. Weak spirit loses its water quicker than strong; but in from 6 to 12 hours the alcohol may be concentrated when a suitable heat is employed. This economical method is particularly applicable in obtaining alcohol for the preparation of varnishes. When the alcohol is to serve for other purposes it must be freed, by distillation, from certain matters dissolved out of the bladder. Alcohol may likewise be strelngthened, as Sommeiing has ascertained, when the vessel that contains the spirit is bound over with a bladder which does not come into contact with the liquid. Thus, too, all other liquors containing alcohol and water, as wine, cider, &c, may be made more sl irituous. To procure absolute alcollol, we must take chloride of calcium recently fused, reduce it to a coarse powder, and mix it with its own weight of spirits of wine, ofsp. gr. 0.833, in a bottle, which is to be well stoppered, and to be agitated till the salt is dissolved. The clear solution is to be pouted into a retort, and half of the volume of tlie alcohol employed, or so much as has the sp. gr. 0.791 at 78~ Fahr., is to be distilled off, drop by drop, at a gentle heat. Quicklime has also been employed for the same purpose, but it is less powerful and convenient. Alcohol, nearly free from water, may be obtained without distillation, by adding dry carbonate of potash to a spirit of wine, of sp. gr. 0'825. The water combines with the potash, and falls to thle bottom in a dense liquid, while the pure spirit floats on the surface. This contains, however, a little alkali, which can be separated only by distillation. Anhydrous alcohol is composed by weight of 52'18 carbon, 13'04 hydrogen, and 34'78 of oxygen. It has for its symbol C4 H6 02 = C4 14, II2 O2; or one atom of ether -+ one atom of water; it is therefore a hydrate of ether. It has a very powerful attraction for water, and absorbs it from the atmosphere; therefore it must be kept in well-closed vessels. It also robs vegetable and animal bodies of their moisture; and hence common alcohol is employed for preserving anatomical preparations. Alcolol is a solvent for many substances: resins, essential oils, camphor, are abundantly dissolved by it, forming varnishes, perfu;med spirits, &c. The solution of a resin or essential oil in alcohol becomes milky on the addition of water, which, by its attraction for alcohol, separates tlese substances. Several salts, especially the deliquescent, are dissolved by it, and some of them give a color to its flame; thus the solutions of the salts of strontia in alcohol burn with a crimson flame; those of copper and borax green, lime reddish, and baryta yellow. When water is mixed with alcohol, heat and a condensation of volume are the result; these effects being greatest with 54 per cent. of alcohol and 46 of water, and thence decreasing with a greater proportion of water. For alcohol which contains 90 per cent. of water, this condensation amounts to 1'94 per cent. of the volume; for 80 per cent., 2'87; for 70 per cent., 3-44; for 60 per cent., 3-73; for 40 per cent., 3-44; for 30 per cent., 2-72; for 20 per cent., 1'72; for 10 per cent., 0'72. Hence, to estimate the quantity of alcohol in any spirit, it is necessary that the specific gravity be ascertained for each determinate proportion of alcohol and water that are mixed together. When this is done, we may, by means of an aeroneter constructed for liquids lighter than water, determine the strength of the spirit, either by a scale of specific gravities or by an arbitrary graduation corresponding to certain commercial objects, and thus we may determine tl'e percentage of alcohol in whisky or brandy of any strength or purity. An areometer intended for this use has been called an alcoholmeter, in particular when the scale of it is so graduated that instead of the specific gravity, it indicates immediately the percentage of anhydrous alcohol in a given weight or volume of the liquid. The scale graduated according to the percentage of pure alcohol by weight, constitutes the alcoholmeter of Richiter; and that by the percentage in volume, the alcoholmeter of Tralles and Gay Lussac. As liquors are sold in general by the measure, not by the weight, it is convenient, therefore, to know the alcoholic content of the mixtures in the percentage by volume Tralles has constructed new tables upon the principles of those of Gilpin, in which the proportion is given by volume, and anhydrous alcohol is assumed for the basis which at'00 Fahr., has a specific gravity of 0'7939 compared with water at its maximum density, rr a specific gravity of 0'7946 compared with water of the temperature of 60~ Fahr. Gilpin's alcohol of 0'825'contains 92'6 per cent. by volume of anhydrous alcohol. According to the experiments of Tralles alcohol contracts between-26~ C. and + 37 C. with tolerable uniformity; for each degree the contraction is 0'00846 of the volume of the alcohol. In the following table its contractions are reckoned downwards fiom the boiling point by Gay Lussac. 20 ALCOHOL. Temp. Volume. Temp. Volume. Temp. Volume.'78~04 1000- 480~4 965-3 230~4 938-6 73~-4 994-4 43~'4 960'0 18~04 9340 68~ 4 988-6 38~'4 954 4 13~-4 929-3 630~4 982-5 33~ 4 948-'9 8~04 924-5 580~4 975-7 280~4 943-6 3~04 9190 530~4 970'9 Spirituous vapor passed through an ignited tube of glass or porcelain is converted into carbonic oxide, water, hydrogen, carburetted hydrogen, olefiant gas, naphthaline, empyreumatic oil, and carbon; according to the degree of heat and nature of the tube these products vary. Anhydrous alcohol is a non-conductor of electricity, but is decomposed by a powerful voltaic battery. Alcohol burns in the air with a blue flame into carbonic acid and water; the water being heavier than the spirit, because 46 parts of alcohol contain 6 of hydrogen, which form 54 of water. In oxygen the combustion is accompanied with great heat, and this flame, directed through a small tube, powerfully ignites bodies exposed to it. If we moisten sand in a capsule with absolute alcohol, and cover it with previously heated nickel powder, protoxide of nickel, cobalt powder, protoxide of cobalt, protoxide of uranium, oxide of tin (these six bodies being procured by ignition of their oxalates in a crucible), or finely powdered manganese peroxide, combustion takes place, and continues as long as the spirituous vapor lasts. The following table exhibits the per centage of anhydrous alcohol by volume, at I temperature of 60~ Fahr., in correspondence with the specific gravities of the spirits, water being considered at 60~ Fahr. to have a specific gravity of 0-9991. Alcoholmetrical Table of Tralles. Alcohol in 100 Alcohol in 1001 measures of Specific gravity Difference of measures of Specifir gravity Difference of spirit. at 600 Fahr. the sp. gr. spirit. aL 600 Fahr. the sp. gr. 0 9991 51 9315 20 1 9976 15 52 9295 20 2 9961 15 53 9275 20 3 9947 14 54 9254 21 4 9933 14 55 9234 20 5 9919 14 56 9213 21 6 9906 13 57 9192 21 7 9893 13 58 9170 22 8 9881 12 59 9148 22 9 9869 12 60 9126 22 10 9857 12 61 9104 22 11 9845 12 62 9082 22 12 9834 11 63 9059 23 13 9823 11 64 9036 23 14 9812 11 65 9013 23 15 9802 10 66 8989 24 16 9791 11 67 8965 24 17 9781 10 68 8941 24 18 9771 10 69 8917 24 19 9761 10 70 8892 25 20 9751 10 71 8867 25 21 9741 10 72 8842 25 22 9731 10 73 8817 25 23 9720 11 74 8791 26 24 9710 10 75 8765 26 25 9700 10 76 8739 26 26 9689 11 77 8712 27 27 9679 10 78 8685 27 28 9668 11 79 8658 27 29 9657 11 80 8631 27 30 9646 11 81 8603 28 31 9634 12 82 8575 28 32 9622 12 83 8547 28 33 9609 13 84 8518 29 ALCOHOL. 21 Alcoholmetrical Table of Tralles (continued). A h in 10 Alcohol in 100. Alcohol in 100 measures of Specific gravity Difference of measures of Specific gravity Difference of spirit. at 600 Fahr. the sp. gr. spiri at 600 Fahr. the sp gr. 34 9596 13 85 8488 30 35 9583 13 86 8458 30 36 9570 13 87 8428 30 37 9556 14 88 8397 31 38 9541 15 89 8365 32 39 9526 15 90 8332 33 40 9.510 16 91 8299 33 41 9494 16 92 8265 34 42 9478 16 93 8230 35 43 9461 17 94 8194 36 44 9444 17 95 8157 37 45 9427 17 96 8118 39! 46 9409 18 97 8077 41 47 9391 18 98 8034 43 48 9373 18 i99 7988 46 49 9354 19 100 7939 49 50 9335 19 Remarks on the preceding Table of.Alcohol. The third column of this table exhibits the differences of the specific gravities, which give the denominator of the fraction for such densities as are not found sufficiently near in the table; and the difference of their numerators is the next greatest to the density found in the table. For example: if the specific gravity of the liquor found for 60~ Fahr. = 9605 (the per centage will be between 33 and 34), the difference from 9609 (which is the next greatest number in the table)= 4, and the fraction is -4- therefore the true per centage is3314. From the construction of this table the per centage of alcohol by weight may also be found. For instance: we multiply the number representing the volumes of alcohol (given in the table for any determinate specific gravity of the mixture) by the specific gravity of the pure alcohol, that is, by 7939, and the product is the number of pounds of alcohol in so many pounds as the specific gravity multiplied by 100 gives. Thus, in the mixture of 9510 specific gravity, there are 40 measures of alcohol; hence there are also in 95,100 pounds of this spirit 7939-40= 31-756 pounds of alcohol; and in 100 pounds of the spirits of 0'9510 specific gravity, 33-39 pounds of alcohol are contained. As the preceding table gives the true alcoholic content when the portion of spirit under trial has the normal temperature of 60~ Fahr., the following table gives the per centage of alcohol for the specific gravities corresponding to the accompanying temperatures. For example: if we have a spirituous liquor at 80~ Fahr., whose specific gravity is 0'9342, the alcohol present is 45 per cent. of the volume, or that specific gravity at that temperature is equal to the specific gravity 0-9427 at the normal temperature of 60~ Fahr. This table may also be employed for every degree of the thermometer and Temperature. Temperature. Alcohol Alcohol ___ per cent. per bent. 300 F. 35~ F.400 45 F. 50~ F. 550 F. 600 F. 650 F. 70q F. 750 F. 80~ F. 850 F. 0 999 9997 9997 9998 9997 9994 0 9991 9987 9991 9976 9970 9962 5 9924 9926 9926 9926 9925 9922 5 9919 9915 9909 9903 9897 9889 10 9868 9869 9868 9S67 9S65 9861 10 9857 9852 9845 9839 9831 9823 15 9S23 9822 9820 9817 9813 9807 15 9802 9796 9788 9779 9771 9761 20 9786 9782 9777 9772 9766 9759 20 9751 9743 9733 9722 9711 9700 25 9753 9746 9738 9729 9720 9709 25 970 900 90 978 9665 9652 9638 30 9717 9707 9695 9684 9672 9659 30 9646 9632 9618 9603 9588 9572 35 9671 9658 9644 9629 9614 9599 35 9583 9566 9549 9532 9514 9495 40 9615 9598 9581 9563 9546 9528 40 9510 9491 9472 9452 9433 9412 45 9544 9525 9506 9486 9-467 9447 45 9427 9106 9385 9364 9342 9320 50 9460 9140 9420 9399 9378 9356 50 9335 9313 9290 9267 9244 9221 55 9368 9347 9325 9302 9279 9256 55 9234 9211 9187 9163 9139 9114 60 9267 9245 9222 9198 9174 9150 60 9126 9102 9076 9051 9026 9000 65 9162 9138 9113 9088 9063 90:8 65 9013 8988 8962 8936 89)9 8882 70 9016 9021 8996 8970 8 894 8917 70 82 8866 8839 8812 8784 875 75 8925 8899 8873 8847 8820 8792 75 8765 8738 8710 8681 8652 8622 80 8798 8771 8744 8716 86S8 8659 80 8631 8602 8573 8544 8514 8483 85 8663 8635 8606 8577 8547 8517 85 8488 8458 8427 8396 8365' 8333 90 8517 8486 8455 8425 83:)5 8363 90 8332 8300 8268 8236 8204 8171 22 ALCOHOL. every per centage, so as to save computation for the intervals. It is evident from in spc:tion that a difference of 5~ Fahr. in the temperature changes the specific gravity of the liquor by a difference nearly equal to 1 volume per cent. of alcohol; thus at 35c and 85~ Fahr. the very same specific gravity of the liquor shows nearly 10 volumes pet cent. of alcohol more or less; the same, for example, at 60 and 40 per cent. The importance of extreme accuracy in determining the density of alcoholic mixtures in the United Kingdom, on account of the great revenue derived from them to the State, and their consequent high price in commerce, induced the Lords of the Treasury a few years ago to request the Royal Society to examine the construction and mode of applying the instrument now in use for ascertaining and charging ihe duty on spirits. This instrlment, which is known and described in the law as Sikes's hydrometer, possesses, in many respects, decided advantages over those formerly in use. The committee of the Royal Society state, that a definite mixture of alcohol and water is as invariable in its value as absolute alcohol can be; and can be more readily, and with equal accuracy, identified by that only quality or condition to which recourse can be had in practice, namely, specific gravity. The committee further proposed, that the standard spirit be that which, consisting of alcohol and water alone, shall have a specific gravity of 0-92 at the temperature of 62~ Fahr., water being unity at the same temperature; or, in other words, that it shall at 62~ weigh 9- or 23 of an equal bulk of water at the same temperature. This standard is rather weaker than the old proof, which was 1, or 0-923; or in the proportion of nearly 1*1 gallon of the present proof spirit per cent. The proposed standard will contain nearly one half by weight of absolute alcohol. The hydrometer ought to be so graduated as to give the indication of strength; not upon an arbitrary scale, but in terms of specific gravity at the temperature of 62~. The committee recommend the construction of an equation table, which shall indicate the same strength of spirit at every temperature. Thus in standard spirit at 62~ the hydrometer would indicate 920, which in this table would give proof spirit. If that same spirit were cooled to 40~, the hydrometer would indicate some higher number; but which, being combined in the table with the temperature as indicated by the thermometer, should still give proof or standard spirit as the result. It is considered advisable, in this and the other tables, not to express the quality of the spirit by any number over or under proof, but to indicate at once the number of gallons of standard spirit contained in, or equivalent to, 100 gallons of the spirit under examination. Thus, instead of saying 23 over proof, it is proposed to insert 123; and in place of 35-4 under proof, to insert its difference to 100, or 64'6. It has been considered expedient to recommend a second table to be constructed, so as to show the bulk of spirit of any strength at any temperature, relative to a standard bulk of 100 gallons at 62~. In this table a spirit which had diminished in volume, at any given temperature, 0-7 per cent., for example, would be expressed by 99-3; and a spirit which had increased at any given temperature 0-7 per cent., by 100-7. When a sample of spirit, therefore, has been examined by the hydrometer and thermometer, these tables will give first the proportion of standard spirit at the observed temperature, and next the change of bulk of such spirit from what it would be at the standard temperr:ure. Thus, at the temperature of 51~, and with an indication (sp. gr.) of 8240, _00 gallons of the spirit under examination would be shown by the first table to be equal to 164-8 gallons of standard spirit of that temperature; and by the second table it would appear that 99-3 gallons'of the same spirit would become 100 at 62~, or in reality contain the 164-8 gallons of spirit in that state only in which it is to be taxed. But as it is considered that neither of these tables can alone be used for charging the duty (for neither can express the actual quantity of spirit of a specific gravity of 0-92 at 62~ in 100 gallons of stronger or weaker spirit at temperatures above or below 620), it is considered essential to have a third table, combining the two former, and expressing this relation directly, so that upon mere inspection it shall indicate the proportion of standard spirit in 100 gallons of that under examination in its then present state. In this table the quantities should be set down in the actual number of gallons of standard spirit at 62~, equivalent to 100 of the spirit under examination; and the column of quantities may be expressed by the term value, as it in reality expresses the proportion of the only valuable substance present. As this will be the only table absolutely necessary to be used with the instrument for the purposes of the excise, it may, perhaps, be thcught unnecessary to print the former two. _______________I~ ~~ ALCOHOL. 23 The following specimen table has been given by the committee — Temperature 45~. Temperature 75~. Indication.* Strength. Value. Indication. Strength. Value. 9074 114 5 8941 114'5 7 114'3 4 114'3 9 1142 5 114 2 81 114 0 8 114 0 3 1139 9 113 9 5 113 -7 52 113'7 6 113 6 3 113 6 9 113 -4 6 113 4 90 113 3 7 113 3 3 113 1 9 1131 11 The mixture of alcohol and water, taken as spirit in Mr. Gilpin's tables, is that of which the specific gravity is 0-825 at 60~ Fahr., water being unity at the same temper. ature. The specific gravity of water at 60~ being 1000, at 62~ it is 99,981. Hence, in order to compare the specific gravities given by Mr. Gilpin with those which would result when the specific gravity of water at 62~ is taken at unity, all the former numbers must be divided by 99,981. Table of the Specific Gravities of different Mixtures, by Weight, of Alcohol and Water, at different Temperatures; constructed by Mr. Gilpin, for the use of the British Revenue on Spirits. o 100 100 100 100 100 100 100 100 100 100 "- Pure Alcohol Alcohol Alcoh lhol Alohol AlAlcohlAlcohol Alcohol Alcohol Alcohol S' Alcohol 5 10 15 20 25 30 35 40 45 50 a Water. Water. Water. Water. Water. Water. Water. Water. Water. Water. Leg. 30 0-83896 0-84995 0-85957 0-86825 0-87585 0-88282 0-88921 0'89511 0-90054 0-90558 0-91023 35 -83672 -84769 -85729 -86587'87357 -88059 -88701 -89294 -89S39 -90345 -90811 40 -83445 -84539 -85507 *86361 87184 -87838'88481 -89073 -89617 -90127'90539; 45 -83214 -84310 -85277 -86131 86905 -87613 -88-255 88849 -89396'89909'90380 50 -82977 -84076 -85042'85902'86676 -87384 -88030 -88626 -89174 -89684 -901160 55 -82736 -83834'84802 -85664 -86441 -87150 -87796 888393 -88945 -89458 -89933 60 -82500 -83599 -84568 85430 -86208 -86918 -87569 -88169 -88720 -89232 -89707 65 82262 83362.84334.85193 85976 -86686 -87337'87938 -88490 -89006 -89479 70 -82023 -83124 -84092 -84951 -85736 -86451 -87105'87705 -88254 -88773 -89252 75 -81780 -82878 -83851.84710 -85496 -86212 -86864'87466 -88018 -88538 -89018 80 -81530 -82631 -83603 -84467 -852481 85966 -86622'87228 -877761 88301 -88781 85 81291 -82396 83371 -84243 -85036 -85757.86411.87021.87590 -88120 -88609f 90 -81044 -82150 -83126'84001 -84797 -85518 -86172.86787 87360 87889 -88376 95 -80794 -81900 -82877 -83753 -845501 85272 -85928'86542 -871141 87654 -88146 100) -80548 -81657 -82639 -83513 -84038 *85031 -85688 -86302 -86879 -87421 -87915 100 100 100 1 00 100 100 100 100 100 100 Temperature, Alcohol Alcohol Alcohol Alcohol Alcohol Alcohol Alcohol Alcohol Alcohol Alcohol Fahr. 55 60 65 70 75 80 85 90 95 100 Water. Water. Water. Water. Water. Water. Water. Water. Water. Water Deg. 30 0-91449 1091847 0-92217 1092563 0-92889 0-93191 0-93474 1093741 0-93991 1094222 35'91241'91640 -92009 -'92355 -92680 -92986 -93274 -93541 -93790 -94025 40'91026 91428'91799 -92151 92176 -92783'93072 -93341 -93592 -93827 45 -90812 91211 -91584 -91937 -92264 -92570 -92859 -93131 -93382 -93621 50 -90596'90997'91370 -91723 -92051 -92358 -92617 -92919 -93177 -93419 55 -90367 -90768 -911441 91502 -91837 9-2145 -92436'92707 -929631 93208 60 -90144'90545 90927 -91287 -91622 -919331 92-225 -92499 -92758 -93002 65 -89920'90328'90707'91066 -91400 -91715 -92010 -92283 -92546 -92794 70'89695'90104 -90414 -90847 -91181 -91493'91793 -92069 -92333 -92580 75 -891641 89872'90252 -90617'90952'91270'91569'91849 -921111 92364 80 -89225 -89639'90021 -90185'90723'910461 91340'91622 -91891'92142 85-' 89043 -89460'89843'90209'90)558'90882'91186'91465 -91729'91969 90 88817 -89230 -89617 -89988'90342 -90688 -90967'91218 -91511 -91751 95'-88588 89003'89390'89-63'90119'90443'90747'91029 -91290 91531 100 -83571 88769'891581 895361 89889.'90215'90522'90805 -91066 41310 * By specific gravity. 24 ALCOHOL. Table of the Specific Grav:ties of different Mixtures, &c. (continued).?. 95 90 85 80 75 70 65 60 55 50 e rAlc lcohol A lcohol A looh hl A lcohol A lcoho l Alcohol Alcohol 1 100 100 100 100 100 1 100 0 1. IV Water. Water. W ater. Water. Water. Water. Water. W ater.. Water. Deg. 30 0 94447 0-94675 0-94920 0-95173 0-95429 68 095681 092 095944 96209 96470 096719 35 -94249 -94484 -94734 94988 95246 -95502 -95772 -96048 -96315 ~ 96579 40 -94058 94295 94547 -94802 -95060 -95328 -95602 958709 -96159 96434 45 -9360 -94096 -94340 94605 94871'95143 -95423'95703 -95993 96180 50 -93658 93897 -94149 -94414 ~1083 -'94958 95243 -95534 -95831 *9b126 55 -93452 -93696 -93948 -94213 4486 94767 95057 95 5357 -95662 ~95906 60 -93247 93493 -93749 -94018 -64296 94579 -91876 -95181 95493 95804 65 93040 -93285 -935460 93S22 -94099 -94388 -946o9 -95000 -95318'95635,0 92828 -93(876 93337 -9361 -9388 -94190, 94500. 94813 95139 ~95469 75 92613 -92865 -93132 -93413 -93695 -93989 -94301 -94623 -94957 -95292 80 -92393 -92646 92917 193201 -934sS8 *93785 -)4102 -94431 -94768'95111 I i 45 40 35 30 25 20 15 10 5 Temperature, Alc,hol Alholol Alcohol Alc ohol Alcohol A1 c. A cohol Alcohol Alcohol Fahr. 100 100 100 100 160 100 100 100 100 Water. XWater. Water. Water. VWater. Water Water. Water. Water. Degrees. 30 0-96967 0-97200 0-97418 0-97635 0-97860 0-98108 0-98412 0-98804 0-99334 35' 9f;840 1 97086 97319 -97556 97801 -98076 -98397 -98804 -99344 40 960706 -96967 -97220 -97472 -97737 -98033 -98373 -98795 -99345 45 -96563 -96,40 -97110 97384 -97666 - 97980 -98'38 -98774 99338 50 96420 967(08'96995 -97284 -97589 1 97920 98293 *987,451 99316 55.9627,2 ~96575 -9(877'97181 -97500 ( 97847 -98239 -98702'99284 60 -96122 -96437 *96752 -97074 -97410.97771 -98176 -98654 -99244 65 -9 5962'96288 *96'020 I96959 97(309 1 97()88 -98106 -98594 -99194 70 -9580(2 96143 -96484 - 9836 97203 -97596 1 98028 ~98527 -99134 75 -95638 -95987 -96344 -967018. 97 ()3 9674,i5 -97943 -984541 99066 80 -95467 -958261 -96192 -.96568 99t1(3 973.85 1 97845 -98367 -9 8991J Experiments were made, by direction of the committee, to verify Gilpin's tables, which showed that the error introduced in ascertaining the strength of spirits by tables founded on Gilpin's numbers must be quite insensible in the practice of the revenue. The discrepancies thus detected, on a mixture of a given strength, did not amount in any one instance to unity in the fourth place of decimals. From a careful inspection of such documents the committee are of opinion, that Gilpin's tables possess a degree of accuracy far surpassing what could be expected, and sufficiently perfect for all practical or scientific purposes. The following table is given by Mr. Lubbock, for converting the apparent specific gravity, or indication. into true specific gravity. c - = Temperature.. +. 0I _ -I0 30~ 320 3' 3 420~ 47~ 52~ 57~ 62~ 67~ 72~ 77~ 800~' *82 -00()083 -00078'-00065 -00052 10(039 -00025 00012 000()11 00024 -00035 100042 -82 83 -00(084 -00079 (00066 00052 -00039 00026' 000)12 -00(012 -00024 -00036 -00042 -83 *84 00o085 -00080 -00066 00053' -00039 -00026 0001 000(12 100024 100036 -00043 *84 85 -00086 -000(l -00067 -00054'000140 00026- *'0001 3 -000112 00025 -00037 -00043 85 *80 -00087 10082 1 00068 -00)0 00040 -00(027 00013 -00012 100025 -00037 -00044 - 86 *87 -00088 0008 0009 (00055 00041 00027 1000813 00012 100025 100037 00044 87 88 -00089 -00084 -00070 -00055 0)0041 -00027 00013 0001 000276 00038 -00045 88 *89 -00090 -00085 -00070 -00055 -00042 - 00028 00013 00012 -00026'00038 -00045 -89 *90 -00091 -00085 -00071 -(00()56 00042 -00028 *0()014 -00013 (00026 -00039 -00046 90 *91 -00092 -0000086 0072 00057 -00043 -00028 -00014 -00013 -0026 -00039 -00046 91 *92 *00093 -00087 -00073 -00058 -00043 00029'-00014 00013 -0027 -00040 -00047 1-2 I93 -00094 -010088 -00073 -00059 -00044 -00029 -00014 100(13 -00027 -00040 -00047 -93 94 00095 -00089 -00074 -00059 -00044 -00029 -00014 00013 -00027 -00040 -00048 -94 *95 -00096 -00090 -00075 -00060 -000(45 -00029 -(00014 -00013 -00028 -00041 -00048 -95 *96 -00097 -00091 -00076 -00060 -00045 -00030 -000j4 -00013 -00028 -00041 -00049 -96 97 -00098 -0(0(92 -00077 -00061 -00046'-OW30 -00015 -00014 -00028 -00042 -00049 -97 ~98 -00099 -00093 -00077 -00062 -00046 -00030 -00015 -00014 00028 -00042 -00050 -98 1 99 -00100 -00094 -00078 -00062 -00047 -00031 -00015 -00014 -00029 -00043 -00050 -99 ~-100 -00101 600095 -000791'00063 -00047 -00031 -00015 100 *-^ ^ ^ ^^_______.___________________ i ALCOHOL 25 The hydrometer constructed, under the directions of the Commissioners of Excise, by Mr. Bate, has a scale of 4 inches in length divided into 100 parts, and 9 weights. It has Uhus a lange of 900 divisions, and expresses Fig. 5. specific gravities at the temperature of 62~ Fahr. In order to render this instrument so accurate a measurer of the specific gravity, at the standard temperature, as to involve no error of an appreciable amount,. Mr. Bate has constructed the weights (which in this instrument are immersed in the fluid of different specific gravities) so that each successive weight should have an increase of bulk over the preceding weight equal to that part of the stem occupied by the scale and an increase of weight sufficient to take the whole of the scale, and no more, down to the liquid. This arrangement requires great accuracy of workman- ship, and enhances the price of the instrument. But it allows of increased strength in the ball, where it is very much required, and it gives, upon inspection only, the indication (apparent specific gravity) by which the general table is to be examined and the result ascertained. Fig. 5 represents this instrument and two of its nine ballast weights. It comprehends all specific gravities between 820 and 1000. It indicates true specific gravity with almost perfect accuracy at the temperature of 62~ Fahr.; but it does not exclude other instruments from being used in conjunction with tables. The latter are, in fact, independent of the instrument, and may be used with gravimeters, or any instrument affording indications by specific gravity at a given temperature. SEE SPIRITS. The commercial value of spirituous liquors being much lower in France than in England, a less sensible instrument becomes sufficient for the wants of that country. Baume's and Cartier's hydrometers, with short arbitrary scales, are very much employed, but they have been lately superseded by an ingenious and ready instrument contrived by M. Gay Lussac, and called by him an alcoometre. He takes for the term of comparison pure alcohol by volume, at the temperature of 15~ Cent., and represents the strength of it by 100 centimes, or by unity. Consequently, the strength of a spirituous liquid is the number of centimes in volume of pure alcohol which that liquid contains at the temperature of 15~ Cent. The instrument is formed like a common hydrometer, and is graduated for the temperature of 15~ Cent. Its scale is divided into 100 parts or degrees, each of which denotes a centime of alcohol; the division 0 at the bottom of the stem corresponds to pure water, and the division 100 at its top, to pure alcohol. When immersed in a spirituous liquor at 15~ Cent. (593 Fahr.) it announces its strength directly. For example: if in spirits supposed at the temperature of 15~ Cent. it sinks to the division 50, it indicates that the strength of this liquor is 50 per cent., or that it contains 50 centimes of pure alcohol. In our new British proof spirit, it would sink to nearly 57, indicating 57 by volume of pure alcohol, allowing for condensation, or 50 by weight. A table of correction is given for temperature, which he calls " Table of real strength of spirituous liquors." The first vertical column of this table contains the temperatures, from 00 to 30~ Cent., and the first horizontal line the indications of the alcoometre. In the same table we have most ingeniously inserted a correction for the volume of the spirits when the temperature differs from 15' Cent. If we. take 1000 litres or gallons, measured at the temperature of 2~, of a spirituous liquor whose apparent strength is 44c; its real strength at 15~ will from the preceding mode of correction be 49c. On heating this liquid to 15~, in order to find its real specific gravity or strength, its bulk will become greater; and, instead of 1000 litres or gallons, which it measured at 2~, we shall have 1009 at 15~ C. This number is inscribed.in smaller characters in the same square cell with the real force, precisely under 49c. All the numbers in small characters, printed under each real s'rength, indicate the volume which 1000 litres of a spirituous liquor would have, when measured at the temperature at which its apparent strength is taken. In the above example, the quantity in litres or gallons of pure alcohol contained in 1000 litres or gallons of the spirits, measured at the temperature of 2~, will be, therefore,1009 lit. X 0-49 = 494 lit. 41. This quantity of pure alcohol, thus estimated, is called richness of spirit in alcohol, or simply richness. Let us take an example similar to the preceding, but at a higher temperature than 15~ Cent. Suppose we have 1000 litres measured, at the temperature of 25', of spirits whose apparent strength is 53c, what is the real quantity of pure alcohol which this spirit contains at the temperature of 15~? We shall find in the table, first of all, that the real strength of the spirits is 49C*3. As to its bulk or volume, it is very clear that the 1000 litres in cooling from 255 to 15~, will occupy a smaller space. This volume will be 993 litres; it is inscribed directly below 49c*3, the real strength. We 26 ALCOHOL. shall therefore have of pure alcohol, contained in the 1000 litres of spirits, measuled a the temnerature of 253, or their richness, 993 lit. X 0'493 = 489 lit. 55. Alcometrical Table of real S.rength, by M. Gay Lussac. Temperature. 31 32c 33c eIc 35c 36c 37e 38c 39c 40c Deg. 10 33 0 34 35 36 37 38 39 40 41 42 1002 1002 1003 1003 1003 1003 1003 1003 1003 1003 11 32-6 33 6 346 35-6 36-6 37-6 38-'6 396 40-6 416 1002 1002 1002 100(2 1002 1002 1002 1002 1003 1003 12 32 2 33-2 34-2 35-2 36-2 37 2 38 2 39 2 40 2 41-2 1001 1001 1002 1002 1002 1002 1002 1002 1002 1002 13 31-8 32-8 33 8 34-8 35.-8 36 - 37 8 38-8 39-8 40 S 1001 1001 1001 10(1 1001 1001 1001 1001 1001 1001 14 31-4 32-4 334 34 4 35 -4 36-4 37-4 3S 4 39 4 40-4 1001 1001 100(1 1001 1001 1001 1001 1001 1001 1001 15 1 3 32 33 34 35 36 37 38 39 40 100 1000 1000 1()(10 1000 10 00 1000 1000 100( 1](00 16 30 6 31 6 32-5 33-5 34*5 35 - 3 35 36 375 5 39-5 1000 1000 9 999 999 999 9 S 999 999 999 17 30-2 31-2 32-1 33-1 341 35 -1 36-1 37 1 38 1 39-1 999 999 999 999 999 99g9 999 9999 999 )9 18 29-8 308 31-7 32-7 33-7 34 7 35-7 36-7 37-7 3897 999 999 99S 998 998 998 998 998 998 998 19 29-4 30 4 31 3 32 3 33-3 343 35 -3 36 3 37-3 38 -3 998 998 98 998 9 998 998 998 998 997 997 20 29 30 30-9 31-9 32 9 33 9 34-9 35 9 36 9 37 9 993 998 997 997 997 997 997 9 97 97 997 21 28-6 29-6 30 5 31-5 32-5 33-5 34-5 35 -5 36-5 37-5 997 997 997 997 997 997 997 996 996 9936 22 28-2 29-2 30 1 311 32-1 33 1 34 1 35-1 36 1 37 1 997 997 99( 996 996 996 996 996 996 996 23 27-8 28-8 29 7 30*7 31 7 32-7 33-7 34 7 35-7 36 -7 996 996 996 996 996 996 996 "95 9995 995 24 27 4 28 4 29-3 30*3 31 3 32-3 33 3 34-3 35 3 36 3 9(6 996 995 9 995 995 995 995 995 994 25 27 28 28-9 29-9 30-9 31-9 32-9 33-9 34-9 35-9 995 905 09 5 9 99 90 0. 99 04!1 994 994 Temperature. 4l 42c 43c 44e. 45c 46c 4,c 48c 49f 50c J)eg. 10 43 44 45 46 469 479 489 49-9 509 51-8 1003 1001 1004 1001 100 1001 1004 1004 1004 1004 11 42-6 43 6 44-6 45-6 46-6 47-6 48-6 49-5 505 51-5 1003 1003 100(3 1003 1003 1003 1003 1003 1003 1003 12 42 2 43-2 44-2 45-2 46-2 47-2 482 49-2 502 51-1 1002 10( I 10()2 1002 1002 1002 1002 1009 002 100(2 13 41-8 42 8 43 8 44 -8 45-S 46 8 47-8 48-8 49-8 50-8 1001 1001 1001 1002 1002 1002 1002 1002 1002 1002 14 41 4 424 434 4-4 45 4 -4 46-4 47 -4 484 49-4 504 1001 1001 1001 1001 1001 1000 1001 1001 1001 1000 15 41 42 43 44 45 46 47 48 49 50 1000 1000 1000 1000 1000 1000 10)0 1000 1000 1(00 16 406 416 426 436 44-6 45 6 46-6 47 6 [ 486 49-6 999 999 999 999 999 999 999 99) 999 999 ALCOHOL. 27 Alcometrical Tabe of real Strength, by M. Gay Lussac (continued). F -~ -'-' —-'l __ _ _ _ Temperature. 4c 42c 43c 44e 43 5e 46c 4c 48c 4 50c 17 40' - 40 41-2 42 2 43-2 44 9 45-2 46-2 47-2 48-2 49-2 999 99 99 998 999 998 998 998 9 998 18 39 8 408 418 42 8 43-8 44 9 45 9 46-9 47 9 48 9 998 998 998 998 998 998 998 998 998 998 19 394 404 414 42 543 435 -4 455 465 475 48-5 997 997 99( 997 997 997 997 997 997 997 ~0 39 40 4 42 1 43 31 441 451 461 47 -2 4782 997 99 9 7 997 997 6 996 996 996 996 996 21 38-6 39-6 40-6 4147 42-7 43 7 448 458 46-8 47-8 996 990i 99i 99 996 996 996 99fi 995 995 2^ 3 3S 2 39 2 40 2 41 3 42 3 43 3 44 3 45 -3 46 4 47 4 969 95 995 955 9995 9 95 995 995 995 995 23 378 38-38 39 8 40 9 419 42 9 43-9 44 9 46 47 24 37-4 384 394 40 5 41'5 42-'5 43-6 44-6 45 6 46-6 I 994 9 4994 994 9 994 994 994 994 993 993 25 37 38 39 40 1 42 1 42 2 43 2 44-2 452 6 3 I 991 994)1 9 1-3 99 993 93'99 jS 993 93 Temperature. 5c 52( 53c 54c 5c 56 57c 5c 59 60c Deg 10 528 53 54 855-8 56-8 578 588 597 607 61-7 104 104 1)0 1004 1004 1004 1004 004 100 4 1 521 5 5 |5 35 54-4 55-4 56-4 57-4 58-4 59-4 60-4 61-4 103 1 1()3 1903 1003 1 (00 1 1003 103 1003 10(03 1103 12 52-1 53-1 54-1 55 56 57 58 59 60 61 100-2 10(12 1002 1002 10(02 1002 |1(02 1002 1002 1002 51.8 52-7 53-7 54-7 55.7 56 - 57-7 58-7 59-7 60-7 11002 111)2 11( 02 10(2 11002 1002 1002 1002 1002 1002 14 51-4 52-3 53-3 54-3 55-3 56-3 57-3 58 -3 59-3 60-3 1(01 1001 1()1 1001 1001 1001 1001 11001 1001 1001 15 51 52 53 54 5 56 57 58 9 60 1 0 10(0 I 000 10 10 1000 I 1O( I l I 00 000 G 1000 16 50-6 51-6 52-6 53-6 54-6 55-6 56-6 57-6.58-6 59-6 999 99999 9 99 999 999 999 999 999 999 17 50-3 51-3 52-3 53-3 54-3 55-3 56-3 57-3 58-3 59-3 999 8 99 998 998 998 9998 998 998 998 998 18s 49-9 50 9 51 9 52-9 53-9 54 -9 55-9 56-9 57-9 58-9 998 998 998 998 998 998 998 997 997 997 19 49-5 50-6 516 52-6 53-6 54-6 55-6 56-6 57-6 58-6 997 997 997 997 997 997 997 997 997 997 20 49-2 50-2 51-2 52-2 53-2 54-2 55-2 56-2 57-2, 58-2 996 996 996 996 996 996 99 996 996 996 996 21 48-8 49-8 50-8 51-8 52-9 53-9 54-9 55-9 56-9 57-9 995 995 995 995 995 995 996 995 995 995 22 48-4 49-4 50-4 51 -4 52-5 53-5 54-5 55-5 56-5 57.-5 995 995 995 994 994 994 994 994 994 994 23 48 49-1 501 51* 52 53-1 54-1 551 561 57 991 994 994 991 994 994 994 993 993 993 24 47-6 487 497 507 518 52-8 53-8 54-8 55-8 56-8 993 993 1993 993 993 993 993 993 993 992 25 47-3 48-3 49-3 50-3 514-4 524 53- 4 54-4.55-1 566-5s 1 09? 99? 9"3 992 92 992 92 1 992 9192 1 21.1 21,ol~, -W,~W ~.W~i~W- -- 100I1,0 O, O o o ]lO 24 ~ ~ ~ ~ l O O[5[5 28 ALCOHOL. Alcometrical Table of real Strength, by M. Gay Lussac (continued). Temperature. g j C. 61c 62c 63c 64c 65c 66c 67c 6sc 69c 70c Deg. 10 62-7 63-7 647 65-7 66-7 67-6 68-6 69-6 706 71-6 1004 1004 1004 1004 104.1004 004 1004 1004 1004 11 62 4 63 4 64 -4 654 66-4 67-3 68 3 69-3 70 3 71-3 1003 1003 1003 1003 1003 1003 1003 1004 1004 1004 12 62 63 64 65 66 67 68 69 70 71 1002 1)02 1002 1002 1002 1002 1003 1003 1003 1003 13 61.7 62-7 63-7 64-7 65 7 66-7 67-7 68-7 69-6 70-6 1002 1002 1002 1002 1002 1002 1002 1002 1002 1002 14 61-3 62-3 63-3 64-3 65- 3 66-3 67-3 68-3 69-3 70 -3 1001 1001 1001 1001 1001 1001 1001 1001 1001 1001 15 61 62 63 64 65 66 67 68 69 70 1000 1000 10(0 1000 1000 1000 1000 1000 1000 1000 16 60-6 61 -7 62-7 63-7 64-7 65-7 66-7 67-7 68 -7 69-7 999 999 999 999 999 999 999 999 999 999 17 60-3 61-3 62-3 63-3 64-3 65-3 66-3 67-3 68-3 69-3 998 998 98 998 998 998 998 998 998 998 18 59-9 61 62 63 64 65 66 67 68 69 997 997 997 997 997 997 997 997 997 997 19 59-6 60-6 61-6 62-7 63-7 64-7 657 667 67-7 68-7 997 997 9)7 99 7 997 997 97 997 997 990 C96 20 59-2 60-3 61-3 62-3 63-3 64-3 65 4 66-4 67-4 68-4 996 996 996 996 996 996 996 996 996 996 21 58-9 59-9 61 62 63 64 65 66 67 68-1 995 995 995 995 995 995 995 995 995 995 22 58-5 59 5 60-6 61-6 62-7 63-7 64-7 65-7 66-7 67-8 994 994 994 994 94 94 994 994 994 994 23 58-1 59-2 60-2 61-3 62-3 63-3 64-3 65-4 66-4 67-4 993 993 993 993 993 993: 993 993 993 993 24 57-8 58-9 59-9 61 62 63 64 65 66 67-1 99-2 992 992 992 992 992 992 992 9992 25 57-5 58-5 59-5 60-6 61-6 62-6 63-7 64-7 65-7 66-7 992 ) 00 -) 001 00) 0 091 99(1 99199191 Ten,.erat re. TemperaC. 72c 73c 74e 75e 76c 77c 78c 79c 80c I)Deg. 10 72-6 73 5 74 -5 75-5 76-5 77 5 78 -5 79 5 80-5 81-5 1004 10) 1(05 1005 1005 1005 1005 1005 1005 1005 11 72-3 73-2.74-2 75-2 76-2 77-2 78-2 79-2 I0-2 81-2 1004 10)04 1004 1004 1004 1004 10041 1004 1004 1004 12 72 72-9 73-9 74-9 75-9 76-9 77-9 78-9 79-9 80-9 1003 1003 103 103 1003 1)03 1003 1003 1003 1003 1003 13 71-6 72-6 73-6 74-6 75-6 76-6 77-6 78-6 79-6 80-6 1002 10921 1002 1002 1002 1002 1002 1002 1002 1002 14 71-3 72-3 73-3 74-3 75-3 76-3 77-3 78-3 79-3 80-3 -1001 1001 1001 1001 1001 1()01 1001 1001 1001 1001 I I. I.. - I - I I 15 71 72 73 74 75 76 77 78 79 80 1000 1000 1000 100( 1000 1000 1000 1000 1000 1000 16 70-7 71-7 72-7 73-7 74-7 75-7 76-7 77-7 78 7 79-7 999 999 999 399 9 99 9 999 999 999 999 17 70-3 71-3 72-3 73 3 74-3 75-4 76-4 77 4 78-4 79.4 998 9981998 998 1 998 998 998 998 998 998 ALCOHOL. 29 Alcometrical Table of real Strength, by A1. Gay Lussac (continued). T3.rperature. 71e 72c 7 3c 74c. ^5e 76 7 c 78c 79c 80c (,. Deg. 18 70 71 72 73 74 75-1 76-1 77-1 78 1 79 -1 997 9 997 997 997 997 997 997 997 997 997 19 69 7 70 7 71-7 72-7 73-7 74-7 75-8 76-8 77-8 78-8 996 996 996 996 996 996 996 996 996 996 20 69 4 70 4 71 4 72 4 73 4 74 4 75 5 76 5 77 5 78 5 996 996 995 995 995 995 I995 995 995 995 21 69-1 701 71-1 721 731 74-1 7 2 76-2 772 78-2 995 9395 9 39931 991 991 994 994 994 994 22 68 -8 69 -8 70 -8 71 8 72-8 73 -8 74 8 75 9 76 -9 77 9 994 994 991 994 993 993 993 993 993 993 23 68 4 69 4 70 5 715 | 72 5 73 5 74 5 75 5 76 6 77 -6 993 993 993 993 992 992 992 992 992 992 24 6 81 691 70 1 71-2 72 2 732 742 1 75-2 763 77-3 992 992 992 992 992 992 992 991 991 991 25 67-8 68-8 69-8 70 8 71 8 72-8 73-9 74-3 9 76 77 991 991I 99 91 1 991 9 991 1 991 } 9 991 Temperature. C.Teperaure 81C 82C 83c 84c 85c 86c 87c 88c 89c 90c Deg. 10 82 -4 83-4 84 4 85-4 86-4 87-4 8-3 89 3 90 2 91-2 1005 1005 1005 1005 1005 1005 1005 1005 1005 1005 11 82 2 83 1 84-1 85 1 86 1 87-1 88 89 90 91 1004 1004 1004 1004 1004 1004 1004 1004 1004 1004 12 819 82 9 83-9 84S 85-8 86 878 87 87 89-7 90-7 1003 1003 1003 1003 1003 1003 1003 1003 1003 1003 13 81.6 82 6 83 6 84-6 855 5 86 5 87-5 88 5 89 5 90-5 1002 10)02 1002 1002 1002 1002 1002 1002 1002 1002 14 81-3 82 3 83-3 84-3 85-3 86-3 87-3 -88-2 89-2 90-2 11)01 1001 10)1 1001 1001 1001 1001 1 1001 1001 001 15 81 82 83 84 85 86 87 88 89 90 1000 1000 1000 1000 1000 1000 1100 1000 1000 100 16 80 7 81 7 82-7 83 847 84 7 85-7 86-7 87 7 7 88-7 89-7 99 999 999 999 999 99 999 999 999 999 9 99 17 80 4 81-4 82-4 83-4 84-4 85-4 86-4 87-4 88-4 89-5 998 998 998 998 998 998 998 998 998 998 1 8 80-1 81-1 S2-1 831 84-1 85-2 86-2 87-2 88 2 89-2 997 997 997 997 997 997 997 997 997 997 19 79-8 80-8 81 9 82 9 83-9 84-9 85-9 86 9 87-9 88-9 996 996 996 996 996 996 996 996 996 996 20 79 5 80 5 81-6 S2-6 83 6 84-6 85-6 86-6 87-7 88-7 9T95 (5 995 995'995 995 995 995 995 995 | 21 79-2 80 2 81-3 82-3 83 3 84-3 85-3 86-4 87-4 88-4 994 994 994 991 994 994 994 994 994 994 22 789 79-9 81 82 83 84 85 86-1 871 88-2 993 993 993 993 993 993 993 993 993 993 23 78-6 79-6 80-7 81-7 82-7 83-8 84-8 85-8 86-8 87-9 992 992 992 992 992 992 992 992 99 2 992 24 78 3 79-3 80-4 81-4 82-4 83-5 84 -. 85-5 86-5 87-6 991 991 991 99 991 991 991 991 991 991 26 78 79 80-1 81-1 S2-1 l83 2 84 2 85-2 86-3 87-4 991 991 990 9 90 0 99 990 1 990 990o 90 80 ALCOHOL. I consider the preceding table, which I have extracted from the longer taoles o M. Gay Lussac, as an important addition to tire resources of British dealers and manu. facturing chemists. With the aid of his little instrument, which may be got for a trifle from its ingenious maker, M. Collardeau, Rue Fauburg St. Martin at Paris, cr constructed by one of the London hydrometer artists, the per centage of real alcohol, and the real value of any spirituous liquor, may be determined to sufficient nicety for most lpurposes, in a far easier manner than by any instrumlents now used in this country. It has been adopted by the Swedish gove rnment, with M. Gay Lussac's tables M. Gay Lussac's table gives, by inspection, the true bulk of the spirits as corrected for temperature; that is their volume, if of the normal temperature of 15~ Cent. (59a Fahr). Now this is important information; for, if a person buys 1000 gallons of spirits in hot weather, and pays for them exactly according to their strength corrected for temperature, he will not have 1000 gallons when the we.Jler is in its mean state. He may lose, in this way, several gallons, without being aware of it from his hydrometer. Sometimes, after moist autumns, when damaged grain abounds, the alcohol distilled from its fermented wash contains a peculiar volatile body. When we apply our nose to this species of spirits in its hot state, the volatile substance dissolved in it irritates the eyes and nostrils; it has very nearly the same smell as an alcoholic solution of cyanogen, as any chemist may discover by standing near the discharge pipe of the refrigeratory worm of a raw-grain whisky still. Such spirits intoxicate more strongly than pure spirits of the same strength, and excite, in mlany persons, even temporary flenzy. It is a volatile fatty matter, of a very fetid odor, when obtained by itself, as I have procured it in cold weather at some of the great distilleries in Scotland. It does not combine with bases. At the end of a few months, it spontaneously decomposes in the spirits and leaves them in a less nauseous and noxious sItate. By largely diluting the spirits with water, and distilling at a moderate temperature, the greater part of this oil may be separated. Part of it comes over with the strongest alcohol, and part with the latter runnings, which are called by the distillers strong and weak feints. The intermediate portion is purer spirit. The feints are always more or less opalescent, or become so on dilution with water, and then throw up an oily pellicle upon their surface. The charcoals of light wood, such as pine or willow, well calcined, and infused in sufficient quantity with the spirits prior to rectification, will deprive them of the greater part of that oily contamination. Animal charcoal, well calcined, has also been found useful; but it must be macerated for some time with the empyreumatic spirits, before distillation. Another mode of separating that offensive oil is, to agitate the impure spirits with a quantity of a fat oil, such as olive oil, or oil of almonds, to decant off the oil, and re-distil the spirits with a little water. Digestion and agitation with calcined magnesia, for some time, followed by filtration and distillation, are also good means of improving the flavor of alcohol. The taste of the oil of grains is'best recognized by agitation with water, whereby, on standing, the diluted spirit throws up a film of oil, visible by reflected light. If the spirit be mixed with a few drops of nitrate of silver and exposed for some time to sunshine, the oil will react upon the oxide of silver, and cause a brown tinge; but if there be no oil present, the spirits will remain limpid. If one part of hydrate of potash, dissolved in a little water, be mixed with 160 parts of spirits, and if the mixture be well shaken, thon slowly evaporated down to 15 parts and mixed with 15 parts of dilute sulphuric acid in a phial, to be then corked, there will soon exhale from the mixture a peculiar offensive odor, characteristic of the quality and origin of the impure spirit, whether obtained from raw grain, from malt, from potatoes, rye, arrack, rum, brandy, &o. This excellent process may be used also for testing wines. Lime and alkalis always injure the flavor of ar ltnt spirits of all kinds. Some foreign chemlsto direct empyreumatic or rank spirits to be rectified with the addition of chloride of lime. I have tried this method in every way, and on a considerable scale, but never found the spirits to be improved by it. They were rather deteriorated. See BRANDY, DISTILLATION, FERMENTATION, GIN, RuM, and WHISKY. Anhydrous or absolute alcohol, when swallowed, acts as a mortal poison, not only by its peculiar stimulus oi the nervous system, but by its abstracting the aqueous particles from the soft tissue of the stomach, with which it comes in contact, so as to destroy its organization. The absence of water in alcohol may be tested by sulphate of copper calcined to whiteness, which imparts a blue tinge to the liquid. 46 parts of. absolute alcohol contain 6 parts of hydrogen; and hence, by being burnt in a tubulated globular receiver connected with a condensing worm, they afford 54 parts of water. If the spirit was free from oil, the water will be quite pure, as the carbonic acid flies off. The high price of alcohol in this country, in consequence of the heavy fiscal duties, and its low price in most other countries, where it is nearly duty free, has led to its oontraband importation under various disguises. Sometimes it is introduced under tba ALGAROVILLA. 81 mask of oil of turpentine, from which it can be sufficiently freed by rectification for the purpose of the gin manufacturers. Sometimes it is disguised with wood naphtha, or wood vinegar; from the latter of which it may be separated by distillation in a water bath; but from the former it is more difficult to extricate it, as alcohol and wood spirit are nearly equally volatile. It has also been disguised with coal naphtha; but from this it may be easily separated by distillation, on account of the great difference between the boiling points of the two liquids; besides, coal naphtha will not combine with water, as alcohol does. When the object is to discover whether wood spirit contains alcohol, we may proceed as follows:-Add to the suspected liquid a little nitric acid, of specific gravity 1-45. If alcohol be present, in even small proportion, an effervescence will ensue, from the evolution of etherised nitrous gas, with its characteristic ethereous smell. On treating the mixture with a nitrous solution of mercury, as in the process for fulminate of mercury, an effervescence will take place, the dense vapor of etherised mercurial gas will appear, and a certain proportion of fulminate will be formed, corresponding pretty closely to the proportion of alcohol in the wood naphtha mixture. As the boiling point of wood spirit is only about 1450, while that of alcohol, of like specific gravity (0-825), is 173~ F., a good criterion of the proportion of the two liquids present in the mixture may be found in its boiling temperature. Pure wood spirit, when mixed with the above nitric acid, becomes of a rubv tint, but remains tranquil. Alcohol continues colorless, but enters into violent ebulltion. and is nearly all dissipated in fumes. Alcohol diluted with water has a less resultant density than wood spirit of like strength similarly diluted. While alcohol thus becomes of 0-920, wood spirit becomen 0'926 or 0927. If wood spirit be contained in alcohol, it may be detected to the greatest minuteness ty the test of caustic potash, a little of which, in powder, causing wood spirit to become speedily yellow and brown, while it gives no tint to alcohol. Thus 1 per cent. of wood spirit may be discovered in any sample of spirits of wine. For further details upon this analytical inquiry, see iry pamphlet entitled The Revenue in J(opardy. ALDEHYDE; a name compounded out of alcohol dehydrogenated, being a substance formed by depriving alcohol of its hydrogen. The process is too intricate for description here. It is a limpid liquid, of 0-790 specific gravity, boiling at 218~0 C., and not reddeninc litmus. It has a peculiar ethereous smell: when its vapor is inhaled it causes suffocation, and even in small quantities a spasmodic constriction of the thorax. It is composed of 4 atoms of carbon =-24, 4 of hydrogen = 4, and 2 of oxygen = 16; or in 100 of 54'55, 9-09 and 36 S3 respectively. It is very inflammable. ALE. The fermented infusion of pale malted barley, combined with infusion of hops. See BEER. ALEM8IC, a STILL; which see. ALEMBROTH, salt of. The salt of wisdom, of the alchemists; a compound of biclloride of mercury and sal ammoniac, from which the old white precipitate of mercury is made. ALGAROTH, powder of. A compound of oxide and chloride of antimony, being a precipitatt obtained by pouring water into the acidulous chloride of that metal. AL(AROVILLA. This substance is called by the Spaniards Algaroba, from the resemblance it bears to the fruit of the Carob (Ceratonia siliqua), which is a native of Europe, in the southern countries of Spain and Portugal. The substance lately analysed by me is the fruit of a tree which grows in (Chili, of which the botanical name is Prosopis pallida, according to Captain Bagnald, R.N., who first brought a sample of it to this country in the year 1832. It consists of pods bruised and agglutinated more or less with the extractive exudation of the seeds and husks. According to a more recent deter'mination, algarovilla is said to be the product of the tree Juga Marth:e of Santa Martha, a province of New Carthagena. It is an astringent substance replete with tannin, capable, by its infusion in water, of tanning leather, for which purpose it possesses more than four times the power ot god oak bark. Its active matter is very soluble in water at a boiling temperature. The seeds are merely nutritive and demulcent, but contain no astringent property. This resides in the husks. The seeds in the entire pod constitute about 1-5th of the weight, and they are three or four in number in each oblong pod. Alcohol of 60 per cent. over proof dissolves 64 parts in 100 of this substance. The solution consists chiefly of tannin, with a very little resinous matter. Water dissolves somewhat more of it, and affords a very styptic-tasted solution, which precipitates solution of isinglass very copiously, like infusion of galls and catechu. Its solution forms with sulphate of iron a black precipitate, which ii kept floating by means of the gum present, and thereby constitutes good ink. My report to the merchant was written with a corn mination thuis nade, in proportions taken at random; and there is no doubt that by 82 ALKALI. using a stronger decoction of the algarovilla, along with a proper proportion of cop. peras, an excellent black ink might be prepared without any other addition. I find that a decoction of th'. algarovilla affords with cotton cloth, mordanted with tin solution, as also with acetat; of alumina liquor, a brilliant yellow dye; the former being the brighter and fuller of the two. A tincture of algarovilla might be used as an astringent in medicine; or probably a decoction of the whole substance would be preferable, on account of the demulcent quality of the seeds when bruised. As an article of commerce it cannot be rated at a high price, nor should it pay much duty till its value as an article of manufactures or medicine be fully ascertained. ALIZARINE. See MADDER. ALKALI. A class of chemical bodies, distinguished chiefly by their solubility in water, and their power of neutralizing acids, so as to form saline compounds. The alkalis of manufacturing importance are, ammonia, potash, and soda. These alkalis change the purple color of red cabbage and radishes to a green, the reddened tincture of litmus to a purple, and the color of turmeric and many other yellow dyes to a brown. Even when combined with carbonic acid, the three alkalis exercise this discoloring power, which the alkaline earths, lime, and barytes, do not. The same three alkalis have an acrid, and somewhat urinous taste; the first two are energelic solvents of animal matter; and the three combine with oils so as to form soaps. They unite with water in every proportion, and also with alcohol; and the three combine with water after being carbonated. ALKALI-ORGANIC; OR ORGANIC BASES. Many plants and ingredients of plants which exercise a powerful specific operation upon the living system of man and other animals contain peculiar combinations which have in chemistry a decidedly alkaline reaction; and have hence been called alkaloids. They unite directly with both hydrogen and oxygen acids, and in this respect differ essentially from methyloxide, acthyloxide, and amyloxide. Sertiirnier was the first discoverer of these bases, having recognised in opium the alkaloid now called morphia. Soon afterwards Pelletier and Caventou discovered analogous bases in the strychnos nux vomica, as also in white hellebore. As these bases possessed in a remarkable degree the peculiar action of each plant upon the human system, chemists set themselves diligently to search in the poisonous and narcotic extracts for similar principles. From the discovery, however, of quinia, cinchonia, piperine, &c., it appeared, that not only the poisonous ingredients of plants, but others possessed of pecutliar medicinal qualities, constituted peculiar alkaloids. These occur in plants always combined with organic acids, which are also often of a peculiar nature. Thus the base of opium occurs combined with meconic acid, and the base of chelidonium with chelidonic acid. The acid constituent, how ever, is often the malic or one of the forms of the tannic. Wohler first made the discovery that through the decomposition of cyanate of ammonia urea was formed, which possessed the property of combining with several acids, especially the nitric and oxalic, under like conditions with the bases existing in nature. Unverdorben extracted from animal empyreumatic oil several basic compounds, such as odorine, ammoline, &c., and Runge out of coal-tar obtained kyanol and leukol. Fritszche obtained by the decomposition of anthranilic acid, aniline, whose identity with kyanol has been since shown by Hofmann. Zinin made the discovery that by the operation of sulphuretted hydrogen upon nitrobenzide and upon nitronaphtalide, certain organic bases were formed with separation of sulphur, such as aniline, benzidine, naphtalidine, &c. Laurent discovered lophine and amarine, bases which result through the operation of ammonia upon oil of bitter almonds. Thiosinnamine is formed by the action of ammonia upon the volatile oil of mustard, &c. Composition of alkaloids or organic bases.-The whole of these bases contain nitrogen combined with carbon and hydrogen, and most of them contain also oxygen. These alkaloids combine also with hydrogen and oxygen acids, as ammonia does, and thereby are distinguished essentially from acthyloxide, methyloxide, and amyloxide. If we reckon ammonia as a hydrogen basis, the organic bases must belong to the same category. Their oxygen constituent does not correspond to their capacity of saturation, which follows from the fact, that alkaloids exist which are free from oxygen. The production of the organic bases is different according as they belong to volatile or non-volatile bodies. The volatile may be obtained when the plants in which they exist are distilled with a somewhat dilute potash lye. The distilled liquor contain? always besides the organic base a little ammonia. It is to be exactly saturated with sulphuric acid, then evaporated by gentle heat, and the remainder treated with absolute alcohol or with ether, in which the sulphuric salt of the organic base dissolves. This solution is to be mixed with water, the spirit is to be distilled off, the remainder decomposed with potash lye, next agitated with ether, which dissolves out the alkaloid, which remains after the evaporation of the ether. In this way nicotine is obtained. The non ALKALIMETRY 33 volatile bases are commonly obtained by extracting the constituents of the plant with water acidulated with sulphuric or muriatic acid, and from the concentrated solution precipitating the bases by means of an alkaline substance, such as potash, lime, ammonia, or magnesia. Tle precipitate is to be dried and boiled in alcohol, which dissolves the alkaloid. This may be purified by repeated crystallizations aided by animal charcoal, &c. ALKALIMETER. An instrument for measuring the alkaline force or purity of any of the alkalis of commerce. It is founded on the principle, that the quantity of real alkali present in any sample is proportional to the quantity of acid which a given weight of it can neutralize. ALKALIMETRY. Nearly forty years have elapsed since I was led, by peculiar circumstances, to construct a very simple method of testing alkalis, the l;inciple of which I soon afterward applied to acids, bleaching powder, dye-stuffs, and most other chemical substances extensively used in manufactures.* In 1814 and 1815, during the summer vacation of my Glasgow classes, I was engaged in delivering courses of lectures on chemistry in the Belfast Academical Institution, and had many of the most eminent members of the Linen Board of that town for my pupils. Being occasionally consulted upon the qualities of the alkalis, which were used to the value of 200,0001. by the linen bleachers of Ireland, I saw the importance to them of a simpec alkalimetrical test, both for purchasing and for using their barillas and potashes. The following extract from the Belfast News Letter, of July 9th, 1816, will show the nature of my contrivance:" This day one of the porters of the Linen Hall, Belfast, was called into the libraryroom at the request of Dr. Ure, who being quite unknown to Dr. Ure, and never having seen any experiments made with acids and alkalis, he took the instrument at our desire, which being filled with colored acid, by pouring it slowly on adulterated alkali, which we had previously prepared, he ascertained exactly the per-centage of genuine alkali in the mixture. Belfast, 25th June, 1816. "JOHN S. FERGUSON, Chairman. JAMES M'DONNEL, M. D. JOHN M. STOUPE. S. THOMSON, M. D." Of these gentlemen, two were leading members of the Linen Board, and the others the two principal physicians of the town. The publication of the details of my method of alkalimetry was delayed till arrangements were made for its general introduction, under the direction of the Linen Board of Dublin, whose professor of chemistr —, Mr. W. Higgins, as well as Dr. Barker, professor of chemistry in Trinity College, ranted certificates of the " accuracy and the national importance" of the instrument. The alkaline matter then importel into Ireland was often largely contaminated with common salt, even to the extent of 80 or 90 per cent. During the procrastin? ion of the Board, I lent my Treatise on Alkalimetry to Dr. Henry, of Manchester, who inadvertently published an account of it, though with reference to me, in the -ext edition {p' his Elements of Chemistry. Having, in the lorg inter-il since, cont.vea,any modifications of the instrument, and having extended its prihcip}' esting other articles I am induced to offer it now to the world, in consequence of the recent appearance of a publication upon the same subject, by two very ingenious chemists of Liebig's school, Drs. R. Fresenius and H. Will. Of their system of alkalimetry, &c., a copious abstract appeared in the lunlalen der Chimie und Pharmacie for July last, and about the same time a pamphlet was published by Winter, at Heidelberg, under the title Neue Verfahrungsweisen zur Bestimmung des Werthes der Pottasche und Soda, der Saiiren, und des Braunstein; or "New Processes for determining the Value of Potash and Soda, of Acids, and Black Oxide of Manganese." However accurate these processes may be, and however apt for a German or French student of chemistry, they are, in my apprehension, not at all fitted for the familiar use of manufacturers and dealers in any country, and certainly not for those of the United Kingdom. Descroizillos was the first person who contrived an instrument, called an alkalimeter, to ascertain the alkaline strength of potash and soda, without much calculation. His method was described in the snnales de Chimie for 1806, tom. lx., and a translation of it appeared in our Philosophical Magazine, vol. xxviii., for July * Among others to nitrate of potash, nitrate of soda, and to white lead, either in powder or in paint. My nitrorneter enables a person not at all versant in chemistry to ascertain in a quarter ol'n hour, out by two distinct processes, the quantity of pure nitrate in either of these salts, to one padt in 200. The cerussa-metel is equally simple and expeditious. 4 34 ALKALIMETRY. and August of the following year. His apparatus consisted of a glass tube, 8 or S inches long, and 7 or 8 lines in diameter, closed at one end, but terminated at the other in a kind of small funnel (with a beak or spout), connected to the tube by a narrow neck, having a calibre of two lines and a half. Upon the shoulder, under the throat, theie was a hole for admitting air to the long tube in the act of being emptied, by sloping its mouth downward. This cylindrical vessel was to contain 38 grammes of water, which space was divided into 76 equal parts, which it was extremely important to proportion accurately. The liquor was prepared by taking concentrated sulphuric acid, at 66~ Baumc (1-845 spec. grav.), and diluting it with nine times its weight of water. The instrument being poised in a balance, he introduced into it very exactly two grammes of the above test acid, and when the instrument stood upright, he scratched a line at the level of the liquor, and thus proceeded by addition of successive grammes to graduate the whole, till 36 were added, after which he subdivided these spaces by lines into 72 demi-aramme volumes. He then proceeds to describe eight different subsidiary articles required for his operations: " Allkglimetricatririals ofpotash.-Weigh exactly one deii-gramme ofpotash, ic it ipto a glass, and pour upon it about four fifths of a decilitre of water; facilitate the solution of the potash by stirring it with a small chip of wood, three or four times in an hour and a half, a minute at each time. When the solution is (Jected, pour it into the smail tin measure, No. 4, which is to be then filled up with water; pour it back again into the glass, in which you must still pour a measure full of pure water; stir this new mixture also three or four times within half an hour, in order to facilitate the precipitation of a slight sediment, which soon falls down. This sediment being completely formed, slope the glass with caution, in order to fill with clear liquor the small measure; then empty this last into another large glass; after this place round the edges of a plate drops of syrup of violets; pour also into the alkalimeter test liquor until the line marks 0; take it afterward with the left hand, inclining it upon the glass which contains the moiety of the clean alkaline solution: the acid liquor will fall into it by hasty drops, or in a very small thread, which you may moderate at pleasure, by retarding the entrance of the air at the lateral hole or vent, upon which must be placed the end of the finger; at the same time, with a small stick or match, assist the mixture and facilitate the development of the carbonic acid which is manifested by effervescence. When you have emptied the alkalimeter to about the line 40, try if the saturation approaches, by drawing your small stick from the mixture, and resting it upon the drops of syrup of violets, which should become green, if the potash is not of a very inferior quality. If, on the contrary, the violet color is not altered, or what would be worse, if it be changed into red, there would be, in the first case, an indication of s5'uration, and in the second a proof of super-saturation. But this is not the case with good potashes; at that line, the liquor tried can alter the syrup of violets into green only; or cause to return to the violet, and even to the green, the drops which had been changed into red at the time of a former trial; we must, therefore, in general add more acid, which occasions a new effervescence. This addition must always be made with caution, and we must touch every time a drop of syrup of violets in order to stop. When at last the latter assumes a red hue, then, after having restored the alkalimeter to a perpendicular position, in order to see at what line the testing liquor stops, you must reckon one degree less, in order to compensate the excess of saturation. The mean term of potashes is 56; this implies that they require for their saturationfifty-five hundredths of their weight of sulphi Lic acid." For the analysis of commercial sodas of all kinds, M. Descroizilles prescribes using ten and a half deci-grammes of this alkali, instead of the ten deci-grammes for potashes, and proceeds as above detailed. In his table of results annexed, we find American potashes called 60~ to 63~. American pearlashes - - - 50~ to 55~ Dantzic potash - - - 45 to 55 Alicant soda - - - - 20 to 33 It is obvious, from these statements, that the alkalimeter so made and graduated denoted comparative, but not absolute, quantities of alkalis present in the commercial samples. The rest of his very long memoir is occupied with what he calls the graduation of potashes and sodas, the economy of their graduation, the proportions of carbonic acid in them, the processes of caustification, the presence of potash in all lime which is burnt by a wood fire, origin of neutral soda, and probable origin of natrum; without any more explicit instructions. The instrument, as left in this vague state, never was employed, nor could it come into use, among English manufacturers and dealers, ALKALIMETRY. 35 The next alkalimeter, of which an account has been published, was ny own. In constructing this instrument, I availed myself of the lights recently shed on chemical pro. portions by Dr. Dalton's atomic theory, and I thus made it to represent, not relative, but absolute measures of the amount of real alkali existing in any commercial sample. The test-liquor used at that time was sulphuric acid, which is most readily and accurately diluted to the requisite degree by means of a glass bead, very carefully made, of the specific gravity that the standard acid should have. In order to make the test-liquor, therefore, nothing more is requisite than to put the bead into distilled water, and to add to it somewhat dilute but pure sulphuric acid, slowly and with agitation, till the bead rises from the bottom, and floats in the middle of the liquor at the temperature of 60j Fahr. The delicacy of this means of adjustment is so great, that a single degree of increase of heat will cause the bead to sink to the bottom-a precision which no hydrometer can rival. The test-tube, about 14 inches long, contains generally 1,000 grains of water, and is graduated into 100 equal parts by means of equal measures of mercury. The test-liquor is faintly tinged with red cabbage or litmus; so that the change of color, as it approaches to the saturating pitt. on adding it to 100 grains of the commercial alkali, becomes a sure guide in conducting the experiment to a successful issue. One hundred measures of this test-liquor neutralize exactly 100 grains of absolute soda (oxide of sodium), and of course very nearly 150 of potash. A bead may also be adjusted for test-liquors, of which 1,000 grain measures neutralize 100 of potash, and therefore 661 of soda, as well as other proportions, for special purposes of greater minuteness of research. One may be so graduated as to indicate clearly a difference of 1 of a grain of ammonia. In making such nice experiments, it is of course requisite to free the alkaline matter beforehand from s-lphurets, sulphites, and hyposulphites, by igniting it in contact with chlorate of potash, as long since recommended by GayLussac. With such means in careful hands, all the problems of alkalimetry may be accurately solved by an ordinary operator. On the same principle, my A.cidimeter is constructed; pure water of ammonia is made of such a standard strength by an adjusted glass bead, as that 1,000 grain measures of it neutralize exactly a quantity of any one real acid, denoted by its atomic weight, upon either the hydrogen or oxygen scale or radix; as for example, 40 grains of sulphuric acid. Hence it becomes a universal acidimeter; after the neutralization of 10 or 100 grains of any acid, as denoted by the well-defined color in the litmustinted ammonia, the test-tube measures of ammonia expended being multiplied by the atomic weight of the acid, the product denotes the quantity of it present in 10 or 100 grains. The proportion of any one free acid in any substance may thus be determined with precision, or to one fiftieth of a grain, in the course of five minutes. Like methods are applied to Chlorometry, and other analytical purposes, with equal facility; adapting the test-liquor to the particular object in view. Instead of using beads for preparing the alkalimetric and acidimetric test-liquors, specific gravity bottles, or hydrometers, may of course be employed; but they furnish incomparably more tedious, and less delicate means of adjustment. To adapt the above methods to the French weights and measures, now used generally also by the German chemists, we need only substitute I00 deci-grammes for 100 grains, and proceed in the graduation, &c., as already described. The possession of two reciprocal test-liquids affords ready and rigid means of verification. For. microscopic analyses of alkaline and acid matter, a graduated tube of small bore, mounted in a frame.with a valve apparatus at top, so as to let fall drops of any size, and at any interval, is desirable; and such I have employed for many years. Of this kind is my ammonia-meter, uw ed in the ultimate analysis of guanos and other azotized products, in conjunction with a modified apparatus on the principle of that of Varrentrapp and Will. It may be remarked, that when the crude alkali contains some hyposulphite, it should not be calcined with chlorate of potash, because one atom jf hyposulphurous acid is thereby converted into two atoms of sulphuric, which of course saturate double the quantity of alkali, previously in combination with the hyposulphurous acid. In such cases it is preferable to change the condition of the sulphurets, sulphites, and hyposulphites, by adding a little neutral chromate of potash to the alkaline solution, whence result sulphate of chromium, water, and sulphur, three bodies, which will not affect the accuracy of the above alkalimetrical process. In the annals of Philosophy for October, 1817, I described a new instrument for analyzing the earthy and alkaline carbonates, and for determining the quantity of base present in them from the volume of carbonic acid, disengaged by their solution in acids, upon the data of the atomic theory. This method was applied to the analysis of the carbonates of ammonia, soda, potash, lime, maanesian limestone (dolomite), &v. "The indications of the above analytical instrument are so minute as to cnrble us, by the help of the old and well-known theorem for computing the proporticrs of two 36 ALKALIMETRY. metals from the specific gravity of an alloy to deduce the proportions of the bases from the volume of gas disengaged by a given weight of a mixed carbonate."* That small instrument consisted of a bent glass tube, open at one end, and terminated at the other with an egg-shaped bulb from two to three inches in diameter, and it Raquired for operating with it, about five pounds of quicksilver. The following glass tapparatus (fig. 6) will be found more generally convenient, and equally exact. A is a cylinder, 2 inches in diameter, and 14 inches long. It conUDdq dtains 10,000 grains of water in the graduated portion; 0, or zero 6 being at the top. It has a tubulure in the side close to the bottom, throu7h the cork of which a short tube passes tight, and is connected to a collar of caoutchouc, E, which serves for a joint lC to the upright tube, B, resting near its open upper end in a hooked wire. Through the cork in the mouth of the cylinder, the taper tail of the flask c passes air-tight. The small tube F, open at both ends, is cemented at bottom into the tail of c, and rises to the shoulder of the flask. The cork of c is perforated, and receives air-tight the taper tube r, which can also be closed with the stopcock. In operating with this apparatus, proceed as follows:Fill the cylinder with water, and cover its surface with half o ~10 | an inch of oil. Insert the tail of the flask. Put into the flask c, 58'6 grains of carbonate of potash, or 45'2 of carbonate of soda, so according as common pearl-ash or soda-ash is to be tested, along with as much water as will cover fully the lower end of D, and sto | | then introduce this tube. Have a bottle containing about 40 90 1 \ parts of oil of vitriol, previously mixed with 60 of water, and IA l cooled. Take of this, in a pouring or dropping glass, 100 water 5s grain measures, and suck this quantity gradually up into the tube a, then shut the stopcock. On opening it slightly the acid will 60 fall into c, and as slowly as may be prudent. The carbonic acid B gas, forthwith disengaged, will depress the water in A, cause an 701 overflow of it from the tube B, whieh, being held in the left hand, 80 must have its swanbeak placed over a basin, and progressively soI0 lowered to the level of the descending water in the cylinder. 9 When all the sulphuric acid has been introduced by the right E hand, the orifice of D is to be corked, and the tube B continually 1050: lowered with the left, till the effervescence being finished, the 4_ r water in A remains stationary. The number on the centigrade scale, opposite to the surface of the oil, deducting 100 grain measures for the bulk of dilute acid added, denotes the per-centage of pure carbonate of potash, or of soda, in the sample under examination. The above prescribed weights of these two carbonates, when pure, disengage each by the action of sulphuric acid (used here in small excess) 10,000 water grain measures of carbonic acid gas, or 100 measures of the scale on A. The cylinder which I employ contains about 12,000 water grain measures, so that the bottom of the centigrade scale is fully two inches above the level of the lower tubulure. This capacity and the graduation into 120 parts, will be found convenient in certain cases, particularly in analyzing bicarbonates of potash and soda.1 We may estimate 10,0)0 water grain measures of carbonic acid at 600 Fahr., to weigh 18'4 grains, and we thus perceive what a magnified scale we should possess, if we applied the vernier contrivance here, as we do to barometers. At any rate, he must be an awkward operator who can not determine the value of an alkaline carbonate, by the above means, to one part in a thousand. In operating upon limestones, marles, &c., 42 1 grains should be taken as the standard weight of assay, because that weioht of pure carbonate of lime should give out on solution in dilute muriatic acid 10,000 water grain measures of carbonic acid gas. Since 100 water grain measures of liquid hydrochloric acid, specific gravity 1*14, will supersaturate the lime in the above weight of carbonates, that quantity may be used in the experiment. The preceding instrument will be found more convenient in experimenting, as also the system of indication, than one on similar principles constructed by the ingenious Dr. Mohr, of Coblenz. In examining bicarbonates of potash and of soda, the weights to be used in the above apparatus are 42 grains of the former, and 35- grains of the latter, each of which Dictionary of Chemistry, 1821. t For the greatest precision hot acid may he used in the above experiment, by taking in a graduated test-tube seventy-five grains of water, and filling it up to the line 100 with concentrated sulphuric acid. This mixture being poured in successive portions into the flask c (represented much too large in pro. portion to the cylinder A), will ensure the expulsion of all the carbonic acid from c, which may be after. ward cooled by wrapping round it a towel dipped in cold water. ALKALIMETRY. 37 quantities, if the salts be perfect, will disengage 10,000 water grain measures of carbonic acid gas, by the action of sulphuric acid. There will be no harm in taking the formerly prescribed measure of the sulphuric acid though considerably less would answer the purpose. The centigrade measures of gas obtained in A will indicate the carbonated state of the two alkalis respectively. Their alkaline force may be most readily ascertained by my old alkalimeter, with colored test acid. Since the bicarbonates usually sold in our shops, especially that of soda, are far from being exact atomic compounds, they should be always examined, both for their base and acid, which may also be well done in the following way, where the quantity of carbonic acid gas is determined by weight instead of by volume. For this purpose, a small compact apparatus of the annexed form (fig. 7) will be found convenient; it is to be used in conjunction with my B alkalimeter. A in the dotted line is the phial for receiving'7;-7 the carbonate to be tested. B, the funnel into which the test acid is to be poured; c c, an inverted syphon filled 7IJJI/J 1' with pieces of chloride of calcium for absorbing the aqueous I> C vapors exhaled by the carbonic acid. The loss of weight in the phial above that in the tube.of test acid shows the quantity of acid gas, and the indication of the alkalimeter tube, that of alkaline base, from which data the proportion of neutral carbonate and bicarbonate may be immediately deduced. Thus, 100 grains of bicarbonate of soda should give out 51- grains of carbonic acid, and saturate 37'6 centigrade measures of the test acid, equivalent to 37'6 grains of real soda. But if neutral carbonate of soda be present, less gas will be given out, and more or less alkali may be indicated, according to the degree of dryness of the neutral soda. The amount of water in the bicarbonate may be determined by igniting 20 grains in a test tube, connected with the chlorcalcium inverted syphon; 10} grains of carbonic acid gas should be expelled, and 24 of water, making a total loss of 1221l grains, of which 28 will be found as water ab24 sorbed by the chlorcalcium. But since a very moderate heat D suffices to expel the second atom of carbonic acid from the ~~I I bicarbonate of soda, the readiest mode of estimating its quality is to heat, over a spirit lamp, in a small flask, or retort, connected air-tight by a tube with the mouth of the cylinder A, (fig. 6) 70- grains of the supposed bicarbonate. Of the perfect salt this quantity should give out pretty exactly 10,000 grain measures of gas; and whatever aliquot part of this volume is evolved will indicate, without calculation, the relative value of the substance as a bisalt. Thus if 8,500 grain measures of gas are obtained, 85 parts of bicarbonate of soda are present in 100. The crystalline form of bicarbonate of potash is a tolerably good criterion of its quality. The quantity of caustic alkali mixed with carbonate may be readily determined, with sufficient accuracy, by the expert use of my alkalimeter; because, till the caustic portion be nearly neutralized, little or no carbonic gas is expelled. When the effervescence at length begins, the test measures already expended denote the percentage of caustic alkali. It is not right to disregard the alkali which is present in the state of sulphuret, because as such it is effective in many processes of the chemical arts; in the manufacture of yellow soap, crown glass, in the bleaching of linen and cotton goods, &c. The alkalimeter, directly applied, will show the alkali present in this form, when compared with that indicated after ignition of the crude alkali with chlorate of potash, or after its treatment with yellow chromate of potash.* A few years ago I had the following apparatus made for the ready analysis of carbonates, by ascertaining the loss of weight they suffered from the disengagement of their carbonic acid gas, during their solution in an acid. A, B (fig. 8) are two globes, of about two inches in diameter each; A has its inferior neck strangled into a bore nearly capillary; B stands lower, with its centre line on a level with the narrow neck of n. The tubes of these globes are about one half inch in diameter. c is shut at top with a perforated cork, through which enters, air-tight, a small glass tube, which is bent across to the mouth of the tube E, and then passes down into it a little below the centre line of If the alkaline carbonate contains sulphuret, sulphite, or hyposulphite, a teaspoonful of yellow chromate of potash may be added to it, wherefrom result suip;ate of chromium, water, and sulphur, which remain in the apparatus without effecting its weight. The mutual action of neutral chromate of potash, and of sulphuret of potash, &c., has been discussed in aringenious paper published by Doppng, ir. the Annalen dcr Chimie for May, 1843, I. 172. -3~8 ~ALKALIMETRY. the globe B. This globe is rather more than half filled with sulphuric acidwhen the instrument is employed in the analysis of the carbonates. The standard weight of car. bonate of soda == 24 grains, or of carbonate of potash 8 31- grains, is then put into A, having previously laid a minute globe of glass over the lower orifice; the cork, with its small tube, is now firmly adjusted; and the apparatus is weighed in its upright position, either by suspena E i C sion with a hook to the end of the beam, or by resting it on the scale in a light socket of any kind. It is next laid hold of, and inclined so as to cause a little of the acid in B to pass over into A. Effervescence ensues with greater or-less vehemence, according to the nature of the carbonate and quantity of the acid introduced. Should it be too violent, and threaten an overflow by intumescence, it can he in. stantly abated to any degree by the slightest slope of the instrument. Now, this power of control forms the peculiar feature and advantage of this contrivance; whereas in all other forms of such apparatus that I know, whether by sucking over or pouring in, if a little too much acid comes upon the carbonate, the experiment is effectually A marred. The gas disengaged in A must necessarily traverse the sulphuric acid in B, and'e stripped of its moisture before escaping into the air. Having superB \> a/ saturated the alkaline base, and cooled the apparatus, we weigh it again, and the loss of weight in grains and tenths denotes the per-centage of soda or potash, provided their neutral carbonates had been the subjects of experi. ment. For limestone, on the same plan of computation, 22| grains may be taken. It deserves to be noted, that the present instrument has only one junction, and needs no chloride of calcium, a substance so apt by its swelling to burst the glass tubes that contain it.* II. ACIDIMETRY. I have already stated, that water of ammonia of standard strength, faintly tinted with litmus, affords a most exact and convenient acidimeter, when poured or let fall from a graduated dropping-tube. Bicarbonate of potash also, when dissolved in water, so that 1,000 grain measures contain one atom of the salt counted in grains, is a good test-liquor for the same purpose; for if the centigrade measures expended in effecting neutralization are multiplied by the atomic weight of Lhe given acid, the product is the quantity in grains of acid present..1cidimetry may be likewise exactly performed by measuring in the cylindric gas. meter (fig. 6) the volumes of carbonic acid gas disengaged from pure bicarbonate ol potas X or soda, by a given weight of any acid, taking care to use a small excess of the salt. Thus, for example, 16-8 grains of dry and 201 of hydrated sulphuric acid disengage 10,000 water grain measures of gas from bicarbonate of potash. Therefore, if 201 grains of a given sulphuric acid be poured into the flask offig. 6, upon about 50 grains of the bicarbonate, powdered and covered with a little water, it will cause the evolution of a volume of gas proportioned to its strength. If the acid be pure oil of vitriol, that weight of it will disengage 10,000 grain measures of gas; but if it be weaker, so much less gas-the centigrade measures of which will denote the per-centage value of the acid. If the question be put, how much dry acid is present per cent. in a given sulphuric acid, then 16'8 grains of the acid under trial must be used; and the resulting volume of carbonic acid gas read on the scale will denote the per-centage of dry acid.t For nitric acid, we should take 22'6 grains; for hydrochloric or muriatic acid, 15'34; for acetic acid, 21'6; for citric acid, 24*6; for tartaric acid, 28 grains: then in each case we shall obtain a volume of carbonic acid gas proportioned to the strength and purity of these acids respectively. The nitric, hydrochloric, and acetic acids are re. ferred to in their anhydrous state; the tartaric and citric in their crystalline. If the latter two acids be pure, a solution of 24'6 grains of the first and of 28 of the last * 1,000 water grain measures of sulphuric acid of specific gravity 1-032, or 32 above water, neutralize 32 grains of soda, and, consequently, one atom, on the hydrogen scale, of each of the other bases, reckoned in grains. Having in the course of many years subjected my tables of sulphuric, nitric, and muriatic acids, as well as of ammonia, to strict cross-examination, I have found them trustworthy for all alkalimetrical and acidimetrical purposes. t The bicarbonate must be free fret carbonate, a point easily secured by washing its powder with rold water, and drying it in the air. ALKALIMETRY. 39 will disengage from 50 grains of bicarbonate of potash 10,000 grain measures of car. bonic acid gas.* Acidimetrical operations may likewise be performed by determining the weight of carbonic acid gas expelled from the bicarbonate of potash or' soda, by a given quantity of any acid, in the apparatus eitherfig. 7, or fig. 8. Here the weights to be taken are as follows, in reference to Grains. Dry Sulphuric acid - - 9127 Nitric - -. 1233 " Hydrochloric - - - 829 Acetic - -11-67 Crystallized Tartaric - - - 13-31 {" Citric - 15-13 Each of these quantities of real acid, with 25 or 26 grains of bicarbonate of potash, will give off 10 grains of carbonic acid gas; and hence whatever weight the apparatus loses, being reckoned in grains and tenths of a grain, denotes the 9 per-centage of acid in the sample under trial, without the necessity of any arithmetical reduction. Persons accustomed to the French metrical system may use deci-grammes instead of I grains, and they will arrive at the same per-centage results. The preceding experiments, in reference to the weight of carbonic acid gas expelled for the purpose c either alkalimetry or acidimetry, may also be made by means of hie ordinary apparatus represented in fig. 9. A is a small matrass which contains the acid or carbonated alkali at its bottom; and conversely the alkali'or acid, for their mutual decomposition in the small test-tube, C c ^ shown first at b nearly upright and filled, but afterward at a, horizontal and emptied. B is a bulbous tube filled with fragments of chlorcalcium for absorbing the aqueous vapor that l'% rises with the carbonic acid gas, and d c is a small bent tube which dips into the liquid in the matrass. The weighings, &c., may be conducted as already detailed; and when the effervescence is completed, the residuary gas is sucked up through B, while the atmospheric air enters to replace it at the orifice d of the bent tube. The NEW methods which pervade the whole treatise of Drs. F resenius and Will are all based on the principle of estimating alkalinity, acidity, and the oxygen in manganese (or chlorometry) by the weight of carbonic acid gas evolved. As in tcking these measures the gas must be discharged without carrying water off with it, an elegant and ingenious little piece of apparatus has been invented by the authors for effecting that purpose, and it will do it well. A and B (fig. 10) are two flasks (wide-mouthed medicine-bottles may be employed). A must have a capacity of from 2 ounces to 2'10 b ounces of water; it is advisable that B should be somewhat smaller, say of a capacity of about 1 to 11 ounces. Both flasks are closed by means of ~~d c-~ h doubly perforated corks. These perforations serve for the reception of the tubes a, c, and d. c is a tube bent twice at right angles, which enters at ~L its one end just into the flask A, but descends at its other end, near to the bottom of B. These tubes are open at both ends when operating; except the top end b of the tube a, which is closed by means of a pellet of wax. The substance to be examined is weighed and put into the flask A, into which water is then poured to the extent of one third of its capacity. B is filled with common English sulphuric acid to about half its capacity. sB / A Both flasks are then corked (by which they be. come united by the rectangular tube), and the apparatus is weihed. i \ i* /|~ j The air of the whole apparatus is next rarefied by applying suction to the tube d: the consequence is, that the sulphuric acid contained in B ascends into * The expulsion of the gas may be completed by surrounding the flask with a towel dipped in n)t Kater. 40 ALKALIMETRY. the tube c, and thus a portion of it flows over into B. Immediately upon its coming into contact with the carbonate contained in A, carbonic acid gas is disengaged, and in its escape must necessarily traverse the oil of vitriol in B, and therein deposite all its aqueous vapor before issuing from d. The sulphuric acid in passing over into A heats the mixture at the same time, and thus promotes the expulsion of the gas. Whenevei this ceases to flow, a little more sulphuric acid must be sent over into A by suctior from d (or rather from a recurved tube attached, pro tempore, to it); an artifice which may be repeated till no more gas can be expelled, even when the contents of A are heated, as they must be at the end by the excess of oil of vitriol.; From the aperture b of the tube a, which has been all the time closed, the hit of wax is now to be removed, and to the tube connected with d, suction is to be applied, till all the carbonic acid lodged in the apparatus be replaced by atmospheric air. The whole is to be then cooled, wiped, and weighed; the loss of weight indicates exactly the quantity of carbonic acid which existed in the carbonate submitted to experiment. The process is no less neat than it is simple, and does honor to the ingenuity of its inventors. Their mode of deducing the per-centage of alkali from the quantity of carbonic acid discharged in the operation is also quite exact, and suitable for con. tinental chemists familiar with gramme weights and calculations, but certainly not for persons conversant only with ounces, drams, and scruples, or even with grain subdivisions. The whole book, however excellent, needs, for te British public, transposition, before it can serve in this country the purpose inten ed by its scientific authors. Thus, in section 4, where several restults of their analyses are given, the statements have a somewhat mysterious aspect. Should any one ask why the oracular number of 4-83 grammes of carbonate of soda is used as their standard weight for analysis, he can obtain no response in the book, either in a note or anywhere else. A German or French student, familiar with chemical computation, will probably be able to discover that 4-83 grammes of pure carbonate of soda contain, by Berzelius's tables of atomic weights, 2 grammes of carbonic acid; for 53-47 (1 atom of carbonate): 22 15 (1 of carbonic acid):: 4-83: 2-00. Such is the simple solution of this apparent enigma, and of some other similar puzzles in the book. Indeed, unless the reader is aware of that proportion, he can not see the grounds of the accordance in the results between experiment and theory, or why the numbers 2'010, 1.993, and 2-020, are presented as. specimens of great precision. This accordance gives satisfaction when it is known that these numbers, in experiments 1, 2, and 3, oscillate on one side or other so near to the theoretical number 2-00. But 4 grammes and 83 centi-grammes, as also 1 gramme and 995 milli-grammes, are awkward weights for an ordinary English chemist or apothecary, which would require a month or two's residence in the laboratories of Giessen and Paris to manipulate with readiness. Again, in testing carbonate of potash, our authors take 6-29 grammes as their unity of weight, undoubtedly, because, if pure, it should discharge, by saturation with the sulphuric acid, 2 grammes of carbonic acid. Here, however, they have not stuck so rigidly as the school of Giessen usually does to Berzelius's atomic numbers; for his atom of carbonate of potash is 69-42; whence, 2215: 69-42:: 200: 668, hydrogen= 1-00; or 276-44 866-33:: 2-00: 6-268 oxygen = 100. Admitting the value of the new method in testing neutral carbonates, it can not be directly applied to the mixed carbonate and bicarbonate of soda, so commonly sold in this country for bicarbonate; nor is it applicable to the case of a mixture of caustic and carbonated alkali, without the tedious process of previous treatment with carbonate of ammonia and heat. The new German method of acidimetry consists in determining how much carbonic acid gas is disengaged from a standard bicarbonate of soda, by a given weight of any acid. The twin-flask apparatus (fig. 10) is used. The weighed portion of acid is put into A, and a sufficient quantity of the soda into a test-tube, which is suspended upright with a silk thread fastened by the pressure of the cork to the mouth of the flask. On letting the thread loose, the test-tube falls, and the cork being instantly replaced, the whole gas evolved is forced to pass through the sulphuric acid in B, and there to deposite its moisture. The experiment is conducted in other respects as already described tor alkalimetry. The following extract from Drs. Fresenius and Will's New Methods of dlkalimetry, &c., will show the Giessen plan of calculating results:"The amount of anhydrous acid contained in the hydrated acid under examination is determined from the amount of carbonic acid escaped, as follows:" Two measures of carbonic acid bear the same proportion to one measure of the anhydrous acid in question, as the amount of carbonic acid expelled does to the amount sought of anhydrous acid. Thus, let us suppose, for instance, we have examined dilute sulphuric acid, and obtained 1-5 grammes of carbonic acid, the arrangement would be: ALKALIMETRY. 41 550 (2 X 275): 501 = 1-5: x x = 1l36. The amount of sulphuric acid operated upon consequently wJuld contain 1'36 grammes of anhydrous acid. Let us suppose the weight of this amount to have been 15 grammes, the sulphuric acid under examination would contain a per-centage amount of 9'06; for 15: 1-36 = 100: x x = 9-06."* " SECTION XXIX. Stating the Quantities of the various Acids to be used in their Examination.-To enable our readers at once, without the trouble of calculation, to determine from the weight of carbonic acid expelled, the exact amount of anhydrous acid contained in those acids which are of most frequent occurrence, we have subjoined lists of certain quantities to be taken of each acid for experiment, so that the number of centi-grammes of carbonic acid expelled will directly indicate the per-centage amount of anhydrous acid in the acid under examination. "Multiples of those weights may of course be substituted for the numbers given, according to the degree of dilution of the acid under examn.;ation. In such cases the number of centi-grammes of the carbonic acid expelled must be divided by the same number, which has served as the multiplier. "These numbers are obtained by dividing the atomic weight of the acid by 550 (2 X 275, one eq. of carbon),t as follows:"Two eq. of carbonic acid, corresponding to one eq. of the acid to be exam ined, how much should be taken of the latter to expel 1'00 grammes of carbonic acid? "The arrangement of sulphuric acid, for instance, is as follows:550: 501=- 100: x x = 0-91 (or, more correctly, 0-911). " When examining acids, it is most advisable to use that multiple of the unity (ac. cording to the degree of concentration) which will expel from one to two grammes of carbonic acid. " I. SULPHURIC ACID. "Unity 0'91 grammes (or, more correctly, 0-911 grammes). "Multiples:2 X 0-911 = 1-822 grammes. 3 X 0-911 = 2-733 " 4 X 0-911 = 3-644 " 5 X 0-911 4-555 c 6 X 0911 = 5-466 " 7 X 0911 = 6-377 " 8 X 0-911 = 7-288 " 9 X 0-911 = 8-199 " 10 X 0-911 = 9-110,C 15 X 0-911 - 13-665 " 20 X 0-911 = 18-220 " 30 X 0-911 = 27-330 " &c. " Thus, knowing that 0-91 of anhydrous sulphuric acid will expel 1I00 of carbonic acid, it will be easy to determine what multiple ought to be used, according to the de. gree of concentration of the acid to be examined.": III. CHLOROMET~Y, And the testing of Black Oxide of Manganese for its available Oxygen. The value of manganese may be estimated very exactly by measuring the quantity of chlorine which a given weight of it produces with hydrochloric acid; the chlorine bcein at the same time estimated by the quantity of solution of green sulphate of iron, which it will peroxidize. A piocess of this kind was long ago practised with chloride of lime (bleaching powder or liquor) by Dr. Dalton; and it has been since improved by Mr. Waltercrum. As the conversion of two atoms of green sulphate of iron into red sulphate requires only one atom of oxygen, this change may be effected by the reaction of one atom of chlorine in liberating one atom of oxygen, while this appro. oriates one of hydrogen from the hydrochloric acid. * New Metho Is of A7kalimetry, 4c., pp. 93, 94. t A typographical error in Mr. Bullock's edition; it zhc-J'd be carbonec acid. t New Methods of Alkalimetry, 4tc., pp. 103-105. 42 ALKALIMETRY. The weight of 2 atoms of green sulphate of iron is 278 = (139 X 2), consisting of atoms of protoxide = 72, X 2 of sulphuric acid = 80. X 14 of water = 126; in all = 278 and this weight is equivalent to 36 of chlorine, to 8 of oxygen, and to 44 of peroxide of manganese.* Therefore, if we take a solution of copperas, containing 278 grains in 1,000 water grain measures, that volume of liquid will represent, by the conversion of its protoxlde into peroxide, exactly one atom, either of peroxide of manganese = 44 grains, or 1 atom of chlorine = 36. Hence the following plan of restarch:luto the flask or phial c of my chlorometric apparatus (fig. 11), put 100 grains of the manganese to be tested, and into the globes A, B, pour out of an alkalimetrical tube charged with 1,000 grain measures of the above equivalent copperas solution, from 200 to 500 grain measures, according to the supposed quality of the manganese; then introduce through the funnel d, some hydrochloric acid of known specific gravity (suppose 1'1), containing nearly 20 per cent. of chlorine, also from a charged alkalimetrical tube, and apply gentle heat to the bottom of the flask by placing it in a capsule of water standing over a spirit-lamp. The chlorine evolved will rise up through IB fI < A the tubef, which passes merely beyond the cork, and will enter into the solution in B and A, converting it into red sulphate. Have ready some dry paper imbued with solution of red ferrocyanide of potassium (red prussiate of iron). - Dip a slip of whalebone into the liquor in the globe A, through the funnel e (represented in the figure rather too high above the globe), and touch the paper with its point. As long as it forms a blue spot, some of the iron still exists as black oxide, and the process is to be urged by the addition of a little more hydrochloric acid to the manganese, ^~~11 *^.as long as chlorine gas continues to be disengaged, and while it maintains the level of the liquor in A above that in B. Whenever the liquor, by the reaction of the chlorine, ceases vy \. to stain the test-paper blue, more of the solution from the ~/ N~ graduated tube must be added till it begins to do so. By the cautious administration of the hydrochloric acid on the one hand, and of the copperas liquor on the other, the term C of saturation will be arrived at in a few minutes. The manganese has then produced all the chlorine which it can yield. The number of water grain measures, of the liquor, or degrees of its alkalimeter scale being multiplied by 44, will give a product denoting the per-centage of pure manganese present in the sample; or being multiplied by 36, a product which will denote the quantity of chlorine by weight which 100 grains of it can serve to generate. Since one atom of pure manganese (44 grains), in producing 36 grains of chlorine, consumes 2 atoms = 74 grains of hydrochloric acid, the quantity of this acid expended from the graduated tubes, beyond the due proportion of chlorine obtained, will show how much of the acid is unprofitably consumed by foreign substances in the manganese. In fact, every grain of chlorine should, with pyrolusite, be generated by an expenditure of little more than 2 grains of real muriatic acid, or 10 grains weight of the dilute acid, = about 9 grain measures of the graduated tube. Liquid hydrochloric acid of spec. grav. 1'093 contains in 1,000 grain measures exactly 200 grains of real acid. Hence 100 grains of pure pyrosulite should produce about 82 grains of chlorine, and consume about 169 of real muriatic acid= 845 grain measures of liquid acid, spec. grav. 1'093. Instead of taking 100 grains of manganese as the testing dose, 10 or 20 grains may be taken according to the dimensions of the apparatus and the exactness of the operator. But if it be wished to obtain direct per-centage of manganese by the graduated tubes without the trouble of reduction, then for a dose of 10 grains take a solution of fresh green copperas (free from adhering moisture), containing 632 grains in 10,000 grain measures. Proceed as above directed. If the manganese be a pure peroxide, 10 grains of it * Berzelius, in the 4th edition of his Lethr)urh, rates the atom of the green sulphate of iron (ferrous sulphate; at 129'43, hydrogen = ], and considers it. after Mitscherlich, to contain only 6 atoms of water. I have ascertained, by the most careful experiments, that it contains 7 atoms of water; and that 139 grains of it, or 138-44 (Berzelius) are equivalent to 1 atom of chlorbarium, and to very nearly 40 grains of peroxide of iron. This renarkable error has probably arisen from an attempt to measure the proportion of water in the salt from its loss of weight by desiccation. But I have found it impossible by this means to expel more than 6 atoms of water without causing partial decomposition of the salt by disengagement of sulphuric acid. The copperas so dried acquires such an affinity for water, that it absorbs fully one tenth of ite wveight of moisture from the atmosphere in the course of an hour. ALKALIMETRY. 43 will generate as much chlorine as will peroxidize exactly 1,000 grain measures, or 100 degrees by the test-tube of the copperas solution. But if the manganese contain only 40 or 50 per cent. of peroxide, then 40 or 50 centigrade measures of the said solution will be equivalent to the chlorine evolved fiom it by the reaction of hydrochloric acid. If the object is on the other hand to obtain direct indications as to chlorine, then a test solution of copperas, containing 772 grains in 10,000 grain measures, will serve to show, by the peroxidizement of each 10 grain measures, or of one degree of the cen testimal scale of the test-tube, the reaction of one grain of chlorine available foi bleaching, &c., in the chloride of lime or of soda, &c. The test solutions of copperas should be kept in well-corked bottles, containing a little powdered sulphuret of iron at their bottom, which is to be shaken up occasionally in order to preserve the iron in the state of protoxide. The manganese should always be treated with dilute nitric acid before submitting it to the above-described ordeal; and if it exhibits effervescence, 100 grains of it should be digested with the acid for a sufficient time to dissolve out all the carbonates present, then thrown upon a filter, washed and dried before weighing it for the testing operation. The loss of weight thereby sustained denotes the per-centage of carbonates, and if calcareous it will measure the waste of acid that would ensue from that source alone, in using that manganese for the production of chlorine. That manganese is most chlorogenous which contains no carbonates, the least proportion of oxide of iron, and of sesquioxide of manganese. The plan of testing manganese with oxalic and sulphuric t cids was originally practised by M. Berthier and Dr. Thomson, but is lately modified by Drs. Fresenius and Will, who employ oxalate of potash, as likely to afford more exact results. Thev prescribe a multiple by 3 of 993 milli-grammes = 2'979 grammes, as the quantity of manganese best adapted to experiment; but this quantity will not be found convenient by ordinary British operators. I, therefore, take leave to prescribe the following proportions: Into the vessel A of my twin-globe apparatus (fig. 8), put 100 grains of the ground manganese under trial, along with 250 grains of oxalate of potash and a little water; poise the whole in the scale of a balance; then, by gentle inclination, cause a little of the strong sulphuric acid to pass from B up into A. The oxygen thereby liberated from the manganese, reacting in its nascent state upon the oxalic acid, will convert it into carbonic acid gas; which, in passing through B, will deposite its moisture before escaping into the air. Whenever the extrication of gas ceases, after such a quantity of oil of vitriol has been introduced into the globe A, as both to complete the decomposition of the oxalic acid and to heat the mixture, withdraw the cork for a moment, to replace the'carbonic acid with air, then cool, and weigh the apparatus. The loss of weight, in grains, will denote the per-centage value of the manganese; that is, the proportion per cent. of perfect peroxide in the sample. If the manganese be pure no black powder should remain. The preceding experiment is founded upon the following principle: One atom of peroxide of manganese = 44, contains one atom of oxygen separable by sulphuric acid, and capable of converting one atom of oxalic acid into two atoms of carbonic acid, also =-44, which fly off; and cause therefore a loss of weight equal to that of the. whole peroxide. To one atom of oxalic acid, which consists of three atoms of oxygen, and two of carbon-if one atom of oxygen be added, the sum is obviously four atoms of oxygen and two of carbon = 2 atoms of carbonic acid. The apparatus (fig. 10) of Drs. Fresenius and Will will answer perfectly well for making the same experiment, the manganese being put into A, with about two and a half times its weight of oxalate of potash, and the sulphuric acid being drawn over into the mixture by suctinn, as above described. The economy of any sample of manganese in reference to its consumption of acid, in generating a given quantity of chlorine, may be ascertained also by the oxalic acid test: 44 grains of the pure peroxide, with 93 grains of neutral oxalate of potash, and 98 of oil of vitriol disengage 44 grains of carbonic acid, and afford a complete neutral solution; because the one half of the sulphuric acid, = 49 grains, goes to forrm an atom of sulphate of manganese, and the other half to form an atom of sulphate of potash. The deficiency in the weight of carbonic acid thrown off will show the deficiency of peroxide of manganese; the quantity of free sulphuric acid may be measured by a test solution of bicarbonate of potash, and the quantity neutralized, compared to the car bonic gas produced, will show, by the ratio of 98 to 44, the amour.t of acid unprofitablJ consumed. 44 ALKALIMETRY. In fig. 6, the tube, D, may also be graduated, and may contain the quantity of acid, for the purpose either ~f alkalimetry or acidimetry: and if the lower orifice be capillary, it will allow none of its contents to flow out, tl1 the st. pcock in the top orifice is opened. In fig. 7, such a tube as r (fig. 6, may be substituted with advantage fol the funnel, B; and as that tube, D, may be made of such dimensions as to contain'enough of acid to supersaturate the bases of the carbonates in the phial, A, there will be no necessity for a separate vessel to hold the decomposing acid. Thus the apparatus becomes very light, convenient, and may be placed in the small scale of a fine balance; whereas the twin matrasses of Drs. Fresenius and Will (fig. 10), as furnished by Mr. Bullock, require a very large pan or scale to stand in. I flatter myself that the instrument,fig. 7, so mounted, will be found an acceptable present to practical chemists, and that it will enable them readily to examine, not only carbonates, but also manganese and bleaching substances, with great precision, by the weight of carbonic acid gas disengaged, on the principles above explained. Into the twin globe apparatus (fig. 8), after the sulphuric acid is poured into B, a little waLer should be poured into c, before the carbonate is introduced into the latter. By this means, the capillary throat of the tube under A will not be apt to get choked with concrete salt. The following quotations are from -the work of Drs. Fresenius and Will, as edited by Mr. Bullock for the English reader. An accurate comparison may thus be made between the relative utility of their methods and mine to the practice of ordinary operators:" SECTION XXXIV. Examination of Manganese: having at the same time due regard to the amount of Acid required for its complete Decomposition.-We have stated, at Section 30, that it is not a matter of indifference, with regard to the amount of acid employed in the production of chlorine from manganese, what are the minerals which this substance contains in admixture with the peroxide. The following modification of our method will give the most correct information on this point:"Sulphuric acid of commerce is taken, and its amount of anhydrous acid deter. mined, as directed at Section 26, or by means of an accurate hydrometer. Of this sulphuric acid as much is weighed into A (fig. 10), as to give an amount of 5'47 grammes of anhydrous acid. "The following table will show the amount which ought to be taken, acoording tc the various degree of concentration of the acid:Per-centage Amount to Per-centage Amount to Specific weight amount of be used for Specific weight amount of be used for found. anhydrous the exami- found. anhydrous the examiacid found. nation. acid found. nation. 1-8485 81-54 6-708 1-8336 76-65 7-136 1-8480 81-13 6-742 1-8313 76-24 7-174 1-8475 80-72 6-776 1-8290 75-83 7-213 1-8467 80-31 6-811 1-8261 75-42 7-252 1-8460 79-90 6-846 1-8233 75-02 7-291 1-8449 79-49 6-881 1 8206 74 61 7-331 1-8439 79-09 6-916 1-8179 74-20 7-371 1 8424 78-68 6-951 1-8147 73-79 7-412 1-8410 78-28 6-987 1-8115 73-39 7-453 1-8393 77-84 7-027 1-8079 72-97 7-495 1-8376 77-40 7-067 1-8043 7 57 7-537 1-8356 77-02 7-101' As much water is then poured into A as will fill the flask to about one fourth; and, lastly, from 6-5 to 7 grammes of neutral oxalate of potash, or from 5'5 to 6 grammes of neutral oxalate of soda, are added; 2-98 grammes of the (finely-pounded) manganese to be examined are then weighed (the manganese must have been previously tested for carbonate alkaline earths: compare this section at the end) into a small glass tube, such as used in acidimetry, and described in Section 25. About the same quantity of pure pyrolusite,* in powder, is then put into another similar tube. The tube, with the manganese to be examined, is then suspended in A (fig. 10), as described at Section 26, and the apparatus prepared, as directed at Section 3. The * " Any variety of pyrolusite will serve this purpose, provided it be free from other manganese ores. if it contains heavy spar, it may be employed directly; but should it contain alumina oi lime, it must be treated first with dilute nitric acid, at a gentle heat, until all soluble parts have been dissolved; ft is then washed and dried. Artificially prepared, hydrated peroxide of manganese may be sv'stitutt-d for pyrolusite." ALKALIMETRY. 45 apparatus is then placed on one scale of a balance, together with the other little tube containing the pyrosulite, and exactly weighed. "The cork of A is then somewhat raised to allow the little tube with the manganese to fall into the flask. The evolution of carbonic acid commences immediately, and continues until all the manganese is decomposed. When the operation begins to get on mote slowly, the flask, A, is placed in boiling water, and allowed to remain there until no more bubbles appear. The little wax-stopper is then removed* from a, the lask, A, taken out of the hot water, and suction applied to d, until the sucked air tastes no longer of carbonic acid. The apparatus, after having been allowed to cool, is wiped dry, and replaced in the original scale, where the little tube with the pyrolusite still remains; weights are then substituted for the loss of carbonic acid. The number of centigrammes required, divided by three, directly indicates the per-centage amount of peroxide of manganese (vide Section 32). The centigrammes substituted for the loss of carbonic acid are then removed from the balance, and the little tube with the pyrosulite is thrown into A. (The little wax-stopper must of course previously be replaced on a). If no fresh evolution of carbonic acid takes place, the manganese examined consists of pure pyrosulite, and the experiment is at an end. But should a fresh evolution of carbonic acil take place, the operation must be further conducted, and brought to a close, exactly as just stated (vide suprd). The apparatus is then replaced on the balance, with an additional weight of three grammes on the same scale. If this is sufficient to restore a perfect equilibrium, no loss of acid has taken place; the manganese, indeed, contains other matters in admixture, but only such as do not consume any acid. But if the scale with the apparatus sinks, this is a certain sign that a portion of the acid has been lost by combining with the oxides which the manganese under examination contains. The number of centigrammes required to restore the perfect equilibrium of the balance, multiplied by 0'6114, immediately indicates how much anhydrous sulphuric acid has been wasted in the decomposition of 100 parts of the manganese under examination. The same number, multiplied by )-333, indicates the amount of acid wasted in every 100 parts of sulphuric acid employed for the decomposition of the manganese in question. The same number, multiplied by 0*5552, indicate how much anhydrous hydrochloric acid would be wasted in the decomposition of 100 parts of the manganese. The same number, multiplied by 0'333, indicates also how much acid would be wasted in every 100 parts of hydrochloric acid employed for the decomposition of the manganese. "These figures result from the following equations:"I. 275 (eq. of carbonic acid): 501 (eq. of sulphuric acid) ==the carbonic acid obtained minus (in proportion to the sulphuric acid used): x. x=this carbonic acid X 591, i. e. X 1-822. Thus, the number obtained for x indicates the amount of sulphuric acid corresponding to the amount of carbonic acid obtained minus. "II. 2 98 of manganese: 100=x of equation I.: x. x=x of I. X o i. e. X 0-33557. "The x of the first equation tells us how much sulphuric acid has been wasted without contributing to the decomposition of 2-98 grammes of the manganese; the x of the second equation tells us the same for 100 parts of manganese. "If, therefore, the amount of carbonic acid obtained minus be directly multiplied by the product of the quotients of I. and II., 1-822 and 0-33557, i. e. with 0-61141 (the number given above), the amount of anhydrous sulphuric acid wasted in the decomposition of every 100 parts of manganese will immediately be found. " III. 5-47 (the amount of sulphuric acid used): 100=the x of I.: x. x=the x of I. X 1 o i. e. X 0-18282. "Of 5-47 of sulphuric acid, the x of I. has been wasted, 100 corresponds to the x of TI [. "The x of III. is, therefore, found directly by multiplying the amount of carbonic acid obtained minus with the product of the quotients, 1'822 and 0'18282, i. e.= 0-33301. "The figures for hydrochloric acid are found in the same manner (4'967 of hydro, chloric acid must be taken instead of 5-47 of the sulphuric acid)."t *" This must of necessity be done while the flask is still standing in the hot water, or else the sul. phuric acid will recede upon the apparatus being removed from the hot water." t New Moehods of Alkalimetry, and of determining the Commercial Value of Acids and Manganese By Drs. C. R. Fresenius and H Will. Edited by J Lloyd Bullock: pp. 123-128. 46 ALLOY. ALKANA, is the name of the root and leaves of Lausania inermis, which have been long employed in the East, to dye the nails, teeth, hair, garments, &c. The leaves, ground and mixed with a little limewater, serve for dyeing the tails of horses in Persia and Turkey. ALKANET, the root of. (.dnchusa tinctoria.) A species of bugloss, cultivated chiefly in the neighborhood of Montpellier. It affords a fine red color to alcohol and oils; but a dirty red to water. Its principal use is for coloring ointments, cheeses, and pommades. The spirituous tincture gives to white marble a beautiful deep stain. ALLIGATION. An arithmetical formula, "useful, on many occasions, for ascertaining the proportion of constituents in a mixture, when they have undergone no change of volume by chemical action. When alcoholic'iquors are mixed with water, there is a condensation of bulk, which renders that arithmetical rule inapplicable. The same thing holds, in some measure, in the union of metals by fusion. See ALLOY. ALLOY. (Alliage, Fr.; Legirung, Germ.) This term formerly signified a ccmpound of gold and silver, with some metal of inferior value, but now means any compound of any two or more metals whatever. Thus, bronze is an alloy of copper and tin; brass, an alloy of copper and zinc; and type metal, an alloy of lead and antimony. All the alloys possess metallic lustre, even when cut or broken to pieces; they are opaque; are excellent conductors of heat and electricity; are frequently susceptible of crystallizing; are more or less ductile, malleable, elastic, and sonorous. An alloy which consists of metals differently fusible is usually malleable in the cold, and brittle when hot, as is exemplified with brass and gong metal. Many alloys consist of definite or equivalent proportions of the simple component metals, though some alloys seem to form in any proportion, like combinations of salt or sugar with water. It is probable that peculiar properties belong to the equivalent or atomic ratio, as is exemplified in the superioi quality of brass made in that proportion. One metal does not alloy indifferently with every other metal, but it is governed in this respect by peculiar affinities; thus, silver will hardly unite with iron, but it combines readily with gold, copper, and lead. In comparing the alloys with their constituent metals, the following differences may be noted; in general, the ductility of the alloy is less than that of the separate metals, and sometimes in a very remarkable degree; on the contrary, the alloy is usually harder than the mean hardness of its constituents. The mercurial alloys or amalgams are, perhaps, exceptions to this rule. The specific gravity is rarely the mean between that of each of its constituents, but is sometimes greater and sometimes less, indicating, in the former case, an approximation, and in the latter, a recedure, of the particles from each other in the act of their union. The following tables of binary alloys exhibit this circumstance in experimental detail:Alloys having a density greater than the Alloys having a density less than the mean of their constituent3. mean of their constituents. Gold and zinc Gold and silver Gold and tin Gold and iron Gold and bismuth Gold and lead Gold and antimon Gold and copper Gold and cobalt Gold and iridium Silver and zinc Gold and nickel Silver and lead Silver and copper Silver and tin Silver and lead Silver and bismuth Iron and bismuth Silver and antimony Iron and antimony Copper and zinc Iron and lead Copper and tin Tin and lead Copper and palladium Tin and palladium Copper and bismuth Tin and antimony Lead and antimony Nickel and arsenic Platinum and molybdinum Zinc and antimony. Palladium and bismuth. It would he hardly possible to infer the melting point of an alloy from that of each of tls constituent metals; but, in genera, the fusibility is increased by mutual affinity in their state of combination. Of this, a remarkable instance is afforded in the fusible metal consisting of 8 parts of bismuth, 5 of lead, and 3 of tin, which melts at the heat of boiling water, or 212~ Fahr., though the melting point deduced from the mean of its components should be 514~. This alloy may be rendered still more fusible by adding a very little mercury to it, when it forms an excellent material for certain anatomical inlections, and for filling the hollows of carious teeth. Nor do the colors of alloys depend,,n any considerable degree, upon those of the separate metals; thus, the color uf copper, ALLOY. 47 instead of being rendered paler by a large addition of zii;s thereby con erted into the rich-looking pinchbeck metal. By means of alloys, we multiply, as it were, the numbers of useful metals, and sometimes give usefulness to such as are separately of little value. Since these compounds can be formed only by fusion, and since many metals are apt to oxydize readily at their melting temperature, proper precautions must be taken in making alloys to prevent this occurrence, which is incompatible with their formation. Thus, in combining tin and lead, rosin or grease is usually put on the surface of the melting metals, the carbon produced by the decomposition of which protects them, in most cases, sufficiently from oxydizement. When we wish to combine tin with iron, as in the tinning of cast-iron tea kettles, we rub sal ammoniac upon the surfaces of the hot metals in contact with each other, and thus exclude the atmospheric oxygen by means of its fumes. When there is a notable difference in the specific gravities of the metals which we wish to combine, we often find great difficulties in obtaining homogeneous alloys; for each metal may tend to assume the level due to its density, as is remarkably exemplified in alloys of gold and silver made without adequate stirring of the melting metals. If the mass be large, and slow of cooling, after it is cast in an upright cylindrical form, the metals sometimes separate, to a certain degree, in the order of their densities. Thus, in casting large bells and cannon s with copper alloys, the bottom of the casting is apt to contain too much copper and the top too milch tin, unless very dexterous manipulation in mixing the fused materials have been employed immediately before the instant of pouring out the melted mass. When such inequalities are observed, the objects are broken and re-melted, after which they form a much more homogeneous alloy. This artifice of a double melting is often had recourse to, and especially in casting the alloys for the specula of telescopes. When we wish to alloy three or more metals, we often experience difficulties, either because one of the metals is more oxydable, or denser, or more fusible, than the others, or because there is no direct affinity between two of the metals. In the latter predicament, we shall succeed better by combining the three metals, first in pairs, for example, and then melting the two pairs together. Thus, it is difficult to unite iron with bronze directly; but if, instead of iron, we use tin plate, we shall immediately succeed, and the bronze, in this manner, acquires valuable qualities from the iron. Thus, also, to render brass better adapted for certain purposes, a small quantity of lead ought to be added to it, but this cannot be done directly with advantage: it is better to melt the h ad first along with the zinc, and then to add this alloy to the melting copper, or the copper to that alloy, and fuse them together. We have said that the difference of fusibility was often an obstacle to metallic combination; but this circumstance may also be turned to advantage in decomposing certain alloys by the process called eliquation. By this means silver may be separated from copper, if a considerable quantity of lead be first alloyed with the said copper; this alloy is next exposed to a heat just sufficient to melt the lead, which then sweats out, so to speak, from the pores of the copper, and carries along with it the greater part of the silver, for which it has a strong affinity. The lead and the silver are afterwards separated from each other, in virtuZ of their very different oxydability, by the action of heat and air. One of the alloys most useful to. the arts is brass; it is more ductile and less easily oxydized than even its copper constituent, notwithstanding the opposite nature of the zinc. This alloy may exist in many different proportions, under which it has different names, as tombac, similor, pinchbeck, &c. Copper and tin form, also, a compound of remarkable utility, known under the names of hard brass, for the bushes, steps, and bearings of the axles, arbors, and spindles in machinery; and of bronze, bell-metal, &c. Gold and silver, in their pure state, are too soft and flexible to form either vessels or coins of suff:ient strength and durability; but when alloyed with a little copper, they acquire the requisite hardness and stiffness for these and other purposes. When we have occasion to unite several pieces of the same or of different metals, we employ the process called soldering, which consists in fixing together the surfaces by means of an interposed alloy, which must be necessarily more fusible than the metal or metals to be joined. That alloy must also consist of metals which possess a strong affinity for the substances to be soldered together. Hence each metal would seem to require a particular kind of solder, which is, to a certain extent, true. Thus, the solder for gold trinkets and plate is an alloy of gold and silver, or gold and copper; that of silver trinkets, is an alloy of silver and copper; that of copper is either fine tin, for pieces that must not be exposed to the fire, or a brassy alloy called hard solder, of which the zinc forms a considerable proportion. The solder of lead and tinplate is an alloy of lead and tin, and that of tin is the same alfby with a little bismuth. Tinning, gilding, and silvering may also be reckoned a species of alloys, since the tin, gold, and silver are superficially united in these cases to other metals. Metallic alloys possess usually more tenacity than could be inferred from their con 48 ALLOY. stituents; thus, an alloy of twelve parts of lead with one of zinc has a tenacity double tnat of zinc. Metallic alloys are much more easily oxydized than the separate metals, a phenomenon which may be ascribed to the increase of affinity for oxygen which results from the tendency of the one of the oxydes to combine with the other. An alloy of tin and lead heated to redness takes fire, and continues to burn for some time like a niece of bad turf. Every alloy is, in reference to the arts and manufactures, a new metal, on account of its chemical and physical properties. A vast field here remains to be explored. Not above sixty alloys have been studied by the chemists out of many hundred which may be made; and of these very few have yet been practically employed. Very slight modifications often constitute very valuable improvements upon metallic bodies. Thus, the brass most esteemed by turners at the lathe contains from two to three per cent. of lead; but such brass does not work well under the hammer; and, reciprocally, the brass which is best under the hammer is too tough for turning. That metallic alloys tend to be formed in definite proportions of their constituents is clear from the circumstance that the native gold of the auriferous sands is an alloy with silver, in the ratios of 1 atom of silver united to 4, 5, 6, 12 atoms of gold, but never with a fractional part of an atom. Also, in making an amalgam of 1 part of silver with 12 or 15 of mercury, and afterwards squeezing the mixture through chamois leather, the amalgam separates into 2 parts: one, containing a small proportion of silver and much mercury, passes through the skin; and the other, formed of 1 of silver and 8 of mercury, is a compound in definite proportions, which crystallizes readily, and remains in the knot of the bag. An analogous separation takes place in the tinning of mirrors; for on loading them with the weights, a liquid amalgam of tin is squeezed out, while another amalgam remains in a solid form composed of tin and mercury in uniform atomic proportions. But, as alloys are generally soluble, so to speak, in each other, this definiteness of combination is masked and disappears in most cases. NM. Chaudet has made some experiments on the means of detecting the metals of alloys by the cupelling furnace, and they promise useful applications. The testing depends upon the appearances exhibited by the metals and their alloys when heated on a cupel. Pure tin, when heated this way, fuses, becomes of a grayish black color, fumes a little, exhibits incandescent points on its surface, and leaves an oxyde, which, when withdrawn from the fire, is at first lemon-yellow, but when cold, white. Antimony melts, preserves its brilliancy, fumes, and leaves the vessel colored lemon-yellow when hot, but colorless when cold, except a few spots of a rose tint. Zinc burns brilliantly, forming a cone of oxyde; and the oxyde, much increased in volume, is, when hot, greenish, but when cold, perfectly white. Bismuth fumes, becomes covered with a coat of melted oxyde, part of which sublimes, and the rest enters the pores of the cupel; when cold, the cupel is of a fine yellow color, with spots of a greenish hue. Lead resembles bismuth very much; the cold cupel is of a lemon-yellow color. Copper melts, and becomes covered with a coat of black oxyde; sometimes spots of a rose tint remain on the cupel. Alloys.-Tin 75, antimony 25, melt, become covered with a coat of black oxyde, have very few incandescent points; when cold, the oxyde is nearly black, in consequence of the action of the antimony: a 4o- part of antimony may be ascertained in this way in the alloy. An alloy of antimony, containing tin, leaves oxyde of tin in the cupel: a To part of tin may be detected in this way. An alloy of tin and zinc gives an oxyde which, while hot, is of a green tint, and resembles philosophic wool in appearance. An alloy containing 99 tin, 1 zinc, did not present the incandescent points of pure tin, and gave an oxyde of greenish tint when cold. Tin 95, bismuth 5 parts., gave an oxyde of a gray color. Tin and lead give an oxyde of a rusty brown color. An alloy of lead and tin, containing only 1 per cent. of the latter metal, when heated, does not expose a clean surface, like lead, but is covered at times with oxyde of tin. Tin 75, and copper 25, did not melt, gave a black oxyde: if the heat be much elevated, the under part of the oxyde is white, and is oxyde of tin; the upper is black, and comes from the copper The cupel becomes of a rose color. If the tin be impure from iron, the oxyde produced by it is marked with spots of a rust color. The degree of affinity between metals may be in some measure estimated by the greater or less facility with which, when of different degrees of fusibility or volatility, they unite, or with which they can, after union, be separated by heat. The greater or less tendency to separate into differently proportioned alloys, by long-continued fuslon, may also give some information upon the subject. Mr. Hatchett remarked, in his elaborate researches on metallic alloys, that gold made standard with the usual precaul tions, by silver, copper, lead, antimony, &c., and then cast, after long fusion, into verticabars, was by no means a uniform compound; "but that the top of the bar, corresponding LO the metal at the bottom of the crucible, contained the larger proportion of gold. Hence, for a more thorough combination, two red-hot crucibles should be employed, and the liquefied metals should be alternately poured from the one into the other. To pre ALLOY. 49 vent unnecessary oxidisement from the air, the crucibles should contain, besides the metal, a mixture of common salt and pounded charcoal. The metallic alloy should also be occasionally stirred up with a rod of pottery ware. The most direct evidence o' a, chemical change having been effected in alloys is; when the compound melts at a lower temperature than the mean of its ingredients. Iron, which is nearly infusible, acquires almost the fusibility of gold when alloyed with this precious metal. The analogy is here strong with the increase of solubility which salts acquire by mixture, as is exemplified in the difficulty of crystallizing residuums of saline solutions, or mother waters, as they are called. VWhen there is a strong affinity between the two metals, their alloy is generally denser than the mean, and vice versd. This is exemplified in the alloys of copper with zinc and tin on the one hand; and with copper and lead on the other. When one of the metals is added in excess, there result an atomic compound and an indefinite combination, as would appear from Musohenbroek's experiments. Thus, 1 of lead with 4 of silver give a density of 10'480. 1 do 2 do 11-032. do 3 do 10-831. The proportion of the constituents is on this principle estimated in France by the test of the ball applied to pewter; in which the weight of the alloyed ball is compared with that of a ball of pure tin or standard pewter cast in the same mould. Alloys possess the elasticity belonging to the mean of their constituents, and also the specific caloric. According to M. Rudberg, while lead solidifies at 325~ C., and tin at 228~, andt their atomic alloy at 187~, which he calls the fixed point, for, compound Pb Spa. The action of the air is in general less on alloys than on their components; to which, however, there are remarkable exceptions, as for example, with the alloy of 3 parts of lead and 1 of tin, which when heated to redness burns briskly into a red oxide. When two metals, as copper and tin, are combined, which oxidize at different temperatures, they may be separated by fusion with exposure to the air, an artifice practised on the church bells in France to procure tin for making cannon metal bronze. Cupellation of the precious metals is a like phenomenon. An alloy too slowly cooled is often apt to favor the crystallization of one or more of its components, and thus to render it brittle; and hence an iron mould is preferable to one of sand when there is danger of such a result. It is not a matter of indifference in what order the metals are melted together in making an alloy. Thus, if we combine 90 parts of tin and 10 of copper, and to this alloy add 10 of antimony; or if we combine 10 parts of antimony with 10 of copper, and add to that alloy 90 parts of tin, we shall have two alloys chemically the same; and still it will be easy to discover that, in other respects, fusibility, tenacity, &c., they totally differl. Whence this result? Obviously fi om the nature of their combination, dependent upon the order pursued in the preparation, and which continues after the mixture. In the alloys of lead and antimony also, if the heat be raised in combining the two metals together much above their fusing points, the alloy becomes harsh and brittle; probably because some alloy formed at that high temperature is not soluble in the mass. In common cases the specific gravity affords a good criterion whereby to judge of the proportion of two metals in an alloy. But a very fallacious rule has been given in some respectable works for computing the specific gravity that should result from the alloying of given quantities of two metals of known densities, supposing no chemical condensation or expansion of volume to take place. Thus, it has been taught, that if gold and copper be united in equal weights, the computed specific gravity is merely the arithmetical mean between the numbers denoting the two specific gravities. Whereas the specific gravity of any alloy must be computed by dividing the sum of the two weights by the:umr of the two volumes, compared, for convenience sake, to water reckoned unity. Or, in another form, the rule may be stated thus:-Multiply the sum of the weights into the products of the two specific-gravity numbers for a numerator; and multiply each specific gravity-number into the weight of the other body, and add the two products together for a denominator. The quotient obtained by dividing the said numerator by the denominator, is the truly computed mean specific gravity of the alloy. On comparing with that density, the density found by experiment, we shall see whether expansion or condensation of volume has attended the metallic combination. Gold having a specific gravity of 19'36, and copper of 8-87, when they are alloyed in equal weights, give, by the fallacious rule of the arithmetical mean of the densities 936 - = 14-11; whereas the rightly computed mean density is only 12'16. It is evident that, on com. paring the first result with experiment, we should be led to infer that there had been a prodigious condensation of volume, though expansion has actually taken place. Let 5 6bC ALUM. W, w be the two weights; P, p the two specific gravities, then M, the mean speeific gravity, is given by the formula M (W —w) Pp. 2 - - (P —)2= twice Pw+pW P -- p the error of the arithmetical mean; which is therefore always in excess. Alloys of a somewhat complex character are made by AIr. Alexander Parkes, of Birmingham, of a white or pale color, by melting together 331 lbs. of foreign zinc, 64 of tin, 14 of iron, and 3 of copper; or 50 zinc, 48 tin, 1 iron, and 3 copper; or any intermediate proportion of zinc and copper may be used. The iron and copper are first melted together in a crucible, the tin is next introduced, in such quantities at a limn as not to solidify the iron and copper; the zinc is added lastly, and the whole mixed by stirring. The flux recommended for this alloy is 1 part of lime, 1 part of Cumberland (iron?) ore, and 3 parts of sal ammoniac. Another of his alloys is composed of 66 lbs. of foreign zinc, 336 tin, 34 antimony; or 701 zinc, 192 tin, and 21 antimony; or any intermediate proportions, and with or without arsenic. He uses black flux. When to be applied to the sheathing of ships, from 8 to 16 oz. of metallic arsenic are added to every 100 lbs. of alloy. A third class of alloys consists of equal parts of iron and nickel; the cokter is next added, and lastly the zinc, or the copper and zinc, may be added as an alloy. 100 lbs. may consist of 456 lbs. of iron and nickel (partes cequales), and 104 lbs. of foreign zinc; or 303 lbs. of alloy of iron and nickel (p. e.), 46 copper, and 264 zinc; or any intermediate propor. tions of zinc and copper. He uses also an alloy of 60 lbs. of copper, 20 of zinc, and 20 of silver; or 60 copper, 10 nickel, 10 silver, and 20 zinc; the copper and nickel being first fused together. His fifth alloy is called by him a non-conductor of heat! It is made of 25 nickel, 25 iron, and 50 copper; or 15 nickel, 25 iron, and 60 copper; the last being added after the fusion of the others. Mr. Parkes also proposes to deposit metals by means of electricity from their iodides, chlorides, and phosphates, while in fusion by heat, either singly or combined with compatible haloids. ALMOND. (Amande, Fr.; Handel, Germ.) There are two kinds of almond which do not differ in chemical composition, only that the bitter, by a curious chemical reaction of its constituents, generates in the act of distillation a'quantity of a volatile oil, which contains hydrocyanic acid. Vogel obtained from bitter almonds 8-5 per cent. of husks. After pounding the kernels, and heating them to coagulate the albumen, he procured, by expression, 28 parts of an unctuous oil, which did not contain the smallest particle of hydroevanic acid. The whole of the oil could not be extracted in this way. The expressed mass, treated with boiling water, afforded sugar and gum, and, in consequence of the heat, some of that acid. The sugar constitutes 6'5 per cent. and the gum 3.. The vegetable albumen extracted, by means of caustic potash, amounted to 30 parts: the vegetable fibre to only 5. The poisonous aromatic oil, according to Robi quet and Boutron-Charlard, does not exist ready-formed in the bitter almond, but seems to be produced under the influence of ebullition with water. These chemists have shown that bitter almonds deprived of their unctuous oil by the press, when treated first by alcohol, and then by water, afford to neither of these liquids any volatile oil. But alcohol dissolves out a peculiar wlite crystalline body, without smell, of a sweetish taste at first, and afterwards bitter, to which they gave the name of amnygdaline. This substance does not seem convertible into volatile oil. See AMIYGDALINE. Sweet almonds, by the analysis of Boullay, consist of 54 parts of the bland almond oil, 6 of uncrystallizable sugar, 3 of gum, 24 of vegetable albumen, 24 of woody fibre, 5 of husks, 3'5 of water, 0'5 of acetic acid including loss. We thus see that sweet almonds contain nearly twice as much oil as bitter almonds do. ALMOND OIL. A bland fixed oil, obtained usually fiom bitter almonds by the action of a hydraulic press, either in the cold, or aided by hot iron plates. See OIL. ALOE. A series of trials has been made within a few years at- Paris to ascertain the comparative strength of cables made of hemp and of the aloe from Algiers; and they are said to have all turned to the advantage of the aloe. Of cables of equal size, that made of aloe raised a weight of 2000 kilogrammes (2 tons nearly); that made of hemp, a weight of only 400 kilogrammes. At the exposition of objects of national industry, some years ago, in Brussels, I saw aloe cordage placarded, as being far preferable to hempen; but I believe without just grounds. ALUDEL. A pear-shaped vessel open at each end, of which a series are joined for distilling mercury in Spain. See MERCURY. ALUM. (Almn, Fr.; Alaum, Germ.) A saline body, consisting of the earth of clay, called alumina by the chemists, combined with sulphuric acid and potash, or sulphuric acid and ammonia, into a triple compound. It occurs in the crystallized form of cetahedrons, has an acerb subacid taste, and reddens the blue color of litmus or red cabbage ALUM. 51 Alum works existed many centuries ago at Roccha, formerly called Edessa, in Syria, rhence the ancient name of Roch alum given to this salt. It was afterwards made at Foya Nova, neat Smyrna, and in the neighborhood of Constantinople. The Genoese,.ind other trading people of Italy, imported alum from these places into western Europe, for the use of the dyers of red cloth. About the middle of the fifteenth century, alum began to be manufactured at La Tolfa, Viterbo, and Volaterra, in Italy; after which time the importation of oriental alum was prohibited by the pope, as detrimental to the interests of hib dominions. The manufacture of this salt was extended to Germany at the beginning of the sixteenth century, and to England at a somewhat later period, by Sir Thomas Chaloner, in the reign of Elizabeth. In its pure state, it does not seem to have been known to the ancients; for Pliny, in speaking of something like plumose alum, says, that it struck a black color with pomegranate juice, which shows that the green vitriol was not separated from it. The stypteria of Dioscorides, and the alumen of Pliny, comprehended, apparently, a variety of saline substances, of which sulphate of iron, as well as alumina, was probably a constituent part. Pliny, indeed, says, that a substance called in Greek'Yypa, or watery, probably from its very soluble nature, which was milk-white, was used for dyeing wool of bright colors. This may have been the mountain butter of the German mineralogists, which is a native sulphate of alumina, of a soft texture, waxy lustre, and unctuous to the touch. The only alum manufactories now worked in Great Britain, are those of Whitby, in England, and of Hurlett and Campsie, near Glasgow, in Scotland; ana these derive the acid and earthy constituents of the salt from a mineral called alum slate. This mineral has a blueish or greenisi black color, emits sulphurous fumes when heated, and acquires thereby an aluminous taste. The alum manufactured in Great Britain contains po;ash as its alkaline constituent; that made in France contains, commonly, ammonia, either alone, or with variable quantities of potash. Alum may in general be examined by water of ammonia, which separates from its watery solutions its earthy basis, in the form of a light flocculent precipitate. If the solution be dilute, this precipitate will float long as an opalescent cloud. If we dissolve alum in 20 parts of water, and drop this solution slowly into water or caustic ammonia till this be nearly, but not entirely, saturated, a bulky white precipitate will fall down, which, when properly washed with water, is pure aluminous earth or clay, and dried forms 10-82 per cent. of the weight of the alum. If this earth, while still moist, be dissolved in dilute sulphuric acid, it will constitute, when as neutral as possible, the sulphate of alumina, which requires only two parts of cold water for its solution. If we now decompose this solution, by pouring into it water of ammonia, there appears an insoluble white powder, which is subsulphate of alumina, or basic alum; and contains three times as much earth as exists in the neutral sulphate. If, however, we pour into the solution of the neutral sulphate of alumina a solution of sulphate of potash, a white powder will fall if the solutions be concentrated, which is true alum; but if the solutions be dilute, by evaporating their mixture, and cooling it, crystals of alum will be obtained. When newly precipitated alumina is boiled in a solution of alum, a portion of the ewith enters into combination with the salt, constituting an insoluble compound, which falls in the form of a white powder. The same combination takes place if we decompose a boiling hot solution of alum with a solution of potash, till the mixture appears nearly neutral by litmus paper. This insoluble or basic alum exists native in the alum-stone of Tolia. near Civita Vecchia, and it consists in 100 parts of 19'72 parts of sulphate of potash, 61-99 basic sulphate of alumina, and 18-29 water. When this mineral is treated with a due quantity of sulphuric acid, it dissolves, and is converted into the crystallizable alum of commerce. These experimental facts develop the principles of the manufacture of alum, which is prosecuted under various modifications, for its important uses in the arts. Alum seldom occurs ready-formed in nature; occasionaliy, as an efflorescence on stones, and in certain mineral waters in the East Indies. Th n alum of European commerce is fabricated artificially, either from the alum schists or stones, or from clay. The mode of manufacture differs according to the nature of these earthy compounds. Some of them, such as the alum-stone, contain all the elements of the salt, but mixed with other matters from wllich it must be freed. The schists contain only the elements of two of the constituents, namely, clay and sulphur, which are convertible into sulphate of alumina, and this may be then made into alum by adding the alkaline ingredient. To this class belong the alun-slates, and other analogous schists, containing brown coal. 1. lanufacture of Jllum from the dllum Stone.-The alum-stone is a rare mineral, being found in moderate quantity at Tolfa, and in larger in Hungary, at Bereghszasz, and Muszag, where it forms entire beds in a hard substance, partly characterized by numerous cavities, containing drusy crystallizations of alum-stone or basic alum. The larger tumDS contain more or fewer flints disseminated through them, and are, according tc 52 ALUM.'heir quality, either picked out to make alum, or are thrown away. The sorted pieces are roasted or calcined, by which operation apparently the hydrate of alumina, associated with the sulphate of alumina, loses its water, and, as burnt clay, loses its affinity fox alum. It becomes, therefore, free; and during the subsequent exposure to the weather the stone gets disintegrated, and the alum becomes soluble in water. The calcination is performed in common lime-kilns in the ordinary way. In the regulation of the fire it is requisite, here, as with gypsum, to prevent any fusion or linning together of the stones, or even any disengagement of sulphuric or sulphurous acids, which would cause a corresponding defalcation in the product of alum. For this reason the contact of the ignited stones with carbonaceous matter ought to be avoided. The calcined alum-stones, piled in heaps from 2 to 3 feet high, are to be exposed to the weather, and meanwhile they must be continually kept moist by sprinkling them with water. As the water combines with the alum the stones crumble down, and fall, eventually, into a pasty mass, which must be lixiviated with warm water, and allowed to settle in a large cistern. The clear supernatant liquor, being drawn off, must be evaporated, and then crystallized. A second crystallization finishes the process, and furnishes a marketable alum. Thus the Roman alum is made, which is covered with a fine red film of peroxyde of iron. 2. flum Manufaclure from.lum Schist.-The greater portion of the alum found in British commerce is made from alum-slate and analogous minerals. This slate contains more or less iron pyrites, mixed with coaly or bituminous matter, which is occasionally so abundant as to render them somewhat combustible. In the strata of brown coal and bituminous wood, where the upper layers lie immediately under clay beds, they consist of the coaly substance rendered impure with clay and pyrites. This triple mixture constitutes the essence of all good alum schists, and it operates spontaneously towards the production of sulphate of alumina. The coal serves to make the texture open, and to allow the air and moisture to penetrate freely, and to change the sulphur and iron present into acid and oxyde. When these schists are exposed to a high temperature in contact with air, the pyrites loses one half of its sulphur, in the form of sublimed sulphur or sulphurous acid, and becomes a black sulphuret of iron, which speedily attracts oxygen, and changes to sulphate of iron, or green vitriol. The brown coal schists contain, commonly, some green vitriol crystals, spontaneously formed in them. The sulphate of iron transfers its acid to the clay, progressively, as the iron, by the action of the air with a little elevation of temperature, becomes peroxydized; whereby sulphate of alumina is produced. A portion of the green vitriol remains, however, undecomposed, and so much the more as there may happen to be less of other salifiable bases present in the clay slate. Should a little magnesia or lime be present, the vitriol gets more completely decomposed, and a portion of Epsom salt and gypsum is produced. The manufacture of alum from alum schists may be distributed under the six following heads:-l. The preparation of the alum slate. 2. The lixiviation of the slate. 3. The evaporation of the lixivium. 4. The addition of the saline ingredients, or the precipitation of the alum. 5. The washing of the aluminous salts; and, 6. The crys. tallization. 1. Preparation of the dlum Slate.-Some alum slates are of such a nature that, being piled in heaps in the open air, and moistened from time to time, they get spontaneously hot, and by degrees fall into a pulverulent mass, ready to be lixiviated. Th'e greater part, however, require the process of ustulation, from which they derive many advantages. The cohesion of the dense slates is thereby so much impaired that their decomposition becomes more rapid; the decomposition of the pyrites is quickened by the expulsion of a portion of the sulphur; and the ready-formed green vitriol is partly decomposed by the heat, with a transference of its sulphuric acid to the clay, and the production of sulphate of alumina. Such alum-slates as contain too little bitumen or coal for the roasting process must be interstratified with layers of small coal or brushwood over an extensive surface. At Whitby the alum rock, broken into small pieces, is laid upon a horizontal bed of fuel, composed of brushwood; but at Hurlett small coal is chiefly used for the lower bed. When about Ibur feet of the rock is piled on, fire is set to the bottom in various parts; and whenever the mass is fairly kindled, more rock is placed over the top. At Whitby this piling process is continued till the calcining heap is raised to the height of 90 or 100 feet. The horizontal area is also augmented at tne same time till it forms a great bed nearly 200 feet square, having therefore about 100,000 yards of solid measurement. The rapidity of the combustion is tempered by plastering up the crevices with small schist moistened. When such an immense mass is inflamed, tbe heat is sure to rise too high, and an immense waste of sulphur and sulphuric acid must ensue. This evil has been noticed at the Whitby works. At Hurlett the height to which the heap is piled is only a few feet, while the horizontal area is expanded; which is a much more judicious ar~angement. At Whitby 130 tons of calcined schist produce on an average 1 ton of alum. ALUM. 53 In this humid climate it would be advisable to pile up on the top of the horizontal strata of brushwood or coal, and schist, a pyramidal mass of schist, which having its surface plastered smooth, with only a few air-holes, will protect the mass from the rains, and at the same time prevent the combustion from becoming too vehement. Should heavy rains supervene, a gutter must be scooped out round the pile for receiving the aluminous lixivium, and conducting it into the reservoir. It may be observed, that certain alum schists contain abundance of combustible matter, to keep up a suitable calcining heat after the fire is once kindled; and therefore nothing is needed but the first layer of brushwood, which, in this case, may be laid over the first bed of the bituminous schist. A continual, but very slow heat, with a smothered fire, is most beneficial for the ustulation of alum slate. When the fire is too brisk, the sulphuret of iron may run with the earthy matters into a species of slag or the sulphur will be dissipated in vapor, by both of which accidents the product of alum will be impaired. Those bituminous alum schists which have been used as fuel under steam boilers have suffered such a violent combustion that their ashes yield almost no alum. Even the best regulated caicining piles are apt to burn too briskly in high winds, and should have their draughtholes carefully stopped under such circumstances. It may be laid down as a general rule, that the slower the combustion the richer the roasted ore will be in sulphate of alumina. When the calcination is complete, the heap diminishes to one half its original bulk; it is covered with a light reddish ash, and is open and porous in the interior, so that the air can circulate freely throughout the mass. To favce this. access of air, the masses should not be too lofty; and in dry weather a little water.hould be occasionally sprinkled on them, which, by dissolving away some of the saline matter, will make the interior more open to the atmosphere. When the calcined mineral becomes thoroughly cold, we may proceed to the lixiviation. But as, from the first construction of the piles or beds till their complete calcination, many weeks, or even months, may elapse, care ought to be taken to provide a sufficient number or extent of them, so as to have an adequate supply of material for carrying on the lixiviating and crystallizing processes during the course of the year, or at least during the severity of the winter season, when the calcination may be suspended, and the lixiviation becomes unsatisfactory The beds are known to be sufficiently decomposed by the efflorescence of the salt which appears upon the stones, from the strong aluminous taste of the ashes, and from the appropriate chemical test of lixiviating an aliquot average portion of the mass, and seeing how much alum it will yield to solution of muriate or sulphate of potash. 2. The Lixiviation.-The lixiviation is best performed in stone-built cisterns; those of wood, however strong at first, are soon decomposed, and need repairs. They ought to be erected in the neighborhood of the calcining heaps, to save the labor of transport, and so arranged that the solutions from the higher cisterns may spontaneously flow into the lower. In this point of view, a sloping terrace is the best situation for an alum work. In the lowest part of this terrace, and in the neighborhood of the boiling-house, there ought to be two or more large deep tanks, for holding the crude lixivium, and they should be protected from the rain by a prope~ shed. Upon a somewhat higher level the cisterns of the clear lixivium may beplaced. Into the highest range of cisterns the calcined mineral is to be put, taking care to lay the largest lumps at the bottom, and to cover them with lighter ashes. A sufficient quantity of water is now to be run over it, and allowed to rest for some time. The lixivium may then be drawn off, by a stopcock connected with a pipe at the bottom of the cistern, and run into another cistern at a somewhat lower level. Fresh water must now be poured on the partly exhausted schist, and allowed to remain for a sufficient time. This lixivium, being weak, should be run off into a separate tank. In some cases a third addition of fresh water may be requisite, and the weak lixivium which is drawn off may be reserved for a fiesh portion of calcined mineral. In order to save evaporation, it is always requisite to strengthen weak leys by employing them instead of water for fresh portions of calcined schist. Upon the ingenious disposition and form of these lixiviating cisterns much of the economy and saccess of an alum work depend. The hydrometer should be always used to determine the degree of concentration which the solutions acquire. The lixiviated stone, being thus exhausted of its soluble ingredients, is to be removed from the cisterns, and piled up in a heap in any convenient place, where it may be left either spontaneously to decompose, or, after drying, may be subjected to another calcination. The density of the solution may be brought, upon an average, up to the sp. gr. of from 1'09 to 1'15. The latter density may always be obtained by pumping up the wea.er solutions upon fresh calcined mine. This strong liquor is then drawn off; when thl sulphate of lime, the oxyde of iron, and the earths are deposited. It is of aJvantage to leave the liquor exposed for some time, whereby the green vitriol may pass into a per 54: ALUM. sulphate of iron with the deposition of some oxyde, while the liberated acid may eorahin. with some of the clay present, so as to increase the quantity of sulphate of ulumina, The manufacture of alum is the more imperfect, as the quantity of sulphate of iron left undecomposed is greater, and therefore every expedient ought to be tried to convert the sulphate of iron into sulphate of alumina. 3. The evaporation of the Schist Lixivinim.-As the aluminous liquors, however well settled at first, are apt, on the great scale, to deposite earthy matters in the course of their concentration by heat, they are best evaporated by a surface fire, such as that employed at Hurlett and Campsie. A water-tight stone cistern must be built, having a layer of well rammed clay behind the flags or tiles which line its bottom and sides. This cistern may be 4 or 6 feet w.'e, 2 or 3 feet deep, and 30 or 40 feet long, and it is covered in by an arch of stone or brickwork. At one extremity of this tunnel, or covered canal, a fire-grate is set, and at the other a lofty chimney is erected. The cistern being filled it the brim with the alum ley, a strong fire is kindled in the reverberatory grate, anc. the flame and hot air are forced to sweep along the surface of the liquor, so as to keep it in constant ebullition, and to carry off the aqueous parts in vapor. The soot which is condensed in the process falls to the bottom, and leaves the body of the liquor clear. As the concentration goes on, more of the rough lixiviium is run in from the settling cistern,?laced on a somewhat higher level, till the whole gets charged with a clear liquor of a specific gravity sufficiently high for transferring into the proper lead boilers. At Whitby, the lead pans are 10 feet long, 4 feet 9 inches wide, 2 feet 2 inches deep at the one end, and 2 feet 8 inches deep at the other. This increase of depth and corresponding slope facilitates the decantation of the concentrated lixivium T.y means of a syprhon, applied at the lower end. The bottom of the pan is supported by a series of parallel iron bars, placed very near each other. In these lead pans the liquor is concentrated, at a brisk boiling heat, by means of the flame of a flue beneath them. Every morning the pans are emptied into a settling cistern of stone or lead. The specific gravity of the liquor should be about 1*4 or 1'5, being a saturated solution of the saline matters present. The proper degree of density must vary, however, with different kinds of lixivia, and according to the different views of the manufacturer. For a liquor which consists of two parts of sulphate of alumina, and one part of sulphate of iron, a specific gravity of 1'25 may be sufficient; but for a solution which contains two parts of sulphate of iron to one of sulphate of alumina, so that the green vitriol must be withdrawn first of all by crystallization, a specific gravity of 1'4 may be requisite. The construction of an evaporating furnace well adapted to the concentration of aluminous and other crude lixivia, is described under SODA. The liquor basin may be made of tiles or flags puddled in clay, and secured at the seams with a good hydraulic cement. A mortar made of quicklime mixed with the exhausted schist in powder, and iron turnings, is said to answer well for this purpose. Sometimes over the reverberatory furnace a flat pan is laid, instead of the arched top, into which the crude liquor is put for neutralization and partial concentration. In Germany, such a pan is made of copper, because iron would waste too fast, and lead would be apt to melt. From this preparation basin the under evaporating trough is gradually supplied with hot liquor. At one side of this lower trough there is sometimes a door, through which the sediment may be raked out as it accumulates upon the bottom. Such a contrivance is convenient for this mode of evaporation, and it permits, also, any repairs to be readily made; but, indeed, an appa ratus of this kind, well mounted at first, will serve for many years. In the course of the final concentration of the liquors, it is customary to add some o; the mother waters of a former process, the quantity of which must be regulated by a proper analysis and knowledge of their contents. If these mother waters contain much free sulphuric acid, from the peroxydation of their sulphate of iron, they may prove useful in dissolving a portion of the alumina of the sediment which is always present in greater or less quantity. 4. The precipitation of the Alum by adding Alkaline Salls.-As a general rule, it is most advantageous to separate, first of all, Irom the concentrated clear liquors, the alum in the state of powder or small crystals, by addition of the proper alkaline matter, and to leave the mingled foreign salts, such as the sulphate of iron or magnesia, in solution, instead of trying to abstract these salts by a previous crystallization. In this way we not only simplify and accelerate the manufacture of alum, and leave the mother waters to be worked up at any convenient season, but we also avoid the risk of withdrawing any of the sulphate of alumina with the sulphate.of iron or magnesia. On this account, the concentration of the liquor ought not to be pushed so far as that, when it gets cold, it should throw out crystals, but merely to the verge of this point. This density may be determined by suitable experiments. The clear liquor should now be run off into the precipitation cistern, and have the ___________________ —---------------- ALUM. 55 proper quantity of sulphate or muriate of potash, or impure sulphate or carbonate of ammonia added to it. The sulphate of potash, which is the best precipitant, forms 18-34 parts out of 100 of crystallized alum; and therefore that quantity of it, or its equivalent in muriate of potash, or other potash or ammoniacal salts, must be introduced into the aluminous liquor. Since sulphate of potash takes 10 parts of cold water to dissolve it, but is much more soluble in boiling water, and since the precipitation of alum is more abundant the more concentrated the mingled solutions are, it would be prudent to add the sulphite solution as hot as may be convenient; but, as muriate of potash is fully three times more soluble in cold water, it is to be preferred as a precipitant, when it can be procured at a cheap rate. It has, also, the advantage of decomposing the sulphate of iron present into a muriate, a salt very difficult of crystallization, and, therefore, less apt to contaminate the crystals of alum. The quantity of alkaline salts requisite to precipitate the alum, in a granular powder, from the lixivium, depends on their richness in potash or ammonia, on the one hand, and on the richness of the liquors in sulphate of alumina on the other; and it must be ascertained, for each large quantity of product, by a preliminary experiment in a precipitation glass. Here, an aliquot measure of the aluminous liquor being'taken, the liquid precipitant must be addcl in successive portions, as long as it causes any cloud, when the quantity added wll be indicated by the graduation of the vessel. A very exact approximation is not practicable upon the great scale; but, as the mother waters are afterwards mixed together in one cistern, any excess of the precipitant, at one time, is corrected by excess of aluminous sulphate a another, and the resulting alum meal is collected at the bottom. When the precipitated saline powder is thoroughly settled and cooled, the supernatant mother water must be drawn off by a pump, or rather a syphon or stopcock, into a lower cistern. The more completely this drainage is effected, the more easily and completely will the alum be purified. This mother liquor has, generally, a specific gravity of 1'4 at a mehum temperature of the atmosphere, and consists of a saturated solution of sulphate or muriate of black and red oxyde of iron, with sulphate of magnesia, in certain localities, and muriate of soda, when the soaper's salt has been used as a precipitant, as also a saturated solution of sulphate of alumina. By adding some of it, from time to time, to the fresh lixivia, a portion of that sulphate is converted into alum; but, eventually, the mother water must be evaporated, so as to obtain from it a crop of ferruginous crystals; after which it becomes capable, once more, of giving up its alum to the alkaline precipitants. When the aluminous lixivia contain a great deal of sulphate of iron, it may be good policy to withdraw a portion of it by crystallization before precipitating the alum. With this view, the liquors must be evaporated to the density of 1'4, and then run off into crystallizing stone cisterns. After the green vitriol has concreted, the liquor should be pumped back into the evaporating pan, and again brought to the density of 1-4. On adding to it, now, the alkaline precipitants, the alum will fall down from this concentrated solution, in a very minute crystalline powder, very easy to wash and purify. But this method requires more vessels and manipulation than the preceding, and should only be had recourse to from necessity; since it compels us to carry on the manufacture of both the valuable alum and the lower priced salts at the same time; moreover, the copperas extracted at first from the schist liquors carries with it, as we have said, a portion of the sulphate of alumina, and acquires thereby a dull aspect; whereas the copperas obtained after the separation of the alum is of a brilliant appearance. 5. The washing, or edulcoration, of the.dlum Powder.-This crystalline pulverulent matter has a brownish color, from the admixture of the ferruginous liquors; but it may be freed from it by washing with very cold water, which dissolves not more than one sixteenth of its weight of alum. After stirring the powder and the water well together, the former must be allowed to settle, and then the washing must be drawn off. A second washing will render the alum nearly pure. The less water is employed, and the more effectually it is drained off, the more complete is the process. The second water may be used in the first washing of another portion of alum powder, in the place of pure water. These washings may be added to the schist lixivia. 6. The crystallization.-The washed alum is put into a lead pan, with just enough Vter to dissolve it at a boiling heat; fire is applied, and the solution is promoted by stl:ring. Whenever it is dissolved in a saturated state, it is run off into the crystallizing vessels, which are called roching casks. These casks are about five feet high, three feet wide in the middle, somewhat narrower at the ends; they are made of very strong staves, nicely fitted to each other, and held together by strong iron hoops, which are driven on Pro tempore, so that they may be easily knocked off again, in order to take the staves asunder. The concentrated solution, during its slow cooling in these close vessels, forms large regular crystals, which hang down from the top, and project from the sides, while a thick layer or cake lines the whole interior of the cask. At the end of eight or ten days 56 ALUM. mno, or less, acccording to the weather, the hoops and staves are removed, when a cask. of apparently solid alum is disclosed to view. The workman now pierces this mass with a pickaxe at the side near the bottom, and allows the mother water of the interior to run off on the sloping stone floor into a proper cistern, whence it is taken and added to another quantity of washed powder to be crystallized with it. The alum is next broken into lumps, exposed in a proper place to dry, and is then put into the finished bing for the market. There is sometimes a little insoluble basic alum (subsulphate) left at the bottom of the cask. This being mixed with the former mother liquors, gets sulphuric acid from them; or, being mixed with a little sulphuric acid, it is equally converted into alum. When, instead of potash or its salts, the ammoniacal salts are used, or putrid urine, with the aluminous lixivia, ammoniacal alum is produced, which is perfectly similar to the potash alum in its appearance and properties. At a gentle heat both lose their water of crystallization, amounting to 451 per cent. for the potash alum, and 48 for the ammoniacal. The quantity of acid is the same in both, as, also, very nearly the _aantity of alumina, as the following analyses will show:Potash alum. Ammonia alum. Sulphate of potash - - 18-34 Sulphate of ammonia 2'-88 Sulphate of alumina - - 36-20 Sulphate of alumina - 38'64 Water - - - - 45-46 Water - - 4848 100-00 100-00 Or otherwise, Potash alum. Ammonia alum. 1 atom sulphate of potash - 1089-07 1 atom sulphate of ammonia - 716*7 1 alumina - 2149-80 1 alumina - 2149-8 24 water - - - - 2669'52 24 water - -- 2699-5 5938-39 5566*0 Or, Potash alum. Ammonia alum. Alumina - - - 10-82 Alumina - - - - 1190 Potash - 9-94 Ammonia - 389 Sulphuric acid - - - 33-77 Sulphuric acid - - - 3610 Water - -- 45-47 Water -- 48-11 100-00 100-00 When heated pretty strongly, the ammoniacal alum loses its sulphuric acid and ammonia, and only the earth remains. This is a very convenient process for procuring pure alumina. Ammoniacal alum is easily distinguished from the other by the smell of ammonia which it exhales when triturated with quicklime. The Roman alum, made from alum-stone, possesses most of the properties of the schist-made alums, but it has a few peculiar characters: it crystallizes always in opaque cubes, whereas the common alum crystallizes in transparent octahedrons. It is probable that Roman alum is a sulphate of alumina and potash, with a slight excess of the earthly ingredient. It is permanent when dissolved in cold water; for after a slow evaporation it is recovered in a cubical form. But when it is dissolved in water heated to 110~ Fahr. and upwards, cr when its solution is heated above this pitch, subsulphate of alumina falls, and on evaporation octahedral crystals of common alum are obtained. The exact composition of the Roman alum has not been determined, as far as I know. It probably differs from the other also in its water of crystallization. The Roman alum contains, according to MiM. Thenard and Roard, only:21~ of sulphate of iron, while the common commercial alums contain Ao'0 o. It may be easily purified by solution, granulation, crystallization, and washing, as has been already explained. Alum is made extensively in France from an artificial sulphate of alumina. For this purpose clays are chosen as free as possible from carbonate of lime and oxyde of iron. They are calcined in a reverberatory furnace, in order to expel the water, to peroxydize the iron, and to render the alumina more easily acted on by the acid. The expulsion of the water renders the clay porous and capable of absorbing the sulphuric acid by capillary attraction. The peroxydation of the iron renders it less soluble in the sulphuric acid; and the sil'ca of the clay, by reacting on the alumina, impairs its Ngregation, and makes it more readily attracted by the acid. The clay should, therefiore, ALUM. 57 be moderately calcined; but not so as to indurate it like pottery ware, for it would then sufler a species of silicious combination which would make it resist the action of acids, The clay is usually calcined in a reverberatory furnace, the flame of which serves thereafter to heat two evaporating pans and a basin for containing a mixture of the calcined clay and sulphuric acid. As soon as the clay has become friable in the furnace it is taken out, reduced to powder, and passed through a fine sieve. With 100 parts of the pulverized clay, 45 parts of sulphuric acid, of sp. gr. 1-45, are well mixed, in a stone basin, arched over with brickwork. The flame and hot air of a reverberatory furnace are made to play along the mixture, in the same way as described for evaporating the schist liquors. See SODA. The mixture, being stirred from time to time, is, at the end of a few days, to be raked out, and to be set aside in a warm place, for the acid io work on the clay, during six or eight weeks. At the end of this time it must be washed, to extract the sulphate of alumina. With this view, it may be treated like the roasted alum ores above described. If potash alum is to be formed, this sulphate of alumina is evaporated to the specific gravity of 1-38; but if ammonia alum, to the specific gravity of only 1'24; because the sulphate of ammonia, being soluble in twice its weight of water, will cause a precipitation of pulverulent alum from a weaker solution of sulphate of alumina than the less soluble sulphate of potash could do. The alum stone, from which the Roman alum is made, contains potash. The fi:llowing analysis of alunite, by M. Cordier, places this fact in a clear light:Sulphate of potasn - - - 853 Sulphate of alumina - - - - 3850 Hydrate of alumina - 42-97 100-00 To transform this compound into alum, it is merely necessary to abstract the hydrate of alumina. The ordinary alum stone, however, is rarely so pure as the above analysis would seem to show; for it contains a mixture of other substances; and the above are in iifferent proportions. Alum is very extensively employed in the arts, most particularly in dyeing, lake making, dressing sheep-skins, pasting paper, in clarifying liquors, &c. Its purity for the dyer may be tested by prussiate of potash, which will give solution of alum a blue tint in a few minutes if it contain eveh a very minute portion of iron. A bit-of nut-gall is also a good test of iron. Alum liquors.-In the alum works on the Yorkshire coast, 8 different liquors are met with. 1st. "Raw Liquor." The calcined alum shale is steeped in water till the liquor has acquired a specific gravity of 9 or 10 pennyweights, according to the language of the alum-maker. 2d. "Clarified Liquor." The raw liquor is brought to the boiling point in lead pans, and suffered to stand in a cistern till it has cleared: it is then called clarified liquor. Its gravity is raised to 10 or 11 pennyweights. 3d. "Concentrated Liquor." Clarified liquor is boiled down to about 20 pennyweights. This is kept merely as a test of the comparative value of the potash salts used by the alum-maker. 4th. "Alum Mother Liquor." The alum pans are fed with clarified liquor, which is boiled down to about 25 or 30 pennyweights, when a proper quantity of potash salt in solution is mixed with it, and the whole run into coolers to crystallize. The liquor pumped from those rough crystals is called "alum mothers." 5th. " Salts Mothers." The alum mothers are boiled down to a crystallizing point, and afford a crop of " Rough Epsom," which is a sulphate of magnesia and protoxide of iron. 6th and 7th. "Alum Washings." The rough crystals of Alum (No. 4) are washed twice in water, the first washing being about 4 pennyweights, the second about 21, the difference in gravity being due to mother liquor clinging to the crystals. 8th. "Tun Liquor." The washed crystals are now dissolved in boiling water, and run into the "roching tuns" (wood vessels lined with lead) to crystallize. The mother liquor of the "roch alumr" is called "tun liquor;" it is, of course, not quite so pure as a solution of roch alum in water. The alum-maker's sp. gr. bottle holds 80 pennyweights of water, and by 10 penny weights he means 10 more than water, or 90. The numbers on Twaddle's hydrorreter, divided by 2'5, give alum-makers' pennyweights... bS _ALUM. The alum maker tests his samples of potash salts comparatively by dissolving equa weights of the different samples in equal measures of alum liquor at 20 pennyweights, neated up to the boiling-point, and weighing the quantity of alum crystals produced on cooling. For the above information I am indebted to my friend, Mr. Maurice Scanlan, who superintended for some time the Mulgrave alum works. He informs me that 616 tons of the alum rock at the Mulgrave Works, to the north of Whitby, yield, after calcination, &c., one ton of alum. It has been computed that with sulphur at 61. per ton, sulphuric acid of sp. gr.,1'750 can be produced at 31. per -ton, including the mere cost of making: this acid contains 2 atoms of water: 174 tons of this acid, and 87{ tons of sulphate of potash, with the pipe-clay, will form 474 tons of alum; so that the nett cost would be 5221. for the acid 10471. for the sulphate of potash,=15691.; Nwhich sum divided by 474, gives a quotient of 31. 6s. for the nett cost of 1 ton of alum by the direct process. At the pit 1 ton of alum-rock or mine, costs 31. 4s.; to which, adding the cost of the potash salt for 1 ton of alum, 31. 15s., they constitute together an amount of 6l. 19s. From the latter sum 11. 10s. must, however, be deducted for the value of rough Epsoml salt produced, leaving a balance of 51. 9s. for the cost of a ton of mine-alum, prior to evaporation and crystallization. A patent was obtained in November, 1839, by Mr. William Wiesman, of Duesburg, for improvements in the manufacture of alum. He subjects potter's clay to a moderate red heat, grinds it, and subjects the powder, in leaden pans, to the action of concentrated sulphuric acid (76~ Beaume6), taking care to use excess of clay and a moderate heat. This mixture is to be stirred till it is dry, then treated with boiling water, in order to dissolve the sulphate of alumina formed. So far the process is old and well known. The novelty consists in freeing the saline solution from iron by ferrocyanure of potassium (prussiate of potash). When the iron has been all thrown down in the form of prussian blue, the liquor is allowed to settle, the supernatant pure sulphate is drawn off, and evaporated till it forms on cooling a concrete mass, which may be moulded into the shape of bricks, &c., for the convenience of packing. Alum, g nan.factsure of.-The manufacture of alum from clay and clay slate, or shale, is now beginning to assume a considerable aspect in the list of our manufactures, and several improvements in this way have lately been patented, which promise to extend largely this branch of industry. One in particular, for the fabrication of alum from the ash or residue left after the combustion of a kind of coal, called Boghead coal, seems based on the sound principle of industrial economy which turns every waste product to profitable account. It was but the other day that this very Boghead ash was a serious impediment to the sale of the coal, and perceptibly diminished its price in the market. Now, however, it constitutes a decided item of value, and powerfully vindicates the right of chemistry to the title of a useful and profitable science. In preparing alum from clay or shale, it is of infinite importance that so much and no more heat be applied to the clay or shale, in the first instance, as will just expel the.water of combination, without inducing contraction. A temperature of 600~ Fahr. is well adapted to effect this object, provided it be maintained for a sufficient period. When this has been carefully done, the silicate of alumina remaining is easily enough acted upon by sulphuric acid, either slightly diluted or of the ordinary commercial strength. The best form of apparatus is a leaden boiler, divided into two parts by a perforated septum or partition, also in lead-though on a very large scale, brickwork set in clay might be employed. Into one of the compartments the roasted clay or shale should be put, and diluted sulphuric acid being added, the bottom of the other compartment may be exposed to the action of a well-regulated fire, or-what is better-heated by means of steam through the agency of a coil of leaden pipe. In this way a circulation of the fluid takes place throughout the mass of shile; and, as the alumina dissolves, the dense fluid it produces, falling continually towards the bottom of the boiler, is replaced by dilute acid, which, becoming in its turn saturated, falls like the first; and so on in succession, until either the whole of the alumina is taken up, or the acid in great part neutralized. The solution of sulphate of alumina, thus obtained, is sometimes evaporated to dryness, and' sold under the name " concentrated alum;" but more generally it is boiled down until of the specific gravity of about 1'35, then one or other of the carbonates, muriate, or sulphates of potash or amimonia, or a mixture of these, is added to the boiling fluid; and as soon as the solution is complete, the whole is run out into a cooler to crystallize. The rough alum thus made is somletimes purified by a subsequent recrystallization, after which it is "roched" for the market-a process intended merely to give it the ordinary commercial aspect, but of no ireal value in a chemical point of view. Alum not unfrequently contains iron, an impurity which unfits it for many uses in the arts, and more especially for the purposes of the dyer. The best mode cf AMBER. 59 ascertaining the presence of this impurity, and demonstrating its amount, is that previously stated in the commencement of this article,-that is, mix a solution of the suspected alum with tartaric acid, or an alkaline tartrate, and then add an excess ol carbonate of soda; after which, pour in a few drops of hydrosulphate of ammonia, when, if iron be present, a black precipitate will ensue. If the alum contains lime or magnesia, then the addition of carbonate of soda causes a white precipitate, which must be removed by filtration before applying the hydrosulphate of ammonia. Alum meanufactutre simplified. —The alum shale, or schist, is the material whence the alum is obtained: this shale is roasted in heaps, in the open air, in order to rendel it porous, and more absorbent of the sulphuric acid. To the roasted shale, sulphuric acid of sp. gr. 1-75 is added, by which means sulphate of alumina is formed. In order to wash out from the almost dry mass this sulphate of alumina, and at the same time to supply the equivalent of the sulphate of ammonia necessary to constitute the formation of the double salt of alumina and ammonia, the boiling hot mother liquor of a previous operation is employed; and, as this mother liquor, when re moved from the alum crystallizers, contains free sulphuric acid, the ammonia from a still, containing the ammoniacal liquor of the gas works, is distilled into it, and the boiling hot solution of sulphate of mnmonia thus formed dissolves out the sulphate of alumina from the shale. The alum liquor thus obtained is of such a specific gravity, that it crystallizes without the necessity of having recourse to evaporation, and thus a considerable saving in fuel is effected. In order to obtain ammoniacal salts, such as sulphate an I muriate, with the greatest possible economy, a series oi two or more-say, for instance, four-cylindrical boilers are employed, each of which is placed at such a distance above the other, that the contents of the upper boiler may be drawn off into the one next below It. The uppermost boiler is provided with an exit pipe, and has also a supply pipe, connecting the boiler with a reservoir of ammoniacal gasliquor. Into the lowermost vessel of the series passes a pipe conveying high pressure steam, by means of which the liquor in the boiler soon becomes heated to the boiling point. The vapor of ammonia and water pass off through an exit pipe into the boiler placed next above it in the series, the liquor in which also quickly boils, and vapor of ammonia and water pass off in the same way as before to the next vessel above it, and so throughout the series. By the time the vapor of ammonia passes off from the uppermost boiler, it has been so concentrated that, on passing it into sulphuric or muriatic acid, a concentrated solution of either of those salts is obtained, of sufficient sp. gr. to crystallize without evaporation, and thus a considerable saving in fuel and,ime is effected, and the ammoniacal liquor most thoroughly exhausted. Fresh sup)lies of ammoniacal liquor are constantly furnished to the uppermost vessel from the eservoir; the partially exhausted liquors are run from the higher to the lower vessels in succession, and the exhausted liquors run off to waste, from time to time, from the lowermost vessel of the series. ALUMINA. The pure earth of clay, or argillaceous earth. It is the oxide of the metal aluminum, the basis of the aluminous salts, and the principal constituent of porcelain, pottery, bricks and tiles. AMADOU. The French name of the spongy combustible substance called in German znzdersehwvamm, prepared fiom a species of agaric, the boletus igniarius, a kind of mushroom which grows on the trunks of old oaks, ashes, beeches, &c. It must be plucked in the months of August and September. It is prepared by removing the outer bark with a knife, and separating carefully the spongy substance of a yellow brown color, which lies within it, from the ligneous matter below. This substance is cut into thin slices, and beat with a mallet to soften it, till it can be easily pulled asunder between the fingers. In this state the boletus is a valuable substance for stopping oozing hemorrhages, and some other surgical purposes. To convert it into tinder it must receive a finishing preparation, which consists in boiling it in a strong solution of nitre; drying it, and beating it anew, and putting it a second time into the solution. Sometimes, indeed, to render it very inflammable, it is imbued with gunpowder, whence the distinction of black and brown amadou. All the puff balls of the lycopodium genus of plants, which have a fleshy or filamentous structure, yield a tinder quite ready for soaking in gunpowder water. The Iindoos employ a leguminous plant, which they call solu, for the same purpose. Its thick spongy stem, being reduced to charcoal, takes fire like amadou. AMALGAM. When mercury is alloyed with any metal, the compound is called an amalgam of that metal; as, for example, an amalgam of tin, bismuth, &c. AMALGAMATION, This is a process used extensively in extracting silver and gold from certain of their ores, founded on the property which mercury has to dissolve these metals as disseminated in the minerals, and thus to separate them from the tarthy matters. See MERCURY, METALLURGY, and SILVER. AMBER. (Succin, Fr.; Bernstein, Germ.) A mineral solid, of a yellow colour L=. 60 A MBER. of various shades, which burns quite away with flame, and consists of carbon, hydrogen; and oxygen, in nearly the same proportions, and the same state of combination, as vege table resin. Its specific gravity varies, by my trials, from 1'080 to 1'085. It becomes negatively and powerfully electrical by friction. When applied to a lighted candle it takes fire, swells considerably, and exhales a white smoke of a pungent odor; but does not run into drops. Copal, which resembles it in several respects, differs in being softer, and in melting into drops at the flame; and mellite, or honey-stone, which is a mineral of a similar color, becomes white when laid on a red-hot coal. The texture of amber is resino-vitreous, its fracture conchoidal, and lustre glassy, It is perfectly homogeneous; sufficiently hard to scratch gypsum, and to take a fine polish. It is, however, scratched by calcareous spar. When amber is distilled in a retort, crystalline needles of succinic acid sublime into the dome, and oil of amber drops from the beak into the receiver. Fossil resins, such as that of Highgate, found in the London clay formation, do not afford succinic acid by heat: nor does copal. Amber is occasionally found of a whitish and brownish color. The most interesting fact relative to this vegeto-mineral is its geological position, which is very characteristic and well determined. It is found almostuniformly in separate nodules, disseminated in the sand, clay, or fragments of.?'nite of the plastic clay, and lignite formation, situated between the calcaire grossier (crag limestone) of the tertiary strata above, and the white chalk below. The size of tblise nodules varies from a nut to a man's head; but this magnitude is very rare in true amber. It does not occur either in continuous beds, like the chalk flints, nor in veins; but it lies at one time in the earthy or friable strata, which accompany or include the lignites; at another, entangled in the lignites themselves; and, is associated with the minerals which constitute this formation, principally the pyrites, the most abundant of all. The pieces of amber found in the sands, and other formations evidently alluvial, those met with on the seacoasts of certain countries, and especially Pomerania, come undoubtedly from the above geological formation; for the organic matters found still adhering to the amber leave no doubt as to its primitive place. Amber does not, therefore, belong to any postdiluvian or modern soil, since its native bed is covered by three or four series of strata, often of considerable thickness, and well characterized; proceeding upwards from the plastic clay which includes the amber: these are, the crag limestone, the bone gypsum, with its marls, the marly limestone, the upper marl sandstone, which covers it, and, lastly; the fresh water or lacustrine formation, often so thick, and composed of calcareous and silicious rocks. The amber bed is not, however, always covered with all these strata; and it is evei rare to see a great mass of one of them above the ground which contains it; because, were it buried under such strata, it would be difficult to meet with such circumstances as would lay it spontaneously open to the day. But by comparing observations made in different places, relatively to the patches of these formations, which cover the amber deposites, we find that no other mineral formations have been ever seen among them except those above detailed, and thus learn that its geological locality is completely determined. The proper yellow amber therefore, or the Borussic, from the country where it has been most abundantly found, belongs to the plastic clay formation, intermediate, in England, between the chalk and the London clay. It is sometimes interposed in thin plates between the layers of the lignites, but more towards the bark of the fibrous lignites, which retain the form of the wood, than towards the middle of the trunk of the tree; a position analogous to that of the resinous matters in our existing ligneous vegetables. The fibrous lignites which thus contain amber belong to the dicotyledinous woods. Hence that substance seems to have been formed during the life of the vegetable upon which it is now incrusted. It must be remembered that the grounds containing the amber are often replete with the sulphates of iron, alumina, and lime, or at least with the pyritous elements of these salts. Some specimens of amber have a surface figured with irregular meshes, indicating a sort of shrinkage from consolidation, and consequently a matter that was at one time fluid, viscid, or merely soft. From optical examination, Dr. Brewster has concluded amber to be of vegetable origin. The different bodies included in the amber, distinguishable from its transparence, demonstrate, indeed, in the most convincing manner, Its primitive state of liquidity or softness. These bodies have long exercised the skill of naturalists. They are generally insects, or remains of insects, and sometimes leaves, stalks, or other portions of vegetables. Certain families of insects occur more abundantly than others. Thus the hymrnnoplera, or insects with four naked merabranaceous wings, as the bee and wasp, and the diplera, or insects with two wings, as gnats, flies, gadflies, &c.; then come the spider tribe; some coleoptera (insects with crustaceous shells or elytra, which shut together, and form a longitudinal suture down the back), or beetles, pr itipally those which live on trees; such as the elaterides, or leapers, and the chrysomelida. The lepidoptera, or insects with AMBER. 61 four nmembranaceous wings, ana pterigostea covered with mail-like scales, are very rare in amber. We perceive from this enumeration, which results from the labors of Germar, Sc'hweiger, &c., that the insects enveloped in this resinous matter are in general such as sit on the trunks of trees, or live in the fissures of their bark. Hitherto, it has not been found possit le to refer them to any living species; but it has been observed in general that they resemble more the insects of hot climates than those of the temperate zones. The districts where amber occurs in a condition fit for mining operations are not numerous; but those in which it is met with in small scattered bits are very abundant. rts principal exploitation is in Eastern Prussia, on the coasts of the Baltic Sea, from Memel to Dantzick, particularly in the neighborhood of Konigsberg, along the shore which runs north and south from Grossdirschh&.m to Pillau, and in several other places near Dantzick. It is collected upon this coast in several ways; 1. In the beds of small streams which run near the villages, and in rounded fragments without bark, or in the sand-banks of r;-ers, in pieces thrown back by the sea, and rounded by the waves. 2. If the pieces thrown up by the waters are not numerous, the fishers, clothed in a leather dress, wade into the sea up to the neck, seek to discover the amber by looking along its surface, and seize it with bag nets, hung at the end of very long poles. They conclude that a great deal of amber has been detached from the cliffs by the sea, when many pieces of lignite (wood coal) are seen afloat. This mode of collecting amber is not free from danger, and the fishers, therefore, advance in troops, to lend each other aid in case of accident; but their success, even thus, is most precarious. 3. The third method of searching for amber is a real mining operation: it consists in digging pits upon the borders of the sandy downs, sometimes to a depth of more than 130 feet. 4. The last mode is by exploring the precipitous sea cliffs in boats, and detaching masses of loose soil from them with long poles terminating in iron hooks; a very hazardous employment. They search the cliffs with great care at the level, where the amber nodules commonly lie, and loosen the seams with their hooks; in which business the boats are sometimes broken against the precipices, or sunk by an avalanche of rubbish. Amber occurs in Sicily, disseminated in beds of clay and marl, which lie below the crag limestone. It is accompanied with bitumen; and, though a scanty deposite, it is mined for sale. The pieces are coated with a kind of whitish bark, present a variety of colors, and include many insects. Amber is found in a great many places in the sandy districts of Poland, at a very great distance from the sea, where it is mixed with cones of the pine. In Saxony it is met with in the neighborhood of Pretsch and Wittemberg, in a bituminous clay mingled with lignite. At the embouchure of the Jenissey, in Siberia, it occurs likewise along with lignite; as also in Greenland. Fine amber is considerably valued for making ornamental objects, and the coarser kinds for certain uses in chemistry, medicine, and the arts. The oriental nations prize more highly than the people of Europe trinkets made of amber; and hence the chief commerce of the Pomeranian article is with Turkey. The Prussian government is said to draw an annual revenue of 17,000 dollars from amber. A good piece of a pound weight fetches 50 dollars. A mass weighing 13 pounds was picked up not long since in Prussia, for which 5000 dollars were offered, and which would bring, in the opinion of the Armenian merchants, from 30,000 to 40,000 dollars at Constantinople. At one time it was customary to bake the opaque pieces of amber in sand, at a gentle heat, for several hours, in order to make it transparent, or to digest it in hot rapeseed oil, with the same view; but how far these processes were advantageous does not appear. When amber is to be worked into trinkets, it is first split on a leaden plate at a lathe (see GEMs, Cutting of), and then smoothed it`o shape on a Swedish whetstone. It is polished on the lathe with chalk and water, or vegetable oil, and finished by friction with flannel. In these processes the amber is apt to become highly electrical, very hot, and even to fly into fragments. Hence, the artists work the pieces time about, so as to keep each of them cool, and feebly excited. The men are often seized with nervous tremors in their wrists and arms from the electricity. Pieces of amber may be neatly joined by smearing their edges with linseed oil, and pressing them strongly together. while they are held over a charcoal fire. Solid specimens of amber, reported to have been altogether fused by a particular application of heat, are nowr shown in the royal cabinet of Dresden. A strong and durable varnish is made by dissolving amber in drying linseed oil. For this purpose, however, the amber must be previously heated in an iron pot, over a clear red fire,, till it soften and be semi-liquefied. The oil, previously heated, is to be now poured in, with much stirring, in the proportion of 10 ounces to the pound of amber; and after the incorporation is complete, and the liquid somewhat cooled, a pound of oil )f turpentine must be added. Some persons prescribe 2 ounces of melted shellaci 62 AMBERGRIS. though by this means they are apt to deepen the colour, already rendered too dark by the roasting. The finest varnish is made with oil of spike. though by this means they are apt to deepen the color, already rendered too dark by ths roasting. The fine black varnish of the coachmakers is said to be prepared by melting 16 ounces cf ariber in an iron pot, adding to it half a pint of drying linseed oil, boiling hot, of pow. deied resin and asphaltum 3 ounces each: when the materials are well united, by stirring over the fire, they are to be removed, and, after cooling for some time, a pint of warm oil of turpentine is to be introduced. The oil of amber enters into the composition of the old perfume called eau de luce; and is convertible, by the action of a small quantity of strong nitric acid, into a viscid mass like shoemakers' rosin, which has a strong odor of musk, and, under the name of titificial musk, has been prescribed, in acoholic solution, as a remedy against hooping cough, and other spasmodic diseases. Acid of amber (succinic acid) is a delicate reagent, in chemistry, for separating red oxyde of iron from compound metallic solutions. AMBERGRIS. (dAmbregric, Fr.;.inbra, Germ.)-A morbid secretion of the liver of the spermaceti whale (physeter macrocephalus), found usually swimming upon the sea. It occurs upon the coasts of Coromandel, Japan, the Moluccas, and Madagascar, ernd has sometimes been extracted from the rectum of whales in the South sea fishery. It has a gray-white color, often with a black streak, or is marbled, yellow and black; has a strong but rather agreeable smell, a fatty taste, is lighter than water, melts at 60~ C. (140~ F.), dissolves readily in absolute alcohol, in ether, and in both fat and volatile oils. It contains 85 of the fragrant substance called ambreine. This is extracted from ambergris by digestion with -alcohol of 0'827, filtering the solution, and leaving it to spontaneous evaporation. It is thus obtained in the form of delicate white tufts: which are convertible into ambreic acid by the action of nitric acid. Ambergris is used in perfumery. AMIANTHUS. A mineral in silky filaments, called also ASBESTUS. AMMONIA. A chemical compound, called also volatile alkali. This substance, in its purest state, is a highly pungent gas, possessed of all the mechanical properties of the air, but very condensable with water. It consists of 3 volumes of hydrogen and 1 of azote condensed into two volumes; and hence its density is 0-591, atmospheric air being 1l000. By strong compression and refrigeration it may be liquefied into a fluid, whose specific gravity is 0-76 compared to water 1'000. Ammonia gas is composed by weight of 82'53 azote and 17-47 hydrogen in 106 parts. It is obtained by mixingo muriate of ammonia, commonly called sal ammoniac, with quicklime, in a retort or still, applying a moderate heat, and receiving the gas either over mercury for chemical experiments, or in water to make liquid ammonia for the purposes of medicine and the arts. Woulfe's apparatus is commonly employed for this condensation. Ammonia is generated in a great many operations, and especially in the decomposition of many organic substances, by fire or fermentation. Urine left to itself for a few days is found to contain much carbonate of ammonia, and hence this substance was at one time collected in great quantities for the manufacture of certain salts of ammonia, and is still used for its alkaline properties in making alum, scouring wool, &c. When woollen rags, horns, bones, and other animal substances are decomposed in close vessels by fire, they evolve a large quantity of ammonia, which distils over in the form of a carbonate. The main source of ammonia now in this country, for commercial purposes, is the coal gas works. A large quantity of watery fluid is condensed in their tar pits, which contains, chiefly, ammonia combined with sulphureted hydrogen and carbonic acid. When this water is saturated with muriatic acid and evaporated it yields muriate of ammonia, or sal ammoniac, somewhat impure, which is afterwards purified by sublimation. See ABBONATE OF AMMONIA and SAL AMMONIAC. The soot of chimneys where coal is burned contains both sulphate and carbonate of ammonia, and was extensively employed, at one time. to manufacture these salts. In making water of ammonia on the great scale, a cast iron still should be preferred, and equal weights of quicklime and sal ammoniac should be brought to the consistence f a pap, with water, before the heat is applied. In this case a refrigeratory worm or,gobe should be interposed between the adopter tube of the capital of the still.tnd the nottles (J Woulfe's apparatus. The muriate of lime, or chloride of calcium, which is left in the still when the whole ammonia is expelled, is of no value. Water is capable of condensing easily about one third of its weight of ammonia gas, or 460 times its bulk. The following table of the quantity of ammonia in 100 parts by weight of its aqueous combinations, at successive densities, is the result of very careful experiments made by me, and recorded in the Philosophical Magazine for March, 1821. AMYGDALINE. 63 Table of Water of ammonia or Volatile dlkali, by Di Ure. Water Ammonia Water Specific Mean of l in gravity by specific Equivalent primes. 0'900 100 100 experiment gravity. 100 26-500 73-500 0.9000 95 25-175 74 825 0-9045 0-90452 Wat. inm. 90 23-850 76-150 0'9090 0'90909 24+ 76 6 to 1 85 22-525 77-475 0-9133 0-91370 80 21-200 78-800 0-9177 0-91838 21-25 + 78-75, 7 to 1 75 19-875 80-125 0-9227 0-92308 70 18-550 81-450 0-9275 09'2780 19-1 + 80'9, 8 to 1 35 17-225 82-775 0-9320 0-93264 17-35 + 82-65, 9 to 1 60 15-900 84-100 0-9363 0-93750 15'9 + 84'1, 10 to 1 55 14-575 85-425 0-9410 0-94241 14-66 + 85'34, 11 to 1 50 13-250 86-750 0-9455 0-94737 13-60 - 86-40, 12 to 1 45 11-925 88-075 09510 0-95238 11-9 88-1, 14 to 1 40 10-600 89-400 099564 0-95744 11-2 +888, 15 to 1 35 9-275 90-725 0-9614 0-96256 30 7-950 92-050 0-9662 0-96774 8-63 -+ 91-3T, 20 to 1 25 6-625 93-375 0-9716 0-97297 7 + 93, 25 to 1 20 5.300 94-700 0-9768 0-97826 6 + 94, 30 to 1 15 3-975 96-025 0-9828 0-98360 45 - 95-5, 40 to 1 10 2-650 97-350 0-9887 0.9%900 3- +97, 60 to 1 5 1-325 1 98-675 0-9945 0-99447 _ AMMONIAC, gum-resin. This is the inspissated juice of an umbelliferous plant (the dorema armeniacum) which grows in Persia. It comes to us either in small white tears clustered together, or in brownish lumps, containng many impurities. It possesses a peculiar smell, somewhat like that of asafoetida, and a bitterish taste. It is employed in medicine. Its only use in the arts is for forming a cement to join broken pieces of china and glass, which may be prepared as follows: Take isinglass 1 ounce, distilled water 6 ounces, boil together down to 3 ounces, and add 1 ounce of strong spirit of wine; boil this mixture for a minute or two; strain it; add, while hot, first, half an ounce of a milky emulsion of gum ammoniac, and then five drams of an alcoholic solution of resin mastic. This resembles a substance sold in the London shops, under the name of diamond cement. The recipe was given me by a respectable dispensing chemist. AMORPHOUS. Without shape. Said of mineral and other substances which occur in forms not easy to be defined. AMYGDALINE is a principle of bitter almonds and of bay-laurel berries. It is obtained by digesting, in a retort, alcohol of 0-825 at its boiling temperature upon the meal of bitter almonds, then distilling off the alcohol by the heat of a water-bath till the residuum assumes the consistence of syrup. To the residuum, diluted with a little water, some yeast is to be added, and the mixture is to be set aside in a warm place for some time to'ferment. Whenever the fermentation is over, the liquor is to be filtered and evaporated on the water-bath to a syrupy consistence. On mixing this syrup with alcohol of 0'825, the amvgdaline falls in a white crystalline powder, which, after being squeezed between folds of filtering-paper, is.to be finally purified, by repeated crystallizations, with alcohol. Its crystals are silky-looking scales, or sh,rt needles, without smell, but with a slight taste of bitter almonds. When heated, they exhale the fragrance of hawthorn flowers, and burn into a bulky charcoal. Cold alco*,ol hardly dissolves them, but boiling alcohol pretty copiously. They are very soluble in water, and produce therefrom, by evaporation and cooling, large transparent prisms, of a silky aspect, which contain 6 atoms, or 10'57 per cent. of water. Their composition in the dry state is as follows: 40 atoms of carbon - - - - 5298 in 100 parts. 27 - hydrogen - - - - 5-84 1 - azote - - - - 306 22 - oxygen - - - - 3812 - 1 atom amygdaline (Liebig) - - - 100'00 The purpose of the fermentation above prescribed is to decompose a portion cf sugar 64 ANCIOR. extracted by the alcohol from the bitter almonds along with the amygdaline, of which latter they afford from 3 to 4 per cent. Almonds, both bitter and sweet, contain also another curious principle, called emnzlsine by Liebig, and synaptase by Robiquet. It is soluble in water, but is precipitated from it in flakes by alcohol. It coagulates at the temperature of about 140~ Fahr. like white of egg. On mixing a solution of 10 parts of amygdaline in 100 parts of water, with 1 part of synaptase in 10 parts of water, a peculiar decomposition immediately takes place. The mixture becomes opaline without losing its transparency; it assumes the odor of bitter almonds, and viemls, on distillation, hydrocyanic (prussic) acid, and the hydrure of benzoil (pure essence of bitter almonds), mixed with vapor of water. Coagulated synaptase has no perceptible action on amygdaline. These facts explain a series of puzzling phenomena, which have been long known. Fresh bitter almonds contain emulsine (synaptase), amygdaline, and an unctuous oil, all in such a state that the first two cannot react upon each other; and by removing the water by desiccation thei. mutual action becomes impossible. On squeezing the almonds the oil is drawn off, and on treating the cake with boiling alcohol the amygdaline is dissolved out, ana the synaptase is coagulated; bu; on moistening the bitter almonds with water the reaction of the two principles becomes instantly effective, as shown by the production of the smell and taste of hydrocyanic acid and of the essential oil. By throwing the bitter almond meal into boiling water the synaptase immediately coagulates, and the above mutual reaction can no longer be obtained, nor the above volatile products. In order properly to prepare the essence of bitter almonds it is therefore necessary to mix 1 part of bitter almond meal with 20 parts of lukewarm water, to leave the mixture to digest for 24 hours, and only then to submit it to distillation. 100 parts of amygdaline produce 47 parts of the crude essence of bitter almonds, which contain 5'9 parts of hydrocyanic acid. AMYLOXIDE-HYDRATE. See FUSEL OIL. ANALYSIS. The art of resolving a compound substance or machine into its constituent parts. Every manufacturer should so study this art, in the proper treatises, and schools of chemistry or mechanics, as to enable him properly to understand and regulate his business. ANCHOR. (Ancre, Fr.; Anker, Germ.) An iron hook of considerable weight and strength, for enabling a ship to lay hold of the ground, and fix itself in a certain situation by means of a rope called the cable. It is an instrument of the greatest importance to the navigator, since utio-I its taking and keeping hold depends his safety upon many occasions, especially near a lee shore, where he might be otherwise stranded or shipwrecked. Anchors are generally made of wrought iron, except among nations who cannot work this metal well, and who therefore use copper. The mode in which an anchor operates will be understood fiom inspection of fig. 12, where from the direction the strain, it is obvious that the anchor cannot move without ploughing up the ground in which its hook or fluke is sunk. When this, however, unluckily takes place, from the nature of the ground, from the mode of insertion of the anchor, or from the violence of the winds or currents, it is called dragging the anchor. When the hold is good, the cable or the buried arm will sooner break than the ship will drive. Anchors are of different sizes, and have different names, according tothe purposes they serve; thus there are sheet, best bower, small bower, spare, stream, and kedge anchors. Ships of the first class have seven anchors, and smaller vessels, such as origs and schooners, three. 12 ANCHOR. 65 The manufacture of anchors requires great knowledge' ]: ~ of the structure of iron, and skill in the art of working, ) rit. I shall give, here, a brief notice of the improved system 13 I introduced by Mr. Perring, clerk of the cheque at Ply. mouth, in which the proportions of the parts are admirably adapted to the strains they are likely to suffer. In fig. 13 A is the shank; B, the arm or fluke; c, the palm; D, the A blade; E, the square; F, the nut; G, the ring; H, the crown. Formerly the shank was made of a number of square iron rods, laid parallel together in a cylindrical form, and bound by iron hoops. When they were welded into one bar, the exterior rods could not fail to be partially burned and wasted by the strong heat. Mr. Perring abated this v^^C H y // evil by using bars of the whole breadth of the shank, and Dons H nle' ~ rplacing them right over each other, hooping them and welding them together at two heats into one solid mass. To any one who has seen the working of puddled iron, with a heavy mill hammer, this operation will not appear difficult. IHe formed the crown with bars similarly distributed with those of the shank. His mode of uniting the flukes to the crown is probably the most valuable part of his invention. The bars and half the breadth of the anchor are first welded separately, and then placed side by side, where the upper half is worked into one mass, while the lower part is left disunited, but has carrier iron bars, or porters, as these prolongation rods are commonly called, welded to the extremity of each portion. The lower part is now heated and placed in the clamping machine, which is merely an iron plate firmly bolted to a mass of timber, and bearing upon its surface four iron pins. One end of the crown is placed between the first of these pins, and passed under an iron strap; the other end is brought between the other pins, and is bent by the leverage power of the elongated rods or porters. Thus a part of the arm being formed out of the crown gives much greater security that a true union of fibres is effected, than when the junction was made merely by a short scarf. The angular opening upon the side opposite B H, fig. 13, is filled with the ch.ck, formed of short iron bars placed upright. When this has been firmly welded, the trusspiece is brought over it. This piece is made of plates similar to'the above, except that their edges are here horizontal. The truss-piece is half the breadth of the arm; so that when united to the crown, it constitutes, with the other parts, the total breadth of the arms at those places. The shank is now shut upon the crown; the square is formed, and the nuts welded to it; the hole is punched out for the ring and the shank is then fashioned. The blade is made much in the way above described. In making the palm, ar iron rod is first bent into the approximate form, notching it so that it may more readily take the desired shape. To one end a porter rod is fastened, by which the palm is carried and turned round in the fire during the progress of the fabrication. Iron plates are next laid side by side upon the rod, and the joint at the middle is broken by another plate laid over it. When the mass is worked, its under side is filled up by similar plates, and the whole is completely welded; pieces being added to the sides, if necessary, to form the angles of the palm. The blade is then shut on to the palm, after which the part of the arm attached to the blade is united to that which constitutes the crown. The smith-work of the anchor is now finished. The junction, or sh.tting on, as the workmen call it, of the several members of an anchor, is effected by an instrument called a monkey, which is merely a mass of iron raised to a certain height, between parallel uprights, as in the pile engine or vertical ram, and let fall upon the metal previously brought to a welding heat. The monkey and the hercules, both silly, trivial names, are similar instruments, and are usually worked, like a portable pile engine, by the hands of several laborers, pulling separate ropes. Many other modes of manufacturing anchors have been devised, in which mechanical power is more extensively resorted to. The upper end of the shank F (fig. 13)is squared to receive and hold the stock steadily, and keep it from turning. To prevent it shifting along, there are two knobs or tenon-like projections. The point of the angle H, between the arms and the shank, is sometimes called the throat. The arm B c generally makes an angle of 56~ with the shank A; it is either round or polygonal, and about half the length of the shank. The stock of the anchor (fig. 12)is made of oak. It consists of two beams which embrace the square, and are firmly united by iron bolts and hoops, as shown in the figure. The stock is usually somewhat longer than the shank, has in the middle a thickness about one twelfth of its length, but tapers at its under side to nearly one half this thick 6 66 ANCHOR. ness at the extremities. In small anchors the stock is frequently made of iron; but in this case it does not embrace the anchor, but goes through a hole made in the square, which is swelled out on purpose. The weight of anchors for different vessels is proportioned to the tonnage; a good rule being to make the anchor in hundred weights one twentieth of the number of tons of the burden. Thus a ship of 1000 tons would require a sheet anchor of 50 cwts. Ships of war are provided with somewhat heavier anchors. Several new forms and constructions of anchors were proposed under Mr. Piper's patent of November, 1822, by the adoption of which great advantages as to strength were anticipated over every other form or construction previously made. The particular object was to preserve such a disposition of the fibres of the metal as should afford the greatest possible strength; in doing which the crossing or bending of the fibres at the junctions of the shank, fukes, and crown, where great strength is rcquired, has been avoided as much as possible, so that the fibres are not disturbed or injured. In this respect most anchors are defective; for in conneci.ng the shanks to the crownpieces, the grain of the metal is either crossed, or so much curved, as to strain the fibre, and consequently induce a weakness where the greatest strength is required. And, further, the very considerable thicknesses of metal which are to be brought into immediate contact by means of the hammer in forging anchors upon the old construction, render it highly probable that faulty places may be left within the mass, though they be externally imperceptible. Mr. Piper's leading principle was, that the fibre of the metal should run nearly straight in all the parts where strength is particularly required. Fig. 14 shows an anchor with one tumbling fluke, which ~14 ) 17 passes through the forked or branched part of the shank. The lower part of this anchor, answering to the crown, has a spindle through it, upon which the fluke turns, and a pin is there introduced for the purpose of confining the fluke when in a holding position. This shank is formed of a solid piece of wrought iron, the fibres of which run straight, and at the crown holes are pierced, which merely bulge the metal without bending the fibres round so as to strain them. The arm and -I USpDfluke, also, are formed of one piece punched through without curling or crossing the fibre, and the spindle which holds the arm to the crown is likewise straight. This spindle extends some distance on each side of the anchor, and is intended to answer the purpose of a stock; for when either of the ends of the spindle comes in contact with the ground, the anchor will be thrown over into a holding position; or an iron stock may be introduced near the shackle, instead of these projecting ends. In the descent of the anchor, the fluke will fall over towards that side which is nearest the ground, and will there be ready to take hold when the anchor is drawn forward..\16 la -Fig. 15 is another anchor upon the same principle, hut slightly varied in form from the last. In this the forked part of the shank is closer than in the former, and there are two arms or flukes connected to the crown-pieces, one of which falls into its holding position as the anchor comes to the ground, and is held at its proper angle by the other fluke stopping against the shank.. Fig. 16 represents another variation in the form of these improved anchors, having two tumbling flukes, which are both intended to take hold of the ground at the same time. The shank is here, as before, made without crossing the grain of the iron, and the eyes for admitting the bolt at the crown and at the shackle are punched out of the solid, not formed by welding or turning the iron round. In this form a guard is introduced at the crown, to answer the purpose of a stock, by turning the flukes over into a hoiding position. The arms and flukes are made, as before described, of the straight fibre of Ihe iron punched through, and the flukes are fixed to the spindle, which passes through the crown-piece. Fig. 17 has a shank without any fork, but formed straight throughout; the guard here is an elongated frame of iron, for the same purpose as a stock, and is, with the tumbling flukes, fastened to the spindle, which passes through the crown of the anchor, and causes the flukes to fall into their holding position. The principles of these new anchors are considered to consist in shanks which are made of straight lengths of metal, and finished so that the fibres of the iron shall not be injured by cross-shuts or uncertain welding; also each arm and palm is made in one solid piece, and finished in straight lines, so that the fibres will not be altered, and the shaft-pin or spindle will also be in one straight line; and this is the improvement claimed. These anchors, being made in separate pieces, give a great advantage to the ANCHOR. 67 workman to execute each part perfectly; for he will not have such heavy weights to lift when hot, which will render these anchors much stronger, with less weight; and if an} accident should happen to them, any part may be tEken separate from the others to be repaired, and several of these parts of the anchor which may be likely to break may be car ied on board, in case of accident. This anchor is so contrived that one of thirty hundred weight may be taken to pieces and put together again, by one man, in twenty minutes; it may also be dismounted, and stowed in any part of the ship, in as little room as straight bars of iron, and speedily put together again. The anchor (fig. 18) patented by Mr. Brunton, in February, 18 al 5 1822, has its stock introduced at the crown part, for the purpose of turning it over into a holding position. The shank is perforated through the solid, in two places, with elliptical apertures, for but this is seldom made use of, because it is convenient to be able to transport the agitator from one place to another. When the agitation is finished, the wedges are to be taken out, and the vials are placed in order upon a table furnished with round cells destined to receive them, and to screen them from too free a light. When we place t'.e vials upon this table, we must give them a brisk circular motion, to collect the chloride of silver scattered round their sides; we must lift out their stoppers, and suspend them in wire rings, or pincers. - We next pour a thousandth of the decime solution into each vial; and 100 { before this operation is terminated, there is formed in the first vials, when there should be a precipitate, a nebulous stratum, very well marked, of about a centimetre in thickness. /1 A wB At the back of the table there is a black board divided into compartments numbered from 1 to 10, upon each of which we mark, with chalk, the thousandths of the decirne liquor put into the correspondent vial. The thousandths of sea salt, which indicate an augmentation of standard, are preceded by the sign +, and the thousandths of nitrate of silver by the sign -. When the assays are finished, the liquor of each vial is to be poured into a large vessel, in which a slight excess of sea salt is kept; and when it is fill, the supernatant clear liquid must be run off with a syphon. The chloride of silver may be reduced without any perceptible loss. After having washed it well, we immerse pieces of iron or zinc into it, and'add sulphuric acid in suibicient quantity to keep up a feeble disengagement of hydrogen gas. The mass must not be touched. In a few days the silver is completely reduced. This is easily recognised by the color and nature of the product; or by treating a small quantity of it with water of ammonia, we shall see whether there be any chloride unreduced; for it will be dissolved by the ammonia, and will afterwards appear upon saturating the ammonia with an acid. The chloiine remains associated with the iron or the zinc in a state of solution. The first washings o' the reduced silver must be made with an acidulous water, to dissolve the oxyat of iron which may have been formed, and the other washings with common water. After decanting the water of the last washing, we dry the mass, and add a little powdered borax to it. It must be now fused. The silver being in a bulky powder, is to be put in successive portions into a crucible as it sinks down. The heat should be at first moderate; but towards the end of the operation it must be pretty strong to bring into complete fusion the silver and the scoriae, and to effect their complete separation. In case it should be supposed that the whole of the silver had not been reduced by the iron or zinc, a little carbonate of potash should be added to the borax. The silver may also be reduced by exposing the chloride to a strong heat, in contact with chalk and charcoal. The following remarks by M. Gay Lussac, the author of the above method, upon the effect of a little mercury in the humid assay, are important:It is well known that chloride of silver blackens the more readily as it is exposed to an intense light, and that even in the diffused light of a room, it becomes soon sensibly colored. If it contains four to five thousandths of mercury, it does not blacken; It remains of a dead white: with three thousandths of mercury, there is no marked discoloring in diffused light; with two thousandths it is slight; with one it is much more marked, but still it is much less intense than with pure chloride. With half a 106 ASSAY. thousandth of mercury Ihe difference of color is not remarkable, and is perceived onlj.n a very moderate light. But when the quantity of mercury is so small that it cannot be detected by the difference of color in the chloride of silver, it may be rendered quite evident by a very simple process of concentration. Dissolve one gramme of the silver supposed to contain of a thousandth of mercury, and let only 4 of it be precipitated, by adding only ~ of the common salt necessary to precipitate it entirely. In thus operating, the I thousandth of mercury is concentrated in a quantity of chloride of silver four times smaller it is as if the silver having been entirely precipitated, four times as much mercury equal to two thousandths, had been precipitated with it. In taking two grammes of silver, and precipitating only 4 by common salt, the precipitate would be, with respect to the chloride of silver, as if it amounted to four thousandths. By this process, which occupies only five minutes, because exact weighing is not necessary, l of a thousandth of mercury may be detected in silver. It is not useless to observe, that in making those experiments the most exact manner of introducing small quantities of mercury into a solution of silver, is to weigh a minute globule of mercury, and to dissolve it in nitric acid, diluting the solution so th:lt it may contain as many cubic centimetres as the globule weighs of centigrammes. Each cubic centimetre, taken by means of a pipette, will contain one milligramme of mercury. If the ingot of silver to be assayed is found to contain a greater quantity of mercury, one thousandth for example, the humid process ought either to be given up in this case, or to be compared with cupellation. When the silver contains mercury, the solution from which the mixed chlorides are precipitated does not readily become clear. Silver containing mercury, put into a small crucible and mixed with lamp-black, to prevent the volatilization of the silver, was heated for three quarters of an hour in a muffle, but the silver increased sensibly in weight. This process for separating the mercury, therefore, failed. It is to be observed, that mercury is the only metal which has thus the power of disturbing the analysis by the humid way. ASSAYrNG OF GOLD.-In estimating or expressing the fineness of gold, the whole mass spoken of is supposed to weigh 24 carats of 12 grains each, either real, or merely proportional, like the assayer's weights; and the pure gold is called fine. Thus, if gold be said to be 23 carats fine, it is to be understood, that in a mass, weighing 24 carats, the quantity of pure gold amounts to 23 carats. In such small work as cannot be assayed by scraping off a part and cupelling it, the assayers endeavor to ascertain its fineness or quality by the touch. This is a method of comparing the color and other properties, of a minute portion of the metal, with those -of small bars, the composition of which is known. These bars are called touch needles, and they are rubbed upon a smooth piece of black basaltes or pottery, which, for this reason, is called the touchstone. Black flint slate will serve the same purpose. Sets of gold needles may consist of pure gold; of pure gold, 23-2 carats with - carat of silver; 23 carats of gold with one carat of silver; 22- carats of gold with 1, carat of silver; and so on, till the silver amounts to four carats; after which the additions may proceed by whole carats. Other needles may be made in the same manner, with copper instead of silver; and other sets may have the addition, consisting either of equal parts of silver and copper, or of such proportions as the occasions of business require. The examination by the touch may be advantageously employed previous to quartation, to indicate the quantity of silver necessary to be added. In foreign countries, where trinkets and small work are required to be submitted to the assay of the touch, a variety of needles is necessary; but they are not much used in England. They afford, however, a degree of information which is more considerable than might at first be expected. The attentive assayer compares not only the color of the stroke made upon the touchstone by the metal under examination, with that produced by his needle, but will likewise attend to the sensation of roughness, dryness, smoothness, or greasiness, which the texture of the rubbed metal excites, when abraded by the stone. When two strokes perfectly alike in color are made upon the stone, he may then wet them with aquafortis, which will affect them very differently, if they be not similar compositions; or the stone itself may be made red-hot by the fire, or by the blowpipe, if thin black pottery be used; in which case the phenomena of oxydation will differ according to the nature and quantity of the alloy. Six principal circumstances appear to affect the operation of parting; namely, the quantity of acid used in partina, or in the first boiling; the concentration of this acid; the time employed in its application;.he quantity of acid made use of in the reprise, or second operation; its concentration; Ind the time during which it is applied. From experiment it has been shown, tnat each of these unfavoraDle circumstances might easily occasion a loss of from the half of ASSAY. 107 a thirty-second part of a carat, to two thirty-second parts. The assayers explain their technical language by observing, that in the whole mass consisting of twenty-four carats, this thirty-second part denotes 1-768th part of the mass. It may easily be conceived, therefore, that if the whole six circumstances were to exist, and be productive of errors, falling the same way, the loss would be very considerable. It is therefore indispensably necessary, that one uniform process should be followed in the assays of gold; and it is a matter of astonishment, that such an accurate process should not have been prescribed by government for assayers, in an operation of such great commercial importance, instead of every one being left to follow his own judgment. The process recommended in the old French official report is as follows: twelve grains of the gold intended to be assayed must be mixed with thirty grains of fine silver,, and cupelled with 108 grains of lead. The cupellation must be carefully attended to, and all the imperfect buttons rejected. When the cupellation is ended, the button must be reduced, by lamination, into a plate of 1 inches, or rather more, in length, and four or five lines in breadth. This must be rolled up upon a quill, and placed in a matrass capable of holding about three ounces of liquid, when filled up to its narrow part. Two ounces and a half of very pure aquafortis, of the strength of 20 degrees of Baum6's areometer, must then be poured upon it; and the matrass _eing placed upon hot ashes, or sand, the acid must be kept gently boiling for a quarter of an hour: the acid must then be cautiously decanted, and an additional quantity of 1l ounces must be poured upon the metal, and slightly boiled for twelve minutes. This being likewise carefully decanted, the small spiral piece of metal must be washed with filtered river water, or distilled water, by filling the matrass with this fluid. The vessel is then to be reversed, by applying the extremity of its neck against the bottom of a crucible of fine earth, the internal surface of which is very smooth. The annealing must now be made, after having separated the portion of water which had fallen into the crucible; and, lastly, the annealed gold must be weighed. For the certainty of this operation, two assays must be made in the same manner, together with a third assay upon gold of twenty-four carats, or upon gold the fineness of which is perfectly and generally known. No conclusion must be drawn from this assay, unless the latter gold should prove to be of the fineness of twenty-bfur carats exactly, or of its known degree of fineness; for, if there he either loss or surplus, it may be inferred that the other two assays, having undergone the same operation, must be subject to the same error. The operation being made according to this process by several assayers, in circumstances of importance, such as those which relate to large fabrications, the fineness of the gold must not be depended upon, nor considered as accurately known, unless all the assayers have obtained a uniform result, without communication with each other. This identity must be considered as referring to the accuracy of half the thirty-second part of a carat. For, notwithstanding every possible precaution or uniformity, it very seldom happens that an absolute agreement is obtained between the different assays of one and the same ingot; because the ingot itself may differ in its fineness in different parts of its-mass. The phenomena of the cupellation of gold are the same as of silver, only the operation is less delicate, for no gold is lost by evaporation or penetration into the boneash, and therefore it bears safely the highest heat of the assay furnace. The button of gold never vegetates, and need not therefore be drawn out to the front of the muffle, but may be left at the further end till the assay is complete. Copper is retained more strongly b- gold than it is by silver; so that with it 16 parts of lead are requisite to sweat out 1 of copper; or, in general, twice as much lead must be taken for the copper alloys of gold, as for those of silver. When the copper is alloyed with very small quantities of gold, cupellation would afford very uncertain results; we must then have recourse to liquid analysis. M. Vauquelin recommends to boil 60 parts of nitric acid at 22~ Baume, on the spiral slip or cornet of gold and silver alloy, for twenty-five minutes, and replace the liquid afterwards by acid of 32~, which must be boiled on it for eight minutes. This process is free from uncertainty when the assay is performed upon an alloy containing a considerable quantity of copper. But this is not the case in assaying finer gold; for then a little silver always remains in the gold. The surcharge which occurs here is 2 or 3 thousandths; this is too much, and it is an intolerable error when it becomes greater, which often happens. This evil may be completely avoided by employing the following pr.oc-ss of M. Chaudet. He takes 0-500 of'he fine gold to be assayed; cupels it with 1P500 of silver, and 1-000 of lead; forms, with the button from the cupel, a riband or strip three inches long, which he rolls into a cornet. He puts this into a matrass with acid at 22~ B., which he boils for 3 or 4 minutes. He replaces this by acid of 32~ B., and boils for ten minutes; then decants off, and boils again with acid of 32~, which must be finally boiled for 8 or 10 minutes. Gold thus treated is very pure. He washes the cornet, and puts it entire into a small 108 AUTOMATIC. crucible permeable to water; heats the crucible to dull redness under the muffle, when the oold assumes the metallic lustre, and the cornet becomes solid. It is now taken Out of the crucible and weighed. When the alloy contains platinum, the assay presents greater difficulties. In general, to separate the platinum from the gold with accuracy, we must avail ourselves of a peculiar property of platinum; when alloyed with silver, it becomes soluble in nitric acid. Therefore, by a proper quartation of the alloy by cupellation, and boiling the button with nitric acid, we may get a residuum of pure gold. If we were to treat the button with sulphuric acid, however, we should dissolve nothing but the silver. The copper is easily removed by cupeilation. Hence, supposing that we have a quaternary compound of copper, silver, platinum, and gold, we first cupel it, and weigh the button obtained; the loss denotes the copper. This button, treated by sulphuric acid, will suffer a loss of weight equal to the amount of silver present. The residuum, by quartation with silver and boiling with nitric acid, will part with its platinum, and the gold will remain pure. For more detailed explanations, see PLATINUM. ATOMIC WEIGHTS OR ATOMS, are the primal quantities in which the different objects of chemistry, simple or compound, combine with each other, referred to a common body, taken as unity. Oxyren is assumed by some philosophers, and hydrogen by others, as the standard of comparison. Every chemical manufacturer should be thoroughly acquainted with the combining ratios, which are, for the same two substances, not only definite, but multiple; two great truths, upon which are founded not merely the rationale of his operations, but also the means of modifying them to useful purposes. The discussion of the doctrine of atomic weights, or prime equivalents, belongs to pure chemistry; but several of its happiest applications are to be found in the processes of art, as pursued upon the greatest scale. For many instructive examples of this proposition, the various chemical manufactures may be consulted in this Dictionary. ATROPIA; a vegetable alkali extracted from the Atropa belladonna, or deadly night-shade. It is composed of about 70'98 carbon, 7-83 hydrogen, 4*83 azote, and 16 36 oxygen in 100 parts. It is prepared by treating the expressed juice of the fiesh plant, or watery extract of the dry, with caustic soda unto slight alkaline reaction, and then agitating the mixture with one and a half times its volume of ether. The atropia is taken up by the ether, but again deposited from it when the ethereous solution is left at rest for some time. The treatment with ether is repeated upon the first precipitate, till the atropia becomes pure. Other processes are prescribed. ATTAR OF ROSES. See OILS, VOLATILE, and PERFUMERY. AURUM. MUSIVUM. Mosaic gold, a preparation of tin; which see. AUTOMATIC, a term which I have employed to designate such economic arts as are carried on by self-acting machinery. The word "manufacture," in its etymological sense, means any system or objects of industry executed by the hands; but in the vicissitude of language, it has now come to signify every extensive product of art which is made by machinery, with little or no aid of the human hand, so that the most perfect manufacture is that which dispenses entirely with manual labor.* It is in our modern cotton and flax mills that automatic operations are displayed to most advantage; for there the elemental powers have been made to animate millions of complex organs, imparting to forms of wood, iron and brass, an intelligent agency. And as the philosophy of the fine arts, poetry, painting, and music, may be best studied in their individual masterpieces, so may the philosophy of manufactures in these its noblest creations.s. The constant aim and effect of these automatic improvements in the arts are philanthropic, as they tend to relieve the workman either from niceties of adjustment, wliichi exhaust his mind and fatigue his eyes, or from painful repetition of effort, which distort and wear out his frame. A well arranged power-mill combines the operation of many work-people, adult and young, in tending with assiduous skill a system of productive nachines continuously impelled by a central force. How vastly conducive to the commercial greatness of a nation, and the comforts of mankind, human industry can become, when no longer proportioned in its results to muscular effort, which is by its nature fitful and capricious, but when made to consist in the task of guiding the work of mechanical fingers and arms regularly impelled, with equal precision and velocity, by some indefatigable physical agent, is apparent to every visitor of our cotton, flax, silk, wool, and machine factories. This great era in the useful arts is mainly due to the genius of Arkwright. Prior to the introduction of his system, manufactures were avery where feeble and fluctuating in their development, shooting forth luxuriantly fot a season, and again withering almost to the roots' like annual plants. Their perennial growth then began, and attracted capital, in copious streams, to irrigate the rich domains * Philosophy of Manufactures, p. 1. t Ibid., p. 2, AUTOMATON. 109 of industry. When this new career commenced, about the year 1170, the annual consumption of cotton in British manufactures was under four millions of pounds' weight, and that of the wL.ole of Christendom was probably not more than ten millions. In 1850 the consumption in Great B.itain and Ireland was about five hundred and eighty-eight millions of pounds, and that of Europe and the United States together one thousand and ninety-two millions. In our spacious factory apartments the benignant power of steam summons around him his myriads of willing menials, and assigns to each the regulated task, substituting for painful muscular effort upon their part, the energies of his own gigantic arm, and demanding in return, only attention and dexterity to correct such little aberrations as casually occur in his workmanship. Under his auspices and in obedience to Arkwriaht's polity, magnificent edifices, surpassing far in number, value, usefulness, and ingenuity of construction, the boasted monuments of Asiatic, Egyptian, and Roman despotism, have, within the short period of fifty years, risen up in this kingdom, to show to what extent capital, industry, and science, may augment the resources of a state, while they meliorate the condition of its citizens. Such is the automatic system, replete with prodigies in mechanics and' political economy, which promises, in its futurs growth, to become the great minister of civilization to the terraqueous globe, enabling this country, as its heart, to diffuse, along with its commerce, the life-blood of knowledge and religion to myriads of people still lying "in the region and shadow of death."* Of these truths, the present work affords decisive evidence in almost every page. AUTOMATON. In the etymological sense, this word (self-working) signifies every mrechanical construction which, by virtue of a latent intrinsic force, not obvious to common eyes, can carry on, for some time, certain movements more or less resembling the results of animal exertion, without the aid of external impulse. In this respect, all kinds of clocks and watches, planetariums, common and smoke jacks, with a vast number of the machines now employed in our cotton, silk, flax, and wool factories, as well as in our dyeing and calico printing works, may be denominated automatic. But the term, automaton, is, in common language, appropriated to that class of mechanical artifices in which the purposely concealed power is made to imi'ate the arbitrary or voluntary motions of living beings. Human figures, of this kind, are sometimes styled.ndroides, from the Greek term, like a man. Although, from what we have said, clock-work is not properly placed under the head automaton, it cannot be doubted that the art of making clocks, in its progressive improvement and extension, has given rise to the production of automata. The most of these, in their interior structure, as well as in the mode of applying the Inoving power, have a distinct analogy with clocks; and these automata are frequently mounted in connexion with watch work. Towards the end of the 13th century, several tower clocks, such as those at Strasburg, Lubec, Prague, Olmutz, had curious mechanisms attached to them. The most careful historical inquiry proves that automata, properly speaking, are certainly not older than wheel-clocks; and that the more perfect structures of this kind are subsequent to the general introduction of spring-clocks. MIany accounts of ancient automata, such as the flying doves of Archytas of Tarentum. Regiomontanus's iron flies, the eagle which flew towards the emperor Maximilian, in Nuremburg, in the year 1470, were deceptions, or exaggerated statements; for, three such masterpieces of art would form now, with every aid of our improved mechanisms, the most difficult of problems. The imitation of flying creatures is extremely difficult, for several reasons. There is very little space for the moving power, and the only material possessed of requisite strength being metal, must have considerable weight. Two automata, of the celebrated French mechanician, Vaucauson, first exhibited in the year 1738, have been greatly admired; namely, a flute-player, five and a half feet high, with its cubical pedestal, which played several airs upon the German flute; and that, not by any interior tube-work, but through the actual blowing of air into the flute, the motina of the tongue, and the skilfiul stopping of the holes with the fingers; as also a duck, which imitated many motions of a natural kind in the most extraordinary manner. This artist has had many imitators, of whom the brothers Droz of Chaux de Fonds were the most distinguished. Several very beautiful clock mechanisms of theirs are known. One of them with a figure which draws; another playing on the piano; a third which writes, besides numerous other combined automata. Frederick Von Knauss completed a writing machine at Vienna, in the year 1760. It is now in the model cabinet of the Polytechnic Institute, and consists of a globe 2 feet in diameter, containing the mechanism, upon which a figure 7 inches high sits, and writes upon a sheet of paper fixed to a frame, whatever has been placed beforehand upon a regulating cylinder. At the end of every line, it rises and moves its hand sideways, in order to begin a new line. Very complete automata have not been made of late years, because they are very * Philosophy of Manufactures, p. 18 110 AUTOMATON. expensive; and by soon satisfying curiosity, they cease to intcitst. Ingenious met chainicians find themselves better rewarded by directing their talents to the self-acting machinery of modern manufactures. We may notice here, however, the mechanical trumpeter of Malzl, at Vienna, and a similar work of Kauffmann, at Dresden. II French Switzerland some artists continue to make minute automata which excite ne little wonder; such as singing canary birds, with various movements of a natural kind; also little birds, sometimes hardly three-quarters of an inch long, in snuff-boxes and watches of enamelled gold. Certain artificial figures which have been denominated automata, hardly deserve the name; since trick and c-nfedcracy are more or less concerned in their operation. To this head belong a number of figures apparently speaking by mechanism; a clock which begins to strike, or to play, when a person makes a sign of holding up his finger; this -effect being robably produced by a concealed green-finch, or other little bird, instructed to set off the dteente of the wheel-work at a signal. It is likely, also, that the chess player of Von Kempelen, which excited so much wonder in the last century, had a concealed confederate. Likewise, the very ingenious little figures of Tendler, father and son, which imitated English horsemen and rope-dancers, constructed at Eisenerz, in Styria, are probably no more true automata than the fantoccili, or figures of puppets which are exhibited in great perfection in many towns of Italy, especially at Rome. The moving power of almost all automata is a wound-up steel spring; because in comparison with other means of giving motion, it takes up the smallest room, is easiest concealed, and set a-going. Weights are seldom employed, and only in a partial way. The employment of other moving powers is more limited; sometimes fine sand is made to fall on the circumference of a wheel, by which the rest of the mechanism is moved. For the same purpose water has been employed; and, when it is made to fall into an air-chamber, it causes sufficient wind to excite musical sounds in pipes. In particular cases quicksilver has been used, as, for example, in the Chinese tumblers, which is only a physical apparatus to illustrate the doctrine of the centre of gravity. Figures are frequently constructed for playthings which move by wheels hardly visible. An example of this simplest kind of automaton which may be introduced here, as illustrating the self-acting principles of manufactures, is shown in the figure. Fig. 102 exhibits the outlines of an automaton, representing a swan, with suitably combined movements. The mechanism may be described, for the sake of clearness of explanation, under distinct heads. The first relates to the motion of the whole figure. By means of this 102 part it swims upon the water, e~Vm ~0 in directions changed from time to time without exterior agency. Another construc_ t -— tion gives to the figure the faculty of bending its neck on G^|| / /"^^*~>\ *several occasions, and to 1 l /6 ^ JX such an extent that it can plunge the bill and a portion r n /JI^ ry g Xof the head under water. Lastly, it is made to move its head and neck slowly from side to side. =-'' ^ c 3 On the barrel ofthe spring, exterior to the usual ratchet wheel, there is a main-wheel, marked 1, wnich works into the pinion of the wheel 2. The wheel 2 moves a smaller one, shown merely in dotted lines, and on the long axis of the latter, at either end there is a rudder, or water-wheel, the paddles of which are denoted by the letter a. Both of these rudder-wheels extend through an oblong opening in the bottom of the figuie down into the water. They turn in the direction of the arrow, and impart a straight-forward movement to the swan. The chamber, in which these wheels revolve, is made water tight, to prevent moisture being thrown upon the rest of the machinery. Ey the wheel 4, motion is conveyed to the fly-pinion 5; the fly itself 6, serves to regulate the working of the whole apparatus, and it is provided with a stop bar not shown in the engraving, to bring it to rest, or set it a-going at pleasure. Here, as we may imagine, the path pursued is rectilinear, when the rudderwheels are made to work in a square direction. An oblique bar, seen only in section rt b, moveable about its middle point, carries at each end a web foot c, so that the direction of the bar b, and of both feet towards the rudder wheels, determines the form of the path which the figure will describe. The change of direction of that oblique bat AUTOMATON. 111 is effected without other agency. For this purpose, the wheel 1 takes into the pinion 7 and this carries round the crown-wheel 8, which is fixed, with an eccentric disc 9, upon a common axis. While ths crown-whePl rroves in the direction of the arrow, it turns the smaller eccentric portion of the el'iptic disc towards the lever m, which, pressed upon incessantly by its spring, assumes, by degrees, the position corresponding with the middle line of the figure, and afterwards an oblique position; then it goes back again, and reaches its first situation; consequently through the reciprocal turning of the bar h, and the swim-foot, is determined and varied the path which the swan must pursue. This construction is available with all automata, which work by wheels; and it is obvinus, that we may, by different forms of the disc 9, modify, at pleasure, the direction and the velocity of the turnings. If the disc is a circle, for instance, then the chances will lake place less suddenly; if the disc has an outward and inward curvature, upon whose edge the end of the lever presses with a roller, the movement will take place in a serpentine line. The neck is the part which requires the most careful workmanship. Its outward case must be fleyible, and the neck itself should therefore be made of a tube of spiral wire, covered with leather, or with a feathered bird-skin. The double line in the interior, where we see the triangles e, e, e, denotes a steel spring made fast to the plate 10, which forms the bottom of the neck; it stands loose, and needs to be merely so strong as to keep the neck straight, or to bend it a little backwards. It should not be equally thick in all points, but it shoul1 be weaker where the first graceful bend is to be made; and, in general, its stiffness ought to correspond to the curvature of the neck of this bird. The tliangles e are made fast at their base to the front surface of the spring; in the points of each there is a slit, in the middle of which a moveable roller is set, formed of a smoothly turned steel rod. A thin catgut stringf, runs from the upper end of the spring, where it is fixed over all these rollers, and passes through an aperture pierced in the middle of 10, into the inside of the rump. If the catgut be drawn straight back towards f, the spring, and consequently the neck, must obviously be bent, and so much thl more, the more tightly f.s pulled, and is shortened in the hollow of the neck. How this is accomplished by the wheel-work will presently be shown. The wheel 11 receives its motion from the pinion s, connected with the main-wheel 1. Upon 11 there is, moreover, the disc 12, to whose circumference a slender chain is fastened. When the wheel 11 turns in the direction of the arrow, the chain will be so much pulled onwards through the corresponding advance at the point at 12, till this point has come to the place opposite to its present situation, and, consequently, 11 must have performed half a revolution. The other end of the chain is hung in the groove of a very moveable roller 14; and this will be turned immediately by the unwinding of the chain upon its axis. There turns, in connexion with it, however, the large roller 13, to which the catgut f is fastened; and as this is pulled in the direction of the arrow, the neck will be bent until the wheel 11 has made a half revolution. Then the drag ceases again to act upon the chain and the catgut; the spring in the neck comes into play: it becomes straight, erects the neck of the animal, and turns the rollers 13 and 14, back into the;" first position. The roller 13 is of considerable size, in order that through the slight motion of the roller 14, a sufficient length of the catgut may be wound off, and the requisite shortening of the i lek may be effected; which results from the proportion of the diameters of the rollers 11, 13, and 14. This part of the mechanism is attached as near to the sile of the hollow body as possible, to make room for the interior parts, but particularly for the paldle-wheels. Since the catgut,f, must pass downwards on the middle from 10, it is necessary to incline it sideways and outwards towards 13, by means of some small rollers. The head, constituting one piece with the neck, will be depressed by the complete flexure of this; and the bill, being turned downwards in front of the breast, will touch the surface of the water. The head will not be motionless; but it is joined on both sides by a very moveable hinge, with the light ring, which forms the upper part of the clothing of the neck. A weak spring, g, also fastened to the end of the neck, tends to turn the head backwards; but in the present position it cannot do so, because a chain al g, whose other end is attached to the plate 10, keeps it on the stretch. On the bending of the neck, this chain becomes slack; the spring g comes into operation, and throws the head so far back, that, in its natural position, it will reach the water. Finally, to render the turning of the head and the neck practicable, the latter is not closely connected with the rump, while the plate 10 can turn in a cylindrical manner upon it- axis, but cannot become loose outwardly. Moreover, there is upon the axis of the wheel 1, and behind it (shown merely as a circle in the engraving) a bevel wheel, which works into a second similar wheel, 15, so as to turn it in a horizontal direction. The pin 16, of the last wheel, works upon a two-armed lever 19, moveable round the point h, and this lever moves tile neck by means of the pin 17. The shorter arm of the 1 112 AUTOMATON. lever 19 has an oval aperture in which the pin 16 stanas. As soon as this, in con sequence of the movement of the bevel-wheel 15, comes into the dotted position, it pushes the oval ring outwards on its smaller diameter, and thereby turns the lever upon the point h, into the oblique direction shown by the dotted lines. The pin 16, having come ot its way right opposite to its piresent position, sets the lever again straight. Then the lever, by the further progress of the pin in its circular path, is directed outwards to the opposite side; and, at last, when 15 has made an entire revolution, it is quite straight. The longer arm of the lever follows. of course, these alternating movements, so that it turns the neck upon its plate 10, by means of the pin 17; and, as 18 denotes the bill this comes into the dotted position. It may be remarked in conclusion, that the drawing of fig. 102 represents about half the size of which the automaton may be constructed, and that the body may be formed of thin sheet-copper or brass. Fig. 103, 104, 105, show the plan of a third automaton; a horse which moves its feet 103 / \ 105 in a natural way, and draws a carringe with two figures sitting in it. The man appealr to drive the horse with a whip; the woman bends forward firom him in front. The four wheels of the carriage have no connexion with the moving mechanism. In fig. 105, some parts are represented upon a larger scale. The wheel 1, in fig. 103, operates through the two carrier wheels upon the wheels marked 4 and 5. By means of the axis of these two wheels, the feet are set in motion. The left fore-foot, a, then the right hinder foot, move themselves backwards, and take hold of the ground with small tacks in their hoofs, while the two other legs are bent and raised, but no motion of the body takes place. The carriage, however, with which the horse is connected, advances upon its wheels. By studying the mechanism of the foot, a, and the parts connected with it, we can readily understand the principles of the movement. The axis of wheel 4 is crank-shaped on both sides, where it has to operate directly on the fore feet; but for each foot, it is bent in an opposite direction, as is obvious in the front view fig.104. This crank, or properly its part furthest from the axis, serves instead of the pin 16, in the swan, and moves like it in an oval spot, p, fig. 103, a two-armed lever, which gives motion through tooth-work, but not as in the swan, by means of a second pin. This wheelwork renders the motion smoother. The above lever has its fulcrum at n, fig. 1039, about which it turns alternately, to the one and the other side, by virtue of the rotation of the wheel 4. The toothed arch, or the half-wheel on the under side, lays hold of a shorter lever, in a similar arch, upon the upper joint of the foot, which is moved forward and backward upon the pivot m. In virtue of the motions in the direction of the arrow, the foot a will move itself first obliquely backwards, without bending, and the boay will thereby bend itself forward. When the right hand foot makes the same motion, both the other feet are raised and bent. The joints of the foot at d and e are formed of hinges, which are so constructed that they can yield no farther than is necessary at every oblique position of the foot. With the continued rotation of the wheel 4, the lever turns itself about?, in an inverted direction inwards, and impels the uppermost foot-joint forward, so that it forms an acute angle with the body in front. The foot is now twice bent upon its joints. This takes place by the traction of the chain t, which is led over rollers (as the drawing shows) to the foot, and is there fastened. As its upper end has its fixed point in the interior of the body, it is therefore drawn by the eccentric pin r standing in the vicinity of m, and thus bends the foot at the hinges. If there was space for it, a roller would answer better than a pin. By ninges. It there was space for it, a roller would answer better than a pin. By AVENTURINE. 113 the recedure of the uppermost joint into the first position, the tension of the chain t ceases again of itself, while the pin r removes from it, and the foot is again extended in a straight line by the small springs operating upon its two under parts, which were previously bent stiffly by the chain. By the aid of the figures with this explanation, it will be apparent that all the fore feet have a similar construction, that the proper succession of motions will be effected through toothed arcs, and the position of the cranks on the axis of the wheels 4 and 5, and hence the advance of the figure must follow. The wheel 6 puts the fly 7 in motion, by means of the small wheel marked 1; on the fixed points of the 4 chains, by means of'l ratchet-wheel arid a catch, the necessary tension will again be produced when the chains have been dlawn out a little. There is sufficient room for a mechanism which could give motion to the head and ears, were it thought necessary. The proper cause of the motions may now be explained. In fig. 105, a, is a wheel connected with the wound-up spring, by which the motion of the two human figures, and also, if desired, that of the horse may be effected. The axis of the wheel b carries a disc with pins, which operate upon the two-armed lever with its fulcrum e, and thus causes the bending of the upper part of one of tlhe figures, which has a hinge atf. On the axis of that wheel there is a second disc c, for giving mttion to the other figure; which, for the sake of clearness, is shown separate, although it should sit alongside of its fellow. On the upper end of the'double-armed lever d, there is a cord whose other end is connected with the moving armn, in the situation i, and raises it whenever a pin in the disc presses the under part of the lever. A spring h brings the arm back into the original position, when a pin has passed from the lever, and has left it behind. The pins at c and d may be set at different distances fronm.he middle of the disc, whereby the motions of the figures by every contact of another pin, are varied, and are therefore not so uniform, and consequently more natural. For the connection of both mechanisms, namely, the carriage with the horse, various arrangements may be adopted. Two separate traction springs should be employed; one at a, fig. 105, in tire coach-seat; the other in the body of the horse. In the coach-seat at b, the fly with its pinion, as well as a ratchet-wheel, is necessary. By means of the shaft, the horse is placed in connection with the wagon. It may, however, receive its motion from the spring in the carriage, in which case one spring will be sufficient. Upon the latter plan the following construction may be adopted:-To the axis of b, fig. 105, a bevel wheel is to be attached, and from this the motion is to be transmitted to the bottom of the carriage with the help of a second bevel wheel s, connected with a third bevel wheel t. This again turns the wheel u, whose long axis v goes to the middle of the horse's body, in an oblique direction, through the hollow shaft. This axis carries an endless screw 9, fig. 103, with very oblique threads, which works into the little wheel 8, corresponding to the wheel 1, through an opening in the side of the horse, and in this way sets the mechanism of the horse a-going. With this construction of fig. 105, a spring of considerable strength is necessary, or if the height of the carriage-seat does not afford sufficient room, its breadth will answer for placing two weaker springs alongside of each other upon a common barrel. AVENTURINE. According to Wohler's examination, aventurine glass owes its golden iridescence to a crystalline separation of metallic copper from the mass colored brown by the peroxide of iron. In the aventurine glaze for porcelain a crystalline separation of green oxide of chromium from the brown ferruginous mass of the glaze produces a similar effect, This glaze is prepared as follows: 31 part. of fine lixiviated dry porcelain earth from Halle, 43 do. do. dry quartz sand, 14 do. do. gypsumn, 12 do. do. fragments of porcelain, are stirred up with 300 parts of water, and by repeated straining through a linen sieve uniformly suspended in it, and intimately mixed. To this paste is added, under constant agitation and one after the other, aqueous solutions of 19 parts bichromate of potash, 100 " protosulphate of iron, 47 " acetate of lead, and then so much solution of ammonia that the iron is completely separated. The salts of potash and ammonia are removed by frequent decantation with spring water. The baked porcelain vessels'are dipped into tile pasty mixture obtained as above described in the same manner as with other glazes, and then fired in the porcelain furnace. After this they appear covered with a brown glaze, which in reflected light appears to be filled with a countless number of light gold spangles. 9 14 BALANCE A thin fragment of the glass appears, under the microscope, by transmitted light, as a clear brownish glass, in which numerous transparent green six-sided prisms of oxide of chromium, and some brownish crystals, probably of oxide of chromium and peroxide of iron, are suspended. The oxide of chromium therefore separates, on the slow cooling of the glaze in the porcelain furnace, firom the substance of the glaze-a sili. cate of potash, lime, and alumina-saturated with the peroxide of iron, and shines through the brownish mass with a golden color. When the aventurine glaze is mixed with an equal amount of colorless porcelain glaze, the glassy mass no ]onger has a brown color after the burning, but a light greenish-gray, and the eliminated erjystalline spangles likewise exhibit in reflected light their natural green color. AXE. A tool much used by carpenters for cleaving, and roughly fashioning, blocks of wood. It is a flat iron wedge, with an oblong steel edge, parallel to which, in the short base, is a hole for receiving and holding fast the end of a strong wooden handle. In the cooper's adze, the oblong edge is at right angles to the handle, and is slightly curved up, or inflected towards it. AXLES, of carriages.-See WVHEEL CARRIAGES. AXUNGE. Hog's lard; see FAT and OILS. AZOBENZOIDE, and AZOBENZOYLE, prod: lts of the action of pure water of ammonia upon oil of bitter almonds, by making the ammonia pass down through a wide tube filled with the almond pap. The operation must be continued for weeks. AZOTIZED, said of certain vegetable substances, which, as containing azote, were supposed at one time to partake, in some measure, of the animal nature; most animal bodies being characterized by the presence of much azote in their composition. The vegetable products, indigo, caleine, gluten, and many others, contain abundance of azote. AZURE, the tine blue pigment, commonly called smalt, is a glass, colored with oxide of cobalt, and ground to an impalpable powder. The manufacture of azure, or smalt, has been lately improved in Sweden, by the adoption of the following process:The cobalt ore is first roasted till the greater part of the arsenic is driven off. The residuary impure black oxide is mixed with as much sulphuric acid (concentrated) as will make it into a paste, which is exposed at first to a moderate heat, then to a cherry-red ignition for an hour. The sulphate thus obtained is reduced to powder, and dissolved in water. To the solution, carbonate of potash is gradually added, in order to separate the remaining portion of oxide of iron; the quantity of which depends upon the previous degree of calcination. If it be not enough oxidized, the iron is difficult to be got rid of. When, from the color of the precipitate, we find that the potash separates merely carbonate of cobalt, it is allowed to settle, the supernatant liquor is decanted, and precipitated, by Ineans of a solution of silicate of potash, prepared as follows:Ten parts of potash are carefully mixed with fifteen parts of finely ground flints or sand, and one part of pounded charcoal. This mixture is melted in a crucible of brick clay, an operation which requires steady ignition during 5 or 6 hours. The mass, when llelted and pulverized, may be easily dissolved in boiling water, adding to it, by little at a time, tile glass previously ground. The filtered solution is colorless, and keeps well in the air, if it contains one part of glass for 5 or 6 of water. The silicate of cobalt which precipitates upon mixing the two solutions, is the preparation of cobalt most suitable for painting upon porcelain, and for the manufacture of blue glass. See COBALT. B. BABLAH. The rind or shell which surrounds the fruit of the mimosa cineraria; it comes from the East Indies, as also fromn Senegal, under the name of Neb-neb. It contains gallic acid, tannin, a red coloring matter, and an azotized substance; but the proportion of tannin is smaller than in sumnac, galls, and knoppern (gall-nuts of the common oak) in reference to that of gallic acid, which is considerable in the bablah. It has been used, in dying cotton, for producing various shades of drab; as a substitute for the more expensive astringent dye-stuffs. BAGASSE. The sugar-cane, in its dry, crushed state, as delivered from the sugar. mil. It is much employed for fuel in the colonial sugar-houses. BAKING. (CLire, Fr. Backen, Germ.) The exposure of any body to such a heat as will dry and consolidate its parts without wasting them. Thus wood, pottery, and porcelain, are baked, as well as bread. BALANCE.-To conduct arts, manufacturers, and mines, with judgment and success, recourse must be had, at almost every step, to a balance. Experience proves that all material bodies, existing upon the surface of the earth, are constantly solicited by a lorce which tends to bring them to its centre, and that they actually fall towaids it BALANCE. 115 when they are free to move. This force is called gravity. Though the bodies be not fiee, tL3 effort of gravity is still sensible, and the resultant of all the actions which it exercises uponl their material points constitutes what is popularly called their weight. These weights are, therefore, forces which may be compared together, and by melans of machines may be made to correspond or be counterpoised. To discover whether two weights be equal, we must oppose them to each other in a machine where they act in a similar manner, and then see if they maintain an equilibrium; for example, we fulfil this condition if we suspend them at the two extremities of a lev.er, supported at its centre, and whose arms are equal. Such is the general idea of a balance. The beam of a good balance ought to be a bar of well-tempered steel, of such form as to secure perfect inflexibility under any load which may be filly applied to its extremities. Its arms should be quite e,,nal in weight and leneth upon each side of its point of suspension; and this point should be placed in a vertical line over the centre of gravity; and the less distant it is fromi it, the more delicate will be the balance. Were it placed exactly in that centre, the beam would nut spontaneously recover the horizontal position when it was once removed from it. To render its indications mnore readily commensurable, a slender rod or needle is fixed tc it, at rioht angles, in the line passing through its centres of gravity and suspension. The point, or rather edge of suspension, is made of perfectly hard steel, and turns upon a bed of the same. For common uses the arms of a balance can be made sufficier,y equal to give satisfactory results; but, for the more refined purposes of science, that equality, should never be presumed nor trusted to; and, fortunately, exact weighing is quite independent of that equality. To weigh a body is to determine how many times the weight of that body contains another species cf known weight, as of grains or pc'ina., for example. In order to find it out, let us place the substance, suppose a piece of gold, in the left hand scale of the balance; counterpoise it with sand or shot in the other, till the index needle be truly vertical, or stand in the middle of the scale, proving the beam to be horizontal. Now remove gently the piece of gold, and substitute in its place standard multiple weights of any graduation, English or French, till the needle again resumes the vertical position, or till i:s oscillations upon either side of the zero point are equal. These weights will represent precisely the weight of the gold, since they are pl~ced in the same circumstances precisely with it, and make the same equilibrium with the weight laid in the other scale. This method of weighing is obviously independent of the unequal length as well as the unequal weight of the arms of the beam. For its perfection two requisites only are indispensable. The first is that the points of suspension should be rigorously the same in the two operations; for the power of a given weight to turn the beam being unequal, according as we place it at different distances fiom the centre of suspension, did that point vary in the two censecutive weighings, we would require to employ, in the second, a different weight from that of the piece of gold, in order to form an equilibrium with the sand or shot originally put in the opposite scale; and as there is nothing to indicate such inequality in the states of the beam, great errors would result from it. The best mode of securing against such inequality is to suspend the cords of the scales from sharp-edged rings, upon knife edges, at the ends of the beam, both made of steel sc hard tempered as to be incapable of indentation. The second condition is, that the balance should be very sensible, that is, when in equilibrium and loaded, it may be disturbed, and its needle ma;v oscillate, by the smallest weight put into either of the scales. This sensibility deperls solely upon the centre or nail of suspension; and it will be the more perfect the less friction there is between that k-nife-edge surface and the plane which supports it. Both should therefore be as hard and highly polished as possible; and should not be suffered to press against each other, except at the time of weighing. Every delicate b)alance of moderate size, moreover, should be suspended within a glass case, to protect it from the agitations of the air, and the corroding influence of the weather. In some balances a ball is placed upon the index or needle (whether that index stand above or below the beam), which may be nmade to approach or recede fiom the beam by a fine-threaded screw, with the effect of varying the centre of gravity relatively to the point of suspension, and theirehy increasing, at will, either the sensibility, or the stability of the balance. The greater the length of the arms, the less distant the centre of gravity is beneath the centre of suspension, the better polished its central knife-edge of 30~, the lighter the whole balance, and the less it is loaded, the greater will be its sensibility. In all cases the arms must be quite inflexible. A balance made by Ramsden for the Royal Society is capable of weighing ten pounds, and turns with one hundredth of a grain, which is the seven-millionth part of the weight. In pointing out this balance to me one evening, Dr. Wollaston told me it was so delicate, that Mr. Pond, then astronomer royal, when making some observations with it, found its indications affected by his relative position before it, although it was inclosed in a glass case. When he stood opposite the right arm, that 116 BALANCE FOR WEIGHING COIN. end of the beam preponderated, in consequence of its becoming expanded by the radi ation of heat from his body; and when he stood opposite the left arm, he made this preponderate in its turn. It is probable that Mr. Pond had previously adjusted the centres of gravity and suspension so near to each other as to give the balance its maxi mum sensibility, consistent with stability. Were these centres made to coincide, the beam, when the weights are equal, would rest in any position, and the addition of the smallest weight would overset the balance, and place the beam in a vertical position, from which it would have no tendency to return. The sensibility in this case would be the greatest possible; but the other two requisites of level and stability would be entirely lost. The case would be even worse if the centre of gravity were higher than the centre of suspension, as the balance When deranged, if free, would make a revolution of no less than a semi-circle. A balance maybe made by a fraudulent dealer to weigh falsely though its arms be equal, provided the suspension be as low as the centre of gravity, for he has only to toss his tea, for instance, forcibly into one scale to cause 15 ounces of it, or thereby, to counterpoise a pound weight in the other. Inspectors of weights, &c., are not aufait to this fruitful source of fraud among hucksters. BALANCE FOR WEIGHING COIN at the Bank of England, invented by William Cotton, Esq., Governor of the Bank. The new coinage first arlives at the Bank from the Mint in what are called "journies," a single journey weighing 15 lbs," and containing 701 sovereigns. The officers of the Mint are allowed 12 grains plus in every pound weight of metal, for the irregularities incidental to working it into coin; but they usually work to within one half of that allowance, which is technically called "the remedy." There was coined for the Bank in the spring of 1843, 8,000,000 of sovereigns, and the greatest variation from the weight allowed was only 60 grains, or one third of the remledy. Each sovereign should contain a portion of this remedy, to allow for wear in public use; and this extraordinary subdivision of metal is invariably obtained. The usual delivery of new coinage at the Bank contains 100journies, which is counted by weight only, that is, 200 sovereigns are counted into one scale, and the rest of the delivery is weighed in parcels which balance these 200, and this is all the counting the new coinage receives. The regularity and precision of the manipulations at the Mint obviate the necessity of any further examination, either as regards the gross amount or the weight of an individual piece. When the currency returns to the Bank from the public, it becomes necessary to ascertain if it has been reduced below the standard weight, and this imposes an arduous duty on the officers of the Bank. The amount of gold paid daily over the Bank counter varies considerably, but 30,000 may be taken as a rough average; and hence arises a tedious, irksome, and expensive process in weighing so large a number of pieces singly, and in quick succession, separating at the same time the light from the standard coin. The mode of weighing coins by hand requires much dexterity, practice and attention; but, in spite of all these, errors were inevitable, and it was to obviate these that the machine was invented by Mr. Cotton, the Governor of the Bank of England; it was constructed from his plans by Mr. Napier, and is thus described:Its exterior presents a plain brass case, with a small hopper tube on the top plate, about 4~ inches from which there is an opening in the top plate. In this opening is seen a platform in the form of a quadrant. This platform is suspended above one end of the beam, and is to receive the coin to be weighed. On one side of the case is a till to receive the sovereigns as they are weighed, partitioned so that one division is left for standard coin, and the other for such as are light. There is a sliding door to each division, for removing the coins at pleasure. The machine may be worked like a clock with a weight, or by any simple application of power. Its visible action is as follows:-The hopper being filled with gold, upon setting the machine in motion, it immediately places a sovereign on the little platform, which serves, as already stated, in place of a scale plan; and if it is of standard weight a small tongue comes rapidly forward and pushes the sovereign into that side of the till allotted to such coin; if light, another, and similar tongue to the first, pushes the sovereign into the other side of the till. The action of these tongues is at right angles to each other. While a sovereign is being weighed, a succeeding one is on its way from the hopper to the platform, and the moment the preceding sovereign is disposed of, according to its value, another is placed in its stead. To keep the hopper supplied with gold, and remove it from the till as it is filled, is all the attendance necessary. The more minute parts of the mechanical arrangement of the machine, such as the fulcrum, the forceps, &c., ale described in detail; and the following statement by Mr. Miller is given as a comparison with the old method of weighing:" With the bullion-scales 4,000 may be stated as the number a person can weigh in six hours. As the sovereigns now tendered at the Bank counter are most of them new, the scale dips quickly in weighing, and one person can weigh 5,000 in six hours; but a BALANCE FOR WEIGHING COIN. 117 short time ago, before the issue of the new coinage, the same person could weigh only 8,000, as it took a longer time for the scales to indicate. "The bullion scales cannot indicate nearer than 4-100ths of a grain, at the above rate. "The machine is perfectly free from the sources of error to which the scales are subject, and weighs as quickly, whether the sovereigns are new and of full weight, or old and doubtful; it can weigh 10,000 in six hours, and divide coin varying only one-fiftieth of a grain." The paper is illustrated by two drawings of the internal arrangement of the machine, and a model, showing the action of the tongues and platform. Mr. Oldham exhibited, at the Institute of Civil Engineers, the automaton balance at work, weighing coin, and after describing, with the aid of a diagram and model, the action of some of the more delicate parts of the machine, he observed, that in seeking to obtain extraordinary performances by machincrv mechanical propriety of construction was too often overlooked, and premature deterioration, in the action of many parts, was the result. The automaton balance was peculiarly worthy of notice, from the judgment exercised in its relative proportions, as was proved by the fact that after being at work for several months, it had become more delicate in detecting slight variations between standard and light coin, than when it was first constructed. Mr. Cotton's object in this invention should be well understood. Public convenience demanded great accuracy in weighing the currency: by the ordinary mode of weighing gold with the bullion scales, although it was due to the banktellers to state that they gave the utmost attention to their monotonous duty, it was nearly impossible to guard against the various difficulties detailed in the paper. The injury sustained by the optic nerve, from constantly watching the indicator of the scales, was a serious inconvenience to the operative, which, coupled with the incidental sources of error referred to, created even greater absence of delicacy than the papers stated. Errors to the amount of one-third, or even half a grain, were not unfiequent. By the " automaton balance," the number weighed in a given time was increased, and undeviating accuracy obtained. The delicacy of tie instrument was such, that from thirty to thirty-five coins per minute could be passed through the machine, detecting a difference of only one-fifth of a grain. It should be mentioned, that much greater delicacy could be accomplished; that is, to the one-hundredth of a grain, but not at the same rate; because it would be understood that a slow action of the beam was necessary for very small variations, and that must regulate the speed of working; but such delicacy was beyond all useful purposes in those transactions which it was intended to improve. Mr. Cotton said that his attention had been attracted to the point by the inconveniences to which the " tellers" were subjected in weighing gold for the public; with balances so delicately constructed as the bullion-scales, the agitation of the air, by the sudden opening of a door, or even by the breathing of those around, sufficed to cause errors., It was possible, also, by pressing the fulcrum against the bridle, to produce such a degree of friction as materially to interfere with accuracy; and the tellers confessed that after weighing two or three thousand coins, the sight was injured, and they no longerobserved with the same degree of correctness. He therefore imagined that a machine might be contrived, which, being defended from external influence, might weigh coins as fast as by hand, and within one-fourth of a grain; but he certainly did not contemplate attaining such perfection as the machine now possessed. His first idea was, that the light coins should be taken off by forceps, and that those of average weight should be pushed off by the succeeding ones; but it was found that the slightest inaccuracy in the milled edges sufficed to give them a wrong direction; therefore when he had made the first rough sketch, and consulted with his friend, the late Mr. Ewart, he recommended that Mr. Napier, of York Road, Lambeth, should be employed to make the machine, and to him was due the suggestion of the two alternately advancing tongues, as well as several other arrangements of the machinery, which he had so successfully constructed. When the first machine was tried, out of 1000 sovereigns LS0 were found to be light. They were given to a teller to be verified, and he returned several of them as being of the proper weight; but, on again weighing them more carefully, the results given by the machine were found to be correct. As an instance of how many circumstances should be taken into consideration in delicate machines, he might mention, that after being used for a time, the machine varied in its results, and, on examination, it Was discovered, that the end of the level which traversed the pendant had become magnetic, and thus affected the balance. An ivory end was substituted, and ever since that period its accuracy had been maintained. Mr. W. Miller observed that the efficiency of any scales must be determined, in a great degree, by the fineness of the edge of the fulcrum of the beam; and it would be I___.._____..______ 118 BALSAMS. easily inagined that the friction, to which the edge in a pair of bullion scales was subjected, whilst weighing 5000 or 6000 sovereigns per day, must soon impair its delicacy, and consequently the efficiency of the whole apparatus; for, whether the sovereigns were light or heavy, the beam must turn upon its fulcrum. Such was not the case with Mr. Cotton's machine; its beam did not act at all, unless a light scv ereign was placed upon the platform; so that, among 1000 sovereigns, if only 100 were light, the beam of the machine would only move 100 times, while that of the ordinary scales would oscillate 1000 times. An immense advantage was thus given to the machine in point of durability. All weighing was but an approach to correctness, and the nearest point to which the best kind of common scales were sensible, might be stated as -~-ths of a grain, and tth of a grain would hardly covertheir errors; but the machine was sensible tov -ths of a grain, and — 15ths would fully cover its errors, which were not a twentieth part so numerous as those of the scales. BALSAMS (Baumes, Fr. Balsame, Germ.) are native compounds of ethereal or essential oils, with resin, and frequently benzoic acid. Most ot thrm have the con. sistence of honey; but a few are solid, or become so by keeping. They flow either spontaneously, or by incisions made from trees and shrubs in tropical climates. They possess peculiar powerful smells, aromatic hot tastes,'ut lose their odoriferous pro perties by long exposure to the air. They are insolubk in water; soluble, to a con siderable degree, in ether; and completely in alcohol. When distilled with water, ethereal oil comes over, and resin remains in the retort. 1. BALSAMS WITH BENZOIC ACID:Balsam of Peru is extracted from the myroxylon peruiferum, a tree which grows in Peru, Mexico, &c.; sometimes by incision, and sometimes by evaporating the decoction of the bark and branches of the tree. The former kind is very rare, and is imported in the husk of the cocoa-nut, whence it is called balsam en coque. It is >rown, transparent only in thin layers, of the consistence of thick turpentine; an agreeable smell, an acrid and bitter taste; formed of two matters, the one liquid, the other granular, and somewhat crystalline. In 100 parts, it contains 12 of benzoic acid, 88 of resin, with traces of a volatile oil. The second sort, the black balsam of Peru, is much more common than the pieceding, translucent, of the consistence of well-boiled sirup, very deep red-brown color, an almost intolerably acrid and bitter taste, and a stronger smell than the other balsam. Stoltze regards it as formed of 69 parts of a peculiar oil, 20'7 of a resin, little soluble in alcohol, of 6-4 of benzoic acid, of 0'6 of extractive matter, and 0-9 of water. From its high price, balsam of Peru is often adulterated with copaiba, oil of turpentine, and olive oil. One thousand parts of good balsam should, by its benzoic acid, saturate 75 parts of crystallized carbonate of soda. It is employed as a perfume for pomatums, tinctures, lozenges, sealing-wax, and for chocolate and liqueurs, instead of vanilla, when this happens to be very dear Liquid amber, Storax or Styrax, flows fiom the leaves and trunk of the liquid amber s/yracijfua, a tree which grows in Virginia, Louisiana, and Mexico. It is brownish ash-gray, of the consistence of turpentine, dries up readily, smells agreeably, like benzoin, has a bitterish, sharp, burning taste; is soluble in 4 parts, of alcohol, and contains only 1-4 per cent. of benzoic acid. Balsam of Tolu flows from the trunk of the myroxylon toluiferum, a tree which grows in South America; it is, when fresh, of the consistence of turpentine, is brownish-red, dries into a yellowish or reddish brittle resino:s mass, of a smell like benzoin; is soluble in alcohol and ether; affords, with water, benzoic acid. Chinese varnish flows from the bark of the d.ugia sinensis; it is a greenish yellow turpentine-like substance, smells aromatic, tastes strong and rather astringent, in thin.aers dries soon into a smooth shining lac, and consists of resin, ethereous oil, and benzoic acid. It is soluble in alcohol and ether; and has been employed, immemorially, in China, for lackering and varnishing surfaces, either alone or colored. BALSAMS WITHOUT BENZOIC ACID:Copaiva balsam, balsam of copahu or capivi, is obtained from incisions made in the trunk of the Copaifera officinalis, a tree which grows in Brazil and Cayenne. It is pale yellow, middling liquid, clear transparent, has a bitter, sharp, hot taste; a penetrating hisagreeable smell; a specific gravity of from 0-950 to 0-996. It dissolves in absolute alcohol, partially in spirit of wine, forms with alkalis, crystalline compounds. It consists of 45-59 ethereous oil, 52'75 of a yellow brittle resin, and 1'66 of a brown viscid resin. The oil contains no oxygen, has a composition like oil of turpentine, dissolves caoutchouc (according to Durand), but becomes oxydized in the air, into a peculiar species of resin. This balsam is used f:r making paper transparent, for certain lackurs, and in medicine. BANDANNA. 119 This substance, which is extensively used in medicine, is often adi Iterated. For merly some unctuous oil was mixed with it, but as this is easily discovered by its insolubility in alcohol, castor oil has since been used. The presence of this cheaper cil may be detected, 1, by agitating the balsam with a solution of caustic soda, and setting the mixture aside to repose; when the balsam will come to float clear on the top, and leave a soapy thick magma of' the oil below; 2, when the balsam is boiled with water, in a thin film, for some hours, it will become a brittle resin on cooling, but it will remain viscid if mixed with castor oil; 3, if a drop of the oil on white paper be held over a lamp, at a propel distance, its volatile oil will evaporate and leave the brittle resin, without causing any stain around, which the presence of oil will produce; 4, when three drops of the balsam are poured into a watch-glass, alongside of one drop of sulphuric acid, it becomes yellow at the point of contact, and altogether of a saffron hue when stirred about with a glass rod, but if sophisticated with castor oil, the mixture soon becomes nearly colorless like white honey, though after some time the acid blackens the whole in either case; 5, if 3 parts in bulk of the balsam be mixed with 1 of good water of ammonia (of 0'970 sp. grav.) in a glass tube, it will form a transparent solution, if it be pure, but will form a wr'te liniment if it contains castor oil; 6, if the balsam be triturated with a little of the common magnesia alba, it will form a clear solution, from which acids dissolve e at the magnesia, and leave the oil transparent, if it be pure, but opaque if it be adulterated. When turpentine is employed to falsify the balsam, the fraud is detected by the smell on heating the compound. Mecca balsam, or opobalsam, is obtained both by incisions of, and by boiling, the branches and leaves of the Balsamodendron Gileadense, a shrub which grows in Arabia Felix, Lesser Asia, and Egypt. When fresh it is turbid, whitish, becomes, by degrees, transparent; yellow, thickish, and eventually solid. It smells peculiar, but agreeable; tastes bitter and spicy; does not dissolve completely in hot spirit of wine, and contains 10 per cent. of ethereous oil, of the specific gravity 0-876. Japan lac varnish flows from incisions in the trunk of the Rhus Vernix (Melanorrhea usitata) which is cultivated in Japan, and grows wild in North America. The juice becomes black in the air; when purified, dissolves in very little oil; and, mixed with coloring matter, it constitutes the celebrated varnish of the Japanese. For Benzoin and Turpentine, see these articles in their alphabetical places. BANDANNA. A style of calico printing, in which white or brightly colored spots are produced upon a red or dark ground. It seems to have been practised from time immemorial in India, by binding up firmly with thread, those points of the cloth which were to remain white or yellow, while the rest of the surface was freely subjected to the dyeing operations. The European imitations have now far surpassed, in the beauty and precision of the design. the oriental patterns; having called into action the refined resources of mechanical and chemical science. The general principles of producing bright figures upon dark grounds, are explained in the article CALICO-PRINTING; but the peculiarities of the Bandanna printing may be conveniently introduced here. In Brande's Journal for July, 1823, I described the Bandanna gallery of Messrs. MontLith at Glasgow, which, when in full action some years ago, might be reckoned the most magnificent and profitable printing apartment in the world. The white spots were produced by a solution of chlorine, made to percolate down through the Turkey red cotton cloth, in certain points defined and circumscribed by the pressure of hollow lead types in plates, in a hydraulic press. Fig. 106 is an elevation of one press; A, the top or entablature; B B, the cheeks or pillars; C, the upper block for fastening the upper lead perforated pattern to; D, the lower block to which the fellow pattern is affixed, and which moves up and down with the piston of the press; E, the piston or ram; F, the sole or base; G, the water-trough, for the discharged or spotted calico to fall into; H, the small cistern, for the aqueous chlorine or liquor-meter, with glass tubes for indicating the height of liquor inside of the cistern; e e, glass stopcocks, for admitting the liquor into that cistern from the general reservoir; f f, stopcocks for admitting water to wash out the chlorine; g g, the pattern lead-plates, with screws for setting the patterns parallel to each other; m m, projecting angular pieces at each corner, perforated with a half-inch hole to receive the four guide-pins rising from the lower plate, which serve to secure accuracy of adjustment between the two faces of the lead pattern plates; h h, two rollers which seize and pull throuh the discharged pieces, and deliver them into the watertrough. T: the left of D there is a stopcock for filling the trough with water; 1, is the waste tube for chlorine lltnor and water of washing. The contrivance for blowing a stream of air across the cloth, through the pattern tubes, is not represented in the figure 120 BANDANNA. Sixteen engines similar to the above, each possessing the power of piessmlg witl several hundred tons, are arranged in one line,in subdivisions of four; the space. 106 F== --— 1 total length of the apartment is 10C feet. To each press is attached a pair of patterns in lead, (or plates, as they are called,) the manner of forming which will be described in the sequel. One of these plates is fixed to the upper block of the press. This block is so contrived, that it rests upon a kind of universal joint, which enables this plate to apply more exactly to the under fellowplate. The latter sits on the moveable part of the press, commonly called the sill. When this is forced up, the two patterns close on each other very nicely, by means of the guide-pins at the corners, which are fitted with the utmost care. The power which impels this great hydrostatic range is placed in a separate apartment, called the machinery room. This machinery consists of two press cylinders of a peculiar construction, having solid rams accurately fitted to them. To each of these cylinders, three little force-pumps, worked by a steam-engine, are connected. The piston of the large cylinder is eight inches in diameter, and is loaded with a top-weight of five tons. This piston can be made to rise about two feet through a leather stuffing or collar. The other cylinder has a piston of only one inch in diameter, which is also loaded with a top-weight of five tons. It is capable, like the other, of being raised two feet through its collar. Supposing the pistons to be a their lowest point, four of the six small Iorce-pumps are put in action by the steam-engine, two of them to raise the large piston, and two the little one. In a short time, so much water is injected into the cylinders, that the loaded pistons have arrived at their highest points. They are now ready for working the hydrostatic discharge-presses, the water pressure being conveyed from the one apartment to the other, under ground, through strong copper tubes, of small ealibre. Two valves are attached to each press, one opening a communication between the large BANDANNA. 121 tlriving-cylinder and 1ni cylinder of the press, the other between the small driving-cyli der and the press. The function of the first is simply to lift the under-block of the press into contact with the upper-block; that of the second, is to give the requisite compression to the cloth. A third valve is attached to the press, for the purpose of discharging the water from its cylinder, when the press is to be relaxed, in order to remove or draw through the cloth. From twelve to fourteen pieces of cloth, previously dyed Turkey-red, are stretched over each other, as parallel as possible, by a particular machine. These parallel layers arb then rolled round a wooden cylinder, called by the workmen, a drum. This cylinder is nc-v placed in its proper situation at the back of the press. A portion of the fourteen layers of cloth, equal to the area of the plates, is next drawn through between them, by hooks attached to the two corners of the webs. On opening the valve connected with the eightinch driving-cylinder, the water enters the cylinder of the press, and instantly lifts its lower block, so as to apply the under plate with its cloth, close to the. upper one. This valve is then shut, and the other is opened. The pressure of five tons in the one inch prime-cylinder, Is now brought to bear on the piston of the press, which is eight inches in diameter. The effective force here will, therefore, -e 5 tons X 82=320 tons; the areas of cylinders being to each other, as the squares of their respective diameters. The cloth is thus condensed between the leaden pattern-plates with a pressure of 320 tons, in a couple of seconds; -a splendid example of automatic.rt. The next step, is to admit the blanching or discharging liquor (aqueous chlorine, obtained by adding sulphuric acid to solution of chloride of lime) to the cloth. This liquol is contained in a large cistern, in an adjoining house, from which i' is run at pleasure into small lead cisterns H attached to the presses; which cisterns have graduated index tubes, for regulating the quantity of liquor according to the -attern of discharge. The stopcocks on the pipes and cisterns containing this liquor, are all made of glass. From the measure-cistern H, the liquor is allowed to flow into the hollows in the upper lead-plate, whence it descends on the cloth, and percolates through it, extracting in its passage the Turkey-red dye. The liquor is finally conveyed into the waste pipe, from a groove in the under block. As soon as the chlorine liquor has passed through, water is admitted in a similar manner, to wash away the chlorine; otherwise, upon relaxing the pressure, the outline of the figure discharged would become ragged. The passage of the discharge liquor, as well as of the water through the cloth, is occasionally aided by a pneumatic apparatus, or blowing machine; consisting of a large gasometer, from which air subjected to a moderate pressure may be allowed to issue, and act in the direction of the liquid upon the folds of the cloth. By an occasional twist of the air stopcock, the workman also can ensure the equal distribution of the discharging liquor, over the whole excavations in the upper plate: When the demand for goods is very brisk, the air apparatus is much employed, as it enables the workman to double his product. The time requisite for completing the discharging process in the first press is sufficient to enable the other three workmen to put the remaining fifteen presses in play. The discharger proceeds now from press to press, admits the liquor, the air, and the water; ani is followed at a proper interval by the assistants, who relax the press, move forwards another square of the cloth, and then restore the pressure. Whenever the sixteenth press has been liquored, &c., it is time to open the first press. In this routine, about ten minutes are employed; that is, 224 handkerchiefs (16-14) are discharged every ten minutes. The whole cloth is drawn successively forward, to be successively treated in the above method. When the cloth escapes from the press, it is passed between the two rollers in front; from which it falls into a trough of water placed below. It is finally carried off to the washing and bleaching department, where the lustre of both the white and the red is considerably brightened. By the above arrangement of presses, 1600 pieces, consisting of 12 yards each=19,200 yards, are converted into Bandannas in the space of ten hours, by the labor of four workmen. The patterns, or plates, which are put into the presses to determine the white figures on the cloth, are made of lead in the following way. A trellis frame of cast-iron, one Inch thick, with turned-up edges, forming a trough rather larger than the intended lead pattern, is used as the solid ground-work. Into this trough, a lead plate about one half inch thick, is firmly fixed by screw nails passing up from below. To the edges of this lead plate, the borders of the. piece of sheet-lead are soldered, which covers the whole outer surface of the iron frame. Thus a strong trough is formed, one inch deep. The'upright border gives at once great strength to the plate, and serves to confine the liquor. A thin sheet of lead is now laid on the thick lead-plate, in the manner of a veneer on toilet. tables, and is soldered to it round tile edges. Both sheets must be made very smooth beforehand, by hammering them on a smooth stone table, and then finishing with a plane: the surface of the thir shltet (now attached) is to be covered with drawing paper, pasted 122 BARYTA. an, and upon this the pattern is drawn. It is now ready for the cutter. The first thing which he does is to fix down with brass pins all the parts of the pattern which are to be left solid. He now proceeds with the little tools generally used by block. cutters, which are fitted to the different curvatures of the pattern, and he cuts perpendicularly quite through the thin sheet. The pieces thus detached are easily lifted out; and thus the channels are formed which design the white figures on the red cloth. At the bottom of the channels, a sufficient number of small perforations are made through the thicker sheet of lead, so that the discharging liquor may have free ingress and egress. Thus, one plate is finished, from which an impression is to be taken by means of printers' ink, on the paper pasted upon another plate. The impression is taken in the hydrostatic press. Each pair of plates constitutes a set, which may be put into the presses, and removed at pleasure. BARBERRY. The root of this plant contains a yellow coloring matter, which is soluble in water and alcohol, and is rendered brown by alkalis. The solution is employed in the manufacture of Morocco leather. BARILLA. A crude soda, procured by the incineration of the salsola soda, a plant cultivated for this purpose in Spain, Sicily, Sardinia, &c. Good barilla usually contains, according to my analysis, 20 per cent. of real alkali, associated with muriates and sulphates, chiefly of soda, some lime, and alumina, with very little sulphur. Caustic leys made from it were used in the finishing process of the hard soap manufacture. Tile quantity of barilla and alkali imported in 1850 amounted to 34,880 cwts., and in 1851 to 45,740 cwts. The quantity of soda exported in 1850 was 827,403 cwts., and in 1851, 839,183 cwt.; the declared value being respectively 375,3511., and 360,5651. There is no duty on barilla. BARIUM. The metallic basis of Baryta. BARK, the outer rind of plants. Many varieties of barks are known to commerce, but the term is commonly used to express either Peruvian or Jesuits' bark, a most valuable pharmaceutical remedy, or Oak bark, which is very extensively used by tanners and dyers. The quantity of this article imported for the use of the latter amounted in 1850 to 380674 cwts., and in 1851 to 460,895 cwts. The duty on bark has been repealed. BARLEY. (Orge, Fr.; Gerste, Germ.) English barley is that with two-rowed ears, or the hordemzn vulgare distichon of the botanists; the Scotch beer or bigg is the hordeumn vwdgare hexastichon. The latter has two rows of ears, but 3 corns come from the same point, so that it seems to be six-eared. The grains of bigg are smaller than those of barley, and the husks thinner. The specific gravity of English barley varies from 1 25 to 1 33; of bigg ftrom 1-227 to 1-265; the weight of the husk of barley is one-sixth, that of bigg two-ninths. 1000 parts of barley flour contain, according toEinhof, 720 of starch. 56 sugar, 50 mucilage, 36-6 gluten, 12-3 vegetable albumen; 100 water, 2-5 phosphate of lime, 68 fibrous or ligneous matter. Sp. gravity of barley is 1'235 by my trials. BARM. The yeasty top of fermenting beer. See BEER, DISTILLATION, FERMENTATION. BARYTA or BARYTES, one of the simple earths. It may be obtained most easily by dissolving the native carbonate of barytes (Witherite) in nitric acid, evaporating the neutral nitrate till crystals be formed, draining and then calcining these, by successive portions, in a covered platina crucible, at a bright red heat. A less pure baryta may be obtained by igniting strongly a mixture of the carbonate and charcoal, both in fine powder and moistened. It is a grayish white earthy looking substance, fusible only at the jet of the oxy-hydrogen blowpipe, has a sharp caustic taste; corrodes the tongue and all animal matter, is poisonous even in small quantities, has a very powerful alkaline reaction; a specific gravity of 4-0; becomes hot, and slakes violently when sprinkled with water, falling into a fine white powder, called the hydrate of baryta, which contains 101 per cent. of water, and dissolves in 10 parts of boiling water. This solution lets fall abundant columnar crystals of hydrate of baryta as it cools; but it still retains one-twen tieth its weight of baryta, and is called baryta water. The above crystals contain 61 per cent. of water, of which, by drying, they lose 50 parts. This hydrate may be fused at a red heat without losing any more water. Of all the bases, baryta has the strongest affinity for sulphuric acid, and is hence employed either in the state of the above water, or in that of one of its neutral salts, as the nitrate or muriate, to detect the presence and determine the quantity of that acid present in any soluble compound. Its prime equivalent is 7 66, hydrogen being 1,000. Native sulphate of baryta, or heavy spar, is fraudulentlv used to adulterate white lead by the English dealers to a shameful cxtent. BASSORINE. A constituent part of a species of gum which comes from Bassora, as also of gum tragacanth, and of some gum resins. It is semi-transparent, difficult to pulverize, swells considerably in cold or boiling water, and forms a thick mucilage without dissolving. Treated with ten times its weight of nitric acid, it affords nearly 23 per cent. of its weight of mucic acid, being much more than is obtainable from gumn arabic or cherry-tree gum. Bassorine is very soluble in water slightly acidulated with nitric or muriatic acid. This principle is procured by soaking gum Bassora in a great quantity of cold water, and in removing, by a filter, all the soluble parts. BATHS. 123 BATHS. (Bains, Fr.; Baden, Germ.) Warm baths have lately come into very general use, and they are justly considered as indisl ensably necessary in all modern houses of any magnitude, as also in club-houses, hotels, and hospitals. But the mode of constructing these baths, and of obtaining the necessary supplies of hot and cold water, does not appear to have undergone an improvement equal to the extension of their employment. The several points in regard to warm baths, are, 1. The materials of which they are constructed. 2. Their situation. 3. The supply of cold water. 4. The stYpply of hot water. 5. Minor comforts and conveniences. i. As to the materials of which they are constructed.-U- these the best are slabs of polished marble, properly bedded with good water-tight cement, in a seasoned wooden case, and neatly and carefully united at their respective edges. These, when originally well constructed, form a durable, pleasant, and agreeable-looking bath; but the expense is often objectionable, and, in upper chambers, the weight may prove inconvenient. If of white or veined marble, they are also apt to get yellow or discolored by frequent use, and cannot easily be cleansed; so that large Dutch tiles, as they are called, or square pieces of white earthenware, are sometimes substituted; which, however, are difficultly kept water-tight; so that, upon the whole, marble is preferable. Welsh slate has now superseded marble to a great extent. Where there are reasons for excluding marble, copper, tinned, or galvanized iron is the usual material resorted to. The first is most expensive in the outfit, but far more durable than the latter, which are, moreover, liable to leakage at the joints, unless most carefully made. Either the one or the other should be well covered outside and inside with several coats of paint, which may then be marbled or otherwise ornamented. Wooden tubs, square or oblong, and oval, are sometimes used for warm baths; and are cheap and convenient, but neither elegant nor cleanly. The wood always contracts a mouldy smell; and the difficulty and nuisance of keeping themt water-tight, and preventing shrinkage, are such as to exclude them from all except extemporaneous application. 2. As to the situation of the bath, or the part of the house in which it is to be placed.-In hotels and club-houses this is a question easily determined: several baths are usually here required, and each should have annexed to it a properly warmed dressing-room. Whether they are up stairs or down stairs is a question of convenience, but the basement story, in which they are sometimes placed, should always be avoided: there is a coldness and dampness belonging to it, in almost all weathers, which is neither agreeable nor salubrious. In hospitals, there should be at least two or three baths on each side of the house (the men's and women's), and the supply of hot waler should be ready at a moment's notice. The rooms in which the baths are placed should be light, and comparatively large and airy; and such conveniences for getting into and out of the baths should be adopted as the sick are well known to require. The dimensions of these baths should also be larger than usual. In private houses, the fittest places for warm baths are dressing-rooms annexed to the principal bed-rooms; or, where such convenience cannot be obtained, a separate bath-room, connected \vith the dressing-room, and always upon the bed-room floor. All newly-built houses should be properly arranged for this purpose, and due attention should be paid to the warmning of the bath-room, which ought also to be properly ventilated. A temperature of 70~ may be easily kept up in it, and sufficient ventilation is absolutely requisite to prevent the deposition of moisture upon the walls and furniture. The objection which formerly prevailed, in respect to the difficulty of obtaining adequate supplies of water, ill the upper rooms, has been entirely obviated by having cisterns at or near the top of the house; and we would just hint that these should be so contrived as to be placed out of the reach of frost; a provision of the utmost importance in every point of view, and very easily effected in a newly-built house, though it unfortunately happens that architects usually regard these matters as trifles, and treat them with neglect,as indeed they do the warming and ventilation of buildings generally. 3. The supply of water of proper quality and quantity is a very important point, as connected with the present subject. The water should be soft, clean, and pure, and as free as possible from all substances mechanically suspended in it. In many cases it answers to dig a well for the exclusive supply of a large house with water. In most lalrts of London this may effectually be accomplished at a comparatively moderate expense; and, if the well be deep enough, the water will be abundant, soft, and pellucid. The labor of forcing it by a pump to the top of the house is the only drawback; this, 124 BATHS. however, is very easily done by a horse-engine, or there are people enough about town glad to undeltake it at a shilling a day. I am led to these remarks by observing the filthy state of the water usually supplied, at very extravagant rates, by the water comrpanies. It deposits its nastiness in the pipes connected with warm baths, and thlrows down a slippery deposit upon the bottom of the vessel itself, to such an extent as often to preclude its being used, at least as a luxury, which a clear and clean bath really is. This inconvenience may, in some measure, be avoided by suffering the water to throw down its extraneous matters upon the bottom of the cistern, and drawing our supplies fiom pipes a little above it; there will, however, always be more or less deposit in the pipes themselves, and every time the water runs into the cistern the grouts are stirred up and diffused through its mass. 4. and 5.-In public bathing establishments, where numerous and constant baths are required, the simplest and most effective means of obtaining hot water for their supply consists in drawing it directly into the baths from a large boiler, placed somewhere above their level. This boiler should be supplied with proper feeding-pipes and gauges; and, above all things, its dimensions should be ample; it should be of wrought iron or copper. The hot water should enter the bath by a pipe at least an inch and a half in diameter; and the cold water by one of the same dimensions, or omnewhat larger, so that the bath may not be long in filling. The relative proportions of the hot and cold water are, of course, to be adjusted by a thermometer, and every bath should have a two-inch waste-pil)e, opening a-bout two inches from the top of the bath, and suffering the excess of water fieely to run off; so that when a person is immersed in the bath, or when the supplies of water are accidentally left open, there may be no danger of an overflow. When there is a laundry in the upper story of the house, or other convenient place for erecting a copper and its appurtenances, a plan similar to the above may often be conveniently adopted in private houses, for the supply of a bath upon the principal bed-room floor. An attempt is sometimes made to place boilers behind the fires of dressing-rooms, or otherwise to erect them in the room itself, for the purpose of supplying warm water; but this plan is always objectionable from the complexity of the means by which the supply of water is furnished to the boiler, and often dangerous from the flues becoming choked with soot and taking fire. Steam is also apt, in such cases, to escape in quantities into the room; so that it becomes necessary to search for other methods of heating the bath; one or two of the least objectionable of which I shall describe. (1.) A contrivance of some ingenuity consists in suffering the water for the supply of the bath to flow from a cistern above it, through a leaden pipe of about one inch diameter, which is conducted into the kitchen or other convenient place, where a large boiler for the supply of hot water is required. The bath-pipe is immersed in this boiler, in which it makes many convolutions, and, again emerging, ascends to the bath. The operation is simply this:-the cold water passing through the convolutions of that part of the pipe which is immersed in the boiling water, receives there sufficient heat for the purpose required, and is delivered in that state by the ascending pipe into the bath, which is also supplied with cold water and waste-pipes as usual. The pipe may be of lead, as far as the descending and ascending parts are concerned, but the portion forming the worm or convolutions immersed in the boiler should be copper, in order that the water within it may receive heat without impediment. This plan is economical only where a large boiler is constantly kept at work in the lower part of the house; otherwise the trouble and expense of heating such a boiler, for the mere purpose of the bath, render it unavailable. The worm-pipe is also apt to become furred upon the outside by the deposition of the earthy impurities of the water in which it is immersed; it then becomes a bad conductor of heat, is cleansed with Jifficulty, and the plan is rendered ineffective. This system, however, has been adopted, in some particular cases, with satisfaction. (2.) A much more simple, economical, and independent mode of heating a warm bath, by a fire placed at a distance from it, is the following, which is found to answer perfectly in private houses, as well as upon a more extended scale in large establishtments. It is certainly open to some objections, but these are overbalanced by its advantages. A wagon-shaped boiler, holding about six gallons of water, is properly placed over a small furnace in any convenient and safe part of the house, as the kitchen, scuilery, servants' hall, or wash-house. The bath itself, of the usual dimensions and construction, is placed where it is wanted, with a due supply of cold water firom above. Two pipes issue from within an inch of the bottom of the bath at its opposite extremities; one at the head of the bath, about one inch, and the other at the foot, an inch and one-eighth in diameter. These tubes descend to the boiler, the smaller one entering it at the bottom, and the larger one issuing from its top. Under these circumstances, supposing the pipes and boiler everywhere perfectly tight, when the bath is filled, the water will descend into and expel the air from the BATHS. 125 boiler, and completely fill it. Now upon making a gentle fire under the boiler, an ascending current of warm water will necessarily pass upwards through the larger pipe which issues from its top, and cold water will descend by the pipe which enters at the bottom; and thus, by the establishment of currents, the whole mass of water in the Lath will become heated to the desired p{oint; or, if above it, the temperature n.ay easily be lowered by the admixture of cold water. Tile advantages of this form of bath are numerous. The shorter the pipes of communication the better, but they may extend forty or fifty feet without any inconvenience beyond that of expense; so that there is no obstacle to the bath being near the bed-room while the boiler is on the basement story. There is but little time required for heating the bath; the water il which may, if requisite, be raised to about 100~ in about half an hour from the time of lighting the fire. The consumption of fuel is also trifling. The following are the chief disadvantages attendant upon this plan, and the means of obviating them:I, is necessary, when the water has acquired its proper temperature, to arrest the circulation of the water by means of a stopcock or valve adjoining the boiler; the next resource is to withdraw the fir'e from the boiler, or not to use the bath immediately, as it may go on acquiring some heat from the boiler, so that we may become incon-?eniently hot in the bath. When, therefore, this bath is used, we may proceed as follows:-Heat the water in it an hour before it is wanted, to about 100~, and then extinguish the fire.'The water will retain its temperature, or nearly so, for three or four hours, especially if the bath be shut up with a cover; so that when about to use it, cold water may be admitted till the temperature is lowered to the required point, and thus all the above inconveniences are avoided. Another disadvantage of this bath arises from too fierce a fire being made under the boiler, so as to occasion the water to boil within it, a circumstance which ought always to be carefully avoided. In that case, tAe steam rising in the upper part of the,oiler, and into the top pipe, condenses there, and occasions violent concussions, the noise of which often alarms the whole house, and leads to apprehensions of explosion, which, however, is very unlikely to occur; but the concussions thus produced injure the pipes, and may render them leaky; so that in regard to these, and all other baths, &c., we may remark, that the pipes should pass up and down in such parts of the house as will not be injured if some leakage takes place; and under the bath itself should be a sufficiently large leaden tray with a waste-pipe, to receive and carry off any accidental drippings, which might injure the ceilings of the rooms below. In all newlybuilt houses, two or three flues should be left in proper places for the passage of ascending and descending water-pipes; and these flues should in some way receive at their lower part a little warm air in winter, to prevent the pipes freezing; the same attention should also be paid to the situation of the cisterns of water in houses, which should be kept within the house, and always supplied with a very ample waste-pipe, to prevent the danger of overflow. Cisterns thus properly placed, and carefully constructed, should be supplied from the water-mains by pipes kept under ground, till they enter the house, and not carried across the area, or immediately under the pavement, where they are liable to fieeze. (3.) Baths are sometimes heated by steam,which has several advantages; it may either be condensed directly into the water of the bath, or, if the bath be of copper or tinned iron, it may be conducted into a casing upon its outside, usually' called a jacket; in the latter case there must be a proper vent for the condensed water, and for the escape of air and waste steam. Steam is also sometimes passed through a serpentine pipe, placed at the bottom of the bath. But none of these methods are to be recommended for adoption in private houses, and are only advisable in hospitals, or establishments where steam boilers are worked for other purposes than the mere heating of baths. The French make much more use of hot baths than we do, both as respects health and cleanliness, a fact well illustrated by the following statistics. In the year 1780 the whole public bathing establishments in Paris contained only 250 separate baths; in 1813 they contained 300; in 1832 there were 78 houses fitted up with 2374 fixed baths, and 1059 movable ones for transporting to private houses; and at present new bathing establishments are being mounted from day to day in the several quarters of the capital. Galvanized iron is now preferred even to copper for making baths, being equally durable and greatly cheaper. Sulphureous baths are made of sheet zinc, for the alkaline sulphurets act very little upon that metal. The form of the baths is usually made ovoid, because this shape requires less water for immersing the human body tha. the rectangular. Many copper and tin baths have been lately constructed in London, with a littly furnace attached to one end, and surrounded with a case or jacket, into which the water flows and circulates backwards and forwards till the whole mass in the bath gets heated to the due degree. One of the best of these is that constructed by Mr. Benham, 126 BEER. of Wigmore street. The bath must be placed near the fire-grate, and the smoKe-pipe of the attached furnace be conducted up the chimney a certain way to secure a sufficient draught to maintain combustion. The above bath, well managed, heats the water from 50~ to 98~ in about 20 or 25 minutes, as I have experimentally proved. When the proper temperature is attained, the fire must of course be extinguished. BDELLIUM. A gum resin, produced by an unknown plant which grows in Persia and Arabia. It comes to us in yellowish or reddish pieces, smells faintly, like myrrh, and consists of 59 resin, 9-2 gum, 30-6 bassorine, and 1-2 ethereous oil. BEER. (Biere, Fr.; Bier, Germ.) The fermented infusion of malted barley, flavored with hops, constitutes the best species of beer; but there are many beverages of inferior quality to which this name is given, such as spruce beer, ginger beer, molasses beer, &c.; all of which consist of a saccharine liquor, partially advanced into the vinous fermentation, and flavored with peculiar substances. Tie ancients were acquainted with beer, and the Romans gave it the appropriate name of Cerevisia (quasi Ceresas), as being the product of cor? the gift of Geres. The most celebrated liquor of this kind in the old time, was the Pt esian potaticr, so cailed from the town where it was prepared at the mouth of the Nile, Aristotle speaks of the intoxication caused by beer; and Theophrastus very justly de; 3minated it the wine of barley. We may, indeed, infer from the notices found in historians, that drinks analogous to our beer were in use amon, the ancient Gauls, Germans, and in fact almost every people of our temperate zone; and they are still the Lniversal beverage in every land where the vine is not an object of rustic husbandry. The manufacture of beer, or the art of brewing, may be conveniently considered under five heads:1. An examination of the natural productions which enter into its composition; or of barley and hops. 2. The changes which barley must undergo to fit it for making beer; or the processes )f malting and mashing. 3. The formation of a proper wort from the mashed malt and hops. 4. The fermentation of that wort; and, 5. The lining, ripening, and preservation of the beer. I. Of the materials. 1. Barley, wheat, maize, and several other kinds of corn are capable of undergoing those fermentative changes, by which beer may be made; but the first substance is by far the fittest. There are two species of barley, the hordeum vulgare or common barley, having two seeds arranged in a row on its spikes; and the hordeurn hexastichon, i'a which three seeds spring from one point, so that its double row has apparently six seeds. The former is the proper barley, and is much the larger sized grain; the latter is little known in England, but is much cultivated in Scotland under the name of bear or bigg; being a hardy plant adapted to a colder country. The finer the climate in which barley grows, the denser and larger its seed, and the thinner its husk; thus the Norfolk and Suffolk barley is distinguished in these respects from that of Aberdeenshire. Bigg is aless compact grain than barley; the weight of a Winchester bushel (2150'42 cubic inches) of the former is only about 47 lbs., while that of a bushel of the latter is nearly 51 lbs. Their constituents, however, bear much the same proportion to each other. The quality of barley is proved not only by its density when dry, but by the increase of volume which it acquires when steeped in water. Thus, 100 measures of average English barley thereby swell into 124. 100 - of - Scotch ditto, - - - 121. 100 - of - - bigg or bear, - 118. Nay, 100 of very fine Suffolk barley have swollen into - 183. While 100 of an inferior Scotch bigg became no more than - 109. This circumstance indicates so nearly the probable yield of malt, that it is carefully attended to by the officers of excise, who gauge the steep cistern, and levy their duty in conformity with the largest volume. 100 pounds of good barley become almost one half heal ier by the absorption of moisture; and weigh upon an average 147 pounds; the best of course taking up most water. By chemical analysis barley flour seems to consist of 67'18 parts of hordeine, or starch and gluten intimately combined, 7-29 of vegetable fibre, 1-15 of coagulated alburlen, 3-52 parts of gluten, 5-21 of sugar, 4-62 of gum, 0'24 of phosphate of lime, and 9-37 of water. The loss amounted to 1'42. To these principles should be added a peculiar volatile oil of a concrete nature, which is obtained during the process of distilling fe:mented malt wash. (See WHISKEY.) It may also be extracted from barley flour, by the solvent action of alcohol; and never amounts to more than a few parts in the thousand. The husk also contains some of that fetid oil. Proust thought that he had discovered in barley a peculiar principle, to which he gave the name of hordeine; and which he separated from s'arch by the action of both cold and boiling water. He found that by treat BEER. 127 ing barley meal successively with water, he obtained from 89 to 90 parts of a farinaceous substance, composed of from 32 to 33 of starch, and from 57 to 58 of hordeine. Einhof obtained from bailey seeds, 70'05 of flour, 18-75 of husks or bran, and 11-20 of water. According to Proust, hordeine is a yellowish powder, not unlike fine saw-dust. It contains no azote, for it affords no ammonia by distillation, and is therefore very dissimilar to gluten. In the germination of barley, which constitutes the process of malting, the proportion of hordeine is greatly diminished by its conversion into sugar and starch. Other chemists suppose that the hordeine of Proust is merely a mixture of the bran of the barley with starch and gluten. It is obvious that the subject stands in need of new chemical researches. In barley the husk constitutes from one fourth to one fifth of the whole weight; in oats it constitutes one third; and in wheat one terfth. From the analysis of barley flour recently made, it appears to consist in 1000 parts: of water, 1CO; albumen, 22-3; sugar, 56; gum or mucilage, 50; gluten, 37-6; starch, 720; phosphate of lime, 2'5. 2. The hop, humulus lupulus, the female flowers of the plant. Ives first directed attention to a yellow pulverulent substance which invests the scales of the catkins, amounting to about one eighth of their weight; and referred to it the valuable properties which hops irpart to beer. We may obtain this substance by drying the hops at a temperature of 86~ F., introducing them into a coarse canvass bag, and shaking it so that the yellow powder shall pass through the pores of the canvass. This powder bears some resemblance to lycowodium. Df the 13 parts in 100 of this powder, 4 parts are foreign matters, derived from toe scales of the cones; leaving 9 parts of a peculiar granular substance. When distilled with water, this substance affords two per cent. of its weight (2_ for 100 times the weight of hops) of a volatile colorless oil, to which the plant owes its peculiar aroma. This oil dissolves in water in considerable quantity. It appears to contain sulphur (for it blackens solutions of silver), and also acetate of ammonia. No less than 65 per cent. of the yellow dust is soluble in alcohol. Thi3 solution, treated with water and distilled, leaves a resin, which amounts to 52'5 per cent. It has no bitter taste, and is soluble in alcohol and ether. The watery solution from which the resin was separated contains the bitter substance which has been called lupuline by Payen and Chevallier, mixed with a little tannin and malic acid. To obtain this in a state of purity, the free acid must be saturated with lime, the solution evaporated to dryness, and the residuum must be treated with ether, which removes a little resin; after which the lupuline is dissolved out by alcohol, which leaves the malate of lime. On evaporating away the alcohol, the lupuline remains, weighing from 8-3 to 12-5 per cent. It is sometimes white, or sliohtly yellowish, and opaque, sometimes orange yellow and transparent. At ordinary temperatures it is inodorous, but when heated strongly it emits the smell of hops. It possesses the 2haracteristic taste and bitterness of the hop. Water dissolves it only in the proportion of 5 per cent., but it thereby acquires a pale yellow color. Lupuline is neither acid nor alkaline; it is a3ted upon neither by the dilute acids nor alkalis, nor by the solutions of the metallic salts; it is quite soluble in alcohol, but hardly in ether. It contains apparently no azote, for it affords no ammonia by destructive distillation; but only an empyseumatic oil. The yellow dust of hops contains, moreover, traces of a fatty matter, gum, a small quantity of an azotized substance, and several saline combinations in minute quantity. Boiling water dissolves from 19 to 31 per cent. of the contents of the dust, of which a large proportion is resin. Ives thought that the scales of the catkins of hops, when freed from the yellow powder, contained no principles analogous to it; but Payen and Chevallier have proved the' contrary. The cones of hop give up to boiling alcohol 26 per cent. of soluble matter; while the same cones, stripped of their yellow powder, yield only 26 per cent.; and further, these chemists found the same principles in the different parts of the hop, but in different proportions. The packing of the hop catkins or cones is one of the most important operations towards the preservation of this plant; and is probably the cause of the enormous dif ference in value between the English and French hops after a few years keeping. The former, at the end of six years, possess still great value, and may be sold as an article only two or three years old; while the latter have lost the greater part of their value in three years, and are no more saleable at the end offour. In France, it is packed merely by tramping it with the feet in sacks. Under this slight pressure, large interstitial spaces are left amid the mass of the hops, through which the air freely circulates, carrying off the essential oil, and oxygenating some of the other proximate principles, so as to render them inert. By the English method, on the contrary, the hops, after being well rammed into strong sacks hung in frames, are next subjected to the action of a hydraulic press. The valuable yellow powder thus enclosed on every side by inn, merable compact scales, is completely screened fiom the contact of the atmosphere, antl from all its vicissitudes of humidity. Its essential oil, in pa ticular, the basis of its flavvr, is preserved without decay. 128 BEER. According to the experiments of Chevallier and Payen upon the hops of Englana, Flanders, the Netherlands, and the department of the Vosges, those of the county of Kent afforded the largest cones, and were most productive in useful secreted and soluble mat. ters. Next to them were the hops of Alost. The best hops have a golden yellow color, large cones, an agreeable aroma: when rub. bed between the hands, they leave yellow traces, powerfully odoriferous, without any broken portions of the plant, such as leaves, stems, and scaly fragments. When alcohol is digested on good hops, from 9 to 12 per cent. of soluble yellow matter may be obtained by evaporating it to dryness. This is a good test of their quality. The best-flavored and palest hops are packed in sacks of fine canvass, which are called pockets, and weigh about 1I cwt. each. These are bought by the ale brewer. The stronger-flavored and darker-colored hops are packed in bags of a very coarse texture like door-mats, called hop bags: these contain generally about 3 cwt., and are sold to the porter and beer brewers. After the end of a year or two, hops are reckoned to have lost much of their marketable value, and are then sold to the second-rate porter brewers, under the name of old hops. The finest hops are grown in the neighborhood of Canterbury; bat those of Worcester have an agre able mildness of flavor, greatly admired by many ale drinkers. When the bitter and aromatic principles disappear, the hops are no better than so much chaff; therefore, an accurate chemical criterion of their principles would be a great benefit to the brewer. II. Malting.-This process consists of three successive operations; the steeping; the couching, sweating, and flooring; and the kiln-drying. The steeping is performed in large cisterns made of wood or stone, which being filled with clear water up to a certain height, a quantity of barley is shot into them, and well stirred about with rakes. The good grain is heavy, and subsides; the lighter gilins, which float on the surface, are damaged, and should be skimmed off; for they would injure the quality of the malt, and the flavor of the beer made with it. They seldom amount to more than two per cent. More barley is successively emptied into the steep cistern, till the water stands only a few inches, about five, above its surface; when this is levelled very carefully, and every light seed is removed. The steep lasts from forty to sixty hours, according to circumstances; new barley requiring a longer period than old, and bigg requiring much less time than barley. During this steep, some carbonic acid is evolved from the grains, and combines with the water, which, at the same time, acquires a yellowish tinge, and a strawy smell, from dissolving some of the extractive matter of the barley husks. The grain imbibes about one half its weight of water, and increases in size by about one fiflh. By losing this extract, the husk becomes about one seventieth lighter in weight, and paler in color. The duration of the steep depends, in some measure, upon the temperature of the air, and is shorter in summer than in winter. In general from 40 to 48 hours will be found sufficient for sound dry grain. Steeping has for its object to expand the farina of the barley with humidity, and thus prepare the seed for germination, in the same way as the moisture of the earth prepares for the growth of the radicle and plumula in seed sown in it. Too long continuance in the steep is injurious; because it prevents the germination at the proper time, and thereby exhausts a portion of the vegetative power: it causes also an abstraction of saccharine matter by the water. The maceration is known to be complete when the grain may be easily transfixed with a needle, and is swollen to its full size. The following is reckoned a good test:-If a barley-corn, when pressed between the thumb and fingers, continues entire in its husk, it is not sufficiently steeped; but if it sheds its flour upon the fingers, it is ready. When the substance exudes in the form of a milky juice, the steep has been too long continuedj and the barley is spoiled for germination. In warm weather it sometimes happens that the water becomes acescent before the grain is thoroughly swelled. This accident, which is manifest to the taste and smell, must be immediately obviated by drawing off the foul water through the tap at the bottom of the cistern, and replacing it with fresh cold water. It does no harm to renew it two or three times at one steep. The couch.-The water being drawn off, and occasionally a fresh quantity passed through, to wash away any slimy matter which may have been generated in warm weather, the barley is now laid upon the couch floor of stone flags, in square heaps from 12 to 16 inches high, and left in that position for 24 hours. At this period, the bulk of the grain being the greatest, it may be gauged by the revenue officers if they think fit. The moisture now leaves the surface of the barley so completely, that it imparts no dampness to the hand. By degrees, however, it becomes warm; the temperature rising 10~ above the atmosphere, while an agreeable fruity smell is evolved. At this time if the hand be thrust into the heap, it not only feels warm, but it gets bedewed with moisttre. At this sweating stage, the germination begins; the filbils of the radicle first sprout forth from the tip of every grain, and a white elevation appears, that soon BEER. 129 separates into three or more radicles, which grow rapidly larger. About a day after thli appearance, the plumula peeps forth at the same point, proceeding thence beneath the husk to the other end of the seed, in the form of a green leaflet. The greatest heat of the couch is usually about 96 hours after the barley has beren taken out of the steep. In consequence, the radicles tend to increase in length with very great rapidity, and must be checked by artificial means, which constitute the chief art of the maltster. He now begins to spread the barley thinner on the fl(,or, and turns it over several times in the course of a day, bringing the portions of the interior into the exterior surface. The depth, which was originally 15 or 16 inches, is lowered a little at every turning over, till it be brought eventually down to three or four inches. Two turnings a day are generally required. At this period of spread. ing or flooring, the temperature in England is about 62~, and in Scotland 5 or 6 degrees lower. About a day after the radicles appear, the rudiments of the stem, or of the plumula, sprout forth, called by the English maltsters the acrospire. It issues from the same end of the seed as the radicle, but turns round, and proceeds within the husk towards the other end, and would there come forth as a green leaf, were its progress not arrested. The malting, however, is complete before the acrospire becomes a leaf. The barley couch absorbs oxygen and emits carbonic acid, just -s animals (do in breathing, but to a very limited extent; for the grain loses only three pe c0ent. of its weight upon the malt floor, and a part of this loss is due to waste particles. As the acrospire creeps along the surface of the seed, the farina within undergoes a remarkable alteration. The gluten and mucilage disappear, in a great measure, the color becomes whiter, and the substance becomes so friable that it crumbles into meal between the fingers. This is the great purpose of malting, and it is known to be accomplished when the plumula or acrospire has approached the end of the seed. Now the further growth mus! be completely stopped. Fourteen days may be reckoned the usual duration of the germinating stage of the malting operations in England; but in Scotland, where the temperature of the couch is lower. eighteen days, or even twenty-one, are sometimes required. The shorter the period within the above iiiits, the more advantageous is the process to the maltster, as he can turn over his capital the sooner, and his malt is also somewhat the better. Biog is more rapid in its germination than barley, and requires to be still more carefully watched. In dry weather it is sometimes necessary to water the oarley upon the couch. Occasionally the odor disengaged from the couch is offensive, resembling that of rotten apples. This is a bad prognostice indicating either that the barley was of bad quality, or that the workment, throuigh careless shovelling, have crushed a number of the grains in turning them over. Hence when the weather causes too quick germination, it is better to check it by spreading the heap out thinner than by turning it too frequently over. On comparing different samples of barley, we shall find that the best develop the germ or acrospire quicker than the radicles, and thus occasion a greater production of the saccharine principle; this conversion advances along with the acrospire, and keeps pace with it, so that the portion of the seed to which it has not reached is still in its unaltered starchy state. It is never complete for any single barleycorn till the acrospire has come to the end opposite to that fiom which it sprung; hence one part of the corn may be sugary, while the other is still insipid. If the grain were allowed to vegetate beyond this term, the radicles being fully one third of an inch long. the future stem would become visibly green in the exterior; it would shoot forth rapidly, the interior of the grain would become milky, with a complete exhaustion of all its useful constituents, and nothing but the husk would remain. In France, the brewers, who generally malt their barley themselves, seldom leave it on the couch more than 8 or 10 days, which, even taking into account the warmer climate of their country, is certainly too short a period, and hence they make inferior wort to the English brewer, from the same quantity of malt. At the end of the germination, the radicles have become 1- longer than the barley, and are contorted so that the corns hook into one another, but the acrospire is just beginning to push through. A moderate temperature of the air is best adapted to malting; therefore it cannot be carried on well during the heat of summer or the colds of winter. Malt-floors should be placed in substantial thick-walled buildings, without access of the sun, so that a uniform temperature of 59~ or 60~ may prevail inside. Some recommend them to be sunk a little under the surface of the ground, if the situation be dry. During germination a remariable change has taken place in the substance of the grain. The glutinous constituent has almost entirely disappeared, and is supposed to have passed into the matter of the radicles, while a portion of the starch is converted into sugar and c.ucilage. The change is similar to what starch undergoes when dissolved in water, and digested in a heat of about 160P F. along with a little gluten. 10 130 BEER. The thick paste becomes gradually liquid, transparent, and sweet tasted, and the solutlot contains now, sugar and gum, mixed with some unaltered starch. The gluten suffers a change at the same time, and becomes acescent, so that only a certain quantity of starch can be thus converted by a quantity of gluten. By the artificial growth upon the maltfloor, all the gluten and albumen present in barley is not decomposed, and only about one half of the starch is conver,ted into sugar; the other half, by a continuance of the germination, would only go to the growth of the roots and stems of the plant; but it receives its nearly complete conversion into sugar without any notable waste of substance in the brewer's operation of mashing. The kiln-drying.-When the malt has become perceptibly dry to the hand upon the floor, it is taken to the kiln, and dried hard with artificial heat, to stop all further growth, and enable it to be kept, without change, for future use, at any time. The malt-kiln, which is particularly described in the next page, is a round or a square chamber, covered with perforated plates of cast iron, whose area is heated by a stove or furnace, so that not merely the plates on which the malt is laid are warmed, but the air which passes up through the stratum of malt itself, with the effect of carrying off very rapidly the moisture from the grains. The layer of malt should be about 3 or 4 inches thick, and evenly spread, and its heat should be steadily kept at from the 90th to the 100th degree of Fahrenheit's scale, till the moisture be mostly exhaled from it. During this time the malt must be turned over at first frequently, and latterly every three or four hours. When it is nearly dry, its temperature should be raised to from 145~ to 165~ F., and it must be kept at this heat till it has assumed the desired shade of color which is commonly a brownish-yellow or a yellowish-brown. The fire is now allowed to die out, and the malt is left on the plates till it has become completely cool; a result promoted by the stream of cool air, which now rises up through the bars of the grate; or the thoroughly dry browned malt may, by damping the fire, be taken hot from the plates, and cooled upon the floor of an adjoining apartment. The prepared malt nmust be kept in a dry loft, where it can be occasionally turned over till it is used. The period of kiln-drying should not be hurried. Many persons employ two days in this operation. According to the color and the degree of drying, malt is distributed into three sorts; pale, yellow, and brown. The first is produced when the highest heat to which it has been subjected is from 90~ to 100~ F.; the amber yellow, when it has suffered a heat of 122~; and the brown when it has been treated as above described. The black malt used by the porter brewer to color his beer, has suffered a much higher heat, and is partially charred. The temperature of the kiln should, in all cases, be most gradually raised, and most equably maintained. If the heat be too great at the beginning, the husk gets hard dried, and hinders the evaporation of the water from the interior sub. stance; and should the interior be dried by a stronger heat. the husk will probably split, and the farina become of a horny texture, very refractory in the mash-tun. In general, it is preferable to brown malt, rather by a iong-continled moderate heat, than by a more violent heat of shorter duration, which is apt to carbonize a portion of the mucilaginous sugar, and to damage the article. In this way, the sweet is sometimes converted into a bitter principle. During the kiln-drying, the roots and acrospire of the barley become brittle, and fall off; and are separated by a wire sieve whose meshes are too small to allow the malt itself to pass through. A quantity of good barley, which weighs 100 pounds, being jtl,:ciously malted, will weigh, after drying and sifting, 80 pounds. Since the raw grain, dried by itself at the same temperature as the malt, would lose 12 per cent. of its weight in water, the malt process dissipates out of these remaining 88 pounds, only 8 pounds, or 8 per cent. of the raw barley. This loss consists ofl1 per cent. dissolved out in the steep water, 3 - dissipated in the kiln, 3 - by the falling of the fibrils, - of waste. The bulk of good malt exceeds that of the barley from which it was made, by about 8 or 9 per cent. The operation of kiln-drying is not confined to the mere expulsion of the moisture trom the germinated seeds; but it serves to convert into sugar a portion of the starch which remained unchanged, and that in a twofold way; first, by the action of the gluten upon the fecula at an elevated temperature, as also by the species of roasting which the starch undergoes, and which renders it of a gummy nature. (See STARCH.) We shall have a proof of this explanation, if we dry one portion of the malt in a naturally dry atmosphere, and another in a moderately warm kiln; the former will yield less saccharine extract than the latter. Moreover, the kiln-dried malt has a peculiar, agreeable, and faintly burned taste, probably from a small portion of empy. BEER. 131 reumatic oil formed in the husk, and which not only imparts its flavor to the beer, but also contributes to its preservat.on. It is therefore obvious, that the skilful preparation of the malt must have the greatest influence both on the quantity and quality of the worts to be made from it. If the germination be pushed too far, a part of the extractible matter is wasted; if it has not advanced far enough, the malt will be too raw, and too much of its substance will remain as an insoluble starch; if it is too highly kiln dried, a portion of its sugar will be caramelized, and become bitter; and if the sweating was imperfect or irregular, much of the barley may be rendered lumpy and useless. Good malt is dis. tinguishable by the following characters:The grain is round and full, breaks freely between the teeth, and has a sweetish taste, an agreeable smell, and is full of a soft flour from end to end. It affords no unpleasant flavor on being chewed; it is not hard, so that when drawn along an oaken table across the fibres, it leaves a while streak, like chalk. It swims upon water, while unmalted barley sinks in it. Since the quality of the malt depends much on that of the barley, the same sort only should be used for one malting. New barley germinates quicker than old, which is more dried up; a couch of a mixture of the two would be irregular, and difficult to regulate. Description of the malt-kiln.-Figs. 107,108,109,110, exhibit the construction of a wellcontrived malt-kiln. Fig. 107, is the ground plan: fig. 108,is the vertical section; and fig.109,and 110, a horizontal and vertical section in the line of the malt-,lates. The same letto"s denote the same parts in each of the figures. A cast-iron cupola-shaped oven is 108 107 e..".,-' d d, | \ ^ e ci | d 7h h. The oven is surrounded with four pillars, on whose top a stone lintel is laid: a is vaulted arch on each of the four sides of the oven; f is the space between the kiln and the side arch, into which a workman may enter, to inspect and clean the kiln; g g, the walls on either side of the kiln, u-pon which the arches rest; h, the space for the ashes to fall, I c, the fire-door of the kiln;, junction-pieces to conect the pipes r r with the kiln; the mode of attaching them is shown in fig. 109. These smoke-pipes lie iaboupt thee feet der the iron plates, and at the sae iside walls: they are supported upon iron props, which are made fast to the arches. Ing. 108 supported in the middle, upon a wall of brickwork four feet high; and beneath it, are the grate and its ash-pit. The smoke passes off through two equi-distant pipes into the chiffnhey. The oven is surrounded with four pillars, on whose top a stone lintel is laid: a is the grate, 9 inches below the sole of the oven b; c c c c are the four nine-inch strong pillars of brickwork which bear the lintel m; d d d d d d are strong nine-inch pillars, which support the girder and joists upon which perforated plates repose; e denotes a vaulted arcli on each of the four sides of the oven; f is the space between the kiln and the side arch, into which a workman may enter, to inspect and clean the kiln; g g, the walls on either side of the kiln, upon which the arches rest; h, the space for the ashes to fall, k, the fire-door of the kiln; 1 I, junction-pieces to connect the pipes r r with the kiln; the mode of attaching them is shown in fig. 109. These smoke-pipes lie about three feet under the iron plates, and at the same distance from the side walls: they are supported upon iron props, which are made fast to the arches. Infig. 108. i 132 BEER. shows their section; at s s, fig. 109, they enter the chimney, which is prov. ded with two register or damper plates, to regulate the draught through the pipes. These registers are represented by t t, fig. 110, which shows a perpendicular section of the chimney. m, fig. 108,is the lintel which causes the heated air to spread laterally instead of ascending in one mass in the middle, and prevents any combustible particles from falling upon the iron cupola. n n are the main girders of iron for the iron beams o o, upon which.the perforated plates p lie; q,fig. 10S,is the vapor pipe in the middle of the roof, which allows the steam of the drying malt to escape. The kiln may be heated either with coal or wood. The size of this kiln is about 20 feet square; but it may be made proportionally eithel smaller or greater. The perforated floor should be large enough to receive the contents of one steep or couch. The perforated plate might be conveniently heated by steam pipes, laid zig-zag, or in parallel lines under it; or a wire-gauze web n4ight be stretched upon such pipes. The wooden joists of a common floor would answer perfectly to support this steam-range, and the heat of the pipes would cause an abundant circulation of air. For drying the pale malt of the ale brewer, this plan is particularly well adapted. The kiln-dried malt is sometimes ground between stones in a common corn mill, like oatmeal; but it is more generally crushed between iron rollers, at least for the purposes of the London brewers. The crushing mill.-The cylinder malt-mill is constructed as shown in figs. 111, 112. I is the sloping-trough, by which the malt is let down from its bin or floor to the rl'l hopper A of the mill, whence -111(*.o\' ~ 112 it is progressively shaken in xI ~-"~ ~< 1~ L~ _ "'between the rollers B D. The hA rollers are of iron, truly cylint/igl^,.; ~,~ \ i drical, and their ends rest in ae^11z^ \ n I bearers of hard brass, fitted into the side frames of iron. A screw E goes through the upright,. e l B rmo =.C Y - 1 a d and serves to force the bearer P!10.11llO ^ c, p - of the one roller towards that of E, _ — (* X H the other, so as to bring them closer together when the crush. l^ \ l, ing effect is to be increased. G \ I \ l HF / is the square end of the axis, by which one of the rollers may be turned either by the r1 _ ____ ~ e ^^ - A~__hand or by power; the other derives its rotatory motion from a pair of equal-toothed wheels H, which are fitted to the other end of the axes of the rollers. d is a catch which works into the teeth of a ratchet-wheel on the end of one of the rollers (not shown in this view.) The lever c strikes the trough b at the bottom of the hopper, and gives it the shaking motion for discharging the malt between the rollers, from the slide sluice a. e e,fig. 111, are scraper-plates of sheet iron, the edges of which press by a weight against the surfaces of the rollers, and keep them clean. Instead of the cylinders, some employ a crushing mill of a conreal-grooved form like a coffee-mill, upon a large scale. (See the general plan, infra.) The?nashing and boiling.-Mashing is the operation by which the wort is extracted, or eliminated from the malt, and whereby a saccharo-mucilaginous extract is made from it. The malt should not in general be ground into a fine meal, for in that case it would be apt to form a cohesive paste with hot water, or to set, as it is called, and to be difficult to drain. In crushed malt, the husk remains nearly entire, and thus helps to keep the farinaceous particles open and porous to the action of the water. The bulk of the crushed malt is about one fifth greater than that of the whole, or one bushel of malt gives a bushel and a quarter of crushed malt. This is frequently allowed to lie a few days. in a cool place, in order that it may attract moisture from the air, which it does very readily by its hygrometric power. Thus, the farinaceous substance which had been indurated in the kiln, becomes soft, spongy, and fit for the ensuing process of watery extraction. Mashing has not for its object merely to dissolve the sugar and gum already present in the malt, but also to convert into a sweet mucilage the starch which had remained unchanged during the germination. We have already stated that starch, mixed with gluten, and digested for some time with hot water, becomes a species of sugar. This conversion takes place in the mash-tun. The malted barley contains not only a portion of gluten, but diastase more than sufficient to convert the starch contained in it, by this Iacans, into sugar. BEER. 183 The researches of Payen and Persoz show, that the mucilage formed by the reaction of malt upon starch, may either be converted into sugar, or be made into permanent gum, according to the temperature of the water in which the materials are digested. We take of pale barley malt, ground fine, from 6 to 10 parts, and 100 parts of starch; we heat, by means of a water-bath, 400 parts of water in a copper, to about 80~ F.; we then stir in the malt, and increase the heat to 140~ F., when we add the starch, and stir well together. We next raise the temperature to 158~, and endeavor to maintain it constantly at that point, or at least to keep it within the limits of 167~ on the one side, and 158~ on the other. At the end of 20 or 30 minutes, the original milky and pasty solution becomes thinner, and soon after as fluid nearly as water. This is the moment in which the starch is converted into gum, or into that substance which the French chemists call dextrine, from its power of polarizing light to. the right hand, whereas common gum does it to the left. If this merely mucilaginous solution, which seems to be a mixture of gum with a little liquid starch and sugar, be suitably evaporated, it may serve for various purposes in the arts to which gum is applied, but with this view, it must be quickly raised to the boiling point, to prevent the farther operation of the malt upon it. If we wish, on the contrary, however, to promote the saccharine fermentation, for the formation of beer, we must maintain the temperature at between 158~ and 167c for three or four hours, when the greatest part of the gum will have passed into sugar, and by evaporation of the liquid at the same temperature, a starch sirup maybe obtained like that procured by the action of sulphuric acid upon starch. The substance, which operates in the formation of sugar, or is the peculiar ferment of the sugar fermentation, may be considered as a residuum of the gluten or vegetable albumen in the germinating grain: it is reckoned by Payen and Persoz, a new proximate principle called diastase, which is formed during malting, in the grains of barley, oats, and wheat, and may be separated in a pure state, if we moisten the malt flour for a few minutes in cold water, press it out strongly, filter the solution, and heat the clear liquid in a water bath, to the temperature of 158~. The greater part of that albuminous azotized substance is thus coagulated, and is to be separated by a fresh filtration; after which, the clear liquid is to be treated with alcohol, when a flocky precipitate appears, which is diastase. To purify it still further, especially from the azotized matter, we should dissolve it in water, and precipitate again with alcohol. When dried at a low temperature, it appears as a solid white substance, which contains no azote; is insoluble in alcohol, but dissolves in water and proof spirit. Its solution is neutral and tasteless; when left to itself, it changes with greater or less rapidity according to the temperature, and becomes sour at a temperature of from 149~ to 167~. It has the property of converting starch into gum (dextrine) and sugar, and indeed, when sufficiently pure, with such energy that one part of it disposes 2000 parts of dry starch to that change, but it operates the quicker the greater its quantity. Whenever the solution of diastase with starch or with dextrine is heated to the boiling point, it loses the sugar-fermenting property. One hundred parts of well-malted starch appear to contain about one part of this substance. We can now understand the theory of malting, and the limits between which the temperature of the liquor ought to be maintained in this operation; namely, the range between 157~ and 160~ F.' It has been ascertained as a principle in mashing, that the best and soundest extract of the malt is to be obtained, first of all, by beginning to work with water at the lowest of these heats, and to conclude the mash with water at the highest. Secondly, not to operate the extraction at once with the whole of the water that is to be employed; but with separate portions and by degrees. The first portion is added with the view of penetrating equally the crushed malt, an 1 of extracting the already formed sugar; the next for effecting the sugar fermentation by the action of the diastase. By this means, also, the starch is not allowed to run into a cohesive paste, and the extract is more easily drained from the poorer mass, and comes off in the form of a nearly limpid wort. The thicker, moreover, or the less diluted the mash is, so much the easier is the wort fined in the boiler or copper by the coagulation of the albuminous matter: these principles illustrate, in every condition, the true mode of conducting the mashing process; but different kinds of malt require a different treatment. Pale and slightly kilned malt requires a somewhat lower heat than malt highly kilned, because the former has more urdecomposed starch, and is more ready to become pasty. The formner also, for the same reason, needs a more leisurely infusion than the latter, for its conversion into mucilaginous sugar. The more sugar the malt contains, the more is its saccharine fermentation accelerated by the action of the diastase. What has been here said of pale malt, is still more applicable to the case of a mixture of raw grain with malt, for it requires still gentler heats, and more cautious treatment. IlI. The mash-tun is a large circular tub with a double bottom; the uppermost of which is called a false bottom, and is pierced with many holes. There is a space of about 2 or 3 inches between the two, into which the stopcocks enter, for letting in the water and drawing off the wort. The holes of the false bottom should be burned, and not bored 134 BEER *o prevent the chance of their filling up by the swelling of the wood, which wo'lld tbstruct the drainage: the holes should be conical, and largest below, being about oj an inch there, and - at the upper surface. The perforated bottom must be fitted truly at the sides of the mash-tun, so that no grains may pass through. The mashed liquor is let off into a large back, from which it is pumped into the wort coppers. The mash-tun is provided with a peculiar rotatory apparatus for agitating the crushed grains and water together, which we shall presently describe. The size of the wort copper is proportional to the amount of the brewing, and it must, in general, be at least so large as to operate upon the whole quantity of wort made from one mashing; that is, for every quarter of malt mashed, the copper should contain 140 gallons. The mash-tun ought to be at least a third larger, and of a conical form, somewhat wider below than above. The quantity of water to be employed for mashing, or the extraction of the wort, depends upon the greater or less strength to be given to the beer. The seeds of the crushed malt, after the wort is drawn off, retain still about 32 gallons of water for every quartet of malt. In the boiling, and evaporation from the coolers, 40 gallons of water are dissipated from one quarter of malt; constituting 72 gallons in all. If 13 quarters of barley be taken to make 1500 gallons of beer, 2400 gallons of water must therefore be required or the mashing. This example will give an idea of the proportions for an ordinary quality of beer. When the mash is to begin. the copper must be filled with water, and heated. As soon as the water has attained the heat of 145~ m summer, or 167~ in winter, 600 gallons of it are to be run off into the mash-tun, and the 13 quarters of crushed malt are to be gradually thrown in and well intermixed by proper agitation, so hat it may be uniformly moistened, and no lumps may remain. After contiluing the agitation in this way for one half or three quarters of an hour, the water in the copper will have approached to its boiling point, when 450 gallons at the temperature of about 200~ are to be run into the mash-tun, and the agitation is to be renewed till the whole assumes an equally fluid state: the tun is now to be well covered for the preservation of its heat, and to be allowed to remain at rest for an hour, or an hour and a half. The mean temperature of this mash may be reckoned at about 145~. The time which is necessary for the transmuting heat of the remaining starch into sugar depends on the quality of the malt. Brown malt requires less time than pale malt, and still less than a mixture with raw grain, as already explained. After the mash has rested the proper time, the tap of the tun is opened, and the clear wort is to be drawn out into the under back. If the wort that first flows is turbid, it must be returned into the tun, til it runs clear. The amount of this first wort may be about 675 gallons. Seven hundred and fifty gallons of water, at the temperature of 200~, are now to be introduced up through the drained malt, into the tun, and the mixture is to be agitated till it becomes uniform, as before. The mashtun is then to be covered, and allowed to remain at rest for an hour. The temperature of this mash is from 167~ to 174~. While the second mash is making, the worts of the first are to be pumped into the wort copper, and set a-boiling as speedily as possible. The wort of the second mash is to be drawn off at the proper time, and added to the copper as fast as it will receive it, without causing the ebullition to stop. A third quantity of water amounting to 600 gallons, at 200~, is to be introduced into the mas,-tun, and after half an hour is to be drawn off, and either pumped into the wort copper, -:e reserved for mashing fresh malt, as the brewer may think fit. The quantity of extract, per barrel weight, which a quarter of malt yields to wort, amounts to about 84 lbs. The wort of the first extract is the strongest; the second contains, commonly, one half the extract of the first; and the third, one half of the second; according to circumstances. To measure the degrees of concentration of the worts drawn off from the tun, a particular form of hydrometer, called a saccharometer, is employed, which indicates the number of pounds weight of liquid contained in a barrel of 36 gallons imperial measure. Now, as the barrel of water weighs 360 lbs., the indication of the instrument, when placed in any wort, shows by how many pounds a barrel of that wort is heavier than a barrel of water; thus, if the instrument sinks with its poise till the mark 10 is upon a line with the surface of the liquid, it indicates that a barrel of that wort weighs ten pounds more than a barrel of water. See SACCHAROMETER. Or, supposing the barrel of wort weighs 396 lbs., to convert that number into specific gravily, we have the following simple rule:360: 396:: 100: 1-100; at which density, by my experiments, the wort contains 25 per cent. of solid extract. Having been employed to make experiments on the density of worts, and the fermentative changes which they undergo, for the information of a committee of the House ol Commons, which sat in July and August, 1830, I shall here introduce a short abstract o!.hat part of my evidence which bears upon the present subject. Mv first object was to clear up the difficulties which, to common apprehension, huna BEER. 185 over the matter, from the difference in the scales of the sacciarometers mi use among the brewers and distillers of England and Scotland. I found that one quarter of good malt would yield to the porter-brewer a barrel Imperial measure of wort, at the concentrated specific gravity of 1'234. Now, if the decimal part of this number be multiplied by 360, being the number of pounds weight of water in the barrel, the product will denote the excess in pounds, of the weight of a barrel of such concentrated wort, over that of a barrel of water; and that product is, in the present case, 84'24 pounds. Mr. Martineau, jun., of the house of Messrs. Whitbread and Company, and a gentlcman connected with another great London brewery, had the kindness to inform me that their average product from a quarter of malt was a barrel of 84 lbs. gravity. It is ob. vious, therefore, that by taking the mean operation of two such great establishments, 1 must have arrived very nearly at the truth. It ought to be remarked that such a high density of wort as 1'234 is not the result of any direct experiment in the brewery, for infusion of malt is never drawn off so strong; that densily is deduced by computation from the quantity ind quality of several successive infusions; thus, supposing a first infusion of the quarter of malt to yield a barrel of specific gravity 1'112, a second to yield a barrel at 1'091, and a third a barrel at 1*031, we shall have three barrels at the mean of these three numbers, or one barrel at their sum, equal to 1l234. I may here observe that the arithmetical mean or sum is not the true mean or sum of the two specific gravities; but this difference is either not known or disregarded by the brewers. At low densities this difference is inconsiderable, but at high densities it would lead to serious errors. At specific gravity 1-231, wort or sirup contains one half of its weight of solid pure saccharum, and at 1-1045 it contains one fourth of its weight; but the brewer's rule, when here applied, gives for the mean specific gravity 1.':5= 1231 - 1-000. The contents in solid saccharine matter at that density are however 272 per cent., showirg the rule to be 2 lbs. wrong in excess on 100 lbs., or 9 lbs. per barrel. The specific gravity of the solid dry extract of malt wort is 1'264; it was taken in oil of turpentine, and the result reduced to distilled water as unity. Its specific volume is 0*791 1, that is, 10 lbs. of it will occupy the volume of 7-911 lbs. of water. The mean specific gravity, by computation of a solution of that extract in its own weight of water, is 1'1166; but by experiment, the specific gravity of that solution is 1*216, showing considerable condensation of volume in the act of combination with water. The following Table shows the relation between the specific gravities of solutions of malt extract, and the per-centagc of solid extract they contain: Extr Malt. Water. Malt Extract in 100. Sugar in 100. Specific gravity. 600 + 600 50'00 47'00 1-2160 600 900 40'0 37-00 1'1670 600 - 1200 33-3 31'50 1*1350 600 1500 28-57 26-75 1-1130 600 - 1800 25-00 24'00 1-1000 The extract of malt was evaporated to dryness, atr a temperature of about 250~ F., without the slightest injury to its quality, or any empyreumatic smell. Bate's tables have been constructed on solutions of sugar, and not with solutions of extract of malt, or they agree sufficiently well with the former, but differ materially from the latter. Allan's tables give the amount of a certain form of solid saccharine matter extracted from ma and dried at 175~ F., in correspondence to the specific gravity of the solution; but I have found it impossible to make a solid extract from infusions of malt, except at much higher temperatures than 175~ F. Indeed, the numbers on Allan's saccharometer scale clearly show that his extract was by no means dry: thus, at 1*100 of gravity he assigns 29'669 per cent. of solid saccharine matter; whereas there is at that density of solid extract only 25 per cent. Again, at 1'135, Allan gives 40 parts per cent. of solid extract, whereas there are only 33- present. By the triple mashing operations above described, the malt is so much exhausted that it can yield no further extract useful for strong beer or porter. A weaker wort might no doubt still be drawn off for small beer, or for contributing a little to the strength of the next mashing of fresh malt. But this I believe is seldom practised by respectable brewers, as it impoverishes the grains which they dispose of for feed(ing cattle. The wort should be transferred into the copper, and made to boil as soon as possible, for if it remains long in the under-back it is apt to become acescent. The steam moreovel raised from it in the act of boiling serves to screen it from the oxygenating or aciditying influence of Whe atmosphere. Until it begins to boil, the air should be excluded by some kind of a cover. 136 BEER. Sometimes the first wort is brewed by itself into strong ale, the second by itself into an intermediate quality;and the third into small beer; but this practice is not much fol. lowed in this country. We shall now treat of the boiling in of the hops. The wort drawn from the mashtun, whenever it is pumped into the copper, must receive its allowance of hops. Besides evaporating off a portion of the water, and thereby concentrating the wort, boiling has a twofold object. In the first place, it coagulates the albuminous matter, pa'rtly by the heat, and partly by the principles in the hops, and thereby causes a general clarification of the whole mass, with the effect of separating the muddy matters in a flocculent form. Secondly, during the ebullition, the residuary starch and hordeine of the malt are converted into a limpid sweetish mucilage, the dextrine above described; while some of the glutinous stringy matter is rendered insoluble by the tannin principle of the hops, which favors still further the clearing of the wort. By both operations the keeping quality of the beer is improved. This boil must be continued during several hours; a longer time for the stronger, and a shorter for the weaker beers. There is usually one seventh or one sixth part of the water dissipated in the boiling copper. This process is knows to have continued a sufficient time, if the separation of the albuminous flocks is distinct. and if these are found, by means of a proof gauge suddenly dipped to the bottom, to be collected there, while the supernatant liquor has become limpid. Two or three hours' boil is deemed long enough in many well-conducted breweries; but in some of those in Belgium, the boiling is continued from 10 to 15 hours, a period certainly detrimental to the aroma derived from the hop. Many prefer adding the hops when the wort has just come to the boiling point. Their effect is to repress the further progress of fermentation, and. especially the passage into the acetous stage, which would otherwise inevitably ensue in a few days. In this respect, no other vegetable production hitherto discovered can be a substitute for the hop. The odorant principle is not so readily volatilized as would at first be imagined; for when hop is mixed with strong beer wort and boiled for many hbars, it can still impart a very considerable degree of its flavor to weaker beer. By mere infusion in hot beer or water, without boiling,.the hop loses very little of its soluble principles. The tannin of the hop combines, as we have said, with the vegetable albumen of the barley, and helps to clarify the liquor. Should there be a deficiency of albumen and gluten, in consequence of the mashing having been done at such a heat as to have coagulated them beforehand, the defect may be remedied by the addition of a little gelatine to the wort copper, either in the form of calf's foot, or of a little isinglass. If the hops be boiled in the wort for a longer period than 5 or 6 hours, they lose a portion of their fine flavor; but if their natural flavor be rank, a little extra boiling improves it. Many brewers throw the hops in upon the surface of the boiling wort, and allow them to swim there for some time, that the steam may pernetrate them, and open their pores for a complete solution of.their principles when they are pushed down into the liquor. It is proper to add the hops in considerable masses, because, in tearing them asunder, some of the lupuline powder is apt to be lost. The quantity of hop to be added to the wort varies according to the strength of the beer, the length of time it is to be kept, or the heat of the climate where it is intended to be sent. For strong beer, 4- lbs. of hops are required to a quarter of malt, when it is-to be highly aromatic and remarkably clear. For the stronger kinds of ale and porter, the rule, in England, is to take a pound of hops for every bushel of malt, or 8 lbs. to a quarter. Common beer has seldom more than a quarter of a pound of hops to the bushel of malt. It has been attampted to form an extract of hops by boiling in covered vessels, so as not to lose the oil, and to add this instead of the hop itself to the beer. On the great scale this method has no practical advantage, because the extraction of the hop is perfectly accomplished during the necessary boiling of the wort, and because the hop operates very beneficially, as we have explained, in clarifying the beer. Such an extract, moreover, could be easily adulterated..Of the Coolers.-The contents of the c pper are run into what is called the hop. back, on the upper part of which is fixed a drainer, to keep back the hops. The pump is placed in the hop-back, for the purpose of raising the wort to the coolers, usually placed in an airy situation upon the top of the brewery. Two coolers are indispensable when we make two kinds of beer from the same brewing, and even in single brewings, called gyles, if small beer is to be made. One of these coolers ought to be placed above the level of the other. As it is of great consequence to cool the worts down to the fermenting pitch as fast as possible, various contrivances have been made for effecting this purpose. The common cooler is a square wooden cistern, about 6 inches deep, and of such an extent of surface that the whole of one boil may only occupy 2 inches, or thereabouts, of depth in it. For a quantity ofrvort equal to about 1500 gallons its area should be at least 54 feet long and 20 feet wide. The seams of BEER. 137 the cooler must be made perfectly water-tight and smooth, so that no liquor may lodre in them when they are emptied. The utmost cleanliness is required, and an occasicnal sweetening with lime-water. The hot wort reaches the cooler at a temperature of from 200~ to 208~, according to the power of the pump. Here it should be cooled to the proper temperature for the fermenting tun, which may vary from 54~ to 64~, acctrding to circumstances. The refrigeration is accomplished by the evaporation of a por ion of the liquor: it is more rapid in proportion to the extent of the surface, to the low temperature, and the dryness of the atmosphere surrounding the cooler. The renewal of a body of cool dry air by the agency of a fan, may be employed wth great advantage. The cooler itself must be so placed that its surface shall be fieely exposed to the prevailing wind of the district, and be as free as possible from the eddy of surrounding buildings. It is thought by many that the agitation of the wort during its cooling is hurtful. Were the roof made moveable, so that the wort could be readily exposed, in a clear night, to the aspect of the sky, it would cool rapidly by evaporation, on the principles explained by Dr. Wells, in his "Essay on Dew." When the cooling is effected by evaporation alone, the temperature falls very slowly, even in cold air, if it be loaded with moisture. But when the air is dry, the evaporation is vigorous, and the moisture exhaled'does not remain incumbent on the liquor, as in damp weather, but is diffused widely in space. Hei.ce we can understand how wort cools so rapidly in the spring and autumn, when the air is generally dry, and even more quickly than in winter, when the air is cooler, but loaded with moisture. In fact, the cooling process goes on better when the atmosphere is from 50~ to 55~, than when it falls to the freezing point, because in this case, if the air be still, the vapors generated remain on the surface of the liquor, and prevent further evaporation. In summer the cooling can take place only duringthe niaht. In consequence of the evaporation during this cooling process, the bulk of the worts is considerably reduced; thus, if the temperature at the beginning was 208~, and if it be at the end 64~, the quantity of water necessary to be evaporated to produce this refrigeration would be nearly - of the whole, putting radiation and conduction of heat out of the question. The effect of this will be a proportional concentration of the beer. The period of refrigeration in a well-constructed cooler, amounts to 6 or 7 hours in favorable weather, but to 12 or 15 in other circumstances. The quality of the beer is much improved by shortening this period; because, in consequence of the great surface which the wort exposes to the air, it readily absorbs oxayen, and passes into the acetous fermentation with the production of various mouldy spots; an evil to which ill-hopped beer is particularly liable. Various schemes have been contrived to cool wort, by transmitting it through the convolutions of a pipe immersed in cold water. The best plan'is to expose the. hot wort for some hours freely to the atmosphere and the cooler, when the loss of heat is most rapid by evaporation and other means, and when the temperature falls to 1000, or thereby, to transmit the liquor through a zig-zag pipe, laid almost horizontally in a trough of cold water. The various methods described under Refrigerator are more complex, but they may be practised in many situations with considerable advantage. Whilst the wort reposes in the cooler, it lets fall a slight sediment, which consists partly of fine flocks of coagulated albumen combined with tannin, and partly of starch, which had been dissolved at the high temperature, and separates at the lower. The wort should be perfectly limpid, for a muddy liquor never produces transparent beer. Such beer contains, besides mucilaginous sugar and gum, usually some starch, which even remains after the fermentation, and hinders its clarifying, and gives it a tendency to sour. The wort contains more starch the hotter it has been mashed, the less hops have been added, and the shorter time it has been boiled. The presence of starch in the wort may be made manifest by adding a little solution of iodine in alcohol to it, when it will become immediately blue. We thus see that the tranquil cooling of wort in a proper vessel has an advantage over cooling it rapidly by a refrigeratory apparatus. When the wort is sufficiently cool, it is let down into the fermenting tun. In this transfer the cooling might be carried several deere.s lower, were the wort made to pass down throluh a tube enclosed in another tube, along which a stream of cold water is flowing in the cppo. site direction, as we have described in the sequel of ACETIC ACID. These fermenting tuns are commonly called gyle-tuns, or working tuns, and are either square or circular, the latter being preferable on many accounts. iV. Of the Fermentation.-In the great London breweries, the size of these fermenting tuns is such that they contain from 1200 to'1500 barrels. The quantity of wort introduced at a time must, however, be considerably less than the capacity of the vessel, to allow room for the head of yeast which rises during the process; if the vessel be cylindrical, this head is proportional to the depth of the worts. In certain kinds of 138 BEER. fermentation, it may rise to a third of that depth. In general, the fermentation proceeds more uniformly and constantly in large masses, because they are little influenced by vi. zissitudes of temperature; smaller vessels, on the other hand, are more easily handled. The general view of fermentation will, be found under that title; I shall here make a few remarks on what is peculiar to beer. During the fermentation of wort, a portion of its saccharine matter is converted into alcohol, and wort thus changed is beer. It is necessary that this conversion of the sugar be only partial, for beer which contains no undecomposed sugar would soon turn sour, and even in the casks its alcohol undergoes a slow fermentation into vinegar. The amount of this excess of sugar is greater in proportion to the strength of the wort, since a certain quantity of alcohol, already formed, prevents the operation of the ferment on the remaining Twort. Temperature has the greatest influence upon the fermentation of wort. A temperature of from 55~ to 60~ of the liquor, when that of the atmosphere is 55~, is most advantageous for the commencement. The warmth of the wort as it comes into the gyle-tun must be modified by that of the air in the apartment. In winter, when this apartment is cold, the wort should not be cooled under 64~ or 60~, as in that case the fermentation would be tedious or interrupted, and the wort liable to spoil or become sour. In summer, when the temperature of the place rises to above 75~, the wort should be cooled, if possible, down to 55~, for which purpose it should be let in by the system of double pipes, above mentioned. The higher the temperature of the wort, the sooner will the fermentation begin and end, and the less is it in our power to regulate its progress. The expert brewer must steer a middle course between these two extremes, which threaten to destroy his labors. In some breweries a convoluted pipe is made to traverse or go round the sides of the gyle-tun, through which warm water is allowed to flow in winter, and cold in summer, so as to modify the temperature of the mass to the proper fermenting pitch. If there be no contrivance of this kind, the apartment may be cooled it summer, by suspending wet canvass opposite the windows in warm weather, and kindling a small stove within it in cold. When the wort is discharged into the gyle-tun, it must receive its dose of yeast, which has been previously mixed with a quantity of the wort, and left in a warm place till it has begun to ferment. This mixture, called lobb, is then to be put into the tun, and stirred well through the mass. The yeast should be taken from similar beer. Its quantity must depend upon the temperature, strength, and quantity of the wort. In general, one gallon of yeast is sufficient to set 100 gallons of wort in complete fermentation. An excess of yeast is to be avoided, lest the fermentation should be too violent, and be finished in less than the proper period of 6 or 8 days. More yeast is required in winter than in summer; for, at a temperature of 50~, a double quantity may be used to that at 68~. Six or eight hours after adding the yeast, the tun being meanwhile covered, the fermentation becomes active: a white milky-looking froth appears, first on the middle, and spreads gradually over the whole surface; but continues highest in the middle, forming a frothy elevation, the height of which increases with the progress of the fermentation, and whose color gradually changes to a bright brown, the result, apparently, of the oxydation of the extractive contained in this yeasty top. This covering screens the wort from the contact of the atmospherical air. During this time, there is a perpetual disengagement of carlbnic acid gas, which is proportional to the quantity of sugar converted into alcohol. The warmth of the fermenting liquid increases at the same time, and is at a maximum when the fermentation has come to its highest point. This increase of temperature amounts to from 9~ to 14~ or upwards, and is the greater the more rapid the fermentation. But in general, the fermentation is not allowed to proceed so far in the gyle-tun, for after it is advanced a little way, the beer is cleansed, that is, drawn off into other vessels, which are large barrels set on end, with large openings in their top, furnished with a sloping tray for discharging an excess of yeast into the wooden trough, in which the stillions stand. These stillions are placed in communication with a store-tub, which keeps them always full, by hydrostatic pressure, so that the head of yeast may spontaneously flow over, and keep the body of liquor in the cask clean. This apparatus will be explained in describing the brewery plant. See the figures, infri. It must be observed, that the quantity of yeast, and the heat of fermentation, differ for every different quality of beer. For mild ale, when the fermentation has reached 75~ its first flavor begins; at 80~ the flavor increases; at 85~ it approaches the high flavor; at 90~ it is high; but it may be carried to 100~ and upwards, for particular purposes. A wort of 301bs. per barrel (sp. gr. 1-088), ought to increase about 15~, so that in order to arrive at 80~, it should be set at 65~. The quantity of yeast for such an ale should be from 2 to 3 lbs. per barrel. The higher the heat, the less yeast is necessary. If the heat of the fermentation should at any time fall, it must be raised by a supply of fresh yeast, well stirred in; but this practice is not advisable in general, because rousing the worts in the gyle-tun is apt to communicate a rank flavor of yeast to the ale. It is the practice of many experienced brewers to look every 2 hours into the BEER. 139 cyle-tun, chiefly with the view of observing the progress of the heat, which is low at first, but afterwards often increases half a degree per hour, and subsequently declines, as the fermentation approaches its conclusion, till at length the heat becomes uniform, or sometimes decreases, before the fermentation is finished, especially where the quantity operated upon is small. Some brewers recommend, when the fermentation is carried to its utmost period, to add about 7 lbs. of wheat or bean flour to a gyle-tun of 25 or 30 barrels, at the time of cleansing, so as to quicken the discharge of the yeast, by disengagement of more carbonic acid. The flour should be whisked up in a pail, with some of the beer, till the lumps are broken, and then poured in. By early cleansing, the yeast is preserved longer in a state proper for a perfect fermentation than by a contrary practice. For old ale, which is to be long kept, the heat of the fermentation should not exceed 75~, but a longer time is required to complete the fermentation and ensure the future good flavor of the aie. For porter, the general practice is, to use from 4 to 41 lbs. of hops per barrel for keeping; though what is termed mild or mixing porter, has not more than 3 or 3- lbs. The heat of fermentation must not exceed 70~, and begin about 60~. If the heat tend to increase much above that pitch in the gyle-tun, the porter should be cleansed, by means of the stillions. At thic period of the fermentation, care should be taken that the sweetness of the malt be removed, for which purpose more yeast may be.sed than with any other beer of the same strength. The quantity is from 3 to 4 lbs. per barrel, rousing the wort in the gyle-tun every 2 hours in the day-time. When the plan of cleansing casks is not employed, the yeast is removed from the surface of the fermenting tun by a skimmer, and the clear beer beneath is then drawn off into the ripening tuns, called store-vats, in which it is mixed up with different brewings, to suit the taste of the customers. This transfer must take place whenever the extrication of carbonic acid has neatly ceased; lest the alcohol formed should dissolve some of the floating yeast, acquire thereby a disagreeable taste, and pass partially into the acetous state. In this process, during the formation of vinous spirit at the expense of the sugar, the albumen and gluten diffused through the beer, being acted upon by the alcohol, become insoluble; one portion of them is buoyed to the top with the carbonic acid gas, to form the frothy yeast; and another portion falls to form the bottom barm. The former consists of the same materials as the wort, with a large proportion of gluten, which forms its active constituent; the latter is a peculiar deposite, consisting of the same gluten mixed with the various dense impurities cf the wort, and nay be also used as a ferment, but is cruder than the floating yeast. The amount of yeast is proportional to the activity of the fermentation, or extrication of carbonic acid gas, as also to the heat of the mashing process, and the quantity of starch or flour unaltered by germination. Pale malt aflfrds, usually, more yeast than malt highly kilned. When the yeast becomes excessive, from too violent fermentation, it should be skimmed off from time to time, which will tend to cool the liquor and moderate the intestine changes. After the beer is let down into the close store-tuns in the cellar, an obscure fermentation goes on, for a considerable period, in its body, which increases its spirituous strength, and keeps up in it a constant impregnation of carbonic acid gas, so as to render it lively and agreeable to the taste, when it is casked off for sale. It would appear that beer is never stationary in quality, while it is contained in the tuns; for the moment when it ceases to improve by the decomposition of its residuary sugar, it begins to degenerate into vinegar. This result may be produced either by the exhaustion of the saccharine, or by the fermentative matter. The store cellar should therefore be under ground, free fiom alternations of temperature, vibrations of carriages, and as cool as possible. In the great London breweries the fermentation is rendered very complete in the cleansing butts; so that a slow and steady ripening is ensured in the great store-tuns. The gyletuns are too capacious to permit the fermentation to be finished, with either safety or sufficient despatch in them. V. OF RIPENING DIFFERENT KINDS OF BEER.-The varieties of beer depend either upon the difference of their materials, or from a different management of the brewing processes. With regard to the materials, beers differ in the proportion of their malt, hops, and water; and iti the different kinds of malt or other grain. To the class of table or small beers, all those sorts may be referred whose specific gravity does not exceed 1'025, which contain about 5 per cent. of malt extract, or nearly 18 pounds per barrel. Beers of middling strength may be reckoned those between the density of 1'025 and 1'040; which contain at the average 7 per cent. or 25 pounds per barrel. The latter may be nlade with 400 quarters of malt to 1500 barrels of beer. Stronger beers have a specific gravity of from 1'050 to 1-080, and take from 45 to 75 quarters of malt to the same quantity of beer. The strongest beer found in the market is some of the English and Scotch ales, for which from 18 to 27 quarters of malt are taken for 150C 140 BEER, gallons of beer. (jood porter requires from 16 to 18 quarters for that quantity. Beers are sometimes made with the addition of other farinaceous matter to the malt; hut when the latter constitutes the main portion of the grain, the malting of the other kinds of corn becomes unnecessary, for the diastase of the barley-malt changes the starch into sugar during the mashing operation. Even with entirely raw grain, beei is made in some parts of the Continent, the brewers trusting the conversion of the starch into sugar to the action of the gluten alone, at a low mashing temperature, on the principle of Saussure's and Kirchoff's researches. The color of the beer depends upon the color of the malt, and the duration of the boil in the copper. The pale ale is made, as we have stated, from steam or sun-dried malt, and the young shoots of the hop; the deep yellow ale from a mixture of pale yellow' and brown malt; and the dark brown beer from well-kilned and partly carbonized malt, mixed with a good deal of the pale, to give body. The longer and more strongly heated the malt has been in the kiln, the less weight of extract, cceteris paribus, does it afford. In making the fine nild ales, high temperatures ought to be avoided, and the yeast ought to be skimmed oiF, or allowed to flow very readily from its top, by means of the cleansing butt system, so that little ferment being left in it to decompose the rest of the sugar, the sweetness may remain unimpaired. With regard to porter, in certain breweries, each of the three kinds of malt employed for it is separately mashed, after which the first and the half of the second wort is boiled along with the whole of the hops, and thence cooled and set to ferment in the gyle-tun. The third drawn wort, with the remaining half of the second, is then boiled with the same hops, saved by the drainer, and, after cooling, added to the former in the gyle-tun, when the two must be well roused together. It is obvious, from the preceding development of principles, that all amylaceous and saccharine materials, such as potatoes, beans, turnips, as well as cane and starch sirup, molasses, &c., may be used in brewing beer. When, however, a superior quality of brown beer is desired, malted barley is indispensable, and even with these substitutes a mixture of it is most advantageous. The washed roots of the common carrot, of the red and yellow beet, or of the potato, must be first boiled in water, and then mashed intoa pulp. This pulp must be mixed with water in the copper, along with wheaten or oat meal, and the proper quantity of hops, then boiled during 8 or 9 hours. This wort is to be cooled in the usual way, and fermented, with the addition of yeast. A much better process is that now practised, on a considerable scale, at Strasbourg, in making the ale, for which that city is celebrated. The mashed potatoes are mixed with from a twentieth to a tenth of their weight of finely ground barley malt, and some water. The mixture is exposed, in a water-bath, to a heat of 160~ F. for four hours, whereby it passes into a saccharine state, and may then be boiled with hops, cooled, and properly fermented into grod beer. Maize, or Indian corn, has also been employed to make beer; but its malting is somewhat difficult on account of the rapidity and vigor with which its radicals and plumula sprout forth. The proper mode of causing it to germinate is to cover it, a few inches deep, with common soil, in a garden or field, and to leave it there till the bed is covered with green shoots of the plant. The corn must be then lifted, washed, and exposed to the kiln. The Difference of the Fermentation.-The greater or less rapidity with which the worts are made to ferment has a remarkable influence upon the quality of the beer, especially in reference to its fitness for keeping. The wort is a mucilaginous solution in which the yeasty principles, eliminated by the fermentation, will, if favored by regular and slow intestine movements, completely rise to the surface, or sink to the bottom, so as to leave the body fine. But, when the action is too violent, these barmy glutinous matters get comminuted and dispersed throuch the liquor, and can never afterwards be thoroughly separated. A portion of the same feculent matter becomes, moreover, permanently dissolved, during this furious commotion, by the alcohol that is generated. Thus the beer loses not merely its agreeable flavor and limpidity, but is apt to spoil from the slightest causes. The slower, more regularly progressive, and less interrupted, therefore, the fermentation is, so much better will the product be. Beer, in its perfect condition, is an excellent and healthful beverage, combining, in some measure, the virtues of water, of wine, and of food, as it quenches thirst, stimulates, cheers, and strengthens. The vinous portion of it is the alcohol, proceeding from the fermentation of the malt sugar. Its amount, in common strong ale or beer, is about 4 per cent., or four measures of spirits, specific gravity 0*825 in 100 measures of the liquor. The best brown stout porter contains 6 per cent., the strongest ale even 8 per cent.; but common beer only one. The nutritive part of the beer is the undecomposed gum-sugar, and the starch-gum, not changed into sugar. Its quantity is very variable, according to the original starch of the wort, the length of the fermentation, and the age of the be er BEER. 141 1'he main feature of good beer is fine color and transparency; the production of which is an object of great interest to the brewer. Attempts to clarity it in the cask seldom fail to do it harm. The only thing that can be used with advantage for fining foul or muddy beer, is isinglass. For porter, as commonly brewed, it is frequently had recourse to. A pound of good isinglass will make about 12 gallons of finings. It is cut into slender shreds, and put into a tub with as much vinegar or hard beer as will cover it, in order that it may swell and dissolve. In proportion as the solution proceeds, more beer must be poured upon it, but it need not be so acidulous as the first, because, when once well softened by the vinegar, it readily dissolves. The mixture should be frequently agitated with a bundle of rods, till it acquires the uniform consistence of thin t-eacle, when it must be equalized still more by passing through a tammy cloth, or a sieve. it may now be made up with beer to the proper measure of dilution. The quantity generally used is from a pint to a quart per barrel, more or less, accoiding to the foulness of the beer. But before putting it into the butt, it should be diffused through a considerable volume of the beer with a whisk, till a frothy heaa be raised upon it. It is in this state to be poured into the cask, briskly stirred about; after which the cask must be bunged down for at least 24 hours, when the liquor should be limpid. Sometimes the beer will not 5te improved by this treatment; but this should be ascertained beforehand, by drawing off some of the beer into a cylindric jar or vial, and adding to it a little of the finings. After shaking and setting down the glass, we shall observe whether the feculencies begin to collect in flocky parcels, which slowly subside; or whether the isinglass falls to the bottom without making any impression upon the beer. This is always the case when the fermentation is incomplete, or a secondary decomposition has begun. Mr. Jackson has accounted for this clarifying effect of isinglass in the following way. The isinglass, he thinks, is first of all rather diffused mechanically, than chemically dissolved, in the sour beer or vinegar, so that when the finings are put into the foul beer, the gelatinous fibres, being set free in the liquor, attract and unite with the floating feculencies, which before this union were of the same specific gravity with the beer, and therefore could not subside alone; but having now acquired additional weight by the coating of fish glue, precipitate as a flocculent magma. This is Mr. Jackson's explanation; to which I would add, that if there be the slightest disengagement of carbonic acid gas, it will keep up an obscure locomotion in the particles, which will prevent the said light impurities, either alone or when coated with isinglass, from subsiding. The beer is then properly enough called stubborn by the coopers. But the true theory of the action of isinglass is, that the tannin of the hops combines with the fluid gelatine, and forms a flocculent mass, which envelopes the muddy particles of the beer, and carries them to the bottom as it falls, and forms a sediment. When, after the finings are poured in, no proper precipitate ensues, it may be made to appear by the addition of a little decoction of hop. Mr. Richardson, the author of the well-known brewer's saccharometer, gives the following as the densities of different kinds of beer:Beer. Pounds per Barrel. Specific Gravity. Burton ale, 1st sort - - - 40 to 43 1111 to 1-120 2d ditto - - - 35 to 40 1-097 to 1-111 3d ditto - - - 28 to 33 1-077 to 1-092 Common ale - 25 to 27 1-070 to 1-073 Ditto ditto - - - - 21 1-058 Porter, common sort - - 18 1050 Ditto, double - 20 1-055 Ditto, brown stout - - - 23 1-064 Ditto, best brown stout - - 26 1-072 Common small beer - - - 6 1-014 Good table beer - - 12 to 14 1-033 to 1-039 Of Returns or Malt Residuums.- When small beer is brewed after ale or porter, only one mash is to be made; but where this is not done, there may be two mashes, in order to economize malt to the utmost. We may let on the water at 160~ or 165~, it any convenient quantity, infuse for an hour or thereby, then run it off, and pump into the copper, putting some hops into it, and causing it to boil for an instant; when it may be transferred to the cooler. A second mash or return may be made in the same manner, but at a heat 5~ lower; and then disposed of in the boiler with some hops, which may remain in the copper during the night at a scalding heat, and may be discharged inte the cooler in the morning. These two returns are to be let down into the underback immediately before the next brewing, and thence heated in the copper for the next 142 BEER. rmashing of fresh malt, instead of hot water, commonly called liquor, in the breweries, But allowance must be made, in the calculation of the worts, for the quantity of ferment. able matter in these two returns. The nett aggregate saving is estimated from the gravity of the return taken when cold in the cooler. A slight economy is also made in the extra boiling of the used hops. The lapse of a day or two between the consecutive brewings is no objection to the method of returns, because they are too weak in sacchas rnne matter to run any risk of fermentation. In conclusion, it may be remarked that Mr. Richardson somewhat underrates the gravity of porter, which is now seldom under 20lbs. per barrel. The criterion bor transferring from the gyle-tun to the cleansing butts is the attenuation caused by the production of alcohol in the beer: when that has fallen to lOlbs. or 1 llbs., which it usually does in 48 hours, the cleansing process is commenced. The heat is at this time generally 75, if it was pitched at 65~; for the heat and the attenuation go hand in hand. About thirty years ago, it was customary for the London brewers of porter to keep immense stocks of it for eighteen months or two years, with the view of improving its quality. The beer was pumped from the cleansing butts into store-vats, holding from twenty to twenty-five gyles or brewings of several hundred barrels each. The store-vats had commonly a capacity of 5000 or 6000 barrels; and a few were double, and one was treble, this size. The porter, during its long repose in these vats, became fine, and by obscure fermentation its saccharine mucilage was nearly all converted into vinous liquor, and dissipated in carbonic acid. Its hop-bitter was also in a great degree decomposed. Good hard beer was the boast of the day. This was sometimes softened by the publican, by the addition of some mild new-brewed beer. Of late years, the taste of the metropolis has undergone such a complete revolution in this respect, that nothing but the mildest porter will now go down. Hence, six weeks is a long period for beer to be kept in London; and much of it is drunk when only a fortnight old. Ale is for the same reason come greatly into vogue; and the two greatest porter houses, Messrs. Barclay, Perkins, & Co., and Truman, Hanbury, & Co., have become extensive and successful brewers of mild ale, to please the changed palate of their customers. We shall add a few observations upon the brewing of Scotch ale. This beverage is characterized by its pale amber color, and its mild balsamic flavor. The bitterness of the hop is so mellowed with the malt as not to predominate. The ale of Preston Pans is, in fact, the best substitute for wine which barley has hitherto produced. The low temperature at which the Scotch brewer pitches his fermenting tun restricts his labors to the colder months of the year. He does nothing during four of the summer months. He is extremely nice in selecting his malt and hops; the former being made from the best English barley, and the latter being the growth of Farnham or East Kent. The yeast is carefully looked after, and measured into the fermenting tun in the proportion of one gallon to 240 gallons of wort. Only one mash is made by the Scotch ale brewer, and that pretty strong; but the malt is exhausted by eight or ten successive sprinklings of liquor (hot water) over the goods (malt), which are termed in the vernacular tongue, sparges. These waterings percolate through the malt on the mash-tun bottom, and extract as much of the saccharine matter as may be sufficient for the brewing. By this simple method much higher specific gravities may be obtained than would be practicable by a second mash. With malt, the infusion or saccharine fermentation of the diastase is finished with the first mash; and nothing remains but to wash away from the goods the matter which that process has rendered soluble. It will be found on trial that 20 barrels of wort drawn from a certain quantity of malt, by two successive mashings, will not be so rich in fermentable matter as 20 barrels extracted by ten successive sparges of two barrels each. The grains always remain soaked with wort like that just drawn off, and the total residual quantity is three fourths of a barrel for every quarter of malt. The gravity of this residual wort will on the first plan be equal to that of the second mash; but on the second plan, it will be equal only to that of the tenth sparge, and will be more attenuated in a very high geometrical ratio. The only serious objection to the sparging system is the loss of time by the successive drainages. A mash-tun with a steam jacket promises to suit the sparging system well; as it would keep up a uniform temperature in the goods, without requiring them to be sparged with very hot liquor. The first part of the Scotch process seems of doubtful economy; for the mash liquor is heated so high as 180~. After mashing for about half an hour, or till every particle of the malt is thoroughly drenched, the tun is covered, and the mixture left to infuse about three hours; it is then drained off into the under-back, or preferably into the wort copper. After this wort is run off, a quantity of liquor (water), at 180~ of heat, is sprinkled uniformly over the surface of the malt; being first dashed on a perforated circular board, suspended horizontally over the mash-tun, wherefrom it descends like a showei BEER. 143 upon the whole of the goods. The percolating wort is allowed to flow off, ny three or more small stopcocks round the circumference of the mash-tun, to ensure the equal diif fusion of the liquor. The first sparge being run off in the course of twenty minutes, another similar one is afLused; and thus in succession till the whole of the drainage, when mixed with the first mash-wort, constitutes the density adapted to the quality of the ale. Thus, the strong worts are prepared, and the malt is exhausted either for table beer, or for e returl, as pointed out above. The last sparges are made 5~ or 6~ cooler than the first. The quantity of hops seldom exceeds four pounds to the quarter of malt. The manner cf boiling the worts is the same as that above described; but the conduct of the fermentaticn is peculiar. The heat is pitched at 50~, and the fermentation continues froim a fortnight to three weeks. Were three brewings made in the week, seven or eight working tuns would thus be in constant action; and, as they are usuv,.ly in one room, and some of them at an elevation of temperature of 15~, the apartment must be propitious to fermentation, however low its heat may be at the commencement. No mort; yeast is used than is indispensable; if a little more be needed, it is made effective by rousing up the tuns twice a day from the bottom. When the progress of the attenuation becomes so slack as not to exceed half a pound in the day, it is prudent to cleanse, otherwise the top-barm might re-enter the hody of the beer, and it would become yeast-biiten. When the ale is cleansed, the head, which has not been disturbed for some days, is allowed to float on the surface till the whole of the then pure ale is drawn off into the casks. This top is regarded as a sufficient preservative against the contact of the atmosphere. The Scotch do not skim their tuns, as the London ale brewers commonly do. The Scotch ale, when so cleansed, does not require to be set upon close stillions. It thiows off little or no yeast, because the fermentation was nearly finished in the tun. The strength of the best Scotch ale ranges between 32 and 44 pounds to the barrel; or it has a specific gravity of from 1-088 to 1'122, according to the price at which it is sold. In a good fermentation, seldom more than a fourth of the original gravity of the wort remains at the period of the cleansing. Between one third and one fourth is the usual degree of attenuation. Scotch ale soon becomes fine, and is seldom racked for the home market. The following table will show the progress of fermentation in a brewing of good Scotch ale: 20 barrels of mash-worts of 42- pounds gravity = 860-6 20 - returns 611 122 12 ) 982-6 pounds weight of extract per quarter of malt =81 Fermentation: March 24. pitched the tun at 51~: yeast 4 gallons. Temp. Gravity. 25. 52~ 41 pounds. 28. 56~ 39 30. 60~ 34 April 1. 62~ 32 4. 65~ 29 added 1 lb. of yeast. 5. 66~ 25.6 67~ 23 7. 67~ 20 8. 66~ 18 9. 66~ 15 10. 64~ 14-5 cleansed.* The following table shows the origin and the result of fermentation, in a number of practical experiments: Original Gravity of Lbs. per Baanel of!Specific Gravity of Lbs. per Barrel of Attenuation, or Sacthe Worts. Saccharine Matter.I the Ale. Saccharine Matter. charuni decomposed. 1.0950 88-75 1'0500 40-25 0-478 1'0918 85-62 1-0420 38-42 0-552 1-0829 78-125 1-0205 16-87 0-787 1*0862 80-625 1-0236 20-00 0-757 1*0780 73-75 1-0280 24-25 0-698 1-0700 65-00 1-0285 25-00 0-615 1'1002 93*75 1-0400 36-25 i 0-613 " BREWINa (Society for diffusing Useful Knowledge), p. 156. 144 BEER. Fermentation Table - continued. Original Gravity of Ibs. per Bar el of Specific Gravity of Lbs. per Barrel of Attenuation, or Sac-! the Worts. Saccharine Matter. the Ale. Saccharine Matter. charum decomposed. 1.1025 95-93 1-0420 38-42 0-600 1-0978 91-56 1-0307 27-00 0705 1-0956 89-37 1-0358 32-19 0-640 1 1130 105-82 1 0352 31-87 0-661 1-1092 102-187 1-0302 26-75 0-605 1-1171 110-00 1-0400 36-25 0-669 1'1030 96-40 1P0271 23-42 0-757 _ 10660 61-25 1-0214 17-80 0-709 The second column here does not represent, I believe, the solid extract, but the pasty extract obtained as the basis of Mr. Allen's saccharometer, and therefore each of its numbers is somewhat too high. The last column, also, must be in some measure erroneous, on account of the quantity of acohol dissipated during the process of fernlentation. It must be likewise incorrect, because the density due to the saccharine matter will be partly counteracted, by the effect of the alcohol present in the fermented liquor. In fact, the attenuation does not correspond to the strength of the wort; being greatest in the third brewing, and smallest in the first. The quantity of yeast for the above ale brewings in the table was, upon an average, one gallon for 108 gallons; but it varied with its quality, and with the state of the weather, which, when warm, permits much less to be used with propriety. The good quality of the malt, and the right management of the mashing, may be tested by the quantity of saccharine matter contained in the successively drawn worts. With this view, an aliquot portion of each of them should be evaporated by a safety-bath heat to a nearly concrete consistence, and then mixed with twice its volume of strong spirit of wine. The truly saccharine substance will be dissolved, while the starch and other matters will be separated; after which the proportions of each may be determined by filtration and evaporation. Or an equally correct, and much more expeditious method of arriving at the same result would be, after agitating the viscid extract with the alcohol in a tall glass cylinder, to allow the insoluble fecula to subside, and then to determine the specific gravity of the supernatant liquid by a hydrometer. The additional density which the alcohol has acquired will indicate the quantity of malt sugar which it has received. The following table, constructed by me, at the request of Henry Warburton, Esq., M. P., chairman of the Molasses Committee of the House of Commons in 1830, will show the brewer the principle of this important inquiry. It exhibits the quantity in grains weight of sugar requisite to raise the specific gravity of a gallon of spirit of different densities to the gravity of water = 1-000: Specific Gravity of Grains; Weight of Sugar in the Spirit. Gallon Imperial. 0-995 980 0'990 1'890 0-985 2'800 0-980 3-710 0'975 4-690 0-970 5-600 0-965 6-650 0-960 7-070 0'955 8-400 0-950 9-310 The immediate purpose of this table was to show the effect of saccharine matter in disguising the presence or amount of alcohol in the weak feints of the distiller. But a similar table might easily be constructed, in which, taking a uniform quantity of alcoh,l of 0'825, for example, the quantity of sugar in any wort-extract would be shown by lthe increase of specific gravity which the alcohol received from agitation with a certain weight of the wort, inspissated to a nearly solid consistence by a safety-pan, made on the principle of my patent sugar-pan. (See SUGAR.) Thus, the normal quantities being 1000 grain measures of alcohol, and 100 grains by weight of inspissated mashextract, the hydrometer would at once indicate, by help of the table, first, the quantity ner cent. of truly saccharine matter, and next, by subtraction, that of farinaceous matter present in it. Plan, Machinery, and Utensils of a great Brewery.-Figs. 113 and 114 represent the arrangement of the utensils and machinery in a porter brewery on the largest scale; in which, however, it must be observed that the elevation fig. 113 is in a great degree imaginary as to the plane upon which it is taken; but the different vessels are arranged so as BEER. 145 to explain their uses most readi-y, and at the same time to preserve, as nearly as possible, the relative Dositions which are usually assigned to each in works of this nature. Li NN The malt for the supply of the brewery is stored in vast granaries or malt-,ons, usually situated in the upper part of the buildings. Of these, I have been able to represent Dnly one, at A, fig. 113: the others, which are supposed to be on each side of it, cannot 11.' 146 BEER. be seen in this view. In mediately beneath the granary A, on the ground floor, is the mill; in the upper story above it, are two pairs of rollers,figs. 111, 112, and 113, undet a, a, for bruising or crushing the grains of the malt. In the floor beneath the rollers are the mill-stones b, b, where the malt is sometimes ground, instead of being merely bruised by passing between the rollers, under a, a. The malt, when prepared, is conveyed by a trough into a chest d, to the right of b, from which it can be elevated by the action of a spiral screw, fig. 115, enclosed in the sloping tube e, into the large chest or bin B, for holding ground malt, situated immediately over the mash-tun D. The malt is reserved in this bin till wanted, and it is then let down into the mashing-tun, where the extract is obtained by'hot water supplied from the copper G, seen to the right of B. The water for the service of the brewery is obtained from the well E, seen beneath the mill to the left, by a lifting pump worked by the steam engine; and the forcing-pipe f of this pump conveys the water up to the large reservoir or water-back F, placed at tile top of the engine-house. From this cistern, iron pipes are laid to the copper G (on the right-hand side of the figured, as also to every part of the establishment where cold water can be wanted for cleaning and washing the vessels. The copper G can be filled with cold water by merely turning a cock; and the water, when boiled therein, is conveyed by the pipe g nto the bottom of the mash-tun D. It is introduced beneath a false bottom, upon which the malt lies, and, rising'up through the holes in the false bottom, it extracts the saccharine matter from the malt; a greater or less time being allowed for the infusion,,according to circumstances.'l h instant the water is drawn off from the copper, fresh water must be let into it, in order to be ready for boiling the second mashing; because the copper must not be left empty for a moment, otherwise the intense heat of the fire would destroy its bottom. For the convenience of thus letting down at once as much liquor as will fill the lower part of the copper, a pan or second boiler is placed over the top of the copper, as seen in fig. 113; and the steam rising from the copper communi. cates a considerable degree of heat to the contents of the pan, without any expense of fuel. This will be more minutely explained hereafter. (Seefig. 117.) During the process of mashing, the malt is agitated in the mash-tun so as to expose every part to the action of the water. This is done by a mechanism contained within the mash-tun, which is put in motion by a horizontal shaft above it, H, leading from the mill. The mash machine is shown separately in fig. 116. When the operation of mashing is finished, the wort or extract is drained down from the malt into the vessel I, called the under-back, immediately below the mash-tun, of like dimensions, and situated always on a lower level, for which reason it has received this name. Here the wort does not remain longer than is necessary to drain off the whole of it from the tun above. It is then pumped up by the three-barrelled pump k, into the pan upon the top of the copper, by a pipe which cannot be seen in this section. The wort remains in the pan until the wE ter for the succeeding mashes is discharged from the copper. But this delay is no less of time, because the heat of the copper, and the steam arising from it, prepare the wort, which had become cooler, for boiling. The instant the copper is emptied, the first wort is let down from the pan into the copper, and the second wort is pumped up from the under-back into the upper pan. The proper proportion of hops is thrown into the copper through the near hole, and then the door is shut down, and screwed fast, to keep in the steam, and cause it to rise up through pipes into the pan. It is thus forced to blow up through the wort in the pan, and communicates so much heat to-it, or water, called liquor by the brewers, that either is brought near to the boiling point. The different worts succeed each other through all the different vessels with the greatest regularity, so that there is no loss of time, but every part of the apparatus is constantly employed. When the ebullition has continued a sufficient period to coagulate the grosser part of the extract, and to evaporate part of the water, the contents of the copper are run off through a large cock into the jack-back mI, below G, which is a vessel of sufficient dimensions to contain it, and provided with a bottom of cast-iron plates, perforated with small holes, through which the wort drains and leaves the hops. The hot wort is drawn off from the jackback through the pipe h by the three-barrelled pump, which throws it up to the coolers LL, L; this pump being made with different pipes and cocks of communication, to serve all the purposes of the brewery except that of raising the cold water from the well. The coolers L, L, L, are very shallow vessels, built over one another in several stages: and that part of the building in which they are contained is built with lattice-work or shutter flaps, on all sides, to admit free currents of air. When the wort is sufficiently cooled to be put to the first fermentation, it is conducted in pipes from all the different coolers to the largIc fermenting vessel or gyle-tun al, which, with another similar vessel behind it, is of suffi. cient capacity to contain all the beer of one day's brewings. Whenever the first fermentation is concluded, the beer is drawn off from the great fermtenting vessel M, into the small fermenting casks or cleansing vessels N, of which there ri e a great number in the brewery. They are placed four together, and to each four a coinb - -~~ WV I~~V\ ~~L-V BEER. 147 mon spout is provided to carry off the yeast, and conduct it into the troughs u, placed beneath. In these cleansing vessels the beer remains till the fermentation is completed; and it is then put into the store-vats, which are casks or tuns of an immense size, where it is kept till wanted, and is 1 *s'^ i \' finally drawn off into barrels. NNNs c-l tand sent away from the brewervy ~ = =:X -y,0~ W _The store-vats are not represented A!/= tl r |||1^ W in the figure: they are of a conical x shape, and of different diment sions, from fifteen to twenty feet diameter, and usually from fifteen to twenty feet in depth. The sD Hions, l-n-n-^ ^steamn-engine which puts all the machine in motion is exhibited i n its place, on the left side of — I_ ~ -? u. ^ >l l}g ththe figure. On the axis of the,___=- 1-||-||\tn~ ^^~!large fly-wheel is a bevelled spurwhel, which turns another si-\\-t b milar wheel upon the end of a I horizontal shaft, which extends I f ( q r4 I t rfrom the engine-house to the 1t1ig I reat horse-wheel, set in motion =- ^.^iE _^i[|t |i pt by means of a spur-wheel. The h orse-wheel drives all the pinions ___l-/ rbi" i^j 1 11 ^ ifor the mill-stones b b, and also 1 tll he horizontal axis which works 1L_''I, -X X. II Ifir | 1 the three-barrelled pump rk. The i7 111 o l k rollers a, a, are turned by a bevel ~, UM 1wheel upon the upper end of the - _L__ fi fg\\\\Saxis of the horse-wheel, which is * —------ ----- " prolonged for that purpose; and ~ - i.'|it|( | ||"~ W~ ~the horizontal shaft H, for the \\ i _i1 1 1 tathmashing engine, is driven by a J L Ig ^\M \\l 1 pair of bevel wheels. There is likewise a sack-tackle, which is I n l not represented. It is a machine for drawing up the sacks of malt from the court-yard to the highest part of the bu ilding, whence the 11111 j, xow,, 113,uptosacks are wheeled on it truck to the malt-loft A, and the contents of the sacks are discharged.: The horse-wheel is intended to - I-i4 —ll-ll-lli-I,. -j,,,, [, be driven by horses occasionally, - if the steam-engine should fail;, but these engines are now brought — _ p^ 1to such perfection that it is very seldom any recourse of this kind is,< needed. -I____XXX _,_ x^ -X^ 1 IIIFig. 114 is a representation 1 of the ferienling house at the biewery of Messrs. Whitbread and Company, Chiswell Street, ____ \ ^ [v^ n I.London, which is one of the most complete in its arrangement in the world: it was erected after the plan of Mr. Richardson, who conducts the brewing at those works. -^ ~^^ L F The whole of fig. 114 is to be considered as devoted to the same bject as the large vessel m and t the casks N, fig. 113. In fig. 114 r r is the pipe which leads fi-om \ —--- \ — ^ —' -7 the different coolers to convey lthe wort to the great fermenting tessels or squares M, of which there are two, one behind the other; ff represents a part of.he great pipe which conveys all the water from the well %.fig. 113, up to the water cistern 148 BEER. p. This pipe is conducted purposely up the wall of the fermenting-house,fig. 114, and has a cock in it, near r, to stop the passage. Just beneath this passage a branch-pipe p proceeds, and enters a large pipe x x, which has the former pipe r withinside of it. From the end of the pipe x, nearest to the squares M, another branch n n proceeds, and returns to the original pipef, with a cock to regulate it. The object of this arrangement is to make all, or any part, of the cold water flow through the pipe x x, which surrounds the pipe r, formed only of thin copper, and thus cool the wort passing through the pipe r. until it is found by the thermometer to have the exact temperature which is desirable before it is put to ferment in the great square M. By means of the cocks at n and p, the quantity of cold water passing over the surface of the pipe r can be regulated at pleasure, whereby the heat of the wort, when it enters into the square, may be adjusted within half a degree. When the first fermentation in the squares M M is finished, the beer is drawn off from them by pipes marked v, and conducted by its branches w w w, to the different rows of fermenting-tiuns, marked N N, which occupy the greater part of the building. In the hollow between every two rows are placed large troughs, to contain the yeast which they throw off. The figure shows that the small tuns are all placed on a lower level than the bottom of the great vessels M, so that the beer will flow into them, and, by hy. drostatic equilibrium, will fill them to the same level. Wrhen they are filled, the communication-cock is shut; but, as the working off the yeast diminishes the quantity of beer in each vessel, it is necessary to replenish them from time to time. For this purpose, the two large vats o o are filled from the great squares M Mo, before any beer is drawn off into the small casks N, and this quantity of beer is reserved at the highel level for filling up. The two vessels o o are, in reality, situated between the two squares M M; but I have been obliged to place them thus in the section, in order that they may be seen. Near each filling-up tun o is a small cistern t communicating with the tun o by a pipe, which is closed by a float-valve. The small cisterns t are always in communication with the pipes which lead to the small fermenting vessels N; and therefore the surface of the beer in all the tuns, and in the cisterns, will always be at the same level; and as this level subsides'by the working off of the yeast from the tuns, the float sinks and opens the valve, so as to admit a sufficiency of beer from the filling-up tuns o, to restore the surfaces of the beer in all the tuns, and also in the cistern t, to the original level. In order to carry off the yeast which is produced by the fermentation of the beer in the tuns o o, a conical iron dish or funnel is made to float upon the surface of the beer which they contain; and from the centre of this funnel a pipe, o, descends, and passes through the bottom of the tun, being packed with a collar of leather, so as to be water-tight; at the same time that it is at liberty to slide down, as the surface of the beer descends in the tun. The yeast flows over the edge of this funnel-shaped dish, and is conveyed down the pipe to a trough beneath. Beneath the fermenting-house are large arched vaults, P, built with stone, and lined with stucco. Into these the beer is let down in casks when sufficiently fermented, and is kept in store till wanted. These vaults are used at Mr. Whitbread's brewery, instead of the great store-vats of which we have before spoken, and are in some respects preferable, because they preserve a great equality of temperature, being beneath the surface of the earth. The malt-rollers, or machines for bruising the grains of the malt,figs. 111, 112, have been already described. The malt is shot down from A, fig. 113, the malt-loft, into the hopper; and from this it is let out gradually through a sluice or sliding shuttle, a, fig. 113, and falls between the rollers. Fig. 115, is the screw by which the ground or bruised malt is raised up, or conveyed from one part of the brewery to another. K is an inclined box or trough, in the centre of which the axis of the screw H is placed; the spiral iron plate or worm, which is fixed projecting from the axis, aal which forms the screw, is made very nearly to fill the inside of the box. By this means, when the screw is turned, round by the wheels E F, or by any other means, it raises up the malt from the box d, and delivers it at the spout G. This screw is equally applicable for conveying the malt horizontally in the trough K, as slantingly; and similar machines are employed in various parts of breweries for conveying the malt wherever the situation of the works requires. -Fig. 116, is the mashing-machine. a a is the tun, made of wood staves, hooped together. In the centre of it rises a perpendicular shaft, b, which is turned slowly round by means of the bevelled wheels t u at the top. c c are two arms, projecting from that axis, and supporting the short vertical axis d of the spur-wheel x, which is turned by the spur-wheel w; so that, when the central axis b is made to revolve, it will carry the thick short axle d round the tun in a circle. That axle d is furnished with a number of arms, e e, which have blades placed obliquely to the plane of their BEER. 149 motion. When the axis is turned round, these arms agitate the malt in the tun, and give it a constant tendency to rise upward from the bottom. The motion of the axle d is produced by a wheel, x, on the upper end of it, which is turned by a wheel, w, fastened on the middle of the tube b, which turns freely round upon its central axis. Upon a higher point of the same tube b is a bevel wheel, o, receiving motion from a bevel wheel, q, fixed upon the end of the horizontal axis n n, 116 E I//Il'\ t:,,."which gives motion to the whole machine. This same axis has a pinion, p, upon it, which gives motion to the wheel r, fixed near the middle of a horizontal axle, which, at its left hand end, has a bevel pinion, t, working the wheel u, before mentioned. By these means, the rotation of the central axis b will be very slow compared with the motion of the axle d; for the latter will make seventeen or eighteen revolutions on its own axis in the same space of time that it will be carried once round the tun by the motion of the shaft b. At the beginning of the operation of mashing, the machine is made to turn with a slow motion; but, after having wetted all the malt by one revolution, it is driven quicker. For this purpose, the ascending shaft f g, which gives 150 BEER. motion to the machine, has two level wheels, h i, fixed upon a tube, J g, which is, fitted upon a central shaft. These wheels actuate the wheels m and o, upon the end of the horizontal shaft n n; but the distance between the two wheels h and i is such. that they cannot be engaged both at once with the wheels m and o; but the tube f g, to which they are fixed, is capable of sliding up and down on its central axis sufficiently to bring either wheel h or i into gear with its corresponding wheel o or m, upon the horizontal shaft; and as the diameters of n o, and i m, are of very different proportions, the velocity of the motion of the machine can be varied at pleasure, by using one or other. k and k are two levers, which are forked at their extremities, and embrace collars at the ends of the tubef g. These levers being united by a rod, 1, the handle k gives the means of moving the tubef g, and its wheels h i, up or down, to throw either the one or the other wheel into gear. The object of boiling the wort is not merely evaporation and concentration, but extraction, coagulation, and, finally, combination with the hops; urposes which are better accomplished in a deep confined copper, by a moderate heat, than in an open shallow pan with a quick fire. The copper, being incased above in brickwork, retains its digesting temperature much longer than the pan could do. The waste steam of the close kettle, moreover, can be economically employed in communicating heat to water or weak worts; whereas the exhalations from an open pan would prove a nuisance, and would need to be carried off by a hood. The boiling has a four-fold effect: 1. it concentrates the wort; 2. during the earlier stages of heating, it converts the starch into sugar, dextrine, and gum, by means of the diastase; 3. it extracts the substance of the hops diffused through the wort; 4. it coagulates the albuminous matter present in the grain, or precipitates it by means of the tannin of the hops. The degree of evaporation is regulated by the nature of the wort, and the quality of the beer. Strong ale and stout for keeping, require more boiling than ordinary porter or table-beer brewed for immediate use. The proportion of the water carried off by evaporation is usually from a seventh to a sixth of the volume. The hops are introduced during the progress of the ebullition. They serve to give the beer not only a bitter aromatic taste, but also a keeping quality, or they counteract its natural tendency to become sour; an effect partly due to the precipitation of the albumen and starch, by their resinous and tanning constituents, and partly to the antifermentable properties of their lupuline, bitter principle, ethereous oil, and resin. In these respects, there is none of the bitter plants which can be substituted tbr hops with advantage. For strong beer, powerful fresh hops should be selected; for weaker beer, an older and weaker article will suffice. The hops are either boiledc with the whole body of the wort, or extracted with a portion of it; and this concentrated extract added to the rest. The stronger the hops ale, the longer time they require for extraction of their virtues; for strong hops, an hour and a half or two hours boiling may be proper; for a weaker sort, half an hour or an hour may be sufficient; but it is never advisable to push this process too far, lest a disagreeable bitterness, without aroma, be imparted to the beer. In our breweries, it is the practice to boil the hops with a part of the wort, and to filter the decoction through a drainer, called the jack hop-back. The proportion of hops to malt is very various; but, in general, from a pound and a quarter to a pound and a half of the former are taken for 100 lbs. of the latter in making good table-beer. For porter and strong ale, 2 pounds of hops are used, or even more; for instance, one pound of hops to a bushel of malt, if the beer be destined for the consumption of India. During the boiling of the two ingredients, much coagulated albuminous matter, in various states of combination, makes its appearance in the liquid, constituting what is called the breaking or curdling of the wort) when numerous minute flocks are seen floating in it. The resinous, bitter, and oily-ettbreous principles of the hops combine with the sugar and gum, or dextrine of the wort; but for this effect they require time and heat; showing that the boil is not a process of mere evaporation, but one of chemical reaction. A. yellowis:-green pellicle of hop-oil and resin appears upon the surface of the boiling wort, in a somewhat frothy form: when this disappears, the boiling is presumed to be completed, and the beer is strained off into the cooler. The residuary hops may be pressed and used for an inferior quality of beet; or they may be boiled with fresh wort, and be added to the next brewing charge. FIgs. 117,118, represent the copper of a London brewery. Fig. 117 is a vertical section; fig. 118, a ground-plan of the fire-grate and flue, upon a smaller scale: a is the close copper kettle, having its bottom convex within; b is the open pan placed upon its top. From the upper part of the copper, a wide tube, c, ascends, to carry off the steam generated during the ebullition of the wort, which is conducted through four downwards-slanting tubes, d d (two only are visible in this section), into the liquor of the pan b, in order to warm its contents. A vertical iron shaft or spindle, e, passes down through the tube c. nearly to the bottom of the copper, and is there mounted with an iron arm, called a 1A _ 11 BEER. 151 rouser, which carries round a chain hung in loops, to prevent the hops from adhering to the bottom of the boiler. Three bent stays,f, are stretched across the interior, to supp3rt the shaft by a collet at their middle junction. The shaft carries at its upper end a bevel 117 118 117 | 0 01 ~ 1 wheel, g, working into a bevel pinion upon the axis h, which may be turned either by wheel, g, working into a bevel pinion upon the axis h, which may be turned either by power or by hand. The rouser shaft may be lifted by means of the chain i, which, going over two pulleys, has its end passed round the wheel and axle k, and is turned by a winch: I is a tube for conveying the waste steam into the chimney m. The heat is applied as follows:-For heating the colossal coppers of the London breweries, two separate fires are required, which are separated by a narrow wall of brickwork, n,figs. 117, 118. The dotted circle a' a' indicates the largest circumference of the copper, and b' b' its bottom; o o are the grates upon which the coals are thrown, not through folding doors (as of old), but through a short slanting iron hopper, shown at p,fig. 117, built in the wall, and kept constantly filled with the fuel, in order to exclude the air. Thus the lower stratum of coals gets ignited before it reaches the grate. Above the hopper p, a narrow channel is provided for the admission of atmospherical air, in such quantity merely as may be requisite to complete the combustion of the smoke of the coals. Behind each grate there is a fire-bridge, r, which reflects the flame upwards, and causes it to play upon the bottom of the copper. The burnt air then passes round the copper in a semicircular flue, s s, from which it flows off into the chimney m, on whose under end a sliding damper-plate, t, is placed for tempering the draught. When cold air is admitted at this orifice, the combustion of the fuel is immediately checked. There is, besides, another slide-plate at the entrance of the slanting flue into the vertical chimney, for regulating the play of the flame under and around the copper. If the plate t be opened, and the other plate shut, the power of the fire is suspended, as it ought to be, at the time of emptying the copper. Immediately over the grate is a brick arch, u, to protect the front edge of the copper from the first impulsion of the flame. The chimney is supported upon iron pillars, v, v;w is a cavity closed with a slide-plate, through which the ashes may be taken out from behind, by'means of a long iron hook. Fig. 119 represents one of the sluice-cocks, which are used to make the communicat:ons of the pipes with the pumps, or other parts of the brewery. B B represents the pipe in which the cock is placed. The two parts of this pipe are screwed to the side of a box, c c, in which a slider, A, rises and falls, and intercepts, at pleasure, the passage of the pipe. The slider is moved by the rod a. This passes through a stuffing 152 BEER. box, in the top of the box which contains the slider, and has the rack b fastened to it The rack is moved by a pinion fixed upon the axis of a handle e, and the rack and pinion are contained in a frame d which is supported by two pillars. The frame contains a small roller behind the rack, which bears it up towards the pinion, and keeps its teeth up to the teeth of the pinion. The slider A is made to fit accurately against the internal surface of the box c, and to bear against this surface by the pressure of a spring, so as to make a perfectly close fitting. Fig. 120 is a small cock to be placed in the side of the great store vats, for the purpose of drawing off a small quantity of beer to taste and try its quality. A is a. 119 6 ati~c L C -.A part of the stave or thickness of tne great store vat; into this the tube B of the cock is fitted, and is held tight in its place by a nut, a, a, screwed on withinside. At the other end of the tube B, a plug, c, is fitted, by grinding it into a cone, and it is kept in by a screw. This plug has a hole up the centre of it, and from this a hole proceeds side-wise, and corresponds with a hole made through the side of the tube when the cock is open; but when the plug c is turned round, the hole will not coincide, and then the cock will be shut. D is the handle or key of the cock, by which its plug is turned to open or shut it: this handle is put up the bore of the tube (the cover E being first unscrewed and removed), and the end of it is adapted to fit the end of the plug of the cock. The handle has a tube or passage bored up it, to convey the bees away from the cock when it is opened, and from this the passage f, through the handle, leads, to draw the beer into a glass or tumbler. The hole in the side of the plng is so arranged, that, when the handle is turned into a perpendicular direction, with the passage f downwards, the cock will be open. The intention of this contrivance is, that there shall be no considerable projection beyond the surface of the tun; because it sometimes happens that a great hoop of the tun breaks, and, falling down, its great weight would strike out any cock which had a projection; and, if this happened in the night, much beer might be lost before it was discovered. The cock above described, being almost wholly withinside, and having scarcely any projection beyond the outside surface of the tun, is secure from this accident. Fig. 121 is a small contrivance of a vent peg, to be screwed into the head of a common cask when the beer is to be drawn off from it, and it is necessary toadmit some air to 121 allow the beer to flow. A A represents a portion of the head L of the cask into which the tube B is screwed. The top of C thy.i^i0^C this tube is surrounded by a small cup, from which project m\C ~ ~ \\l. the two small handles c c, by which the peg is turned round nA 1 l to screw it into the cask. The cup round the other part of -. lthe tube is filled with water; into this a small cup, D, is inverted; in consequence, the air can gain admission into the cask when the pressure within is so far diminished, that the air will bubble up through the water, and enter beneath the small cup D. The most efficient substance for fining beer hitherto discovered is isinglass, which is prepared by solution in vinegar or old stale beer, and this solution is afterwards reduced with thin mild beer generally brewed for the purpose, in all large establishments, from a raw or return wort. It must next be passed through a fine hair sieve, by means ol rubbing it down with a hard hair-brush, and brought to the proper consistency by thin mild beer. If properly made, it will be clear, transparent, and free from feculencies. Finings serve excellently to remove any extraneous matter that may be found floating in the beer, and thus changes it from bright to brilliant. The common quantity used is from a pint to a quart per barrel, according to the nature of the beer. To ascertain whether the beer is in a fit state for fining, put it into a long glas; cylindric vessel, and add to it a teaspoonful, or thereby, of the fining; then give the mixture a good shake, by turning the vessel up and down, after closing its mouth with BEER. 15o the palm of the hand. If the beer has been well brewed, its aptitude to become bright will be soon shown by the mixture getting thick and curdy; a bright portion will generally show itself at the bottom or middle; after which the finings will gradually mount to the top, taking up all the impurities along with them, till the whole becomes brilliant. Some have said that the finings should carry the impurities down to the bottom; but this, according to Mr. Black,* takes place only with stubborn beer, which would not become thoroughly bright with any quantity of finings which could be introduced. Finings have usually a specific gravity of from 101O to 1'016, and, when added to beer in a fit condition for fining, invariably go to the top, and not to the bottom. In fining beer in a barrel laid on its side, if the finings do not make their appearance at the bung-hole, the beer will not become bright. The isinglass must not be dissolved with heat, nor in hot water. Beer brewed from imperfectly malted grain, or from a mixture of malt and raw corn, gives a fermentation quite different in flavor from that of beer from sound malt. The nose is, in fact, the best guide to the experienced.re-er for ascertaining whether his process is going on well or ill. Ropiness is a morbid state of beer, which is best remedied, according to Mr. Black, by putting the beer into a vat with a false bottom, and adding, per barrel, 4 or 5 pounds of hops, taken gradually away after the first boilings of the worts; and to them may be added about half a pound per barrel of mustard-seed. Rouse the beer as the hops are gradually introduced, and, in some months, the ropiness wil: be perfectly cured. The beer should be drawn off from below the false bottom. For theoretical views, see FERMENTATION; and for wort-cooling apparatus, see REFRIGERATOR. The quantity of beer and ale exported from the United Kingdom amounted in 1850 to 182,480 barrels, and in 1851 to 191,639; the declared value being respectively 558,7 941., and 577,8741. BEER (BAVARIAN). The Germans from time immemorial have been habitually beer drinkers, and have exercised much of their technical and scientific skill in the production of beer of many different kinds, some of which are little known to our nation, whiie one at least, called Bavarian, possesses excellent qualities, entitling it to the attention of all brewers and consumers of this beverage. The peculiarities in the manufacture of Bavarian beer have recently attracted the attention of the most eminent chemists in Germany, especially of Professor Liebig, and much new light has thereby been thrown upon this curious portion of vegetable chemistry, which I shall endeavor to reflect upon the present article. The following is a list of the principal beers at present brewed in Germany. 1. Brown beer of Merseburg; of pure barley malt. 2. - barley malt and beet-root sugar. 3. - barley malt, potatoes, and beet-root syrup. 4. - refined beet-root syrup alone. 5. Covent or thin beer. 6. Berlin white beer, or the Champagne of the north. 7. Broyhan, a famous Hanoverian beer. 8. Double beer of Griinthal. 9. Bavarian beer; 1. Summer beer; 2. Winter beer. 10.- Bock-beer. 11. Wheat Lager-beer (slowly fermented). 12. White bitterbeer of Erlhngen. Considerable interest among men of science, in favor of the Bavarian beer process, has been excited ever since the appearance of Liebig's Organic Chemistry, first published about twelve years ago. In the introduction to this admirable work, he says, "The beers of England and France, and the most parts of those of Germany, become gradually sour by contact of air. This defect does not belong to the beers of Bavaria, which may be preserved at pleasure in half-full casks, as well as full ones, without alteration in the air. This precious quality must be ascribed to a peculiar process employed for fermenting the wort, called in German untergdhrung, or fermentation from below; which has solved one of the finest theoretical problems. "Wort is proportionally richer in soluble gluten than in sugar.t When it is ~et to ferment by the ordinary process, it evolves a large quantity of yeast, in the state of a thick frog h, with bubbles of carbonic acid gas attached to it, whereby it is floated to the surface of the liquid. This phenomenon is easily explained. In the body of the wort along side of particles of sugar decomposing, there are particles of gluten being oxidized * Treatise on Brewing 8vo. p. 68. t It does not surely contain more gluten than it does sugar; at least no experiments, known to mo, prove this proposition. 154 BEER, BAVARIAN. at the same time, and enveloping as it were the former particles, whence the tarbonic acid of the sugar and the insoluble ferment from the gluten being simujtaneously pro. duced, should mutually adhere. When the metamorphosis of the sugar is completed, there remains still a large quantity of gluten dissolved in the fermented liquor, which gluten, in virtue of its tendency to appropriate oxygen, and to get decomposed, induces also the transformation of the alcohol into acetic acid (vinegar). But were all the matters susceptible of oxidizement as well as this vinegar ferment removed, the beer would thereby lose its faculty of becoming sour. These conditions are duly fulfilled in the process followed in Bavaria. " In that country the malt-wort is set to ferment in open backs, with an extensive surface, and placed in cool cellars, having an atmospheric temperature not exceeding 80 or 10~ centigrade (46'~ or 50~ F.). The operation lasts from 3 to 4 weeks; the carbonic acid is disengaged, not in large bubbles that burst on the surface of the liquid, but in very small vesicles, like those of a mineral water, or of a liquor saturated with carbonic acid, when the pressure is removed. The surface of the fermenting wort is always in contact with the oxygen of the atmosphere, as it is hardly covered with froth, and as all the yeast is deposited at the bottom of the back under the form of a very viscid sediment, called in German unterhefe. "' In order to form an exact idea of the difference between the two processes of fermentation, it must be borne in mind that the metamorphosis of gluten and of azotized bodies in general is accomplished successively in two principal periods, and that it is in the first that the gluten is transformed in the interior of the liquid into an insoluble ferment, and that it separates alongside of the carbonic acid proceeding from the sugar. This separation is the consequence of an absorption of oxygen. It is, however, hardly possible to decide if this oxygen comes from the sugar, from the water, or even from an intestine chance of the gluten itself, or, in other words, whether the oxygen combines directly with the gluten, to give it a higher degree of oxidation, or whether it lays hold of its hydrogen to form water. " This oxidation of the gluten, from whichever cause, and the transformation of the sugar into carbonic acid and alcohol, are two actions so correlated, that by an exclusion of the one, the other is immediately stopped." The superficial ferment (oberhefe in German) which covers the surface of the fermenting works is gluten oxidized in a state of putrefaction; and the ferment of deposite is the gluten oxidized in a state of eremacausie. The surface yeast, or barm, excites in liquids containing sugar and gluten the same alteration which itself is undergoing, whereby the sugar and the gluten suffer a rapid and tumultuous metamorphosis. We may form an exact idea of the different states of these two kinds of yeast by comparing the superficial to vegetable matters putrefying at the bottom of a marsh, and the bottom yeast to the rotting of wood in a state of eremacausie, that is, of slow combustion. The peculiar condition of the elements of the sediment ferment causes them to act upon the elements of the sugar in an extremely slow manner, and excites the change into alcohol and carbonic acid, without that of the dissolved gluten. Sugar, which at ordinary temperatures has no tendency to combine with oxygen, enters in the above predicament into fermentation; but the action is rendered much slower by the low temperature, while the affinity of the dissolved gluten for the oxygen of the air is aided by the contact of the sediment. The superficial yeast may be removed without stopping the fermentation, but the under yeast can not be removed without arresting all the phenomena of disoxidation of the second period. These would immediately cease; and if the temperature were now raised, they would be succeeded by the phenomena of the first period. The deposite does not excite the phenomena of tumultuous fermentation, for which reason it is totally unfit for panification (breadbaking), while the superficial yeast alone is suitable to this purpose. If to wort at a temperature of from 46'~ to 50~ F. the top yeast be added, a quiet slow fermentation is produced, but one accompanied with a rising up of the mass, while yeast collects both at the surface and bottom of the backs. If this deposite be removed to make use of it in other operations, it requires by little and little the characters of the unterhefe, and becomes incapable of exciting the phenomena of the first fermenting period, causing only, of 59~ F., those of the second; namely, sedimentary fermentation. It must be carefully observed that the right unterhefe is not the precipitate which falls to the bottom of backs in the ordinary fermentation of beer, but is a matter entirely different. Peculiar pains must be taken to get it genuine, and in a proper condition at the commencement. Hence the brewers of Hessia and Prussia, who wished to make Bavarian beer, found it more to their interest to send for the article to Wurtzburg, or Bamberg, in Bavaria, than to prepare it themselves. When once the due primary fermentation'was been established and well regulated in a brewery, abundanceof the true interhefe may be obtained for all future operations. BEER, BAVARIAN. 155 In a wort made to ferment at a low temperature with deposite only, the presence of the unterhefe is the first condition essential to the metamorphosis of the saccharum, but it is not competent to bring about the oxidation of the gluten dissolved in the wort, and its transformation into an insoluble state. This change must be accomplished at the cost of the atmospherical oxygen. In the tendency of soluble gluten to absorb oxygen, and in the free access of the air, all the conditions necessary for its eremacausis, or slow combustion, are to be found It is known that the presence of oxygen and soluble gluten are also the conditions of acetification (vinegar-making), but they are not the only ones; for this process requires a temperature of a certain elevation for the alcohol to experience this slow combustion. Hence, by excluding that temperature, the combustion (oxidation) of alcohol is obstructed, while the gluten alone combines with the oxygen of the air. This property does not belong to alcohol at a low temperature, so that during the oxidation in this case ot the gluten, the alcohol exists alongside of it, in the same condition as the gluten alongside of sulphurous acid in the muted wines. In wines not impregnated with the fumes of burning sulphur, the oxygen which would have combined at the same time with the gluten and the alcohol does not seize either of them in wines which have been subjected to mutism, but it unites itself to the sulphurous acid to convert it into the sulphuric. The action called sedimentary fermentation is therefore merely a simultaneous metamorphosis of putrefaction and slow combustion; the sugar and the unterhefe putrefy, and the soluble gluten gets oxidized, not at the expense of the oxygen of the water and the sugar, but of the oxygen of the air, and the gluten then falls in the insoluble state, The process of Appert for the preservation of provisions is founded upon the same principle as the Bavarian process of fermentation in which all the putrescible matters are separated by the intervention of the air at a temperature too low bor the alcohol to become oxidized. By removing them in this way, the tendency of the beer to grow sour, or to suffer a further change, is prevented. Appert's method consists in placing in presence of vegetables or meat which we wish to preserve the oxygen at a high temperature, so as to produce slow combustion, but without putrefaction or even fermentation. By removing the residuary oxygen after the combustion is finished, all the causes of an ulterior change are removed. In the sedimentary fermentation of beer, we remove the matter which experiences the combustion; whereas, on the contrary, in the method of Appert, we remove that which produces it. It is uncertain whether the dissolved gluten, in being converted into insoluble yeast by the action of the oxygen, combines directly with the oxygen; that is to say, whether the yeast differs from the soluble gluten merely by having absorbed an additional quantity of oxygen. This question is in fact very difficult to solve by analysis. If the gluten be regarded as a hydrogenated combination, it is obvious that in the fermentation of wine-must, and malt-wort, the hydrogen will be carried off by the oxygen, and the action will then be the same as the transformation of alcohol into aldehyde. When the contact of the atmosphere is excluded, this oxygen can not evidently be derived from the elements of the air, or from those of the water; for it can not be supposed that oxygen will take hydrogen from the water, in order to recompose water with the hydrogen of the gluten. The elements of the saccharnm must therefore furnish this oxygen; or in the course of the formation of the yeast, a portion of the sugar will be decomposed; but thts decomposition is not of the same kind as that which results from the immediate metamorphosis of the sugar into carbonic acid and alcohol; hence a certain portion of the sugar will afford neither alcohol nor carbonic acid, but it will yield less oxgenated products from its elements. These products occasion the great difference in the qualities of fermented liquors, and particularly in their alcoholic strength. In the ordinary fermentation of grape-juice and worts, these liquids do not furnish a quantity of alcohol equivalent to the sugar which they contain, because a certain portion of the sugar serves for the oxidation of the gluten, and is not transformed like the rest. But whenever the liquor has arrived at the second period, the product in alcohol ought to be equivalent to the quantity of sugar present, as happens in all fermentations which are not accompanied with a formation, but a disappearance of the yeast. It is well ascertained that worts furnish in the Bavarian breweries 10 or 20 per cent. more alcohol than they do by the ordinary process of fermentation. It is also a well-established fact that in the manufacture of spirits from potatoes, where no yeast is produced, or merely a quantity corresponding to the proportion of barley-malt added to the potato-wort, a quantity of alcohol may be produced, as also of carbonic acid, corresponding exactly to the quan. tity of carbon in the fecula employed. But, on the contrary, in the fermentation of beet-root juice, it is hardly possible to determine precisely, from the quantity of car. bonic acid evolved, the quantity of sugar contained in the beets, for there is always less carbonic acid than the juice of the fresh root would furnish. In equal volumes, the beer made by the unterhefe process contains more alcohol, and is therefore more heady than that formed by the ordinary process. 156 BEER, BAVARIAN Tie temperature at which fermentation is carried on has a very marked influence upon the quantity of alcohol produced. It is known that the juice of beets set to ferment between 86~ and 95 Fahr. does not yield alcohol, and its sugar is replaced by a less oxygenated substance, mannite, and lactic acid, resulting from the mucilage. In proportion as the temperature is lowered the mannite fermentation diminishes. As to azotized juices, however, it is hardly possible to define the conditions under which the transformation of the sugar will take place, without being accompanied with another decomposition which modifies its products. The fermentation of beer by deposite demonstrates that by the simultaneous action of the oxygen of the air and a low temperature, the metamorphosis of sugar is effected in a complete manner; for the vessels in which the operation is carried on are so disposed that the oxygen of tht air may act upon a surface great enough to transform all the gluten into insoluble yeast, and thus to present to the sugar a matter constantly undergoing decomposition. The oxidizement of the dissolved gluten goes on, but that of the alcohol requires a higher temperature; whence it can not suffer eremacausis, that is, acetification, or conversion into vinegar. At the beginning of the fermentation of must and wort, the quantity of matter lndergoing change is obviously the largest. All the phenomena which accompany it, the disengagement of gas and the rise of temperature, are most active at this period, and in proportion as the decomposition advances, the external signs of it become less perceptible, without, however, disappearing completely before the transformation has reached its limit. The slow and continuous decomposition which succeeds to the rapid and violent disengagement of gases is denominated the after or complementary fermentation. For wine and beer it lasts till all the sugar has disappeared, so that the specific gravity of the liquors progressively diminishes during several months. This slow fermentation is in most cases a truly depositary fermentation; for by the progressive decomposition of the less, the sugar still in solution gets completely trans. formed; but when the air is excluded, that decomposition does not occasion the com. plete separation of the azotized matters in an insoluble shape. In several states of the German confederation, the favorable influence of a rational process of fermentation upon the quality of the beers has been fully recognised. In the Grand Dutchy of Hesse considerable premiums were proposed for the brewing of beer according to the process pursued in Bavaria, which were decreed to those brewers who were able to prove that their product (neither strong nor highly hopped) had kept six months in the casks without becoming at all sour. When the first trials were being made several thousand barrels were spoiled, till eventually experience led to the dis. covery of the true practical conditions which theory had foreseen and prescribed. Neither the richness in alcohol, nor in hops, nor both combined, can hinder ordinary beer from getting tart. In England, says Liebig, an immense capital is sacrificed to preserve the better sorts of ale and porter from souring, by leaving them for several years in enormous tuns quite full, and very well closed, while their tops are covered with sand. This treatment is identical with that applied to wines to make them deposite the wine-stone. A slight transpiration of air goes on in this case through the pores of the wood; but the quantity of azoti7ed matter contained in the beer is so great, relatively to the proportion of oxygen admitted, that this element can not act upon the alcohol. And yet the beer thus managed will not keep sweet more than two months in smaller casks to which air has access. The grand secret of the Munich brewers is to conduct the fermentation of the wort at too low a temperature to permit of the acetification of the alcohol, and to cause all the azotized matters to be completely separated by the intervention of the oxygen of the air, and not by the sacrifice of the sugar, It is only in March and October that the good store beer is begun to be made in Bavaria. In our ordinary breweries, the copious disengagement of carbonic acid from the frothy top of the fermenting tuns and gyles prevents the contact of oxygen from the worts; so that, as the gluten can not be oxidized by the air, it attracts oxygen from the sugar, and thus gives rise to several adventitious hydrogenated products, just as the fetid oil is generated in the rapid fermentation of spirit-wash by the distillers. In this case no inconsiderable portion of the gluten remains undecomposed in the beer, which, by its extreme proneness to corruption, afterward attracts oxygen greedily from the air, and, at temperature above 523, imparts this contact action to the alcohol, and, by a species of infection, changes it into vinegar. Indeed, in most of the rapid fermenta. tions a portion of vinegar is formed, which itself serves as an acetous ferment to the rest of the alcohol; whereas the result of the bottom fermentation is a beer free from vinegar, and certainly hardly a trace of gluten; so that it does not possess the conditions requisite to intestine change or deterioration. This perfection is, however, in my opinion, rarely attained. In my several journeys into Germany I have met with much spurious oi ill-made Bavarian beer The best Contains, when brought to England, a little acid, BEER, BAVARIAN. 157 but no perceptible gluten on the addition of ammonia in excess. Most of our beers, ales, &c., deposits more or less gluten when thus treated. The following table exhibits the results of the chemical examinations of the undermentioned kinds of beer:Quantity in 100 parts oy weight Name of te Beer.alyst Name of the Beer. Water. Malt extr. Alcohol. Carb. acid. Analyst! -_~~~~~~~Ca aci__.I Analyst__.'' — i Augustine double beer-.88-86 8-0 3-6 0-14' Kaiser. Munich -. Salvator beer-do. - 87-62 8-0 4-2 0-18 Do. Bock-beer, from the Royal 88-64 72 4-0 0-16 Do. brewery -do. - Schenk (pot) beer, from a Ba- varian country brewery; a 92-94 4-0 2-9 Do. Bock-beer of9 Brunsw2i9 o 0'16 Do. kind of small beer - Bock-beer of Brunswick, of 8850 6.50 5 0 - - Balhorn. the Bavarian kind - Lager (store) beer, of Bruns- 910 54 350 tto. wick, of the Bavarian kind 0 Brunswick sweet small beer 84-70 14-0 130 - - Do. Brunswick mum - 592 -39-0 1.80 0-1 Kaiser. Malting in Munich.-The barley is steeped till the acrospire, embryo, or seed-germ, seems to be quickened; a circumstance denoted by a swelling at the end of that ear which was attached to the foot-stalk, as also when, on pressing a pile between two fingers against the thumb-nail, a slight projection of the embryo is perceptible. As iong, however, as the seed-germ sticks too firm to the husk, it has not been steeped enough for exposure on the underground malt-floor. Nor can deficient steeping be safely made up for afterward by sprinkling the malt-couch with a watering-can, which is apt to render the malting irregular. The steep-water should be changed repeatedly, according to the degree of foulness and hardness of the barley; first, six hours after immersion, having previously stirred the whole mass several times; afterward, in winter, every twenty-four hours, but in summer every twelve hours. It loses none of its substance in this way, whatever vulgar prejudice may think to the contrary. After letting off the last water from the stone cistern, the Bavarians leave the barley to drain in it during four or six hours. It is now taken out, and laid on the couch floor, in a square heap, eight or ten inches high, and it is turned over, morning and evening, with dexterity, so as to throw the middle portion upon the top and bottom of the new-made couch. When the acrospire has become as long as the grain itself, the malt is carried to the withering (welkboden) or drying-floor, in the open air, where it is exposed (in dry weather) during from eight to fourteen days, being daily. turned over three times with a winnowing shovel. It is next dried on a well-constructed cylinder or flueheated malt-kin, at a gentle clear heat, without being browned in the slightest degree, while it turns friable into a fine white meal. Smoked malt is entirely rejected by the best Bavarian brewers. Their malt is dried on a series of wove wire horizontal shelves, placed over each other; up through whose interstices or perforations streams of air, heated to only 122~ Fahr., rise from the surfaces of rows of hot sheet-iron pipe-flues, arranged a little way below the shelves. Into these pipes the smoke and burned air of a little furnace on the ground are admitted. The whole is enclosed in a vaulted chamber, from whose top a large wooden pipe issues, for conveying away the steam from the drying malt. Each charge of malt may be completely dried on this kiln in the space of from eighteen to twenty-four hours, by a gentle uniform heat, which does not injure the diastase, or discolor the farina.* The malt for store-beer should be kept three months at least before using it, and be freed by rubbing and sifting from the acrospires before being sent to the mill, where it should be crushed pretty fine. The barley employed is the best distichon or common kind, styled hordeeum vulgare. The hops are of the best and freshest growth of Bavaria, called the fine spalter, or saatser Bohemian townhops, and are twice as dear as the best ordinary hops of the rest of Germany. They are in such esteem as to be exported even into France. The Bavarians are so much attached to the beer beverage, which they have enjoyed from their remotest ancestry, that they regard the use of distilled spirits, even in moderation, as so immoral a practice, as to disqualify dram-drinkers for decent society. * I have a set of designs of the Bavarian kiln, but I believe the above description will make its construction sufficiently intelligible. _ 158 BEER, BAVARIAN. Their government has taken great pains to improve this national beverage, by en couraging the growth of the best qualities of hops and barley. The vaults in which the beer is fermented, ripened, and kept, are all underground, and mostly in stony excavations, called felsenkeller or rock-cellars. The beer is divided into two sorts, called summer and winter. The latter is light, and, being intended for immediate retail in tankards, is termed schankbier. The other, or the lagerbier, very sensibly increases in vinous strength in proportion as it decreases in sweetness, by the judicious management of the nachgdhrung, or fermentation in the casks. In several parts of Germany a keeping quality is communicated to beers by burning sulphur in the casks before filling them, or by the introduction of sulphite of lime. But the flavor thus imparted is disliked in Munich, Bayreuth, Regensburg, Nurnberg, Hof, and the other chief towns of Bavaria; instead of which a preservative virtue is sought for in an aromatic mineral or Tyrol pitch, with which the insides of the casks are carfiully coated, and in which the ripe beer is kept and expc;.ed. In December and January, after the casks are charged with the summer or store-beer, the double doors of the cellars are closed, and lumps of ice are piled up against them, to prevent all access of warm air. The cellar is not opened till next August, in order to take out the beer for consumption. In these circumstances the beer becomes transparent like champagne wine; and, since but little carbonic acid gas has been disengaged, little or none of the additionally generated alcohol is lost by evaporation. The winter or schank (pot) beer is brewed in the months of October, November, March, and April; but the summer or store-beer in December, January, and February, or the period of the coldest weather. For the former beer, the hopped worts are cooled down only to from 51~ to 55~, but for the latter to from 41~ to 42-~ Fahr. The winter beer is also a little weaker than the summer beer, being intended to be sooner consumed; since four bushels* (Berlin measure) of fine, dry, sifted malt, of large heavy hordeum vulgare distichon, affords seven eimers of winter beer, but not more than from five and a half to six of summer beer.t At the second infusion of the worts, small beer is obtained to the amount of twenty quarts from the above quantity of malt. For the above quantity of winter beer, six pounds of middling hops are reckoned sufficient; but for the summer beer, from seven to eight pounds of the finest hops. The winter beer may be sent out to the publicans in barrels five days after the fermentation has been completed in the tuns, and, though not quite clear, it will become so in the course of six days; yet they generally do not serve it out in pots for two or three weeks. But the summer beer must be perfectly bright and still before it is racked off into casks for sale. Statement of the Products of a Brewing of Bavarian Beer.-The quantity brewed is 41 Munich eimers (64 maass) = 85' Berlin quarts; and 60 Berlin quarts = 1 eimer; or 24 Munich barrels (of 100 Berlin quarts each); 1 Munich eimer =15 gallons imperial. The beer contains from 50 to 60 parts by weight, of dry saccharum in 1,000 parts. Expenditure. Thaler. Slbg. 24 Berlin bushels of white kiln-dried barley, rather finely crushed, weighing from 12 to 13 cwts. - - 24 0 36 pounds of new fine spalter (parted) hops at 46 thalers the cwt. - 16 17 2 pound of Carageen moss, for clarifying - - 0 3 1 quart of yeast. 1 quart of Tyrol pitch - - - - - - 11 Mash-tax (in Bavaria and Prussia) upon 12 cwts. malt, at the rate of 20 silbergroschen = 2s., the cwt. - - - 8 0 Cost of crushing - - - - - - 1 0 Fuel - - - - - - - - - 4 0 Wages of labor, in the brewhouse and vault - - - 6 0 Do. Do. for cooper in pitching the casks - - - 3 0 Sundry small expenses. - - 2 10 Or Ill. 8s. 76 0 1 thaler = 30 silbergroschen = 3 shillings Deduct for the grains of 12 cwts. of malt, at 10 silbergroschen, or Is. per cwt. = 4 thalers, and for the value in yeast produced= 2 thalers more - 6 0 Total neat expenditure = 101. 10s. - -70 0 r An English quarter of grain is equal to 5 bushels (scheffel) and nearly one third Prussian measure. t 1 Eimer Prussian = 15 English imperial gallons; one Munich scheffelis equal to four Berlin schefels, I Lib. Munich - 1-235 Eng. lbs. Avoird.: 1 Lib. Berlin = 1-031 Ibs. Avoird. BEER, BAVARIAN. 159 This cost for 42 eimers (1 eimer = 14' galls. Imp.) = 6191 gallons= 17'2 London porter barrels, amounts to 41d. per gallon, or 12s. 2d. per barrel. By the above reckoning, a good profit accrues to the brewer, after allowing a liberal sum for the rent of premises, interest of capital, &c. He has less profit from the summer beer. For a brewing of 33 eimers = 505 gallons Imp., containing from 60 to 65 pounds of saccharum in 1,000 pounds of the beer, by Hermstaedt's saccharometer. Expendilure. Thaler. Slbg. 24 Berlin scheffels of white kiln-dried barley-malt, weighing from 12 to 13 centners* - - - - - - - 24 0 48 Berlin pounds of fresh Bavarian fine hops, at 46 thaler per centner 20 0 - pound of Carageen moss 0 3 I quart setting yeast (unterhefe). 1 centner pitch - - - - - - 11 0 Malt tax on 12 centners -8 0 Crushing the malt -.. - 10 Fuel - -- 4 0 Wages, 6 thalers; coopers' do., 3 thalers; and sundries, 3 th. 27 sq. 12 27 81 0 Deduct for grains 4 thalers, and yeast 2 thalers - - 6 0 Neat cost - - - 75 0 This cost of 111. 5s. for 505 gallons amounts to fully 51d. per gallon, and 16s. 6d. the barrel. The cost at Munich is 2-1 thalers the eimer, and 4 thalers the barrel. The eimer of the summer beer, or lagerbier, is sold for 4 thalers. The publicans there, as in London, are known to add more or less water to their beer before retailing it. The yeast (unterhefe) is carefully freed by a scraper from the portions of light top yeast that may have fallen to the bottom; the true unterhefe is then carefully sliced off from the slimy sediment on the wood. In Munich the malt is moistened slightly 12 or 16 hours before crushing it, with from 2 to 3 maast of water for every bushel; the malt being well dried, and several months old. The mash-tun into which the malt is immediately conveyed is, in middle-sized breweries, a round oaken tub, about 4I feet deep, 10 feet in diameter at bottom and 9 at top, outside measure, containing about 6,000 Berlin quarts. Into this tun cold water is admitted late in the evening, to the amount of 25 quarts for each scheffel, or 600 quarts for the 24 scheffels of the ground malt, which are then shot in and stirred about and worked well about with the oars and rakes, till a uniform pasty is formed without lumps. It is left thus for three or four hours; 3,000 quarts of water being put into the copper, and made to boil; and 1,800 quarts are gradually run down into the mash-tun, and worked about in it, producing a mean temperature of 142-5' Fahr. After an hour's interval, during which the copper has been kept full, 1,800 additional quarts of water are run into the tun, with suitable mashing. The copper being now emptied of water, the mash-mixture from the tun is transferred into it, and brought quickly to the boiling point, with careful stirring to prevent its setting on the bottom and getting burned, and it is kept at that temperature for half an hour. When the mash rises by the ebullition, it needs no more stirring. This process is called, in Bavaria, boiling the thick mash, dickmaisch kochen. The mash is next returned to the tun, and well worked about in it. A few barrels of a thin mash-wort are kept ready to be put into the copper the moment it is emptied of the thick mash. After a quarter of an hour's repose the portion of liquid filtered through the sieve-part of the bottom of the tun into the wort-cistern is put into the copper, thrown back boiling hot into the mash in the tun, which is once more worked thoroughly. The copper is next cleared out, filled up with water, which is made to boil for the after or small-beer brewing. After two hours settling in the open tun, the worts are drawn off clear. Into the copper, filled up one foot high with the wort, the hops are introduced, and the mixture is made to boil during a quarter of an hour. This is called roasting the hops. The rest of the wort is now put into the copper, and boiled along with the hops during at least an hour or an hour and a half. The mixture is then laded out through the hop-filter into the cooling-cistern, where it stands three or four inches deep, and is exposed upon an extensive surface to natural or artificial currents of cold air, so as to * 1 Centner = 110 Prussian pounds = 113-44 Ibs. Avoird. t A Bavarian maas = 1l quarts English measure. 160 BEER, BAVARIAN. be quickly cooled. For every 20 barrels of lagerbier, there are allowed 10 of small beer; so that 30 barrels of wort are made in all. For the winter or pot-beer the worts are brought down to about 59~ Fahr. in the cooler, and the beer is to be transferred into the fermenting-tuns at from 54 5~ to 59~ Fahr.; for the summer or lagerbier, the worts must be brought down in the cooler to from 43~ to 45-~, and put into the fermenting-tuns at to from 41~ to 43~ Fahr. A few hours beforehand, while the wort is still at the temperature of 63'~ Fahr., a quantity of lobb must be made, called vorstellen (fore-setting) in German, by mixing the proportion of unterhefe (yeast) intended for the whole brewing with a barrel or a barrel and a half of the worts, in a small tub called the gdhr-tiene, stirring them well together, so that they may immediately run into fermentation. This lobb is in this state to be added to the worts. The lobb is known tc be ready when it is covered with a white froth from one quarter to one half an inch thick; during which it must be well covered up. The large fermenting-tun must in like manner be kept covered, even in the vault. The colder the worts, the more yeast must be used. For the above quantity, at From 57~ to 59~ Fahr., 6 maas of unterhefe. 53~ to 550 8 48~ to 50 10 - 41~ to 33~ 12 Some recommend that wort for this kind of fermentation (the untergihrung) should be set with the yeast at from 48~ to 57~; but the general practice at Munich is to set the summer lager beer at from 41~ to 43~ F. By following the preceding directions, the wort in the tun should, in the course of from twelve to twenty-four hours, exhibit a white froth round the rim, and even a slight whiteness in the middle. After another twelve or twenty-four hours, the froth should appear in curls; and, in a third like period, these curls should be changed into a still higher frothy brownish mass. In from twenty-four to forty-eight hours more, the barm should have fallen dow n in portions through the beer, so as to allow it to be seen in certain points. In this case it may be turned over into the smaller ripening tuns in the course of other five or six days. But when the worts have been set to ferment at from 41~ to 43~ Fahr., they require from eight to nine days. The beer is transferred, after bein- freed from the top yeast by a skimmer, by means of the stopcock near the bottom of the large tun. It is either first run into an intermediate vessel, in order that the top and bottom portions may be well mixed, or into each of the lager casks, in a numbered series, like quantities of the top and bottom portions are introduced. In the ripening cellars the temperature can not be too low. The best keeping beer can never be brewed unless the temperature of the worts at setting, and of course the fermentingvault, be as low as 50~ F. In Bavaria, where this manufacture is carried on under government inspectors, a brewing period is prescribed by law, which is, for the under fermenting lager beer, from Michaelmas (29th September) to St. George (23d April). From the latter to the former period the ordinary top-barm beer alone is to be made. The ripening-casks must not be quite full, and they are to be closed merely with a loose bung, in order to allow of the working over of the ferment. But should the fermentation appear too languid, after six or eight days, a little briskly fermenting lager beer may be introduced. The store lager beer-tuns are not to be quite filled, so as to prevent all the yeasty particles from being discharged in the ripening fermentation; but the pot lager beer-tuns must be made quite full, as this beverage is intended for speedy sale within a few weeks of its being made. As soon as the summer beer-vaults are charged with their ripening-casks, and with ice-cold air, they are closed air-tight with triple doors, having small intervals between, so that one may be entered and shut again, before the next is opened. These vaults are sometimes made in ranges radiating from a centre, and at others in rooms set off at right angles to a main gallery; so that in either case, when the external opening is well secured, with triple air-tight doors, it may be entered at any time, in order to inspect the interior, without the admission of warm air to the beer-barrels. The wooden bungs for loosely stopping them must be coated with the proper pitch, to prevent the possibility of their imparting any acetous ferment. In the Beer Brewer* of A. F. Zimmermann, teacher of theoretical and practical brewing, who has devoted thirty-five years to this business, it is stated, that a ripened tun of lager or store-beer must be racked off all at once, for when it is left half full it becomes flat (schaal); and that the tun of pot lager beer must, if possible, be all drunk off in the same day it is tapped; because on the following day the beer gets an unpleasant taste, even when the bung has not been taken out, but only a small hole has been made, which is opened only at the time of drawing the beer, and is immediately closed again with a * Der Bicr-Brauer, als Meister in seinem fache, &c., illustrates with many plates, Berlin. 1S42. BEER, BAVARIAN. 161 spigot. He ascribes this change to the loss of the carbonic acid gas, with which the beer has got strongly impregnated during the latter period of its ripening, while being kept in tightly-bunged casks. The residuums in these casks are, however, bottled up in Bavaria, whereby the beer, after some time, recovers its brisk and pungent taste. But the beer-topers in Bavaria, who are professedly very numerous, indulge so delicate and fastidious a palate, that when assembled in their favorite pothouse, they wait impatiently for the tapping of a fresh cask, and cease for a while to tipple whenever it is half empty, puffing the time away with their pipes till another fresh tap be made. In the well-frequented beer-shops of Munich a common-sized cask of lag'r beer is thus drank off in an hour. A reputation for superior brewing is there the readiest road to fortune. Bock-Beer of Bavaria.-This is a favorite double strong beverage, of the best lager description, which is so named from causing its consumers to prance and tumble about like a buck or a goat; for the German word bock has both these meanings. It is merely a beer having a specific gravity -ne third greater, and is therefore made with a third greater proportion of malt, but with the same proportion of hops, and flavored with a few coriander-seeds. It has a somewhat darker color tkan the general lager beer, occasionally brownish, taste less bitter on account of the predominating malt, and somewhat aromatic. It is an eminently intoxicating beverage. It is brewed in December and January, and takes a long time to ferment and ripen; but still it contains too large a quantity of unchanged saccharum and dextrine for its hops, so that it tastes too luscious for habitual topers, and is drunk only from the beginning of May till the end of July9 when the fashion and appetite for it are over for the year. Statement of a Brewing of Bavarian Bock-Beer. For 41 Bavarian eimers of 64 maass each (about 15 gallons Imperial) per eimer, or 615 gallons, nearly 17 barrels English in all:Expenditure. Thaler. Slbg. 32 Berlin scheffels of the best pale malt freed from its acrospires, weighing 17 centners, at 1 thaler per centner - - 32 0 48 lbs. (Berlin) of the best Bavarian hops - - - 20 0 l Ib. Carageen moss for clarifying - - - - 0 3 1 lb. Coriander-seeds - - - - - - 0 1 1 Quart setting yeast. I Centner Tyrolese pitch - - - - - - 11 0 Malt-tax - - - - - 11 20 Malt-crushing, fuel, wages, coopering, &c. - - - 16 5 Thalers of 3s. each - - 91 0 Deduct for the value of grains and yeast - - - 7 0 Thalers of neat cost - - - - - - 84 0 This statement makes the eimer of the Bavarian bock-beer amount to about 2 thalers, or 6 shillings; being at the rate of nearly 5 pence per gallon; though without counting rent, interest of capital, or profit. It is, in fact, a malt or barley sweet wine or liqueur; but a very cheap one, as we see by this computation. The chief difference in the process for making bock-beer lies in the mash-worts, and in the hops being boiled a shorter time, to preserve more of the aroma, and acquire less of the bitterness of the hop. The coriander-seeds are coarsely bruised, and added along with the hops and Carageen moss, to the boiling mash-worts, about twenty or thirty minutes before they are laded or drawn off into the mash-tun. Sometimes the hops are boiled apart in a little clear wort, as formerly described. The bock-beer is retailed in Munich at 3 silver groschen, about 31d. the seidel, or pot, which is one English pint. The 25 gallon cask (tonne) is sold at 10 thalers, or 30 shillings. The publicans, therefore, have a very remunerating profit per pot, even supposing that they do not reduce the beer with water like our London craftsmen. Zimmermann assumes the merit of having introduced Carageen moss as a clarifier into the beer manufacture. I do not know whether it may not have been used in this country for the same purpose, or in Ireland, where this fucus (Chondra crispa) grows abundantly. He says that 1 ounce of it is sufficient for 25 gallons of beer; and that it operates, not only in the act of boiling with the hops, but in that of cooling, as also in the squares and backs before the fermentation is begun. Whenever this change, however, takes place, the commixture throws up the gluten and moss to the surface of the liquid in a black scum, which is to be skimmed off, so that the proper yeast may 12 162 BEER, BAVARIAN. not be soiled with it. It occasions the separation of much of the vegetable slime, os mucilage, called by the German brewers pech (pitch). On the Clarifying or Clearing of Beers.-Clarifiers act either chemically-by being soluble in the beer, and by forming an insoluble compound with the vegetable gluten, and other viscid vegetable extracts; gelatine and albumen, under one shape or other have been most used; the former for beer, the latter, as white of egg, for wineor mechanically, by being diffused in fine particles through the turbid liquor, and, in their precipitation, carrying down with them the floating vegetable matters. To this class belong sand, bone-black (in some measure, but not entirely), and other such articles. The latter means are very imperfect, and can take down only such matters as exist already in an insoluble state; of the former class, milk, blood, glue, calf's-foot jelly, hartshorn-shavings, and isinglass, have been chiefly recommended. Calve's-foot jelly is much used in many parts of Germany, where veal forms so common a kind of butcher-meat; but in summer it is apt to acquire a putrid taint, and to impart the same to the beer. In these islands, isinglass swollen and partly dissolved in vinegar, or sour beer, is almost the sole clarifier, called finings, employed. It is costly, when the best article is used; but an inferior kind of isinglass is imported for the brewers. The solvent or medium through or with which it is administered is eminently inju. dicious, as it never fails to infect the beer with an ace us ferment. In Germany their tart wine has been used hitherto for dissolving the isinglass; and this has aiso the same bad property. Mr. Zimmermann professes to have discovered an unexceptionable solvent in tartaric acid, one pound of which dissolved in 24 quarts of water is capable of dissolving two pounds of ordinary isinglass; forming finings which may be afterward diluted with pure water at pleasure. Such isinglass imported from Peters. burg into Berlin costs there only 3s. per lb. These finings are best aided, as already mentioned, to the worts prior to fermentation, as soon as they are let in to the setting. back or tun, immediately after adding the yeast to it. They are best administered by mixing them in a small tub with thrice their volume of wort, raising the mixture into a froth with a whisk (twig-besom, in German), and then stirring it into the worts. The clarification becomes manifest in the course of a few hours, and when the fermentation is completed, the beer will be as brilliant as can be wished; the test of which with the German topers is when they can read a newspaper while a tall glass beaker of beer is placed between the paper and the candle. One quart of finings of the above strength will be generally found adequate to the clearing of 100 gallons of well-brewed lager. beer, though it will be surer to use double that proportion of finings. The Carageen moss, as finings, is to be cut in fine shreds, thrown into the boiling thin wort, when the flocks begin to separate, and before adding the hops; after which the boiling is continued for an hour and a half or two hours, as need be. The clarifying with this kind of finings takes place in the cooler, so that a limpid wort may be drawn off into the fermenting back. Berlin White or Pale Beer (Weiss-bier).-This is the truly patriotic beverage of Prussia Proper, and he is not deemed a friend to his Vaterland who does not swig it. It is brewed from 1 part of barley-malt and 5 parts of wheat-malt, mingled, moistened, and coarsely crushed between rollers. This mixture is worked up first with water at 95~ Fahr., in the proportion of 30 quarts per scheffel of the malt, to which pasty mixture 70 quarts of boiling water are forthwith added, and the whole is mashed in the tan. After it has been left here a little to settle, a portion of -the thin liquor is drawn off by the tap, transferred to the copper, and then for each bushel of malt there is added to it a decoction of half a pound of.Slmark hops separately prepared. This hopped wort, after half an hour's boiling, is turned back with the hops into the mash-tun, of which the temperature should now be 1624~ Fahr., but not more. In half an hour the wort is to be drawn off from the grains, and pumped into the cooler. The grains are afterward mashed with from 40 to 50 quarts of boiling water per scheffel of malt, and this infusion is drawn off and added to the former worts. The whole mixture is set at 66~ Fahr., with a due proportion of top yeast or ordinary barm, and very moderately fermented. According to Zimmermann, a very competent judge, this his native beer is very apt to turn sour, and therefore it must be very speedily consumed. This proneness to acetification is the character of all wheat-malt beers. He recom. mends, what he himself has made for many years, a substitution of potato-starch sugar for this sort of malt, and as much tartaric acid as to give the degree of tartness peculiar to the pale Berlin beer, even in its best state. This acid moreover prevents the beer from running into the acetous fermentation. Potato-Beer.-The potatoes being well washed are to be rubbed down to a pulp by such a grating cylinder-machine as is represented infig. 122, where a is the hopper for receiving the roots (whether potato or beet, as in the French sugar-factories; b is the crushing and grinding-drum; c, the handle for turning the spur-wheel d, which drives the pinion e, and the fly-wheelf; g, h, is the frame. The dotted lines above c, are the BEER, BAVARIAN. 163 122 cullender through which the pulp passes. Fig. 123 is the stopcock used in Bavaria for bottling beer. For every scheffel of potatoes 80 quarts of water are to be put with them into the copper, and made to boil. 123 C e \at t o ol b Crushed malt, to the amount of 12 scheffels, is to be well worked about in the mash tun with 360 quarts, or 90 gallons (English) of cold water, to a thick pap, and then 840 additional quarts, or about 6 barrels (English) of cold water are to be successively introduced with constant stirring, and left to stand an hour at rest. The potatoes having been meanwhile boiled to a fine starch paste, the whole malt. mash, thin and thick, is to be speedily laded into the copper, and the mixture in it is to be well stirred for an hour, taking care to keep the temperature at from 144~ to 156~ Fahr. all the time, in order that the diastase of the malt may convert the starch present in the two substances into sugar and dextrine. This transformation is made manifest by the white pasty liquid becoming transparent and thin. Whenever this 164 BEER, BAVARIAN. happens the fire is to be raised, to make the mash boil, and to keep it at this heat for IC minutes. The fire is then withdrawn, the contents of the copper are to be transferred into the mash, worked well there, and left to settle for half an hour; during which time the copper is to be washed out, and quickly charged once more with boiling water. The clear wort is to be drawn off from the top of the tun, as usual, and boiled as soon as possible with the due proportion of hops; and the boiling water may be addeO in any desired quantity to the drained mash, for the second mashing. Wort made ii this way is said to have no flavor whatever of the potato, and to clarify more easily than malt-wort, from its containing a smaller proportion of gluten relatively to that of saccharum. Ascheffel of good mealy potatoes affords from 26 to 2171 lbs. of thick, well-boiled syrup, of the density of 36~ Baume (see AREOMETER); and 26 lbs. of such syrup are equivalent to a scheffel of malt in saccharine strength. Zimmermann thinks beer so brewed from potatoes quite equal, at least, if not superior, to pure malt beer, both in appearance and quality. Professor Leo, of Munich. has given the following analysis of two kinds of Munich beer:Bock-bier. Heiliger Vater. Specific gravity - - - 1-020 1.030 Alcohol - - - - 4 000 5 000 Extract -- --- 8'200 13-500 Carbonic acid - - - 0085 0077 Water- ------ 87 39.3 81-923 100-000 100'000 Carl states the alcohol in the Bavarian beer of Bamberg at only 2-840 in 100. Extract, 6-349. The following analyses of other German beers are also by Leo:Lichtenhain. perh Ilmenau. Jena. Double Jena. Alcohol- - - - - 3'168 2-567 3-096 3018 2-080 Albumen - - 0 048 0'020 0'079 0 045 0-028 Extract - - - - 4485'316 70'72 6-144 X7 153 Water --- - 92299 90'097 89'753 90-793 90739 100'000 100-000 100'000 100'000 100-000 Under the term extract, in these analyses, is meant a mixture of starch, sugar, dextrine, lactic acid, various salts, certain extractive and aromatic parts of the hop, gluten, and fatty matter. The following statement is from some of the published analyses of other beers: — Alcohol, English ale -- 85 in 100 Burton - - -- 6-2 Scotch -- 5-8 Common London ale - 50Brown stout - - - 5-0 London porter- - 4-0 To the above I add the following analyses of certain ales made lately by myself, as follows:1. After exposing a portion of the liquor in a wine glass till the bubbles of carbonic acid were disengaged, I took the specific gravity in a globe with a capillary bored stopper. 2. I then saturated 5000grain measures of the ale with a test solution of pure car bonate of soda, to determine the quantity of acid present, after which I added an excess of the alkali to precipitate the gluten; which, however, being but small in amount, I did not separate by a filter, dry, and weigh. 3. IJ subjected the supersaturated liquid to distillation, by the heat of 230~ F. in a ehlor-zinc bath till I drew off all its alcohol, of which I noted the quantity in watergrain measures and the specific gravity. _I! BEER (BITTER). 165 4. I evaporated to dryness 500 water-grain measures slowly in a porcelain capsule, to determine the extract. Bavarian. Do. Bock. Allsop's. B&ss's. Specific gravity ------ 1-004 1-013 1'010 1-006 Alcohol - - - - --- 400 450 6 00 7 00 Extract ------- - 4-50 6 40 5 00 4-80 Acetic acid- - - - 0-20 0'20 0-20 0-18 Water- - - - - - - - - - 9130 88-90 88-80 88-02 100-00 100-00 100-00 100.00 The Bavarian beers had been recently imported from Germany in casks lined with pitch. The two samples of English ale are those made chiefly for the Indian market, but, being highly hopped, and comparatively clean, as the'brewers say, have been recommended as a tonic beverage by the faculty. Hodgson's bitter beer was the original of this quality. The above Bavarian beers afford no precipitate of gluten with carbonate of potash; the two English ales become mottled thereby, and yield a small portion of gluten, which had been held in solution by the acid, which is here estimated as the acetic. Common vinegar, excise strength, contains 5 per cent. of such acid as is stated in the above analysis, indicating from 3 to 4 per cent. of table vinegar in the above varieties of beer. ALE, PALE OR BITTER; brewed chiefy for the Indian market and for other tropical countries.-It is a light beverage, with much aroma, and, in consequence of the regulations'egarding the malt duty, is commonly brewed from a wort of specific gravity 1055 or upwards; for no drawback is allowed by the excise on the exportation of beer brewed fi'om worts of a lower gravity than 1 -054. This impolitic interference with the operations of trade compels the manufacturer of bitter beer to employ wort of a much greater density than he otherwise would do; for beer made from wort of the specific gravity 1 042 is not only better calculated to resist secondary fermentation and the other effects of a hot climate, but is also more pleasant and salubrious to the consumer. Under present circumstances the law expects the brewer of bitter beer to obtain 4 barrels of marketable beer from every quarter of malt he uses, which is just barely possible when the best malt of a good barley year is employed. With every quarter of such malt 16 lbs of the best hops are used; so that, if we assume the cost of malt at 60s. per quarter, and the best hops at 2s. per lb., we shall have, for the prime cost of each barrel of bitter beer, in malt 15s., in hops 8s., and together 23s.; from which, on exportation, we must deduct the drawback of 5s. per barrel allowed by the excise, which brings the prime cost down to 18s. per barrel, exclusive of the expense of manufacture, wear and tear of apparatus, capital invested in barrels, cooperage, &c., which constitute altogether a very formidable outlay. As, however, this ale is sold as high as from 50s. to 65s. per barrel, there can be no doubt that the bitter ale trade has long been, and still continues, an exceedingly profitable speculation, though somewhat hazardous, from the liability of the article to undergo decomposition ere it finds a market. The English ale-bibbers were recently horrified by a public report, apparently well authenticated, that French chemistry was largely engaged in preparing immense quantities of that most deadly poison strychnine, for the purpose of drugging the pale bitter ale, in such great vogue at present in Great Britain and its colonies. The fable would have been made more piquant, by suggesting that it was a project of the Prince President of France to indemnify his country for the miseries of Waterloo. It is surprising that such a tale should have been told by any gossip, and almost incredible that it should have been entertained gravely by any chemist of reputation, for the following plain reasons: 1. Strychnine is an exceedingly costly article; 2. It has a most unpleasant metallic bitter taste; 3. It is a notorious poison, and by its use in any brewery would ruin the reputation of the brewer; 4. It cannot be introduced into ordinary beer brewed with hops, because it is entirely precipitated by infusions of that wholesome fragrant herb. In fact, the quercitannic acid of hops is incompatible with strychnia and all its kindred alkaloids. Hence hopped beer becomes in this respect a sanatory beverage; refusing to take up a particle of strychnia, and other noxious drugs of like character. Had the two chemists employed by Messrs. Allsopp to disprove the above calumny in respect to their bitter ale taken the trouble to consult Berzelius, Anthony Todd Thompson, and other writers- on strychnia, they might have saved themselves the vain attempt to dissolve strychnia in the said beer for it all remains at the bottom in combination with the quercitannic acid so abun dantly present. Were the nux vomica powder, from which strychnia is extracted, 166 BERRIES OF AVIGNON. even stealthily thrown into the mash tun, its dangerous principle would be all infal libly thrown down with the grounds in the subsequent hop-boil. The Board of Excise or Inland Revenue having a few years ago, with delusive libe rality, permitted the legislature to grant leave to use sugar in the place of barley malt in breweries, an extensive sugar merchant in London, hoping, under this pretended boon, to acquire a new and wealthy class of customers, employed me to ascertain by experiment the relative values of malt and sugar for the manufacture of beer. Ten samples of muscovado sugar of several qualities were examined, and were founc? to vary very slightly in the proportions of alcohol they could furnish by fermentatior in a brewer's tun; the average being 12 gallons of proof spirit for 112 lbs. of the sugar; whereas an equal quantity of proof spirit could be obtained from 4-8 bushels of malt. One pound of malt yields 3 of a lb of extract, capable of making as much beer as that weight of sugar. On comparing the actual prices of sugar and malt, we shall see how ruinous a business it would be to use sugar instead of malt in a brewery, and hence the delusiveness of the excise generosity towards the beer trade. BEET-ROOT SUGAR. See SUGAR. BELL METAL, an alloy of copper and tin. See COPPER BELLOWS. See METALLURGY. BEN OIL. See OIL OF BEN. BENGAL STRIPES. Ginghams; a kind of cotton cloth woven with colored stripes. BENJAMIN or BENZOIN. (Benjoin, Fr.; Benzoe, Germ.) A species of resin used chiefly in perfumery. It is extracted by incision from the trunk and branches of the styrax benzoin, which grows in Java, Sumatra, Santa Fe, and in the kingdom of Siam. The plant belongs to the decandria monogynia of Linnaeus, and the natural family of the ebenaceme. It hardens readily in the air, and comes to us in brittle masses, whose fracture presents a mixture of red, brown, and white grains of various sizes, which, when white, and of a certain shape, have been called amygdaloid, from their resemblance to almonds. The sorted benzoin is, on the other hand, very impure. The fracture of benzoin is conchoidal, and its lustre greasy: its specific gravity varies from 1-063 to 1'092. It has an agreeable smell, somewhat like vanilla, which is most manifest when it is ground. It enters into fusion at a gentle heat, and then exhales a white smoke, which may be condensed into the acicular crystals of benzoic acid, of which it contains 18 parts in the hundred. Stoltze recommends the following process for extracting the acid: The resin is to be dissolved in 3 parts of alcohol, the solution is to be introduced into a retort, and a solution of carbonate of soda dissolved in dilute alcohol is to be gradually added to it, till the free acid be neutralized; and then a bulk of water equal to double the weight of the benzoin is to be poured in. The alcohol being drawn off by distillation, the remaining liquor contains the acid, and the resin floating upon it may be skimmed off and washed, when its weight will be found to amount to about 80 per cent. of the raw material. The benzoin contains traces of a volatile oil, and a substance soluble in water, at least through the agency of carbonate of potash. Ether does not dissolve benzoin completely. The fat and volatile oils dissolve very little of it. Unverdorben has found in benzoin, besides benzoic acid, and a little volatile oil, no less than three different kinds of resin, none of which has, however, been turned as yet to any use in the arts. Benzoin is of great use in perfumery, as it enters into a number of preparations; among which may be mentioned fumigating pastilles, fumigating cloves (called also nails), poudre d la marechale, &c. The alcoholic tincture, mixed with water, forms virginal milk. Benzoin enters also into the composition of certain varnishes employed for snuff-boxes and walking-sticks, in order to give these objects an agreeable smell when they become heated in the hand. It is likewise added to the spirituous solution of isinglass, with which the best court-plaster is made. BERLIN BLUE. Prussian blue, which see. BERRIES OF AVIGNON, and Persian Berries. (Graines d' Avignon, Fr.; Gelbbeeren, Germ.) A yellowish dye-drug, the fruit of the rhamnus infectorius, a plant cultivated in Provence, Languedoc, and Dauphine, for the sake of its berries, which are plucked before they are ripe, while they have a greenish hue. Another variety comes from Persia, whence its trivial name: it is larger than the French kind, and has superior properties. The principal substances contained in these berries are: 1. A coloring matter, which is united with a matter insoluble in ether, little soluble in concentrated alcohol, and very soluble in water: it appears to be volatile. 2. A matter remarkable for its bitterness, which is soluble in water and alcohol. 3. A third principle in small quantity. A decoction of one part of the Avignon or Persian berry in ten of water affords a brown-yellow liquor, bordering upon green, having the smell of a vegetable extract, and a slightly bitter taste. BIRDLIME. 167 With gelatine tha decoction gives, after some time, a slight precipitate,- alkalis - - - - a yellow hue, - acids - - - a slight muddiness, - lime-water - - - - a greenish-yellow tint, - alum - - - - a yellow color, - red sulphate of iron - - - an olive-green color, - sulphate of copper, - - - an olive color, - proto-muriate of tin - - - a greenish yellow with a slight precipitate. (See CALICO PRINTING). BERYL. A beautiful mineral or gem, of moderate price, usually of a green color of various shades, passing into honey-yellow and sky blue. BEZOAR. The name of certain concretions found in the stomachs of animals, to which many fanciful virtues were formerly ascribed. They are interesting only to the chemical pathologist. BICARBONATE OF POTASH AND OF SODA. These salts, so m.ch used ill medicine, may, according to M. Behrens, be very readily prepared by gradually adding acetic acid to a strong solution of their carbonates; that of soda being hot. The carbonic acid, at the moment of its disengagement, by the stronger Sffinity of the acetic for the alkalis, combines with a portion of them to form bicarbonates, which fall to the bottom of the vessel in which the mixture is made. The supernatant acetate being separated by decantation, the residuary bicarbonate is to be pressed in linen washed with ice-cold water, and dried. This process may be practised by the chamber chemist, but will not afford the bicarbonates at so cheap a rate as the ordinary modes of manufacture. But a far better method of forming these two salts is by exposing each of them in chambers on extensive surfaces, perforated with small holes, to an atmosphere of carbonic acid, generated by the combustion of coke, and purified by being passed through cold water, by the action of an air-pump worked by a steamengine. BILE. (Bile, Fr.; Galle, Germ.) The secreted liquor of the liver in animals. For an account of the uses of animal bile in the arts, see GALL. Bile (ox's) is composed, according to Berzelius, 1. Of biline, fellinic acid, and fat of gall - - - 800 2. Mucus - - -- 0'30 3. Of alkali combined with biline, &c. - - - - 0'41 4. Muriate of soda, extractive matter - - - - 074 5. Phosphate of soda: do. of lime, &c. - - - - 0.11 6. Water - - - - - - - 9044 100-00 Thenard's analysis gives:1. Resin of bile and picromel (acid gallenate of soda) - - 10-54 2. Coloring matter - - - - - - 0'50 3. Soda - -. - 0'50 4. Phosphate of soda - - - - - - 0*25 5. Muriate of soda - - - - - - 040 6. Sulphate of soda - - - 0-10 7. of lime - - - - - - 0'16 8. Traces of oxide of iron -- 9. Water - - - - - - - 87'56 100-00 A substance may be tested for bile by dropping into it two-thirds of its bulk of oil of vitriol very slowly, so that the heat does not exceed 122~ Fahr., adding a few drops of syrup, and shaking the mixture; when it should assume a deep violet hue. BIRDLIME. (Glu, Fr.; Vogelleim, Germ.) The best birdlime may be made from the middle bark of the holly, boiled seven or eight hours in water, till it is soft and tender, then laid by heaps in pits under ground, covered with stones after the water is drained from it. There it must be left during two or three weeks, to ferment in the summer season, and watered, if necessary, till it passes into a mucilaginous state. It is then to be pounded in a mortar to a paste, washed in running water, and kneaded till it be free from extraneous matters. It is next left for four or five days in earthen vessels to ferment and purify itself, when it is fit for use. Birdlime may be made by the same process from the mistletoe (viburnum lantana), young shoots of elder, and the barks of other vegetables, as well as from most parasite plants. Good birdlime is of a greenish color, and sour flavor, somewhat resembling that of linseed oil; gluey, stringy, and tenacious. By drying in the airit becomes brittle and 168 BISCUITS. may be powdered; but its viscosity may be restored by moistening it. It has an acid reaction with litmus paper. It contains resin, mucilage, a little free acid, coloring and extractive matter. The resin has been called VISCINE. All the parts of the mistletoe contain a peculiar viscid gluey substance, which they yield by decoction, particularly of the bark and green portions; as also from the expressed juice of the bark or berries, when it is kneaded with the fingers under water. The birdlime is thus obtained in the form of a white opaque mass, sticking to tht fngers. It may also be extracted from the berries of the mistletoe by means of ether, repeatedly applied, digested with them. It dissolves at first a mixture of green wax and birdlime, but afterwards birdlime alone. By distilling off the ether, the birdlime remains colorless and pure. Birdlime may be considered as a kind of viscid resin which does not dry, and resembling in this respect an ointment of oil or lard and rosin melted together-the old basilicon of the surgeon. Alcohol, even boiling hot, dissolves hardly any birdlime; but merely its waxy impurities, which it deposits in fiocks on cooling. It is soluble in the oils of rosemary and turpentine, as also in petroleum. Heated with the ley of caustic potash, it forms a compound soluble in alcohol. Nitric acid converts it into oxalic acid, and into a fat which solidifies. Macaire has examined a substance which exudes from the receptacle and involucri. of the atractylis gummifera, and describes it as the pure matter of birdlime, which he styles viscine. It is said to be composed in 100 parts of 75-6 carbon, 9-2 hydrogen, and 15'2 oxygen. Common birdlime may be regarded as e mixture of viscine, vegetable mucilage, and vinegar. The young shoots of the ficus elastica afford a milky juice, which is iscine, while the old branches afford a juice rich in caoutchouc. BISCUITS. For the following account of the mechanical system of baking biscuits for the royal navy, I am indebted to the ingenious inventor, Thomas Grant, Esq. Ships' biscuits are now made by machinery; and one of the reasons for this has been that the manual preparation of them was too slow and too costly during the last war. A landsman knows very little of the true value of a biscuit: with a seaman, biscuit is the only bread that he eats for months together. There are many reasons why common loaves of bread could not be used during a long voyage; because, containing a fermenting principle, they would soon become musty and unfit for food, ii made previous to the voyage; while the preparation of them on board ship is subject to insuperable objections. Biscuits contain no leaven, and, when well baked throughout, they suffer little change during a long voyage. The allowance of biscuit to each seaman on board a queen's ship is a pound per day (averaging six biscuits to the pound). The supply of a man-of-war for several months is, consequently, very large; and it often happened during the last war that the difficulty of making biscuits fast enough was so great, that at Portsmouth wagon loads were unpacked in the streets and conveyed on board ships. We shall now describe the mode of making biscuits by hand; and afterwards speak of the improved method. The bakehouse at Gosport contained nine ovens, and to each was attached a gang of five men-the " turner," the "mate," the " driver," the "breakman," and the "idleman." The requisite proportions of flour and water were put into a large trough, and the "driver," with his naked arms, mixed the whole up together into the form of dough-a very laborious operation. The dough was then taken from the trough and put on a wooden platform called the break: on this platform worked a lever called the break-staff, five or six inches in diameter, and seven feet long; one end of this was loosely attached by a kind of staple to the wall, and the breakman, riding or sitting on the other end, worked this lever to and fro over the dough, by an uncouth jumping or shuffling movement. When the dough had become kneaded by this barbarous method into a thin sheet, it was removed to the moulding-board, and cut into slips by means of an enormous knife; these slips were then broken into pieces, each large enough for one biscuit, and then worked into a circular form by the hand. As each biscuit was shaped it was handed to a second workman, who stamped the king's mark, the number of the oven, &c., on the biscuit. The biscuit was then docked, that is, pierced with holes by an instrument adapted to the purpose. The finishing part of the process was one in. which remarkable dexterity was displayed. A man stood before the open door of the oven, having in his hand the handle of a long shovel called a peel, the other end of which was lying flat in the oven. Another man took the biscuits as fast as they were formed and stamped, and jerked or threw them into the oven with such undeviating accuracy that they should always fall on the peel. The man with the peel then arranged the biscuits side by side over the whole floor of the oven. Nothing could exceed (in manual labor alone) the regularity with which this was all done. Seventy biscuits were thrown into the oven ano "egularly arranged in one minute; the attention of each man being vigorously directed to his own department; for a delay cf a single second on the part of any one mar would have disturbed the whole gang. The biscuits do not require many minutes _zzzzzzzzzzzz^^_________ BISCUITS. 169 baring; and as the oven is rept open during the time that it is being filled, the biscuits first thrown in would be overbaked were not some precaution taken to prevent it. The moulder therefore made those which were to be first thrown into the oven larger than the subsequent ones, and diminished the size by a nice gradation. The mode in which, since about the year 1831, ships' biscuits have been made by machinery invented by T. T. Grant, Esq., of the Royal Clarence yard, is this: the meal or flour is conveyed into a hollow cylinder four or five feet long and about three feet in diameter, and the water, the quantity of which is regulated by a gauge admitted to it; a shaft, armed with long knifes, works rapidly round in the cylinder. with such astonishing effect that, in the short space of three minutes, 340 pounds of dough are produced, infinitely better made than that mixed by the naked arms of a man. The dough is removed from the cylinder and placed under the breakingrollers; these latter, which perform the office of kneading, are two in number, and weigh 15 cwt. each; they are rolled to and fro over the surface of the dough by means of machinery, and in five minutes the dough is perfectly kneaded. The sheet of dough, which is about two inches thick, is then cut into pieces half a yard square, which pass under a second set of rollers, by which each piece is extended to the size of six feet by. three, and reduced to the proper thickness for biscuits. The sheet of dough is now to be cut up into biscuits, and no part of the operation is more beautiful than the mode by which this is accomplished. The dough is brought under a stamping or cutting-out press, similar in effect, but not in detail, to that by which circular pieces for coins are cut out of a sheet of metal. A series of sharp knives are so arranged that, by one movement, they cut out of a piece of dough a yard square about sixty hexagonal biscuits. The reason for a hexagonal (six-sided) shape is, that not a particle of waste is thereby occasioned, as the sides of the hexagonals accurately fit into those of the adjoining biscuits; whereas circular pieces cut out of a large surface always leave vacant spaces between. That a flat sheet can be divided into hexagonal pieces without any waste of material is obvious. Each biscuit is stamped with the queen's mark, as well as punctured with holes by the same movement which cuts it out of the piece of dough. The hexagonal cutters do not sever the biscuits completely asunder; so that a whole sheet of them can be put into the oven at once on a large peel or shovel adapted for the purpose. About fifteen minutes are sufficient to bake them; they are then withdrawn and broken asunder by the hand. The corn for the biscuits is purchased at the markets, and cleaned, ground, and dressed; at the government mills; in quality it is a mixture of fine flour and middlings, the bran and pollard being removed. The ovens for baking are formed of fire-brick and tile, with an area of about 160 feet. About 112 lbs. weight of biscuits are put into the ovens at once. This is called a suit, and is reduced to about 110 lbs. by the baking. From twelve to sixteen suits can be baked in each oven every day, or after the rate of 224 lbs. per hour. The men engaged are dressed in clean check shirts and white linen trowsers, apron, and cap; and every endeavor is made to observe the most scrupulous cleanliness. We may now make a few remarks on the comparative merits of the hand and the machine processes. If the meal and the water with which the biscuits are made be not thoroughly mixed up, there will be some parts moister than others. Now, it was formerly foiund that the dough was not well mixed by the arms of the workman; the consequence of which was that the dry parts became burnt up, or else that the moist parts acquired a peculiar kind of hardness which the sailors called " flint:" these defects are now removed by the thorough mixing and kneading which the ingredients receive by the machine. We have seen that 450 lbs. of dough may be mixed by the machine in four minutes, and kneaded in five or six minutes; we need hardly say how much quicker this is than men's hands could effect it. The biscuits are cut out and stamped sixty at a time, instead of singly: besides the time thus saved, the biscuits become more equally baked, by the oven being more speedily filled. The nine ovens at Gosport used to employ 45 men to produce about 1,500 lbs. of biscuit per hour; 16 men and boys will now produce, by the same number of ovens, 2,240 lbs. of biscuits (one ton) per hour. The comparative expense is thus stated: Under the old system, wages, and wear and tear of utensils, cost about Is. 6d. per cwt. of bis cuit: under the new system, the cost is 5d. The bakehouses at Deptford, Gosport, and Plymouth, could produce 7,000 or 8,000 tons of biscuits annually, at a saving of 12,0001. per annum from the cost under the old system. The advantages of machine-made over hand-made biscuits, therefore, are many: quality, cleanliness, expedition, cheapness, and independence of government contractors. Fig. 124 represents the biscuit machinery, as executed beautifully by Messrs. Rennie, i~ ~ ~ ~~______________________________i 1701 BISMUTH. engineers. a, is the breaking roller, table and roller; b, the finishing roller, table ard roller; c, c, docking machines for stamping out the biscuits; d, mixing machine fin 124 05t=~~~~' I.. _% / * making the dough; e, spur pinion to engine shaft; f, spur wheel; g, g, bevel mitrewheels to give the upright motion; 1, h, bevel-wheels for working the mixing machine; i, i, i, ditto for communicating motion to the rolling machines; j, j, k, the crank shaft; 1, 1, connecting rods; am, in, pendulums for giving motion to rollers; n, n, clutches for connecting either half of the machinery to the other. BISMUTH. (Bismuth, Fr.; Wismuth, Germ.) Called also marcasite and tin-glass. It was shown to be a metal somewhat different from lead, by G. Agricola, in 1546; Stahl and Dufay proved its peculiarity; but it was more minutely distinguished by Pott and Geoffroy about the middle of the last century. It is a rare substance, occurring native, as an oxide, under the name of bismuth ochre; as a sulphuret, called bismuth glance; as a sulphuret with copper, called copper bismuth ore; as also with copper and lead, called needle ore. It is found associated likewise with selenium and tellurium. The native metal occurs in various forms and colors, as white, reddish, and variegated; in primitive and floetz formations, along with the ores of cobalt, nickel, copper, silver and bismuth ochre; at the Saxon Erzegebirge, near Schneeberg, and Joh. Georgenstadt; also in Bohemia, Baden, Wurtemberg, Hessia, Sweden, Norway, England, and France. The production of this metal is but a limited object of the smelting-works, of the Saxon Erzegebirge at Schneeberg. It there occurs, mixed with cobalt speiss, in the proportion of about 7 per cent. upon the average, and is procured by means of a peculiar furnace of liquation, which is the most economical method, both as to saving fuel, and oxidizement of the bismuth. The bismuth eliquation furnace at Schneebergis represented in figs. 125,126, and 127, of which the first is a view from above, the second a view in front, and the third a transverse section in the dotted line A B offig. 125. a, is the ash-pit; b, the fire-place; c, the eliquation pipes; d, the grate of masonry or brickwork, upon which the fuel is thrown through the fire-door e e. The anterior deeper lying orifice of the eliquation pipes is closed with the clay-platef; which has beneath a small eircular groove, through which the liquefied metal flows off. g is a wall extending from the hearth-sole nearly to the anterior orifices of the liquation pipes, in which wall there are as many fire-holes, h, as there are pipes in the furnace: i are iron pans, which receive the fluid metal; h, a wooden water BISMUTH. 171 trough, in which the bismuth is granulated and cooled; 1, the posterior and higher lying apertures of the eliquation pipes, shut merely with a sheet-iron cover. The granulations of bismuth drained from the posterior openings fall upon the flat surfaces m, and then 125 1-I 13126 A0 / into the water-trough. n n are draught-holes in the vault between the two pipes, which serve for increasing or diminishing the heat at pleasure. The ores to be eliquated (sweated) are sorted by hand from the gangue, broken into pieces about the size of a hazel nut, and introduced into the ignited pipes; one charge consisting of about w cwt.; so that the pipes are filled to half their diameter, and three fourths of their length. The sheet-iron door is shut, and the fire strongly urged, whereby the bismuth begins to flow in ten minutes, and falls through the holes in the clay-plates into hot pans containing some coal-dust. Whenever it runs slowly, the ore is stirred round in the pipes, at intervals during half an hour, in which time the liquation is usually finished. The residuum, called bismuth barley (graupen), is scooped out with iron rakes into a water trough; the pipes are charged afresh; the pans, when full, have their contents cast into moulds, forming bars of from 25 to 50 pounds weight. About 20 cwt. of ore are smelted in 8 hours, with a consumption of 63 Leipzic cubic feet of wood. The total production of Shneeberg, in 1830, was 9800 lbs. The bismuth thus procured by liquation upon the great scale, contains no small admixture of arsenic, iron, and some other metals, from which it may be freed by solution in nitric acid, precipitation by water, and reduction of the subnitrated oxyde by black flux. By exposing the crude bismuth for some time to a dull red heat, under charcoal, arsenic is expelled. Bismuth is white, and resembles antimony, but has a reddish tint; whereas the latter metal has a blueish cast. It is brilliant, crystallizes readily in small cubical facets, is very brittle, and may be easily reduced to powder. Its specific gravity is 9'83; and by hammering it with care, the density may be increased to 9'8827. It melts at 480~ Fahr., and may be cooled 6 or 7 degrees below this point without fixing; but the moment it begins to solidify, the temperature rises to 480~, and continues stationary till the whole mass is congealed. When heated from 32~ to 212~, it expands I- in length. When pure it affords a very valuable means of adjusting the scale of high-ranged thermometers. At strong heats bismuth volatilizes, may be distilled in close vessels, and is thus obtained in crystalline laminae. The alloy of bismuth and lead in equal parts has a density of 10'709, being greater than the mean of the constituents; it has a foliated texture, is brittle, and of the same color as bismuth. Bismuth, with tin, forms a compound more elastic and sonorous than the tin itself, and is therefore frequently added to it by the pewterers. With 1 of bismuth and 24 of tin, the alloy is somewhat malleable; with more bismuth, it is brittle. When much bismuth is present, it may be easily parted by strong muriatic acid, which dissolves the tin, and leaves the bismuth in a black powder. It has been said, that an alloy of tin, bismuth, nickel, and silver hinders iron from rusting. (Erdmann's Journal.) The alloy of bismuth with tin and lead was first examined by Sir I. Newton, and has been called ever since fusible metal. Eight parts of bismuth, 5 of lead, and 3 of tin, melt at the moderate temperature of 202~ F.; but 2 of bismuth, 1 of lead, and 1 of tin, melt at 200*75~ F. according to Rose. A small addition of mercury of course aids the fusibility. Such alloys serve to take casts of anatomical preparations. An alloy of 1 bismuth, 2 tin, and 1 lead, is employed as a soft solder by the pewterers; and the same ha een ed s been proposed as a bath for tempering steel instruments. Cake-moulds, for the manufacturers of toilet soaps, are made of the same metal; as also excellent cliches for stereotype, of 3 lead, 2 tin, and 5 bismuth; an alloy which melts at 199~ F. This com. pound should be allowed to cool upon a piece of pasteboard, till it becomes of a doughy consistence, before it is applied to the mould, to receive the impress of the stamp. 172 BISTRE. The employment of plates of fusible metal as safety rondelles, to arertures in the tops Jf steam boilers, has been proposed in France, because they would melt and give way at elevations of temperature under those which would endanger the bursting of the vessel; the fualbility of the alloy being proportioned to the quality of steam required for the en gine. It has been found, however, that boilers, apparently secured in this way, burst, while the safety discs remained entire; the expansive force of the steam causing explosion so suddenly, that the fusible alloy had not time to melt or give way. There are two, perhaps three, oxydes of bismuth; the first and the third, or the suboxyde and super-oxyde, are merely objects of chemical curiosity. The oxyde proper occurs native, and ma& be readily formed by exposing the metal to a red-white heat in a muffle, when it takes fire, burns with a faint blue flame, and sends off fumes which condense into a yellow pulverulent oxyde. But an easier process than that now mentioned is to dissolve the bismuth in nitric acid, precipitate with water, and expose the precipitate to a red heat. The oxyde thus obtained has a straw yellow color, and fuses at a high heat into an opaque glass of a dark-brown or black, color; but which becomes less opaque and yellow after it has cooled. Its specific gravity is so high as 8'211. It consists of 89-87 of metal and 10'13 oxygen in 100 parts. The above precipitate, which is a sub-nitrate of bismuth, is called pearl-white, and is employed as a flux for certain enamels; as it augments their fusibility without imparting any color to them. Hence, it is used sometimes as a vehicle of the colors of other metallic oxydes. When well washed, it is employed in gilding porcelain; being added in the proportion of one fifteenth to the gold. But pearl-white is most used by ladies as a cosmetic for giving a brilliant tint to a faded complexion. It is called blanc defard, bythe French. If it contains, as bismuth often does, a little silver, it becomes gray or dingy colored on exposure to light. When the oxyde is prepared, by dropping the nitric solution into an alkaline ley in excess, if this precipitate is well washed and dried, it forms an excellent medicine; and is given, mixed with gum tragacanth, for the relief of cardialgia, or burning and spasmodic pains of the stomach. Another sort of pearl-powder is prepared by adding a very dilute solution of common salt to the above nitric solution of bismuth, whereby a pulverulent sub-chloride of the metal is obtained in a light flocculent form. A similar powder of a mother-of-pearl aspect may be formed by dropping dilute muriatic acid into the solution of nitrate of bismuth. The arsenic always present in the bismuth of commerce is converted by nitric acid into arsenic acid, which, forming an insoluble arseniate of bismuth, separates from the solution, unless there be such an excess of nitric acid as to re-dissolve it. Hence the medicinal oxyde, prepared from a rightly-made nitrate, can contain no arsenic. If we write with a pen dipped in that solution, the dry invisible traces will become legible on plunging the paper in water. It has been proposed to substitute bismuth for lead in assaying silver, as a smaller quantity of it answers the purpose, and, as its oxyde is more fluent, can therefore penetrate the cupel more readily, and give a more rapid result. But, independently of the objection from its high price, bismuth has the disadvantage of boiling up, as well as of rocking or vegetating, with the silver, when the cupellation requires a high heat. In extracting the silver from the galena found in the copper-mine of Yahlun, it has happened sometimes that the silver concreted towards the end of the operation, and produced a cauliflower excrescence, which had to be cupelled again with a fresh dose of lead. It was observed that, in this case, a portion of the silver had passed into the cupel. Berzelius detected in a sample of silver thus concreted the presence of bismuth. The nitrate of bismuth, mixed with solution of tin and tartar, has been employed as a mordant for dyeing lilach and violet in calico printing. BISTRE. (Bistre, Fr.; bister, Germ.) A brown color which is used in water colors, in the same way as China ink. It is prepared from wood-soot, that of beech being pre — ferred. The most compact and best burned parcels of soot are collected from the chimney, pulverized, and passed through a silk sieve. This powder is infused in pure water, and stirred frequently with a glass ruler, then allowed to settle, when the water is decanted. If the salts are not all washed away, the process may be repeated with warm water. The paste is now to be poured into a long narrow vessel filled with water, stirred well, and left to settle for a few minutes, in order to let the grosser parts subside. The supernatant part is then to be poured off into a similar vessel. This process may be repeated twice or thrice, to obtain a very good bistre. At. last the settled deposite is sufficiently fine, and when freed from its supernatant water, it is mixed with gum-water, moulded Into proper cakes, and dried. It is not used in oil painting, but has the same effect in water.colors as brown pink has in oil. [ _ BITUMEN. 173 BITTER PRINCIPLE. (Amere, Fr.; Bitterstoff, Germ.) This principle has not been insulated hitherto by the chemist from the other proximate principles of plants, but its existence is sufficiently recognized by the taste. The following list contains the principal bitter substances, many of which have been used in the arts and in medicine. Name. Part employed. Country. Observations. Quassia Wood Surinam, E. Indies Powerfully bitter Wormwood Herb Great Britain Ditto Aloe Inspissated juice South Africa Ditto Angustura Bark South America Ditto Orange Unripe Fruit South of Europe ) om bi Ditto Peel Ditto Aom c tter Acorus Root Ditto Ditto Carduus Benedictus Herb Greek Archipelago Cascarilla Bark Jamaica Ditto Centaury Herb Great Britain Camomile Flowers Colocynth Fruit Levant Intolerably bitter Colombo Root East Africa Very bitter Fumitory Herb Great Britain Gentiana lutea Root Switzerland Very bitter Ground Ivy Herb Great Britain Walnut Peels With tannin Island moss With starch Hops Scales of the fe- Great Britain Aromatic bitters male flowers Milfoil Herb flowers Great Britain Large-leaved Satyrion Herb Great Britain Rhubarb Root China Disagreable odor Rue Herb Great Britain Bitter and sharp Tansy Herb flowers Ditto Bitter and offensive Bitter trefoil Herb Ditto Simarouba Bark Guiana Bryony Root Great Britain S aittseous an Coffee Seeds Arabia BITUMEN, or ASPHALTUM. (Bitume, Fr.; Erdpech, Germ.) A black substance found in the earth, externally not dissimilar to pit-coal. It is composed of carbon, hydrogen, and oxygen, like organic bodies; but its origin is unknown. It has not been observed among the primitive or older strata, but only in the secondary and alluvial formations. It constitutes sometimes considerable beds, as in the Isle of Trinidad, where it occurs over an extensive district, in scattered masses. The greater part of the asphaltum to be met with in cbmmerce comes from the Dead Sea, on whose shores it is cast up and gathered; whence it has got the name of Jewish bitumen. In its black color and fracture it resembles ordinary pitch. By friction it affords negative electricity. Its average density is 1-16. It melts at the temperature of boiling water, kindles very readily at the flame, burns brightly with a thick smoke and leaves little ashes. Distilled by itself, it yields a peculiar bituminous oil, very little water, some combustible gases, and traces of ammonia. It leaves about one-third of its weight of charcoal after combustion, and ashes, containing silica, alumina, oxide of iron, sometimes a little lime, and oxide of manganese. According to John, asphaltum may be decomposed, by different solvents, into three distinct substances. Water dissolves nothing; alcohol (anhydrous) dissolves out a yellow resin equal to 5 per cent. of the weight of the asphaltum; that resin is soluble in dilute alcohol and in ether. The portion not soluble in the alcohol gives up a brown resin to ether, amounting to 70 per cent. of the weight of the asphaltum. On evaporating off the ether, the resin remains of a brownish-black colour, which dissolves readily in the volatile oils and in the oil of petrolium. The portion of asphaltum which does not dissolve in ether is very soluble in oil of turpentine, and in oil of petroleum; but less so in oil of lavender. These three resinous principles dissolve all together by digestion in the oils of anise, rosemary, turpentine, olive, hemp-seed, nut, and linseed. Caustic potash dissolves a notable quantity of asphaltum; but carbonate of potash has no effect upon it. Asphaltum enters into the composition of hydraulic cements, and into that of black varnishes called japans, for coating iron trays, &c. A similar varnish may be prepared by dissolving 12 parts of fused amber, 2 parts of rosin, and 2 parts of asphaltum, in 6 parts of linseed oil varnish, to which 12 parts of oil of turpentine havebeen added. 174 BITUMEN. There is a kind of bitumen found at Aniches, in France, in the department cf the North, which is black, very fusible and soft. It burns with flame. Alcohol, ether, and oif of turpentine extract from it a fatty substance, which may be saponified with alkalis. The bitumen of Murindo, near Choco, in Columbia, is of a brownish-black color, soft, and has an earthy fracture. It has an acrid taste, burns with a smell of vanilla, and is said to contain a large quantity of benzoic acid. It appears to be the result ol the decomposition of trees containing benzoin. Asphaltum occurs abundantly at the surface of the salt lake Asphaltites, in Judea, produced from springs in the neighborhood; it is floated down, gathers consistence, and accumulates upon the surface of the lake; the winds drive it on the shores, and the inhabitants collect it for sale. Its inspissation diffuses a disagreable smell in the air of that region, which is supposed by the natives to be powerful enough to kill birds when they attempt to fly across the lake. But probaby the most remarkable locality of asphaltum in the world is the entire basin or rather plain of it, in the island of Trinidad, called the Tar Lake. It lies on the highest land in the island, and emits a strong smell, sensible at ten miles' distance. Its first appearance is that of a lake of water, but when viewed mc e nearly it seems to be a surface of glass. In hot weather its surface liquifies to the depth of an inch, and it cannot then be walked upon. It is of a circular form, about three miles in circumference, and of a depth not ascertained. Large fissures frequently open and close up in it, whence the pitch has been supposed to float upon a body of water. The soil for a considerable distance round it, consists of cinders and burnt earth, and presents in many points indications of convulsions by subterranean fire. In several parts of the neighboring woods, there are round holes and fissures in the ground, containing liquid bitumen to the depth of two inches. Mr. Hatchett examined some specimens from Trinidad, and concluded that what had been heretofore supposed to be a pure mineral pitch was in reality only a porous stone of the argillaceous kind, much impregnated with bitumen. These various bitumens belong exclusively to the secondary and tertiary geological formations, and are not found among primitive rocks, except very rarely in veins. They occur most generally in calcareous, argillaceous and sandy strata, and also in volcanic districts. Petroleum frequently floats on the waters which issue from the volcanic mountains, or which lie at their base; even the sea is at times covered with it near the volcanic islands of Cape de Verd. Mr. Breislack observed a petroleum spring rising from the bottom of the sea near the south base of Vesuvius. The substance with which bitumen seems to have the most constant and most remarkable relations is sea-salt; so that almost all the countries most abundant in petroleum, as Italy, Transylvania, Persia, the environs of Babylon, the region of the Dead Sea, &e., contain salt mines, or lakes, or exhibit saline efflorescences. Iron pyrites is often impregnated with petroleum, or contains a bituminous nucleus. The origin of bitumen is as little known as that of most of the productions of nature. Some regard it as an empyreumatic oil, a matter analogous to liquid resin or essential oil, resulting from the destruction of that astonishing multitude of animals and vegetables buried in the earth, whose solid remains are daily brought to view in mineral researches. It has been also supposed that naptha and petroleum are the product of coals decomposed either by the fire of volcanoes, by the subterranean combustion of coal itself, or by the decomposition of pyrites. The latter opinion is not supported by any direct evidence, but the two former are sufficiently probable. Elastic Bitumen is a rare substance, found hitherto only near Castleton, in Derbyshire, in fissures of slaty clay. Bituminous mastic, or cement, has been of late extensively employed in France for covering roofs and terraces, and lining water-cisterns. The mineral bitumen used for the composition of this mastic is procured chiefly from the Obsann (Bas-Rhin), from the Pare (department de l'Ain), and from the Puy-de-la-Poix (department of Puy-deDome). But boiled coal tar answers pretty well. In the neighborhood of those localities, there is a limestone impregnated with bitumen which suits for giving con sistence to the cement. This is well dried, ground to powder, sifted, and stirred while hot, in about one fifth its weight of melted asphaltum, contained in a cast iron boiler, Dry chalk or bricks, ground and sifted, will suit equally well. As soon as this paste is made quite homogeneous, it is lifted out with an iron shovel or spoon, and spread in rectangular moulds, secured with pegs at the joints, fastened to a kind of platform of smoothed planks, covered with strong sheet-iron. The sides of these moulds should be previously smeared over with a thin coat of loam-paste, to prevent their adhesion to the mastic. Whenever the cake is cold, the frame is taken asunder, and it is removed from the iron plate by an oblong shovel, or strong spatula of iron. These cakes or bricks are usually 18 inches long, 12 broad and 4 thick, and weigh about 70 lbs. It is a very remarkable fact, ir. the history of the useful arts, that asphalt, whic: BITUMEN. 175 was so generally employed as a solid and durable cement in the earliest constructions upon record, as in the walls of Babylon, should for so many thousand years have fallen well nigh into disuse among civilized nations. For there is certainly no class sf mineral substance so well fitted as the bituminous by their plasticity, fusibility, tenacity, adhesiveness to surfaces, impenetrability by water, and unchangeableness in the atmosphere, to enter into the composition of terraces, foot-pavements, roofs, %nd every kind of hydraulic work. Bitumen, combined with calcareous earth, forms a compact, semi-elastic solid, which is not liable to suffer injury by the greatest alternations of frost and thaw, which often disintegrate in a few years the hardest stone, nor can it be ground to dust and worn away by the attrition of the feet of men and animals, as sandstone, flags, and even blocks of granite are. An asphalt pavement, rightly tempered in tenacity, solidity, and elasticity, seems to be incapable of suffering abrasion in the most crowded thoroughfares; a fact exemplified of late in a few places in London, but much more extensively, and for a much longer time in Paris. The great Place de la Concorde (formerly Place Louis Quinze) is covered with a beautiful mosaic pavement of asphalt; many of the promenades on the Boulevards, formerly so filthy in wet weather, are now covered with a thin bed of bituminous mastic, free alike from dust and mud; the foot-paths of the Pont Royal and Pont Carousel, and the areas of the great public slaughter-houses, have been for several years paved in a similar manner with perfect success. It is much to be regretted that the asphalt companies of London made the ill-judged, and nearly abortive attempt, to pave the carriage-way near the east end of Oxford street, and especially at a moist season, most unpropitious to the lay;ng of bituminous mastich. Being formed of blocks not more than three or four inches thick, many of which contained much siliceous sand, such a pavement could not possibly resist the crash and vibration of many thousand heavy drays, wagons, and omnibuses, daily rolling over it.* This failure can afford, however, no argument against rightly-constructed foot-pavements and terraces of asphalt. Numerous experirents and observations have led me to conclude that fossil bitumen possesses far more valuable properties, for making a durable mastich, than the solid pitch obtained by boiling wood or coal tar. The latter, when inspissated to a proper degree of hardness, becomes brittle, and may be readily crushed into powder; while the former, in like circumstances, retains sufficient tenacity to resist abrasion. Factitious tar and pitch being generated by the force of fire, seem to have a propensity to decompose by the joint agency of water and air, whereas mineral pitch has been known to remain for ages without alteration. Bitumen alone is not so well adapted for making a substantial mastich as the native compound of bitumen and calcareous earth, which has been properly called asphaltic rock, of which the richest and most extensive mine is unquestionably that of the Val-de-Travers, in the canton of Neufchatel. This interesting mineral deposite occurs in the Jurassic limestone formation, the equivalent of the English oolite. The mine is very accessible, and may be readily excavated by blasting with gunpowder. The stone is massive, of irregular fracture, of a liver-brown color, and is interspersed with a few minute spangles of calcareous spar. Though it may be scratched with the nail, it is difficult to break by the hammer. When exposed to a very moderate heat it exhales a fragrant ambrosial smell, a property which at once distinguishes it from all compounds of factitious bitumen. Its specific gravity is 2'114, water being 1,000, being nearly the density of bricks. It may be most conveniently analyzed by digesting it in successive portions of hot oil of turpentine, whereby it affords 80 parts of a white pulverulent carbonic of lime, and 20 parts of bitumen in 100. The asphalt rock of Val-de-Travers seems therefore to be far richer than that of Pyrimont, which, according to the statement in the specification of Claridge's patent, of November, 1837, contains " carbonate of lime and bitumen in about the proportion of 90 parts of carbonate of lime to about 10 parts of bitumen." The calcareous matter is so intimately combined and penetrated with the bitumen, as to resist the action not only of air and water for any length of time, but even of muriatic acid; a circumstance partly due to the total absence of moisture in the mineral, but chiefly to the vast incumbent pressure under which the two materials have been incorporated in the bowels of the earth. It would indeed be a difficult matter to combine, by artificial methods, calcareous earth thus intimately with bitumen, and for this reason the mastichs made in this way are found to be much more perishable. Many of the factitious asphalt cements contain a considerable quantity of siliceous sand, from which they derive the property of cracking and crumbling down when trodden upon. In fact, there seems to be so little attraction between siliceous matter and bitumen, that their parts separate from each other by a very small disruptive force. Since the asphalt rock of Val-de-Travers is naturally rich enough in c ncrete bitu* See thle conclusion of this article. 176 BITUMEN. men, it may be converted into a plastic workable mastic of excellent quality for foot pavements and hydraulic works at very little expense, merely by the addition of a very small quantity of mineral or coal tar, amounting to not more than 6 or 8 per cent. The union between these materials may be effected in an iron cauldron, by the application of a very moderate heat, as the asphalt bitumen readily coalesces with the tar into a tenacious solid. The mode adopted for making the beautiful asphalt pavement at the Place de la Concorde in Paris was as follows:-The ground was made uniformly smooth, either in a horizontal plane or with a gentle slope to carry off the water; the curb-stones were then laid round the margin by the mason about 4 inches above the level of the ground. This hollow space was filled to a depth of 3 inches with concrete, containing about a sixth part of hydraulic lime, well pressed upon its bed. The surface was next smoothed with a thin coat of mortar. When the whole mass had become perfectly dry, the mosaic pattern was set out on the surface, the moulds being formed of flat iron bars, rings, &c. about half an inch thick, into which the fluid mastic was poured by ladles from a cauldron, and spread evenly over. The mastic was made in the following way:-The asphalt rock was first of all roasted in an oven, about 10 feet long and 3 broad in order to render it friable. The bottom of the oven was sheet iron, heated below by a brisk fire. A volatile matter exhaled, probably of the nature of naptha, to the amount of one-fortieth the weight of asphalt; after roasting, the asphalt became so friable, as to be easily reduced to powder, and passed through a sieve, having meshes about one-fourth of an inch square. The bitumen destined to render the asphalt fusible and plastic was melted in small quantities at a time, in an iron cauldron, and then the asphalt in powder was gradually stirred in to the amount of 12 or 13 times the weight of bitumen. When the mixture became fluid, nearly a bucketful of very small, clean gravel, previously heated apart, was stirred into it; and, as soon as the whole began to simmer with a treacley consistence, it was fit for use. It was transported in buckets, and poured into the moulds. For the reasons above assigned, I consider this addition of rounded, polished, siliceous stones to be very injudicious. If anything of the kind be wanted to give solidity to the pavement, it should be a granitic or hard calcareous sand, whose angular form will secure the cohesion of the mass. I conceive, also, that tar, in moderate quantity, should be used to give toughness to the asphaltic combination, and prevent its being pulverized and abraded by friction. In the able report of the Bastenne and Gaujac Bitumen company, drawn up by Messrs. Goldsmid and Russell, these gentlemen have made an interesting comparison between the properties of mineral tar and vegetable tar: the bitumen composed of the latter substance, including various modifications, extracted from coal and gas, have, so far as they were able to ascertain, entirely failed. This bitumen, owing to the qualities and defects of vegetable tar, becomes soft at 115~ of Fahrenheit's scale, and is brittle at the freezing point; while the bitumen, into which mineral tar enters, will sustain 170~ of heat, without injury. In the course of the winter, 1837-'38, when the cold was at 14~O below zero, C., the bitumen of Bastenne and Gaujac, with which one side of the Pont Neuf at Paris is paved, was not at all impaired, and would, apparently, have resisted any degree of cold; while that in some parts of the Boulevard, which was composed of vegetable tar, cracked and opened in white fissures. The French government, instructed by these experiments, has required, when any of the vegetable bitumens are laid, that the pavement should be an inch and a quarter thick; whereas, where the bitumen composed of mineral tar is used, a thickness of three quarters of an inch is deemed sufficient. The pavement of the bonding warehouse at Bordeaux has been laid upward of 15 years by the Bastenne company, and is now in a condition as perfect as when first formed. The reservoirs constructed to contain the waters of the Seine at Batignolles, near Paris, have been mounted 6 years, and, notwithstanding the intense cold of the winter of 1837, which froze the whole of their contents into one solid mass, and the perpetual water pressure to which they are exposed, they have not betrayed the slightest imperfection in any point. The repairs done to the ancient fortifications at Bayonne, have answered so well, that the government, 2 years ago, entered into a very large contract with the company for additional works, while the whole of the arches of the St. Germain and St. Cloud railways, and the pavements and floorings necessary for these works, are being laid with the Bastenne bitumen. The mineral tar in the mines of Bastenne and Gaujac is easily separated from the earthy matter with which it is naturally mixed by the process of boiling, and is then transported in barrels to Paris or London, being laid down in the latter place to the company at 171. per ton, in virtue of a monopoly of the article purchased by the company at a sum, it is said, of 8,0001. Mr. Harvey, the able superintendent of the Bastenne company, was good enough to supply me with various samples of mineral tar, bitumen, and asphaltic rock, for BITUMEN. 177 analysis. The tar of Bastenne is an exceedingly viscid mass, without any earthy impurity. It has the consistence of bakers' dough at 60~ of Fahrenheit; at 80~ it yields to the slightest pressure of the finger; at 150~ it resembles a soft extract; and at 212C it has the fluidity of molasses. It is admirably adapted to give plasticity to the calcareous asphalts. A specimen of Egyptian asphalt which he brought me, gave by analysis the very same composition as the Val de Travers, namely, 80 per cent. of pure carbonate oi lime, and 20 of bitumen. A specimen to mastic, prepared in France, was found to consist, in 100 parts, of 29 of bitumen, 52 of carbonate of lime, and 19 of silicious sand. A portion of stone called the natural Bastenne rock afforded me 80 parts of gritty silicious matter and 20 of thick tar. The Trinidad bitumen contains a considerable portion of foreign earthy matter; one specimen yielded me 25 per cent. of silicious sand; a second, 28; a third, 20; and a fourth, 30: the remainder was pure pitch. One specimen of Egyptian bitumen, specific gravity 1-2, was found to be perfectly pure, for it dissolved in oil of turpentine without leaving any appreciable residuum. Robinson's Parisian Bitumen company use a mastich made with the pitch obtained from boiling coal-tar mixed with chalk. One piece laid down by this company at Knightsbridge and another at Brighton, are said to.ave gone to pieces. The portion of pavement laid down by them in Oxford street, next Charles street, has been taken up. Claridge's company have laid down their mastich under the archway of the HorseGuards, and in the carriage-entrance at the Ordnance Office; the latter has cracked at the junction with the old pavement of Yorkshire curb-stone. The foot-pavement laid down by Claridge's company at Whitehall has stood well. The Bastenne company has exhibited the best specimen of asphalt pavement in Oxford street; they have laid down an excellent piece of foot-pavement near Northumberland House; a piece, 40 feet by 7, on Blackfriars' Bridge; they have made a substantial job in paving 830 superficial feet in front of the guard-room at Woolwich, which, though much traversed by foot-passengers, and beat by the guard in grounding arms, remains sound; lastly, the floor of the stalls belonging to the cavalry barracks of the Blues at Knightsbridge, is probably the best example of asphaltic pavement laid down in this country, as it has received no injury from the beating of the horses' feet. As the specific gravity of properly-made mastich is nearly double that of water, a cubic foot of it will weigh from 125 to 130 lbs.; and a square foot, three quarters of an inch thick, will weigh very nearly eight pounds. A ton of it will therefore cover 280 square feet. The prices at which the Bastenne Bitumen company sell their products is as follows:Pure Mineral tar, 241. per ton, or 28s. pei cwt. Mastich 81. 8s. per ton, or 10s. per cwt. Side Pavement. Roofs and Terraces. From 50 to 100 feet, Is. 3d. per foot. - Is. 6d. per foot. 100 250 Is. Id. - - Is. 4d. 250 500 ltd. - - Is. Id. 500 750 10d. - - Is. Od. 750 1000.9d. - - lid. 1000 2000 8d. - - 10d. 2000 5000 7d. - - 9d. Where the work exceeds 5,000 feet, contracts may be entered into. For filling up joints of brickwork, &c., from ld. to lid. per foot, run according tc quantity. These prices are calculated for half an inch thickness, at which rate a ton will cover 420 square feet. As the Val-de-Travers company engage to lay down their rich asphaltic rock in London at 51. per ton; and as the mineral tar equal to that of Seissel may probably be had in England a;.ne fourth the price of that foreign article, they may afford to lay their mastich three quarters of an inch thick per the thousand feet, including a sub. stratum of concrete, at a rate of fivepence per square foot, instead of fifteenpence, being the rate charged under that condition by the Bastenne company. These charges are for London and its immediate vicinity. Report of the experimental Pavements laid down in Oxford street, from Charles street to Tottenham Court Road, January, 1839. 1. Robinson's Parisian bitumen, laid in blocks 12 inches square and 5 inches deep; the substance is a compound of bitumen, lime, &c., and five granite stones are inserted in the top of each block; the work is laid in straight courses, the joints cemented with hot bitumen. The quantity of this is 97 square yards, the length is 20 feet, and the price, if adopted, 9s. per square yard. 2. Same as 1, but the courses laid diagonally. The quantity is 97 square yarde, the ength is 20 feet. 13 178 BLACK DYE. 3. Granite paving, 9 inches deep, joined with Clarige's asphalt, the work laid in straight courses. The cost to the parish has been 11 s. 7 d. per yard superficial for the stone and laying, &c., no charge being made by Claridge's Company for the asphalt. The quantity is 240 yards, the length 54 feet. 4. Granite paving, 4- inches deep, jointed with Claridge's asphalt, the work laid in diagonal courses. Cost to the parish 9s. 6d. per square yard. No chaige made for the asphalt. The quantity is 88 square yards, the length 20 feet. 5. The Bastenne Bitumen Company. The blocks are 12 inches long, 61 wide, and 34 deep with bevelled joints, close at bottom, and I inch open at top; the joints cemented with hot bitumen; the substance is bituminous, with a very large proportion of granite imbedded in each block; the price, if adopted, 13s. 6d. per square yard; the length in straight courses, 20 feet. 6. Same as 5, but the courses laid diagonally. The length 40 feet; the total quantity in 5 and 6 is 274 square yards. 7. Aberdeen granite paving, 9 inches deep; laid on a concrete bottom, formed of gravel and lime, the joints of the pavement run with hot lime grout, in straight courses The length is 69 feet; cost, 16s. 5d. per square yard. 8. Same as 7, but the courses laid diagonally; length 38 feet. 9. Aberdeen granite paving, 9 inches deep, in straight courses, without a concrete bottom; joints filled with fine gravel; cost, 12s. 5d. per yard; length, 24 feet. 10. The Scotch Asphaltum company. The work is laid in blocks of divers length, 9 inches wide, and 6- deep; the side joints are straight, the end joints are bevelled alternately. The work is laid in straight courses, and jointed in Roman cement; the substance is, apparently, a bituminous matter mixed with fine gravel. The length is 50 feet; the number of square yards, 210; the price, per yard, if adopted, 13s. 6d. 11. The wood-paving. The blocks are sexagon on the plan, and (with the exception of a few courses that are only 8 inches), 12 inches deep. The work is laid endwise of the grain; the blocks are mostly 8 inches diameter-a few courses are 7 inches. The material is Norway fir; there is no prepared bottom-the blocks are laid on the plain ground, a small layer of gravel being spread to bed them in. From the west end, 22 rows of courses of blocks are of wood in its natural state; 31 rows have been Kyanised; 9 rows at the eastern end have been dipped in Claridge's as. phalt; 6 rows have been dipped in a solution prepared by the patentee; the remainder are of wood in the natural state. The length of this piece is 60 feet: the number of yards, 230; price per yard, if approved, 10s. 6d. 12. Val-de-Travers company. Blocks in straight courses, 12 inches square, 5 inches deep, with square joints. The substance of the blocks is bituminous, with a very large proportion of granite imbedded in each block, the joints cemented with hot bitumen. The length is 25 feet; number of square yards 94; the work is performed gra tuitously. 13. The same company. A layer of clean chippings and hot asphalt poured thereon The face up, with hot asphalt and broken stone imbedded therein. The length is 25 feet: number of yards, 94; the work is gratuitous. 14. Same as 9. The length 47 feet. By order of the Committee, H. KENSETT, Chairman. Statement of the number of carriages passing through Oxford street at the undernamed times and places. 1839. [ i, blocks, supported upon the iron pillars d d. The frame -iL x. v~ - \ etch^^^'?Jis made of strong beams of o ~U \ on ylff 8;' Sfwood, e e, bound together h\. h I. \ l C> /\m /by cross bars with mortises. V\ ~~o ^ M A ^~,^ f f, two of the circular X\~ ~o Meg~^ X ~ ]~ yapertures, each leading to -- — e _ z a quadrantal compartment within the dash-wheel. In the back view (the left-hand half of the figure) the brass grating g g, of a curvilinear form, is seen, through which the jets of water are admitted into the cavity of the wheel; h h, are the round - | e W — _- orifices, through which the 1 foul water runs off, as each.I. quadrant passes the lower part of its revolution; i, a water-pipe, with a stop-cock for regulating the washingl | a l l l;~ jets; kk, thelever for throw0 ing the driving-crab 1, or l __ _______________.l coupling-box, into or out of gear with the shaft of the wheel. This machine is so 1. -1 - — 1 --- i | - constructed, that the water-. L 71 r~- - It{ cock is opened or shut by.7' —( *e~~~ i E^__^. p _the same leverage which ^k 143 k L-',,, tthrows the wheel into or 143 In out of gear. m, a wheel, fixed upon the round extiemity of the shaft of the dash-wheel, which works into the toothed pinion connected BLEACHING. 197 with the prime mover. When the end of the lever k, whose fork embraces the couplingbox upon the square part of the shaft, is pushed forwards or backwards, it shifts the clutch into or out of gear with the toothed wheel m. In the latter case, this wheel turns with its pinion without affecting the dash-wheel. n n, holdfasts fixed upon the wooden frame; to which the boards o o are attached, for preventing the water from being thrown abou, by the centrifugal force. The dash-wheel is generally from 6 to 7 feet in diameter, about 30 inches wide, and requires the power of about two horses to drive it. From one to two pieces of calico may be done at once in each quadrantal compartment, in the course of 8 or 10 minutes; hence, in a day of 13 hours, with two such wheels 1200 pieces of yard-wide goods may be washed. After the process of washing by the dash-wheel, the water is expressed from the cloth by means of the squeezers already described. Bleaching of Linen.-Linen contains much more coloring matter than cotton. The former loses nearly a third of its weight, while the latter loses not more than a twentieth. The fibres of flax possess, in the natural condition, a light gray, yellow, or blond color. By the operation of rotting, or, as it is commonly called, water-retting, which is employed to enable the textile filaments to be separated from the boon, or woody matter, the color becomes darker, and, in consequence probably of the putrefaction of the green matter of the bark, the coloring substance appears. Hence, flax prepared without rotting is much paler, and its coloring matter may be in a great measure removed by washing with soap, leaving the filaments nearly white. Mr. James Lee obtained a patent in 1812, as having discovered that the process of steeping and dew-retting is unnecessary, and that flax and hemp will not only dress, but will produce an equal if not greater quantity of more durable fibre, when cleaned in the dry way. Mr. Lee stated that, when hemp or flax plants are ripe, the farmer has nothing more to do than to pull, spread, and dry them in the sun, and then to break them by proper machinery. This promising improvement has apparently come to naught, having been many years abandoned by the patentee himself, though he was favored with a special act of parliament, which permitted the specification of his patent to remain sealed up for seven years, contrary to the general practice in such cases. The substance which gives steeped flax its peculiar tint is insoluble in boiling water, in acids, and in alkalis; but it possesses the property of dissolving in caustic or carbonated alkaline leys, when it has possessed the means of dehydrogenation by previous exposure to oxygen. Hemp is, in this respect, analogous to flax. The bleaching of both depends upon this action of oxygen, and upon the removal of the acidified dye, by means of an alkali. This process is effected generally by the influence of air in combination with light and moisture acting on the linen cloth laid upon the grass: but chlorine will effect the same object more expeditiously. In no case, however, is it possible to acidify the color completely at once, but there must be many alternate exposures to oxygen or chlorine, and alkali, before the flax becomes white. It is this circumstance alone which renders the bleaching of linen an apparently complicated business. Having made these preliminary observations with regard to the method of applying the alkaline leys used in bleaching linen cloth, I shall now bring the whole into one point of view, by detailing the connexion of these processes, as carried on at a bleach-field, which has uniformly been successful in returning the cloth of a good white, and has otherwise given satisfaction to its employers; and I shall only remark, that I by no means hold it up as the best process which may be employed, as every experienced bleacher knows that processes must be varied, not only according to existing circumstances, but also according to the nature of the linens operated upon. In order to avoid repetition, where washing is mentioned, it must always be understood that the linen is taken to the wash-stocks or dash-wheel, and washed well in them for some hours. This part of the work can never be overdone; and on its being properly executed between every part of the bucking, boiling, steeping in the chloride of lime solution, and souring, not a little of the success of bleaching depends. By exposure is meant, that the linen cloth is taken and spread upon the bleach-green for four, six, or eight days, according as the routine of business calls for the return of the cloth, in order to undergo further operations. A parcel of goods consists of 360 pieces of those linens which are called Britannias. Each piece is 35 yards long; and they weigh, on an average, 10 lbs. each: the weight of the parcel is, in consequence, about 3600 lbs. avoirdupois weight. The linens are first washed, and then steeped in waste alkaline ley, as formerly described under these processes; they then undergo the following operations:1st, Bucked with 60 lbs. pearl-ashes, washed, exposed on the field. 2d, Ditto 80 ditto ditto ditto ditto. 3d, Ditto 90 potashes ditto ditto ditto. 4th^ Ditto 80 ditto ditto ditto ditto. 198 BLEACHING. 5th, Bucked with 80 lbs. pearl-ashes, washed, exposed on the field. 6th, Ditto 50 ditto ditto ditto ditto. 7th, Ditto 70 ditto ditto ditto ditto. 8th, Ditto 70 ditto ditto ditto ditto. 9th, Soured one night in dilute sulphuric acid, washed, 10th, Bucked with 50 lbs. pearl-ashes, washed, exposed on the field. Ilth, Immersed in the chloride of potash or lime 12 hours. 12th, Boiled with 30 lbs. pearl-ashes, washed, exposed on the field. 13th, Ditto 30 ditto ditto ditto ditto. 14th, Soured, washed. The linens are then taken to the rubbing-board, and well rubbed with a strong iather of black soap, after which they are well washed in pure spring water. At this period they are carefully examined, and those which are fully bleached are laid aside to be blued, and made up for the market; while those which are not fully white are returned to be boiled, and steeped in the chloride f lime or potash; then soured, until they are fully white. By the above process, 690 lbs. weight of alkali is taken to bleach 360 pieces of linen, each piece consisting of 35 yards in length; so that the expenditure of alkali would be somewhat less than 2 lbs. for each piece, were it not that some parts of the linens are not fully whitened, as above noted. Two pounds of alkali may therefore be stated as the average quantity employed for bleaching each piece of goods. The method of bleaching linens in Ireland is similar to the foregoing; any alteration in the process depending upon the judgment of the bleacher in increasing or diminishing the quantity of alkali used. But it is common, at most bleach-fields, to steep the linens in the chloride of lime or potash at an early stage of the process, or after the goods have undergone the fifth or sixth operation of bucking. By this means those parts of the flax which are most difficult to bleach are more easily acted upon by the alkali; and, as before noticed, souring early in very dilute sulphuric acid, assists greatly in forwarding the whitening of the linens. Mr. Grimshaw, calico-printer, near Belfast, was the first who recommended early souring, which has since been"very generally adopted. The bleaching of Silk.-Silk in its raw state, as spun by the worm, is either white or yellow of various shades, and is covered with a varpish, which gives it stiffness and a degree of elasticity. For the greater number of purposes to which silk is applied, it must be deprived of this native covering, which was long considered to be a sort of gum. The operation by which this coloring matter is removed is called scouring, cleansing, or boiling. A great many different processes have been proposed for freeing the silk fibres from all foreign impurities, and for giving it the utmost whiteness, lustre, and pliancy; but none of the new plans has superseded, with any advantage, the one practised of old, which consists essentially in steeping the silk in a warm solution of soap; a circumstance placed beyond all doubt by the interesting experiments of M. Roard. The alkalis, or alkaline salts, act in a marked manner upon the varnish of silk, and effect its complete solution; the prolonged agency of boiling water, alone answers the same purpose; but nothing agrees so well with the nature of silk, and preserves its brilliancy and suppleness so perfectly, as a rapid boil with soap-water. It would appear, however, that the Chinese do not employ this method, but something that is preferable. Probably the superior beauty of their white s;ilk may be owing to the superiority of the raw material. The most ancient method of scouring silk consists of three operations. For the first, or the ungumming, thirty per cent. of soap is first of all dissolved in clean river water by a boiling heat; then the temperature is lowered by the addition of a little cold water, by withdrawing the fire, or at least by damping it. The hanks of silk, suspended upon horizontal poles over the boiler, are now plunged into the soapy solution, kept at a heat somewhat under eklallition, which is an essential point; for if hotter, the soap would attack the substance c' the silk, and not only dissolve a portion of it, but deprive the whole of its lustre. The portions of the hanks plunged in the bath get scoured by degrees; the varnish and the coloring matter come away, and the silk assumes its proper whiteness and pliancy. Whenever this point is attained, the hanks are turned round upon the poles, so that the portion formerly in the air may be also subjected to the bath. As soon as the whole is completely ungummed, they are taken out, wrung by the peg, and shaken out; after which, the next step, called the boil, is commenced. Into bags of coarse canvass, called pockets, about 25 lbs. or 35 lbs. of ungummed silk are enclosed, and put into a similar bath with the preceding, but with a smaller proportion of soap, which may therefore be raised to the boiling point without any danger of destroying the silk. The ebullition is to be kept up for an hour and a half, during which time the bags must be frequently stirred, lest those near the bottom should suffer an undue degree of heat. The silk experiences in these two operations a loss of about 25 per cent. of its weight. The third and last scouring operation is intended to give the silk a slight tinge, which BLEACHING. 199 renders the white more agreeable, and better adapted to its various uses in trade. In this way we distinguish the China white, which has a faint cast of red, the silver white, the azure white, and the thread white. To produce these different shades, we begin by preparing a soap-water so strong as to lather by agitation; we then add to it, for the China white, a little annotto, mixing it carefully in; and then passing the silk properly through it, till it has acquired the wished for tint. As to the other shades, we need only azure them more or less with a fine indigo, which has been previously washed several times in hot water, and reduced to powder in a mortar. It is then diffused through boiling water, allowed to settle for a few minutes, and the supernatant liquid, which contains only the finer particles, is added to the soap bath in such proportion as may be requisite. The silk, on being taken out of this bath, must be wrung well, and stretched upon perches to dry; after which it is introduced into the sulphuring chamber, if it is to be made use of in the white state. At Lyons, however, no soap is employed at the third operation: after the boil, the silk is washed, sulphured, and azured, by passing through very clear river water properly blued. The silks intended for the manufacture of blonds and gauzes are not subjected to the jrdinary scouring process, because it is essential, in these cases, for them to preserve their natural stiffness. We must therefore select the raw silk of China, or the whitest raw silks of other countries; steep them, rinse them in a bath of pure water, or in one containing a little soap; wring them, expose them to the vapor of sulphur, and then pass them through the azure water. Sometimes this process is repeated. Before the memoir of M. Roard appeared, extremely vague ideas were entertained about the composition of the native varnish of silk. He has shown that this substance, so far from being of a gummy nature, as had been believed, may be rather compared to bees' wax, with a species of oil, and a coloring matter, which exists only in raw silks. It is contained in them to the amount of from 23 to 24 per cent., and forms the portion of weight which is lost in the ungumming. It possesses, however, some of the properties of vegetable gums, though it differs essentially as to others. In a dry mass, it is friable and has a vitreous fracture; it is soluble in water, and affords a solution which lathers like soap; but when thrown upon burning coals, it does not soften like gum, but burns with the exhalation of a fetid odor. Its solution, when left exposed to the open air, at first of a golden yellow, becomes soon greenish, and ere long putrefies, as a solution of animal matter would do in similar circumstances. M. Roard assures us that the city of Lyons alone could furnish several thousand quintals of this substance per annum, were it applicable to any useful purpose. The yellow varnish is of a resinous nature, altogether insoluble in water, very soluble in alcohol, and contains a little volatile oil, which gives it a rank smell. The color of this resin is easily dissipated, either by exposure to the sun or by the action of chlorine: it forms about one fifty-fifth of its weight. Bees' wax exists also in all the sorts of silk, even in that of China; but the whiter the filaments, the less wax do they contain. M. Roard has observed that, if the silk be exposed to the soap baths for some time after it has been stripped of its foreign matters, it begins to lose body, and has its valuable qualities impaired. It becomes dull, stiff, and colored in consequence of the solution more or less considerable of its substance; a solution which takes place in all liquids, and even in boiling water. It is for this reason that silks cannot be alumed with heat; and that they lose some of their lustre in being dyed brown, a color which requires a boiling hot bath. The best mode, therefore, of avoiding these inconveniences, is to boil the silks in the soap-bath no longer than is absolutely necessary for the scouring process, and to expose them in the various dyeing operations to as moderate temperature as may be requisite to communicate the color. When silks are to be dyed, much less soap should be used in the cleansing, and very little for the dark colors. According to M. Roard, raw silks, white or yellow, may be completely scoured in one hour, with 15 lbs. of water for one of silk, and a suitable proportion of soap. The soap and the silk should be put into the bath half an hour before its ebullition, and the latter should be turned about frequently. The dull silks, in which the varnish has already undergone some alteration, never acquire a fine white until they are exposed to sulphureous acid gas. Exposure to light has also a very good effect in whitening silks, and is had recourse to, it is said, with advantage by the Chinese. Carbonate of soda has been proposed to be used instead of soap in scouring silk, but it has never come into use. The Abbe Collomb, in 1785, scoured silk by eight hours' boiling in simple water, and he found the silks bleached in this way to be stronger than by soap, but they are not nearly so white. A patent has been taken out in England for bleaching them by steam, of which an account will be found under the article SILK. It appears that the Chinese do not use soap in producing those fine white silks which are imported into Europe. Michel de Grubbens, who resided long at Canton, saw and 200 BLEACHING. practised himself the operation there, which he published in the Memoirs of the Academy of Stockholm in 1803. It consists in preparing the silk with a species of white beans, smaller than the Turkey beans, with some wheat flour, common salt, and water. The proportions are 5 parts of beans, 5 of salt, 6 of flour, and 25 of water, to form this vegetable bath. The beans must be previously washed. It is difficult to discover what chemical action can occur between that decoction and the varnish of raw silk; possibly some acid may be developed, which may soften the gummy matter, and facilitate its separation. Baum6 contrived a process which does not appear to have received the sanction of experience, but which may put us in the right way. He macerates the yellow raw silk in a mixture of alcohol at 36~ (sp. gr. 0837) and one thirty-second part of pure muriatic acid. At the end of forty-eight hours, it is as white as possible, and the more so, the better the quality of the silk. The loss which it suffers in this menstruum is only one fortieth; showing that nothing but the coloring matter is abstracted. The expense of this menstruum is the great obstacle to Baume's process. The alcohol, however, might be in a very great measure recovered, by saturating the acid with chalk, and redistillation. Bleaching of Wool.-Wool, like the preceding fibrous matter, it covered with a peculiar varnish, which impairs its qualities, and prevents it from being employed in the raw state for the purposes to which it is well adapted when it is scoured. The English give the name yolk, and the French suint, to that native coat: it is a fatty unctuous matter, of a strong smell, which apparently has its chief origin in the cutaneous perspiration of the sheep; but which, by the agency of external bodies, may have undergone some changes which modify its constitution. It results from the experiments of M. Vauquelin, that the ycfk is composed of several substances; namely, 1, a soap with basis of potash, which constitutes the greater part of it; 2, of a notable quantity of acetate of potash; 3, of a small quantity of carbonate, and a trace of muriate, of potash; 4, of a little lime in an unknown state of combination; 5, of a species of sebaceous matter, and an animal substance to which the odor is due. There are several other accidental matters present on sheeps' wool. The proportion of yolk is variable in different kinds of wool, but in general it is more abundant the finer the staple; the loss by scouring being 45 per cent. for the finest wools, and 35 per cent. for the coarse. The yolk, on account of its soapy nature, dissolves readily in water, with the exception of a, little free fatty matter, which easily separates from the filaments, and remains floating in the liquor. It would thence appear sufficient to expose the wools tc simple washing in a stream of water; yet experience shows that this method never answers so well as that usually adopted, which consists in steeping the wool for some time in simple warm water, or in warm water mixed with a fourth of stale urine. From 15 to 20 minutes of contact are sufficient in this case, if we heat the bath as warm as the hand can bear it, and stir it well with a rod. At the end of this time the wool may be taken out, set to drain, then placed in large baskets, in order to be completely rinsed in a stream of water. It is generally supposed that putrid urine acts on the wool by the ammonia which it contains, and that this serves to saponify the remainder of the fatty matter not combined with the potash. M. Vauquclin is not of this opinion, because he found that wool steeped in water, with sal ammoniac and quick lime, is not better scoured than an equal quantity of wool treated with mere water. He was hence led to conclude that the good effects of putrefied urine might be ascribed to anything else besides the ammonia, and probably to the urea. Fresh urine contains a free acid, which, by decomposing the potash soap of the yolk, counteracts the scouring operation. If wools are better scoured in a small quantity of water than in a great stream, we can conceive that this circumstance must depend upon the nature of the yolk, which, in a concentrated solution, acts like a saponaceous compound, and thus contributes to remove the free fatty particles which adhere to the filaments. It should also be observed that too long a continuance of the wool in the yolk water, hurts its quality very much, by weakening its cohesion, causing the filaments to swell, and even to split. It is said then to have lost its nerve. Another circumstance in the scouring of wool, that should always be attended to, is never to work the filaments together to such a degree as to occasion their felting; but in agitating we must merely push them slowly round in the vessel, or press them gently under the feet. Were it at all felted, it would neither card nor spin well As the heat of boiling water is apt to decompose woollen fibres, we should be careful never to raise the temperature of the scouring bath to near this point, nor, in fact, to exteed 140~ F. Some authors recommend the use of alkaline or soapy baths for scouring wool, but praztieal people do not deviate from the method above described. When the washing is completed, all the wool which is to be sent white into the mar BLEACHING OF PAPER. 201 ket, must be exposed to the action of sulphurous acid, either in a liquid or a gaseous state. In the latter case, sulphur is burned in a close chamber, in which the wools are hung up or spread out; in the former, the wools are plunged into water, moderately impregnated with the acid. (See SULPHURING.) Exposure on the grass may also contribute to the bleaching of wool. Some fraudulent dealers are accused of dipping wools in butter-milk, or chalk and water, in order to whiten them and increase their weight. Wool is sometimes whitened in the fleece, and sometimes in the state of yarn; the latter affording the best means of operating. It has been observed that the wool cut from certain parts of the sheep, especially from the groins, never bleaches well. After sulphuring, the wool has a harsh crispy feel, which may be removed by a weak soap bath. To this also the wool comber has recourse when he wishes to cleanse and whiten his wools to the utmost. He generally uses a soft or potash soap, and after the wool is well soaked in the warm soap bath, with gentle pressure he wrings it well with the help of a hook, fixed at the end of his washing tub, and hangs it up to dry. Bleaching of rags, and paste for paper making. - After the rags are reduced to what is called half stuff, they should have the greater part of the floating water run off, leaving just enough to form a stir-about mass. Into this a clear solution of chloride of lime should be poured, of such a strength as is suited to the color of the rags, which should have been previously sorted; and the engine is kept going so as to churn the rags with the bleaching agent. After an hour, the water may be returned upon the engine, and the washing of the paper resumed. From two to four pounds of good chloride of lime are reckoned sufficient to bleach one hundred weight of rags. When the rags consist of dyed or printed cottons, after being well washed and reduced to half stuff, they should be put into a large cask or butt, supported horizontally by iron axles upon cradle bearings, so that it may be made to revolve like a barrelchurn. For each hundred weight of the colored rags, take a solution containing from four to eight pounds of chloride of lime; add it to the liquid mixture in the butt along with half a pound of sulphuric acid for every pound of the chloride; and after inserting the bung, or rather the square valve, set the vessel in slow revolution backwards and forwards. In a short time the rags will be colorless. The rags and paper paste ought to be very well washed, to expel all the chlorine, and perhaps a little muriatic acid might be used with advantage to dissolve out all the calcareous matter, a portion of which is apt to remain in the paper, and to operate injuriously upon both the pens and the ink. Some of the French paper manufacturers bleach the paste with chlorine gas. Paper prepared from such paste, well washed, is not apt to give a brown tint to maps, as that carelessly bleached with chloride of lime is known to do. BLEACHING OF PAPER. The following are the proportions of liquid chlor de of lime, at 10~ of Gay Lussac's Chlorometre, employed for the different sorts of rags, consisting of two piles, or 200 pounds French. Cotton. litres. No. 1. Fine cotton rags - - - - - 10 2. Clean calicoes - - - - - - 12 3. --- - - - 14 4. White dirty calico, coarse cotton - - - - 16 5. Coarse cotton - - - - - - 18 6. Grey, No. 1 - - - - - - - 20 - No. 2 - - - - - - - 22 Saxon gray - - - - - - -24 No. 2 - - - - - - 26 Pale white and half-white shades - - - - 28 Saxon blues; pale pink, dark blue, velvet - - - 32 It is considered to be much better t bleach the fine rags with liquid chloride of lime, and not with chlorine gas, because they are less injured by the former, and afford a paper of more nerve, less apt to break, and more easily sized. But the coarse or gray rags are much more economically bleached with the gaseous chlorine, without any risk of weakening the fibre too much. Bleaching by the gas is performed always upon the sorted rags, which have been boiled in an alkaline ley, and torn into the fibrous state. They are subjected to the press, in order to form them into damp cakes, which are broken in pieces and placed in large rectangular wooden cisterns. The chlorine gas is introduced by tabes in the.id of the cistern, which falls down by its superior gravity, acting always more strongly upon the rags at the bottom than those above. When the chlorine, disengaged from 150 kilogrammes (330 lbs.) of manganese and 500 kilos. of muriatic acid, is made to act upon 2,500 kilos. of the stuff (supposed dry), it will have completed its effect in the course of a few hours. The quantity of gaseous chlorine is equal to what is contained in the quantity of chloride of lime requisite to pro. luce a like bleaching result. The bleached stuff should be forthwith carefully washed 202 BLOCK MANUFACTURE. to remove all the muriatic acid produced from the chlorine; for if any of this remalr in the paper, it destroys lithographic stones and weakens common ink. BLENDE. (Fr. and Germ.) Sulphuret of zinc, so named from the German blender, to dazzle, on account of its glistening aspect. It is called black jack from its usual color. Its lustre is pearly adamantine. Spec. gravity from 3'7 to 4'2. It contains frequently iron, copper, arsenic, cadmium and silver, all associated with sulphur. It is worked up partly into metallic zinc, and partly into the sulphate of zinc, or white vitriol. It consists of 66'72 zinc, and 33'28 sulphur; being nearly by weight as two to one. See ZINC. BLOCK MANUFACTURE. Though the making of ships' blocks belongs rather to a dictionary of engineering than of manufactures, it may be expected that I should give some account of the automatic machinery for making blocks, so admirably devised and mounted by M. I Brunel Esq., for the British navy, in the dockyard of Portsmouth. The series of machines and operations are as follows:1. The straight cross cutting saw.-The log is placed horizontally on a very low bench, which is continued through the window of the mill into the yard. The saw ia exactly over the place where the log is to be divided. It is let down, and suffered to rest with its teeth upon the log, the back still being in the cleft of the guide. The crank being set in motion, the saw reciprocates backwards and forwards with exactly the same motion as if worked by a carpenter, and quickly cuts through the tree. When it first begins to cut, its back is in the cleft in the guide, and this causes it to move in a straight line; but before it gets out of the guide, it is so deep in the wood as to guide itself; for in cutting across the grain of the wood, it has no tendency to be diverted from its true line by the irregular grain. When the saw has descended through the tree, its handle is caught in a fixed stop, to prevent its cutting the bench. The machine is thrown out of gear, the attendant lifts up the saw by a rope, removes the block cut off, and advances the tree to receive a fresh cut. 2. The circular cross cutting saw.-This saw possesses universal motion; but the axis is always parallel to itself, and the saw in the same plane. It can be readily raised or lowered, by inclining the upper frame on its axis; and to move it sidewise, the saw frame must swing sidewise on its joints, which connect it with the upper frame. These movements are effected by two winches, each furnished with a pair of equal pinions, working a pair of racks fixed upon two long poles. The spindles of these winches are fixed in two vertical posts, which support the axis of the upper frame. One of these pairs of poles is jointed to the extreme end of the upper frame; therefore by turning the handle belonging to them, the frame and saw is elevated or depressed; in like manner, the other pair is attached to the lower part of the saw frame, so that the saw can be moved sidewise by means of their handles, which then swing the saw from its vertical position, These two handles give the attendant a complete command of the saw, which we suppose to be in rapid motion, the tree being brought forward and properly fixed. By one handle, he draws the saw against one side of the tree, which is thus cut into (perhaps half through); now, by the other handle, he raises the saw up, and by the firstmentioned handle he draws it across the top of the tree, and cuts it half through from the upper side; he then depresses the saw and cuts half through from the next side; #nd lastly a trifling cut of the saw, at the lower side, completely divides the tree, which is then advanced to take another cut. The great reciprocating saw is on the same principle as the saw mill in common use in America. 3. The circular ripping saw is a thin circular plate of steel, with teeth similar to those of a pit saw, formed in its periphery. It is fixed to a spindle placed horizontally, at a small distance beneath the surface of a bench or table, so that the saw projects through a crevice a few inches above the bench. The spindle being supported in proper collars, has a rapid rotatory motion communicated to it by a pulley on the opposite end, round which an endless strap is passed from a drum placed overhead in the mill. The block cut by the preceding machine from the end of the tree, is placed with one of the sides flat upon the bench, and thus slides forward against the revolving saw which cuts the wood with a rapidity incredible to any one who has not seen these or similar machines. 4. Boring machine.-The blocks, prepared by the foregoing saws, are placed in the machine represented inJig. 144. This machine has an iron frame, A A, with three legs, beneath which the block is introduced, and the screw near B being forced down upon it, confines it precisely in the proper spot to receive the borers D and E. This spot is de. termined by a piece of metal fixed perpendicularly just beneath the point of the borer E, ahown separately on the ground at x; this piece of metal adjusts the position for the borer D, and its height is regulated by resting on the head of the screw x, which fastens the piece x down to the frame. The sides of the block are kept in a parallel position, by being applied against the heads:f three screws tapped into the double leg of the frame a. The borer D is adapted to bore the hole for the centre pin in a direction exactly per. BLOCK MIANUACTURE. 203 144 145 A_ P 33 peridicular to the surface resting against the three screws; the other, at E, perforates the holes for the commencement of the sheave holes. Both borers are constructed in nearly the same manner; they are screwed upon the ends of small mandrels, mounted in frames similar to a lathe. These frames, G and H, are fitted with sliders upon the angular edges of the flat broad bars, I and K. The former of these is screwed fast to the frame; the latter is fixed upon a frame of its own, moving on the centre screws, at L L, beneath the principal frame of the machine. By this means the borer E can be moved within certain limits, so as to bore holes in different positions. These limits are determined by two screws, one of which is seen at a; the other, being on the opposite side, is invisible. They are tapped through fixed pieces projecting up from the frame. A projecting piece of metal, from the under side of the slider K of the borer E, stops against the ends of these screws, to limit the excursion of the borer. The frames for both borers are brought up towards the block by means of levers M and N. These are centred on a pin, at the op. posite sides of the frame of:he machine, and have oblong grooves through them, which receive screw pins, fixed into the frames G and H, beneath the pulleys P P, which give motion to the spindles. 5. The mortising machine is a beautiful piece of mechanism, but too complicated Jor description within the limits prescribed to this article. 6. The corner saw, fig. 145, consists of a mandrel, mounted in a frame A, and carrying a circular saw L upon the extreme end of it. This mandrel and its frame being exactly similar to those at G and H, fig. 144, does not require a separate view, although it is hid behind the saw, except the end of the screw, marked A. This frame is screwed down upon the frame B B of the machine, which is supported upon four columns. c c, D D, is an inclined bench, or a kind of trough, in which a block is laid, as at E, being supported on its edge by the plane c c of this bench, and its end kept up to its position by the other part of the bench D D. By sliding the block along this bench, it is applied to the saw, which cuts off its angles, as is evident from the figure, and prepares it for the shaping engine. All the four angles are cut off in succession, by applying its different sides to the trough, or bench. In the figure, two of them are drawn as being cut, and the third is just marked by the saw. This machine is readily adapted to different sizes of blocks, by the simple expedient of laying pieces of wood of different thickness against the plane D D, so as to 204 BLOCK MANUFACTURE. fill it up, and keep the block nearer to or farther from the saw, for all the blocks art required to be cut at the same angle, though, of course, a larger piece is to be cut from large than from small blocks. The 4C6ow 14 -,block reduced to the state of E is now taken to } ^ E O^ Q 7. The shaping machine.-A great deal of the apparent complication of this rF1 ((\^^SjG3^/t ^=1e figure arises from the iron cage, which is provided to defend the workmen, lest the blocks, which are revolving in the t circles, or chuck, with an immense velocity, should be loosened by the aceaS{\i?^ ^ ih I> l tion of the tool, and fly out by their centrifugal force. Without this provi-! ^~ /^^//,^ sion, the consequences of such an accident would be dreadful, as the blocks would be projected in all directions, with an inconceivable force. 8. The scoring engine receives two blocks, as they come from the shaping engine, and forms the groove round X{ ~~M ltheir longest diameters for the reception of their ropes or straps, as represented in the two snatch blocks and double block, under figs. 144, 145. A, B, fig. 146, represent the above two blocks, each held between two smal' pillars a (the other pillar is hid behind "^^^ V ~ ~ ~ l^the block), fixed in a strong plate D, and pressed against the pillars by a screw b, which acts on a clamp d. Over the blocks a pair of circular planes or cutters, E E, are situated, both being fixed-on the same spindle, which is turned by a pulley in the middle of it. The spindle is fitted in a frame r F, moving in centres at e e, so as to rise and fall when moved by a handlef. This brings the cutters down upon the blocks; and the depth to which they can cut is regulated by a curved shape g, fixed by screws upon the plate D, between the blocks. Upon this rests a curved piece of metal h, fixed to the frame F, and enclosing, but not touching, the pulley. To admit the cutters to traverse the whole length of the blocks, the plate D (or rather a frame beneath it) is sustained between the points of two centres. Screws are seen at 1, on these centrcs. The frame inclines when the handle L is depressed. At M is a lever, with a weight at the end of it, counterbalancing the weight of the blocks, and plate D, all which are above the centre on which they move. The frame F is also provided with a counterpoise to balance the cutters, &c. The cutters E E are circular wheels of brass, with round edges. Each has two notches in its circumference, at opposite sides; and in these notches chisels are fixed by screws, to project beyond the rim of the wheel, in the manner of a plane iron before its face. This machine is used as follows:-In order to fix the block, it is pressed between the two pins (only one of which at a, can be seen in this view), and the clamp d, screwed up against it, so as just to hold the block, but no more. The clamp has two claws, as is seen in the figure, each furnished with a ring entering the double prints previously made, in the end of the block. These rings are partly cut away, leaving only such a segment of each as will just retain the block, and the metal between them is taken out to admit the cutter to operate between them, or nearly so. In putting the blocks into this machine, the workman applies the double prints to the ends of the claws of the clamps, but takes care that the blocks are higher between the pins a than they should be: he then takes the handle f, and by it presses the cutters E E (which we suppose are standing still) down upon the blocks, depressing them between their pins at the same time, till the descent of the cutters is stopped by the piece h resting on the shape g. He now turns the screws b b, to fix the blocks tight. The cutters being put in motion cut the scores, which will be plainly seen by the mode of adjustment just described, to be of no depth at the pin-hole; but by depressing the handle L, so as to incline the blocks, and keeping the cutters down upon their shape g, by the handle f, they will cut any depth towards the ends of the blocks, which the shape g admits. By this means one quarter of the score is formed; the other is done by turning both blocks together half round in this manner. The centres I are not fitted into the plate D BLOCK MANUFACTURE. 205 itself, but into a frame seen at R beneath the plate, which is connected with it by a centre pin, exactly midway between the two blocks A B. A spring catch, the end of which is seen at r, confines them together; when this catch is pressed back, the plate D can be turned about upon its centre pin, so as to change the blocks, end for end, and bring the unscored quarters (i. e. over the clamps) beneath the cutters; the workman taking the handles f and L, one in each hand, and pressing them down, cuts out the second quarter. This might have been effected by simply lifting up the handle L; but in that case the cutter would have struck against the grain of the wood, so as to cut rather roughly; but by this ingenious device of reversing the blocks, it always cuts clean and smooth, in the direction of the grain. The third and fourth quarters of the score are cut by turning the other sides of the blocks upwards, and repeating the above operation. The shape g can be removed, and another put in its place, for different sizes and curves of block; but-the same pins a, and holding clamps d, will suit many different sizes. By these machines the shells of the blocks are completely formed, and they art next polished and finished by hand labor; but as this is performed by tools and methods which are well Known, it is needless to enter into any explanation: the.finishing required being only a smoothing of the surfaces. The machines cut so perfectly true as to require no wood to be removed in the finishing; but as they cut without regard to the irregularity of the grain, knots, &c., it happens that many parts are not so smooth as might be wished, and for this purpose manual labor alone can be employed. The lignum vitte for the sheaves of the blocks, is cut across the grain of the wooL by two cross-cutting saws, a circular and straight saw, as before mentioned. These machines do not essentially differ in their principle from the great cross-cutting saws we have described, except that the wood revolves while it is cutting, so that a small saw will reach the centre of a large tree, and at the same time cut it truly fat. The limits pre.. scribed for our plates will not admit of giving drawings of these machines, and the idea which could be derived from a verbal description would not be materially different from the cross-cutting saws before mentioned. These machines cut off their plates for the end of the tree, which are exactly the thickness for the intended sheave. These pieces are of an irregular figure, and must be rounded and centred in the crown saw. 9. The crown saw is represented in fig. 147, where A is a pulley revolving by means of an endless strap. It has the crown or trepan saw a fixed to it, by a screw cut within the piece, upon which the saw is fixed, and which gives the ring or hoop of the saw sufficient stability to perform its office. Both the pulleys and saw revolve together upon a truly cylindrical tube b, which is stationary, being attached by a flaunch c to a F fixed puppet B, and on this tube as an axis A 3^3B GE Z the saw and pulley turn, and may be slid ~v l!\\ vS \ E \ endwise by a collar fitted round the centreVA L R Ir piece of the pulley, and having two iron ID J DW l rods (only one of which can be seen at d in the figure), passing through holes made through the flaunch and puppet B. When the saw is drawn back upon its central tube, the end of the latter projects beyond the teeth of the saw. It is by means of this fixed 1^_J^~h Ank |*^ | Nring or tube within the saw, that the piece of wood e is supported during the operation of sawing, being pressed forcibly against it by a screw D, acting through a puppet fixed 147 to the frame of the machine. At the end of this screw is a cup or basin which applies itself to the piece of wood, so as to form a kind of vice, one side being the end of the fixed tube, the other the cup at the end of the screw D. Within the tube b is a collar for supporting a central axis, which is perfectly cylindrical. The other end of this axis, (seen at f,) turns in a collar of the fixed puppet E. The central axis has a pulley F, fixed on it, and giving it motion by a strap similar to the other. Close to the latter pulley a collar g is fitted on the centre piece of the pulley, so as to slip round freely, but at the same time confined to move endways with the pulley and its collar. This collar receives the ends of the two iron rods d. The opposite ends of these rods are, as above mentioned, connected by a similar collar, with the pulley A of the saw a. By this connexion, both the centre bit, which is screwed into the end of the central axis f, and the saw sliding upon the fixed tube b, are brought forward to the wood at the same time, both being in rapid motion by their respective pulleys. 10. The Coaking Engine.-This ingenious piece of machinery is used to cut the three 206 BLUE DYES. semicircular holes which surround the hole bored by the crown saw, so as to produce a cavity in the centre of the disc. 11. Face-turning Lathe.-The sheave is fixed against a flat chuck at the end of a mandrel, by a universal chuck, similar to that in the coaking engine, except that the centre pin, instead of having a nut, is tapped into the flat chuck, and turned by a screwdriver. BLOOD. (Sang, Fr.; Blut, Germ.) The liquid which circulates in the arteries and veins of animals; bright red in the former and purple in the latter, among all the tribes whose temperature is considerably higher than that of the atmosphere. It consists, 1. of a colorless transparent solution of several substances in water; and, 2. of red, undissolved particles diffused through that solution. Its specific gravity varies with the nature and health of the animal; being from 1-0527 to 1-0570 at 60~ F. It has a saline sub-nauseous taste, and a smell peculiar to each animal. When fresh drawn from the vessels, it rapidly coagulates into a gelatinous mass, called the clot, cruor, or crassamentum, from which, after some time, a pale yellow fluid, passing into yellowish green, oozes forth, called the serum. If the warm blood be stirred with a bundle of twigs, as it flows from the veins, the fibrine concretes, and forms long fibres and knots, while it retains its usual appearance in other respects. The clot contains fibrine and coloring matter in various proportions. Berzelius found in 100 parts of the dried clot of blood, 35 parts of fibrine; 58 of coloring matter; 1'3 of carbonate of soda; 4 of an animal matter soluble in water, along with some salts and fat. The specific gravity of the serum varies from 1'027 to 1'029. It forms about three fourths of the weight of the blood, has an alkaline reaction, coagulates at 167~ F. into a gelatinous mass, and has for its leading constituent albumen to the amount of 8 per cent., besides fat, potash, soda, and salts of these bases. Blood does not seem to contain any gelatine. The red coloring matter called hemaline, may be obtained from the cruor by washing with cold water and filtering. Blood was at one time largely employed for clarifying sirup, but it is very sparingly used by the sugar refiners in Great Britain of the present day. It may be dried by evapo. ration at a heat of 130~ or 140~, and in this state has been transported to the colonies for purifying cane juice. It is an ingredient in certain adhesive cements, coarse pigments for protecting walls from the weather, for making animal charcoal in the Prussian blue works, anLd by an after process, a decoloring carbon. It is used in some Turkey red dye-works. Blood is a powerful manure. BLOWING MACHINE. See IRoN, METALLURGY, VENTILATION. BLOWPIPE. (Chalumeau, Fr.; Lothrihre, Germ.) Jewellers, mineralogists, chem. ists, enamellers, &c., make frequent use of a tube, usually bent near the end, terminated with a finely pointed nozzle, for blowing through the flame of a lamp, candle, or gas-jet, and producing thereby a small conical flame possessing a very intense heat. Modifications of blow pipes are made with jets of hydrogen, oxygen, or the two gases mixed in due proportions. BLUE DYES. (Teint, Germ. See ENAMEL.) The materials employed for this purpose are indigo, Prussian blue, logwood, bilberry, (vaccinium myrtillus,) elder berries, (sambucus nigra,) mulberries, privet berries, (ligustrum vulgare,) and some other berries whose juice becomes blue by the addition of a small portion of alkali, or of the salts of copper. For dyeing with the first three articles, see them in their alphabetical places. I shall here describe the other or minor blue dyes. To dye blue with such berries as the above, we boil one pound of them in water, adding one ounce of alum, of copperas, and of blue vitriol, to the decoction, or in their stead equal parts of verdigris an, tartar, and pass the stuffs a.sufficient time through the liquor. When an iron mordant alone is employed, a steel blue tint is obtained; and when a tin one, a blue with a violet cast. The privet berries which have been employed as sap colors by the card painters, may be extensively used in the dyeing of silk. The berries of th e African night-shade (solanum guineense) have been of late years considerably applied to silk on the continent in producing various shades of blue, violet, red, brown, &c., but particularly violet. With alkalis and anids these berries have the same habitudes as bilberries; the former turning them green, the latter red. They usually come from Italy compressed in a dry cake, and are infused in hot water. The infusion is merely filtered, and then employed without any mordant, for dyeing silk, being kept at a warm temperature by surrounding the bath vessel with hot water. The goods must be winced for six hours through it in order to be saturated with color; then they are to be rinsed in running water and dried. One pound of silk requires a pound and a half of the berry, cake. In the residuary bath, other tints of blue may be given. Sometimes the dyed silk is finished by running it through a weak alum water. A color approaching to in! digo in permanence, but which differs from it in being soluble in alkalis, though incapable of similar disoxydizement, is the gardenia genipa and aculeata of South America, whose colorless juice becomes dark blue with contact of air; and dyes stuffs, the skin, BOILERS. 207 and nails of an unchangeable deep blue color, but the juice must be applied in the colorless state. See INDIGO and PRUSSIAN BLUE. BLUE PIGMENTS. Several metallic compounds possess a blue color; especially those of iron, cobalt, and molybdenum. The metallic pigments, little if at all employed, but which may be found useful in particular cases, are the molybdate of mercury, the hydro-sulphuret of tungsten, the prussiate of tungsten, the molybdate of tin, the oxide of copper darkened with ammonia, the silicate of copper, and a fine violet color formed from manganese and molybdenum. The blues of vegetable origin, in common use, are indigo, litmus, and blue cakes. The blue pigments of a metallic nature found in commerce are the following; Prussian blue; mountain blue, a carbonate of copper mixed with more or less earthy matter; Bremen blue or verditer, a greenish blue color obtained from copper mixed with chalk or lime; iron blue, phosphate of iron, little employed; cobalt blue, a color obtained by calcining a salt of cobalt with alumina or oxide of tin; smalt, a glass colored with cobalt and ground to a fine powder; charcoal blue, a deep shade obtained by triturating carbonized vine stalks with an equal weight of potash in a crucible till the mixture ceases to swell, thsn pouring it upon a slab, putting it into water, and saturating the alkali with sulphuric acid. The liquor becomes blue, and lets fall a dark blue precipitate, which becomes of a brilliant blue color when heated. Molybdenum blue is a combination of this metal, and oxide of tin, or phosphate of lime. It is employed both as a paint, and an enamel color. A blue may also be obtained by putting into molybdic acid (made by digesting sulphuret of molybdenum with nitric acid) some filings of tin and a little muriatic acid. The tin deoxidizes the molybdic acid to a certain degree, and converts it into the molybdous, which, when evaporated and heated with alumina recently precipitated, forms this blue pigment. Ultramarine is a beautiful blue pigment, which see. BLUE. Turnbull's and Chinese are both double cyanides of iron. BLUE VITRIOL; sulphate of copper. BOILERS (construction of).-The modifications of the steam engine which hate been adopted since its introduction by Watt, three quarters of a century ago, have been very numerous and varied; and although the progression in its applications and improvements has been most rapid and wonderful, we are still undecided as to the best form of its construction. Sound principles scientifically applied, and the gradually increasing excellence of our mechanical workshops, have enabled us to attain the great perfection which characterizes the working parts of the modern steam engine. The steam engine itself may be regarded as a comparatively perfect machine, and therefore we shall confine our observations almost exclusively to that very important and necessary adjunct-the Boiler-which is the source of its power. With this limitation, a very wide field of inquiry is opened out, and in the earliest steps of the investigation we become perplexed with the endless variety of forms and constructions which at different periods have been adopted by engineers, and which have never, unfortunately, received the same judicious attention that was paid, as I have already remarked, to the steam engine. This is an anomalous and much to be regretted fact, for the boiler, being the source of the motive power, is undoubtedly one of the most important parts of the whole machine. Upon its proper proportions and arrangements for the generation of steam, depend the economy and regularity wi h which the engine can be worked, and upon its strength and excellence of workmanship depends the safety of the lives and property of those who come in contact with it. Regarding the steam engine as one of the most active agents in the extension of our prosperity, and in the civilization of the world, and seeing how it is mixed up with the daily duties and working of society, the safety and efficiency of every part, and more especially the boiler, are subjects of national importance; and it is of great consequence to introduce here such knowledge and experience on this subject of deep interest as has been offered by William Fairbairn, Esq. "The boiler may be considered in its construction, management, security, and eco nomy. 1st. As to the construction. Here I shall have to go a little into detail, in order to show, in construction, the absolute necessity there exists for adhering to form and other considerations essential in the practice of mechanical engineers, so as to effect the maximum of strength, with the minimum of material. In boilers this is the more important, as any increase in the thickness of the plates obstructs the transmission of heat, and exposes the rivets as well as the plates to injury on the side exposed to the action of the furnace. "It has generally been supposed that the rolling of boiler plate iron gives to the sheets greater tenacity in the direction of their length than in that of their breadth; this is, however, not correct; as a series of experiments which Mr. Fairbairn made some years since fully proves that there is no difference in the tensile strength of boiler plates whether torn asunder in the direction of the fibre, or across it. From five different sorts of iron the following results were obtained: 208 BOILERS. Mean Breaking weight Mean Breaking weight Description of Iron. in tons, in the direc- in tons across the tion of the fibre. fibre. Yorkshire plates - - - 25'77 - - - 2'749 Yorkshire plates - - - 2276 - - - 26'37 Derbyshire plates - - - 2168 - - - 1865 Shropshire plates - - - 22'82 - - - 22-00 Staffordshire plates - - - 19*56 - - - 2101 Mean -- 2251 - - - 23-10 "From this it appears that we may safely use iron plates in the construction of boilers, in whatever direction may best suit the convenience of the maker. Next to the tenacity of the plates comes the question of riveting, or the best and surest means of securing them together. On this part of the subject we have been widely astray, and it requires some skill, and no inconsiderable attention, in conducting the experiments, to convince the unreflecting portion of the public, and even some of our boiler makers, that the riveted joints were not stronger than the plate itself. At first sight this would appear the case, but a moment's reflection will soon convince us to the contrary, as, in punching holes along the edge of a plate, it is obvious that the plate must be weakened to the extent of the sectional areas punched out, and that it is next to impossible, under the circumstances, to retain the same strength in the material after such diminution has been effected, as existed in the previously solid plate. This was clearly demonstrated by a series of experiments, which took place some years since, and in which the strength of almost every description of riveted joints was determined by tearing them directly asunder. The results obtained from these experiments were conclusive, as regards the relative strength of riveted joints and the solid plates. In two different kinds of joints-double and single riveted-the strength was found to be, in the ratio of the plate, as the numbers 100, 70 and 56. "Assuming the strength of the plate to be -- 100 The strength of a double riveted joint would be, after allowing for the adhesion of the surfaces of the plate - - - - - 70 And the strength of a single riveted joint - - - - - 56 "These proportions of the relative strengths of plates and joints may, therefore, in practice be safely taken as the standard value, in the construction of vessels required to be steam and water tight, and subjected to pressure varying from 10 lbs to 100 lbs. on the square inch. "In the construction of boilers, exposed to severe internal pressure, it is desirable to establish such forms, and so to dispose the material as to apply the greatest strength in the direction of the greatest strain; and in order to accomplish this, it will be necessary to consider whether the same arrangement be required for all diameters, or whether the form as well as the disposition of the plates should not be changed. To determine these questions in cylindrical boilers, recourse must be had to experiment, or such deduction as may apply to any given case, and such as is founded upon unerring data, derived from experimental research. ~ On this head I am fortunate in having before me the calculations of Professor W. R. Johnson, of the Franklin Institute of America, whose inquiries into the strength of cylindrical boilers are of great value, and from which the following short abstract may be useful. " 1st. To know the force which tends to burst a cylindrical vessel in the longitudinal direction, or, in other words, to separate the head fiom the curved sides, we have only to consider the actual area of the head, and to multiply the units of surface by the number of units of force applied to each superficial unit. This will give the total divellent force in that direction. "To counteract this, we have, or may be conceived to have, the tenacity of as many longitudinal bars as there are lineal units in the circumference of the cylinder. The united strength of these bars constitutes the total retaining or quiescent force, and at the moment when rupture is about to take place the divelIent and the quiescent forces must obviously be equal. " 2d. To ascertain the amount of force which tends to rupture the cylinder along the curved side, or rather along the opposite sides, we may regard the pressure as applied, through the whole breadth of the cylinder, upon each lineal unit of the diameter. Hence the total amount of force which would tend to divide the cylinder in halves, by separating it along two lines, on opposite sides, would be represented by multiplying the diameter by the force exerted on each unit of surface, and this product by the length of the cylinder. But even without regarding the length, we may consider the force requisite to rupture a single band in the direction now supposed, and of one lineal unit BOILERS. 209 in breadth; since it obviously makes no difference whether the cylinder be long or short, in respect to the ease or difficulty of separating the sides. Tile divellent force in this direction is, thirefore, truly represented by the diameter multiplied by the pressure per unit of surface. The retaining o,' quiescent force, in the same direction is only the strength or tenacity of the two opposite sides of the supposed bond. Here also, at the moment when a rupture is about to occur, the divellent force must exactly equal the quiescent force. "' Mr. Johnson then goes on to show that, as the diameter is increased, the product of the diameter and the force or pressure per unit of surface, are increased in the same ratio. This truth I shall endeavor to prove; as, also, that, as the diameter of any cylindrical vessel is increased, the thickness of the metal must also be increased in the exact ratio of the increase of the diameter: the pressure, or as Mr. Johnson calls it, the divellent force, being the same when the diameter of a boiler is increased, it must be borne in mind that the area of the ends is also increased, not in the ratio of the diameter but in the ratio of the square of the diameter: and it will be seen that instead of the force being doubled, as is the case in the direction of the diameter and circumference, it is quadrupled upon the ends, or, what is the same thing, a cylinder double the diameter of another cylinder has to sustain four times the pressure in the longitudinal direction. The retaining force of the thickness of the metal of a cylindrical boiler does not, however, increase in the same ratio as the area of the (ircle, but simply in the ratio of the diameter; consequently, the thickness of the metal will require to be increased in the same ratio as the diameter is increased. From this it appears, that the tendency to rupture by blowing out the ends of a cylindrical bailer will not be greater in this direction than it is in any other direction; we may therefore safely conclude, since we have seen that the tendency to rupture increases in both directions in the ratio of the diameter, that any deviation from that law, as regards the thickness of the plates, would not increase the strength of the boiler. "I have been led to these inquiries from the circumstance that Mr. Johnson appears to reason on the supposition that there are no joints in the plates, and that the tenacity of the iron is equal to 60,000 lbs.-rather more than 26 tons to the square inch. N ow, we have shown by the results of the experiments already adduced, that ordinary boiler plates will not bear more than 23 tons to the square inch; and, as nearly one third of the material is punched out for the reception of the rivets, we must still further reduce the strength, and take 15 tons or about 34,000 lbs.* on the square inch as the tenacity of the material or the pressure at which a boiler would burst. " This I should consider in practice as the maximum power of resistance of boiler elates in their riveted state, and I will now endeavor to show you in a very concise, and I trust not uninteresting investigation, the bearing power of boilers, and the pressure at which they can be worked with safety. It has been stated that the strength of cylindrical boilers, when taken in the direction of their circumference, is in the ratio of their diameters, and when taken in the direction of the ends, as the squares of the diameters,-a proposition which it will not be difficult to demonstrate, as applicable to every description of boiler of the cylindrical form. It will be seen, however, that the strain is not exactly the same in every direction, and that there is actually less upon the material in the longitudinal direction than there is upon the circumference. For example, let us take two boilers, one three feet diameter and the other six feet, and suppose each to be subject to a pressure of 40lbs. on the square inch. In this condition, it is evident that the area or number of square inches in the end of a three-feet boiler is, to that of the area of the six-feet boiler, as 1 to 4; and, by a common process of arithmetic, it will be found that the edges of the plates forming the cylindrical part of the three-feet boiler are subject (at 40 lbs. on the square inch) to a pressure of 40,7121 bs., upwards of iS tons: whereas the plates of the six-feet boiler have to sustain a pressure of 162,848 lbs., or 72 tons, which is quadruple the force to which the boiler only one half the diameter is exposed; and the circumference being only as 2 to 1, there is necessarily double the strain upon the cylindrical plates of the large boiler. -Now this is not the case with the other parts of the boiler, as the circumference of a cylinder increases only in the ratio of the diameter; consequently, the pressure, instead of being increased in the ratio of the square of the diameter, as shown in the ends, is only doubled, the circumference of the six-feet boiler being twice that of the three-feet boiler. " Let us for the sake of illustration, suppose the two cylindrical boilers, such as we have described, to be divided into a series of hoops of one inch in width; and, taking one of these hoops ini the three-feet boiler, we shall find it exposed, ata pressure of 40 lbs. on the square inch, to a force of 1,440 Ibs., acting on each side of a line drawn through * By experiment it is found that the strength of the riveted joints of hilers is only about one-half the strength of the plate itself; bat takingthto consideration the crossing of the joints, 34,000 Ibs. may reasonably be taken as the tenacity of the riveted plates, or the bursting pressure of a cylindrical boiler. 15 210 BOILERS. the axis of a cylinder 36 inches diameter and 1 inch in depth, and which line forms the diameter of the circle. Now, this force causes a strain upon the points a a in the 148 a direction of the arrows in the annexed diagram of the three-feet circle, of 720 lbs., alid, assuming the pressure to be increased till the force becomes equal to the tenacity or retaining powers of the iron at a a, it is evident, in this state of the equilibrium of the two forces, that the least preponderance on the side of the internal pressure would insure fracture. And suppose we take the plates of which the boiler is composed at one quarter of an inch thick, and the ultimate strength at a 34,000 lbs. on the square inch, we shall have 600 4'- 472 per square inch, as the bursting pressure of the boiler. Again, as the forces in this direction are not as the squares, but simply as the diameters, it is clear that at 40 lbs. on the square inch we have in a hoop an inch in depth, or that portion of a cylinder whose diameter is six feet, exactly double the force applied to the points 6 b, which was acting 149 on the points a a, in the diameter of three feet. Now, as& suming the plates to be a quarter of an inch thick, as in the three-feet boiler, it follows, if the forces at the same pressure be doubled in the large cylinder, that the thickness of the plates must also be doubled in order to sustain the same pressure with equal security; or what is the same thing, the six-feet boiler must be worked at half the pressure, in order to insure the same degree of safety as attained in the three-feet boiler at double the pressure. From these facts it may be useful to know, that boilers having increased dimensions should also have increased strength in the ratio of their diameters; or, in other words, the plates of a sixfeet boiler should be double the thickness of the plates of b a three-feet boiler, and so on in proportion as the diameter is increased. "The relative power of force applied to cylinders of different diameters becomes more strikingly apparent when we reduce them to their equivalents of strain per square inch, as applied to the ends and circumference of the boiler respectively. In the three-feet boiler, working at 40 lbs. pressure, we have a force equal to 7201bs. upon an inch width of plate, and one quarter of an inch thick, or 720 by 4 = 2,880 lbs., the force per square inch upon every point of the circumference of the boiler. Let us now compare this with the actual strength of the riveted plates themselves, which, taken as before, at 34,000 bs. on the square inch, we arrive at the ratio of pressure as applied to the strength of the circumference, as 2,880 to 34,000, nearly as 1 to 12, or 472 lbs. per square inch, as the ultimate strength of the riveted plates. "These deductions appear to be true in every case as regards the resisting powers of cylindrical boilers to a force radiating in every direction from the axis towards the circumference; but the same reasoning is, however, not maintained when applied to the ends, or, to speak technically, to the angle iron and riveting, where the ends are attached to the circumference. Now, to prove this, let us take the three-feet boiler, where we have 113 inches in the circumference; and upon this circular line of connection we have, at 40 bs. to the square inch. to sustain a pressure of 18 tons, which is equal to a strain of 360 lbs., acting longitudinally upon every inch of the circumfer ence. Apply the same force to a six-feet boiler, with a circumference or line of connection equal to 226 inches, and we shall find it exposed to exactly four times the force, or 72 tons; but, in this case, it must be borne in mind, that the circumference is doubled, and consequently the strain, instead of being in the quadruple ratio, is only doubled, or a force equal to 720 lbs. acting longitudinally, as before, upon every inch of the circumference of the boiler. From these facts we come to the conclusion, that the strength of cylindrical boilers is in the ratio of their diameters if taken in tile line of curvature, and as the squares of the diameters as applied to the ends or their sectional area; and that all descriptions of cylindrical tubes, to bear the same pressure, must be increased in strength in the direction of their circumference simply as their diameters, and in the direction of the ends as the squares of the diameters. "Again, if we refer to the comparative merits of the plates composing cylindrical vessels subjected to internal pressure, they will be found in this anomalous condition, that the strength in their longitudinal direction is twice that of the plates in the curvi. linear direction. This appears by a comparison of the two forces, wherein we have shown that the ends of the three-feet boiler, at 40 bs. internal pressure, sustain 360 Ibs. of longitudinal strain upon each inch of a plate a quarter of an inch thick; whereas the same thickness of plates has to bear in the curvilinear direction a strain of 720 lbs This ifferencc of strain is a difficulty not easily overcome; and all that we can accom BOILERS. 211 plish in this case will be to exercise a sound judgment in crossing the joints, in the quality of the worknlanship, and the distribution of the material. For the attainment of these objects, the following table, which exhibits the proportionate strength of cylindrical boilers fiom three to eight feet in diameter, may be useful.'Table of equal Strengths in Cylindrical Boilers from 3 to 8 feet diameter, showing the thickness of metal in each respectively, at a pressure of 450 lbs. to the square inch. 1Bursting Pressure equivalent to the Thickness of the Diameter of ultimate strength of the riveted Joints, Plates in Boilers. as deduced from experiment, 34,000 lbs. Decimal parts to the square inch. of an Inch. Ft. Inch. 3 0 450 lbs. 250 3 6 - 291 4 0 -'333 4 6 - 376 5 0 - 416 5 6 - 458 6 0 - 500 6 6 -'541 7 0 -'583 7 6 - -625 8 0 -'666 "Boilers of the simple form, and without internal flues, are subjected only to one species of strain; but those constructed with internal flues are exposed to the same tensile force which pervades the simple form; and, further, to the force of compression which tends to collapse or crush the material of the internal flues. In the cylindrical boiler with round flues, the forces are diverging from the central axis as regards the outer shell, and converging as applied to every separate flue which the boiler contains. "These two forces in a steam boiler are in constant operation; the tendency of the one being to tear up the external plates and force outthe ends, and the other to destroy the form and to force the material into the central area of the flues. These two forces operate widely different upon the resisting powers of the boiler, which, taken in the direction of its exterior envelope, has to resist a tensile strain operating in every dir'ection from within, and the internal flues acting as an arch offer a powerful resistance to compression from without. It might be instructive as well as interesting to exhibit the nature of these powers, and determine the law by which vessels of this description are retained in shape, but this can only be done by experiment; and as these experiments would have to be conducted upon a large scale, and with great accuracy, in order to arrive at satisfactory results, we must abandon the idea for the present, and content ourselves with such information as we already possess.'At some future period I may possibly devote my attention to this subject. It is one of great importance; and a series of well-conducted experiments would, I make no doubt, supply valuable data in the varied requirements of boiler construction, and their comparative powers of resistance to the united force of tension and compression.'-(Mr. Fairbairn's Lecture.) "From the existing state of our knowledge, we must rest satisfied with the fact, that the resisting powers of cylindrical flues to compression will be directly as their diameters; and we may therefore conclude that a circular flue 18 inches in diameter will resist double the pressure of one 3 feet in diameter. Hence it follows that the resistance of wrought iron plates of the circular form is to the force of compression as their diameters-the same, but with greatly diminished powers, as compared with the resistance of wrought iron cylindrical plates to tension. "To show the amount of strain upon a high-pressure boiler 30 feet long, 6 feet diameter, having two centre flues, each 2 feet 3 inches diameter, working at a pressure of 50 lbs. on the square inch, we have only to multiply the number of square feet of sur face, 1,030, exposed to pressure, by 321, and we have the force of 3,319 tons, which a boiler of these dimensions has to sustain. I mention this to show that the statistics of pressure when worked out are not only curious in themselves, but instructive as regards a knowledge of the retaining powers of vessels so extensively used, and on which the bread of thousands depends. To pursue the subject a little further, let us suppose the pressure to be at 450 lbs. on the square inch, which a well-constructed boiler of this description will bear before it bursts, and we have the enormous force of 29,871, or nearly 30,000 tons, bottled up within a cylinder 30 feet long and 6 feet diameter. "This is, however, inconsiderable when compared with the locomotive and some 212 BOILERS. marine boilers, which, from the number of tubes, present a much larger extent of sur. face to pressure. Locomotive engines are usually worked at 80 to 100 lbs. oil the inch, and, taking one of the usual construction, we shall find, at 100 lbs. on the inch, that it rushes forward on the rail with a pent-up force within its interior of nearly 60,000 tons, which is rather increased than diminished at an accelerated speed. " In a stationary boiler charged with steam at a given pressure, it is evident that the forces are in perfect equilibrium, and, the strain being the same in all directions, there will be no tendency to motion. Supposing, however, this equilibrium to be destroyed by accumulative pressure till rupture ensues, it then fo.lows that, the forces in one direction having ceased, the other in an opposite direction, being active, would project the boiler from its seat with a force equal to that which is discharged through the orifice of rupture. The direction of motion would depend upon the position of the ruptured part. If in the line of the centre of gravity, motion would ensue in that direction; if out of that line, an oblique or rotatory motion round the centre of gravity would be the result. " The velocity or quantity of motion produced in one direction would be equal to the intensity or quantity lost; and the velocity with which the body would move would be in the ratio of the impulsive force, or the quantity lost. Therefore, the quantity of motion gained by an exploded boiler in one direction will be as its weight and the quantity lost in that direction. These definitions are, however, more in the province of the mathematician, and may easily be computed from well-known formulae on the laws of motion. "We now come to the rectangular forms, or flat surfaces, which are not so well calculated to resist pressure. Of these we may instance the fire-box of the locomotive boiler, the sides and flues of marine boilers-the latter of which, by the by, are now superseded by those of the tubular form-and the flat ends of the cylindrical boilers, and others of weaker construction. "The locomotive boiler is fiequently worked up to a pressure of 120 lbs. on the square inch, and at times, when rising steep gradients, 1 have known the steam nearly as high as 200 lbs. on the inch. In a locomotive boiler subject to such an enormous working pressure, it requires the utmost care and attention on the part of the engineer to satisfy himself that the flat surfaces of the fire-box are capable of resisting that pressure, and that every part of the boiler is so nearly balanced in its powers of resistance, as that, when one part is at the point of rupture, every other part is on the point of yielding to the same uniform force. This appears to be an important consideration in mechanical constructions of every kind, as any material applied for the security of one part of a vessel subject to uniform pressure, whilst another part is left weak, is so much material thrown away; and in stationary boilers, or in moving bodies, such as locomotive engines and steam vessels, it is absolutely injurious, at least so far as the parts are disproportionate to each other, and the extra weight when maintained in motion becomes an expensive and unwieldy encumbrance. A knowledge of the strength of materials used, judicious care, and the exercise of sound judgment in its distribution, are therefore some of the most essential qualifications of the practical engineer. Our limited knowledge and defective principles of construction are manifest from the numerous abortions which exist, and, although I am free to communicate all that I know on the subject, I nevertheless find myself deficient in many of the requirements necessary for the attainment of sound principles of construction. "Reverting to the question more immediately under consideration, it is, however, essential to give the requisite security to those parts which, if left unsupported, would involve the public as well as ourselves in the greatest jeopardy. " The greater portion of the fire-boxes of locomotive boilers, as before noticed, have the rectangular form, and, in order to economize heat and give space for the furnace, it becomes necessary to have an interior and exterior shell. " That which contains the furnace is generally made of copper, firmly united by rivets, and the exterior shell, which covers the fire-box, is made of iron and united by rivets in the same way as the copper fire-box. Now these plates would of themselves be totally inadequate, unless supported by riveted stays to sustain the pressure. In fact, with one-tenth the strain, the copper fire-box would be forced inwards upon the furnace and the external shell bulged outwards, and with every change of force these two flat surfaces would move backwards and forwards, like the sides of an inflated bladder, at the point of rupture. To prevent this, and give the large flat surfaces an approxi mate degree of strength with the other parts of the boiler, wrought iron or coppel stays, one inch thick, are introduced; they are first screwed into the iron and cop per on both sides to prevent leakage, and then firmly riveted to the interior and exterior plates. These stays are about six inches asunder, forming a series of squares, and each of them will resist a strain of about fifteen tons before it breaks. "Let us now suppose the greatest pressure contained in the boiler to be 200 lbs. on the BOILERS. 213 square inc., and we have 6 x 6 x 200 = 7,200 lbs., or 3i tons, the force applied to a square of 36 inches. Now as these squares are supported by four stays, each capable of sustaining fifteen tons, we have 4 x 15 = 60 tons as the resisting powers of the stays, but the pressure is not divided amongst all the four, but each stay has to sustain that pressure; consequently the ratio of strength to the pressure will be as 4j to 1 nearly, which is a very fair proportion for the resisting power of that part. " We have treated of the sides, but the top of the fire-box and the ends have also to be protected, and there being no plate but the circular top of the boiler from which to attach stays, it has been found more convenient and equally advantageous to secure those parts by a series of strong wrought-iron bars, from which the roof of the fire-box is suspended, and which effectually prevent it fiom being forced down upon the fire. It will not be necessary to go into the calculations of those parts; they are, when riveted to the domo or roof, of sufficient strength to resist a pressure of 300 to 400 lbs. on the square inch. This is, however, generally speaking, the weakest part of the boiler, with the exception, probably, of the flat end above the tubes in the smoke-box, if not carefully stayed. "In the flat ends of cylindrical boilers, and those of the marine principle, the same rule applies as regards construction, and a due proportion of the parts, as in those of the locomotive boilers, must be closely adhered to. Every description of boiler used in manufactories, or on board of steamers, should in my opinion be constructed to a bursting pressure of 400 to 500 lbs. on the square inch; and locomotive engine boilers, which are subjected to a much severer duty, to a bursting pressure of 600 to 700 lbs. "It now only remains for me to state that internal flues, such as contain the furnace in the interior of the boiler, should be kept as near as possible to the cylindrical form, and as wrought-iron will yield to a force tending to crush it about one half of what would tear it asunder, the flues should in no case exceed one half the diameter of the boiler: and with the same thickness of plates they may be considered equally safe with the other parts. But the force of compression is so different from that of tension, that I should advise the diameter of the internal flues to be in the ratio of 1 to 29 instead of 1 to 2 of the diameter of the boiler. "I will not trouble you with a description of the haycock, hemispherical, and wagonshape boilers; they are all bad as respects their powers of resistance, and ought to be entirely disused: I shall congratulate the public when they disappear from the list of those constructions having the confidence of the public, and the consideration of the man of science or the practical engineer. "In conclusion, I have to recommend attention to a few simple rules, which, if carefully observed, will lead to the most satisfactory results. To construct boilers as nearly as possible, of maximum strength, I have already observed they should be of the cylindrical form; and where flat ends are used, they should be composed of plates one half thicker than those which form the circumference. The flues, if two in number, to be of the same thickness as the exterior shell; and the flat ends to be carefully stayed with gussets of triangular plates and angle iron, firmly connecting them with the circimference, as per annexed sketch. "The use of gussets I earnestly recommend, as being infinitely superior to, and more certain in their action and retaining pow 150 ers, than stay rods. Gussets, when used, should 2..~ —....';w= -- be placed in lines diverging from the centre or grea.ter.. - _ X cthe boilers, and made as long as the position of the flues and other circumstances in the and + oher~ proper construction will admit. They are of great vast____=- i=mportance,- = value in retaining the ends in shape, and may ___,, safely be relied upon as imparting an equalit_ of- mat l a -e c d ty of strength to every part of the structure. With these observations, I would direct attention to the facts I have endeavored to inculcate. You will, I am persuaded, find them -embe~ o Ist oFuseful; and I trust the object contemplated A=:-_ — =-~-~ by the committee of your valuable Institution will be fully attained, in the acquisition of greater security and a more perfect principle of construction."* BOILERS (Explosions of).-" In a former lecture 1 endeavored to explain the principles on which boilers should be constructed, and the laws which govern the 6trength and other properties of these important vessels. The subject of construction is onle of vast importance, and those forms which give the greatest security with the least quantity of material, may be considered as the safest examples for imitaticy -the true elements * Lecture at Leeds Mechanics' Instituticn, by William Fairbairn. Esq., a. S. F. R. S. and Corresp. Mdember of tbsq Institute of France. I...... 214 BOILERS. of construction. Boilers, of all other vessels, require, in the variety of their conditions shapes, and dimensions, the study of tile philosopher as well as the hands of the me chanic. They contain, within comparatively narrow bounds, a force which, if properly governed, will propel the largest and most stately vessel against wind and tide; perform the work of a thousand hands, and drive a hundred cars loaded with hundreds of tons, at the speed of the swiftest race horse, from one extremity of the kingdom to the other. They do all this and more; they impart heat and comfort to our dwellings, -are essential for the requirements of our domestic arrangements,-and under the control of judicious management, will advance the interests of commerce, and contribute to the enjoyments of civilized existence. "Reverse the picture, and entrust the construction and management to the hands of incapacity and ignorance, or the reckless follv and hardihood of fancied security, and death and destruction follow as a result. When the mischief is done, we then begin to guess at the causes, and to lament the inconsiderate confidence which led to the employment of incompetency, and all those errors of judgment which invariably present themselves, not before, butt after the event. How often do we hear of the most lamentable accidents terminating in the destruction of life and property, and how often do we lament (when too late) the causes which led to those frightful catastrophes! All these accidents might be prevented, and, instead of using steam, which we now do in our manufactories, at a pressure of 5 to 20 lbs. on the square inch, we might with equal safety use it, and enjoy the advantage of its superior econc-ny, at 60 lbs. on the inch. It shall be my duty to point out how this may be accomplished, and I hope in these endeavors to have the support of every well wisher for increased security to the public, and enlarged economy in the varied requirements of the use of steam. "Before I attempt a solution of this difficult question, I would first direct attention to a few facts which bear more directly upon the question now at issue.' Various notions are entertained as to the causes of boiler explosions, and scientific men are not always agreed as to whether they arise from excessive pressure due to the accumulation of heat, or to some other cause, such as the explosion of hydrogen gas, generated by the decomposition of water suddenly thrown on heated plates, of which we have an exceedingly indefinite conception. That of the decomposition of water is, I believe, a somewhat prevalent opinion, but I apprehend it cannot be the invariable cause, inasmuch as in that case we must assume the boiler to be nearly empty of water, and the plates over the furnace red hot. " It is not unreasonable to suppose that a force of such sudden origin, and so immediate anddestructive in its effects, should suggest the presence of an explosive mixture; but I think it will be difficult, if not impossible, to account for the accumulation of a sufficient quantity of hydrogen, without the presence of oxygen and other gases, in their due proportions, to form an explosive compound. Now as these equivalents cannot be generated all at once by the simple decomposition of water (admitting, for the moment, that the water is decomposed), we must look for some other cause for the fatal and destructive accidents which of late years have become so prevalent. In treating of this subject, I hope to show not only what are the probable causes of explosions, but, what appears equally important, what are not the causes. So many theories (some of them exceedingly problematical) have been brought forward on the occasion of disastrous explosions, that it requires the utmost care and attention to circumstances before they are generally admitted. To acquire satisfactory evidence as to tile precise condition of the boiler and furnace before an explosion, is next to impossible, as most frequently the parties in charge, and from whose mismanagement and neglect we may, in many cases, date the origin of the occurrence, are the first to become the victims of their own indiscretion, and we can only judge from the havoc and devastation that ensues as to the immediate cause of the event. "From this it follows that, in many of the explosions on record, few, if any, of the real circumstances of the case are made known, and we are left to draw conclusions from the appearances of the ruptured parts, and the terrific consequences which too frequently follow as a result. This want of evidence as to the precise condition of a boiler, with all its valves and mountings, preceding an explosion, is much to be regretted, as it causes a degree of mystery to surround the whole transaction; and the vague and sometimes inaccurate testimony of witnesses but too often baffles all attempts at research, and creates additional cause of alarm to all those exposed to the occurrence of similar dangers. "In the discussion of this subject I shall, however, endeavor to trace, from a number of examples in which I have been personally engaged, and from others which have come to my knowledge, the causes which have led to those disastrous effects; and provided I an successful in the discovery of the true origin of the majority of those occurrences, we shall have less difficulty in devising and applying the necessary remedies for their prevention. BOILERS. 212'In my attempts to ascertain facts by a course of reasoning which I shall have to follow in this investigation, I wish it to be understood that it is not my intention to raie doubts and fears, in the public mind, calculated to arrest the progress of commercial enterprise, or to cripple ihe energies of mechanical skill. On the contrary, I am most anxious to promote the advancement of the useful arts, to increase our confidence in the application of increased pressure, and to secure within moderate bounds the economical and useful employment of one of the most powerful agents ever known in the history of practical science. My object in this inquiry will, therefore, be to enlarge our sphere of action by a more comprehensive knowledge of the subject on which it treats; to induce greater caution along with improved construction; and to insure confidence in all those requirements essential to the public security. "For the full consideration of this subject, it will be necessary to divide it into the following heads;"1st. Boiler explosions arising from accumulated internal pressure. "2d. Explosions from deficiency of water. "3d. Explosions produced from collapse. "4th. Explosions from defective construction. "5th. Explosions arising from mismanagement or ignorance;,nd "6th. The remedies applicable for the'prevention of these accidents. "1st. Boiler explosions arising from accumulated interna,, Pressure. "In nine cases out of ten a continuous increasing pressure of steami without the means of escape, is probably the immediate cause of explosion; in some instances it arises from deficiency of water, but accidents of this kind are comparatively few in number, as we often findl, in tracing the causes, that they have their origin in undue pressure, emanating from progressive accumulation of steam of great force and density. Let us take an example, and we shall find that a boiler under the influence of a furnace in active combustion will generate an immense quantity of steam; and unless this is carried off by the safety-valve or the usual channels when so generated, the greatest danger may be apprehended by the continuous increase of pressure that is taking place within the boiler. Suppose that, from some cause, the steam thus accumulated does not escape with the same rapidity with which it is generated,-that the safety-valves are either inadequate to the full discharge of the surplus steam, or that they are entirely inoperative, which is sometimes the case,-and we have at once the clue to the inijulious consequences which, as a matter of fact, are sure to follow. The event may be procrastinated, and repeated trials of the antagonistic forces from within, and the resistance of the plates from without, may occur without any apparent danger, but these experiments often repeated will at length injure the resisting powers of the material, and the ultimatum will be the arrival of the fatal moment when the balance of the two forces is destroyed, and explosion ensues. How very often do we find this to be the true cause of accidents arising from extreme internal pressure, and how very easily these accidents mighlt be avoided by the attachmlent of proper safety-valves, to allow the steam to escape and relieve the boiler of those severe trials which ultimately lead to destruction! If a boiler whose generative power is equal to 100, be worked at a pressure of 10 lbs. on the square inch, the area of the safety-valves should also be equal to 100, in order to prevent a continuous increase of pressure; or, in case of the adhesion of any of the valves, it is desirable that their areas should, collectively, be equal to 100. If two or more valves are used, 100 or 120 would then be the measure of outlet.* Under these precautions, and with a boiler so constructed, the risk of accident is greatly diuiniished; and, provided one of the valves is kept in working order beyond the reach of interference by the engineer, or any other person, we may venture to assume that the means of escape are at hand, irrespective of the temporary stoppage of the usual channels for carrying off the steam. "So many accidents hlave occurred from this cause-the defective state of the safetyvalv6s-that I must request attention whilst I enumerate a few of the most prominent nases that have come before me. In the year 1845 a tremendous explosion took place at a cotton millin Bolton. The boilers, three in number, were situated under the mill, and, roinr the unequal capacity and imperfect state of the safety-valves (as they were probably fast), a terrible explosion of the weakest boiler took place, which tore up the plates along the bottom, and, the steam hacing no outlet at the top, not only burst out the end next the furnace, demolishing the building in that direction, but, tearing up the top on the opposite side, the boiler was projected upwards in an oblique direction, carrying the flours, walls, and every other obstruction before it; ultimately it lodged itself across the railway at some distance from the building. Looking at the disastrous consequences of tils accident, and the number of persons (from 16 to 18) who lost their lives on the occasion, it became a subject of deep interest to the community that a close in vestigation should immediately be instituted, and a recommendation followed that every *This may be stated in other worrss, viz., that the generative powers of a boiler being equal to a given 2u.nber of square inches of area, say 50, the area of the safety-valve should also b' n0. 216 BOILERS. precaution should be used in the construction as well as the management of boil ers. "The next fatal occurrence on record in this district was a boiler at Ashton-under. Lyne, which exploded under similar circumstances, namely, from excessive interior pressure, when four or five lives were lost; and again at Hyde, where a similar accident occurred from the same cause, which was afterwards traced to the insane act ol the stoker or engineer, who prevented all means for the steam to escape by tying down the safety-valve. "There was a boiler explosion at Malaga, in Spain, some years since, and my reason for noticing it in this place is to show that explosions may be apprehended from other causes than those enumrerated in the divisions of this inquiry, and one of these is incrustation. Dr. Ritterbrandt says, in a paper read before the Institution of Civil Engineers by an erninent clhemist, Mr. West-'That a sudden evolution of steam under circumstances of incrustation is no uncommon occurrence.' In several instances I have mnown this to be the case, particularly in marine boilers, where the incrustation from salt water becomes a serious grievance, either as regards the duration of the boiler, or the economy of fuel. " If it were supposed, as Dr. Ritterbrandt observes, that the boiler was incrusted to the extent of halt an inch, it would at once be seen that nothing was more easy than to heat the boiler strongly, even to a red heat, without the Immediate contact of water. Under these circumstances, the hardened deposits, being firmly attached to the plates, and forming an imperfect conductor of heat, would tend greatly to increase the temperature of the iron; and the difference of temperature, thus induced between the iron and the incrustation, and the greater expansibility of the iron, would cause the incrustation to separate from the plates, and the water rushing in between them would generate a considerable charge of highly elastic steam, and thus endanger tile security of the boilers. "These )henomrena were singularly exemplified in the Malaga explosion, which in thus described by Mr. Hick;-'I have ascertained that a very thick incrustation of salt was formed on the lower part of the boiler, immediately over the fire, and so far as it extended the plates appear to have been red hot, being thereby much weakened, and hence tile explosion. The ordinary working pressure of the boiler is 130 lbs. per square inch, and perhaps at the time of the explosion very much above that pressure, as there was only one smnall safety-valve of two and a-halft inches diameter. The boiler was only two feet six inches diameter, and twenty feet long.' "Incrustation, exclusive of being dangerous, is attended with great expense and injury to the boiler by its removal. In the case of the transatlantic, oriental, or other long sea-going vessels, even after the use of brine-pumps, blowing out, &c., a very large amount of incrustation is formed, and considerable sums of money are expended each voyage to remove it. " Other explosions of a more recent date are those which occurred at Bradford and Halifax. They are still fresh in the recollection of the public mind, and are so well known as not to require notice in this place "I cannot, however, leave this part of the subject without reverting to an accident which occurred on the Lancashire and Yorkshire Railway, whichhad its origin in the same cause-excessive internal pressure. This accident is the more peculiar as it led to a long mathematical disquisition as to the nature of the forces which produced results at once curious and interesting. Tie conclusions which I arrived at, although practically right, were, however, considered by some mathematically wrong, as they were firmly combated by several eminent mathematicians; but notwithstanding the number of algebraic formulas and the learned discussions of my friends on that occasion, I have been unable to change the opinions I then formed, for others more conclusive. "The accident here alluded to occurred to the'Irk' locomotive engine, which, in February, 1745, blew up and killed the driver, the stoker, and another person who was standing near tie spot at the time. A great difference of opinion as to the cause of this accident was prevalent in the minds of those who witnessed the explosion, some attributing it to a crack in the copper fire-box, and others to the weakness of the stays over the top. Neither of these opinions was, however, correct, as it was afterwards demonstrated that the material was not only entirely free from cracks and flaws, but the stays were pioved sufficient to resist a pressure of 15) to 200 lbs. on the square inch. The true Cause was afterwards ascertained to arise fiom the fastening down of the safety-valve c, the engine (an active fire being in operation under the boiler at the time), which was under the shed, with the steam up, ready to start with the early morning train. The effect of this was the forcing down of the top of the copper fire-box upon the blazing embers of the furnace, which, acting upon the principle of the rocket, elevated the boiler and engine of 20 tons weight to a height of 30 feet, which, in its ascent made a summerset in the air, passed through the roof of the shed, and ultimately landed at a distance of 6C yards from its original position. The question which excited most interest, was the ab. "olute force required to fiacture the fire-box, its peculiar properties when once liberated BOILERS. 217 and the elastic or continuous powers in operation which forced the engine from its place to an elevation of 30 feet from the position in which it stood. An elaborate mathematical discussion ensued relative to the nature of these forces, which ended in the opinion that a pressure suffic(ient to rupture the fire-box, was, by its continuous action, sufficient to elevate the boiler and produce the results which followed. Another reason was assigned, namely, that an accumulated force of elastic vapor, at a high temperature, with no outlet through the valves, having suddenly burst upon the glowing embers of the furnace, would charge the products of combustion with their equivalents of oxygen, and hence explosion followed. Whether one or both of these two causes were in operation is probably difficult to determine; at all events, we have in many instances precisely the same results produced from similar causes, and unless greater precaution is used in the prevention of excessive pressure, we may naturally expect a repetition of the same fatal consequences. "The preventives against accidents of this kind are, well-constructed boilers of the strongest form, and duly proportioned safety valves; one under the immediate control of the engineer, and the other, as a reserve under the keeping of some'competent authority. "2d. Explosions by deficiency of water. "This division of the subject requires the utmost care and attention, as the circumstance of boilers being short of water is no unusual occurrence. Imminent danger frequently arises from this cause; and it cannot be too forcibly impressed upon the minds of engineers, that there is no part of the apparatus constituting the mountings of a boiler which require greater attention —robably the safety-valves not excepted -t lan that which supplies it with water. A well-constructed pump, and self-acting feeders, when boilers are worked at a low pressure, are indispensable; and where the latter cannot be applied, the glass tubular gauge, steam, and water cocks must have more than ordinary attention. " In a properly constructed boiler every part of the metal exposed to the direct action of the fire should be in immediate contact with the water, and, when proper provision is made to maintain the water at a sufficient height above the part of the plates so exposed, accidents can never occur from this cause. "Should the water, however, get low fiom defects in the pump, or any stoppage of the regulating feed valves, and the plates over the furnace become red hot, we then risk the bursting of the boiler, even at the ordinary working pressure. We have no occasion, under such circumstances, to search for another cause, from the fact that the material when raised to a red-heat has lost about five-sixths of its strength, and a force of less than one-sixth will be found amply sufficient to bear down the plates direct upon the fire, or to burst the boiler. " W hen a boiler becomes short of water, the first, and perhaps the most natural, action is to run to the feed valve, and pull it wide open. This certainly remedies the deficiency, but increases the danger, by suddenly pouring upon the incandescent plates a large body of water, which, coming in contact with a reservoir of intense heat, is calculated to produce highlv elastic steam. Thlis has been hitherto controverted by several eminent chemists and philosophers; but I make no doubt such is the case, unless the pressure has forced the plates into a concave shape, which for a time would retard the evaporization of the water when suddenly thrown upon them. Some curious experimental facts have been elicited on this subject, and those of M. Boutigny, and Professor Bowman, of King's College, London, show that a small quantity of water projected upon a hot plate does not touch it; that it forms itself into a globule surrounded with a thin film, and rolls about upon the plate without the least appearance of evaporation. A repulsive action takes place, and these phenomena are explained upon the supposition that the spheroid has a perfectly reflecting surface, and consequently the heat of the incandescent plate is reflected back upon it. What is, however, the most extraordinary in these experiments, is the fact that the globule, whilst rolling upon a red hot plate, never exceeds a temperature of about 204~ of Fahr.; and in order to produce ebullition, it is necessary to cool the plate until the water begins to boil, when it is rapidly dissipated in steam. "The experiments by the committee of the Franklin Institute on this subject, give some interesting and useful results. That committee found that the temperature at which clean iron vaporized drops of water was 334~ of Fahr. The development of a repulsive force which I have endeavored to describe was, however, so rapid above that temperature, that drops which required but one second of time to disappear at the temperature of maximum evaporation, required 152 seconds when the metal was heated to 395~ of Fahr. The committee go on to state that-' One ounce of water introduced into an iron bowl three-sixteenths of an inch thick, and supplied with heat by an oilbath, at the temperature of 546~, was vaporized in fifteen seconds, while, at the initial temperature of 507~, that of the most rapid evaporization was thirteen seconds.' 218 BOILERS. "The cooling effect of the metal is here strikingly exemplified by the increased rapidity of the evaporization, which at a reduced temperature of 38~ is effected it thirteen instead of fifteen seconds. "This does not, however, hold good in every case, as an increased quantity of water, say from one-eighth of an ounce to two ounces, thrown upon heated plates, raised the temperature of vaporization from 460~ to 600~ Fahr.; thus clearly showing that. the time required for the generation of explosive steam under these circumstances is attended with danger; and it may be doubted whether the ordinary safety valves may not be wholly inadequate for its escape. "Numerous examples may be quoted to show that explosions from deficiency oi water, although less frequent than those arising from undue pressure, are by no means uncommon. They are nevertheless comparatively few in number, and the preventives are good pumps, self-acting feeders (when they can be applied), and all those conveniences, such as water-cocks, water-gauges, floats, alarms, and other indicators of the loss and reduction of walter in the boiler. "3d. Explosions produced from collapse. "Accidents from this cause can scarcely be called explosions, as they arise, not from internal force which bursts the boiler, but from the sudden action of a vacuum within it. In high pressure boilers, fiom their superior strength and circular form, these accidents seldom occur, and the low pressure boiler is effectually guarded against it by a valve which opens inwards by the pressure of the atmosphere whenever a vacuum occurs. In some cases a collapse of the internal flues of boilers has been known to take place, from a partial vacuum within, which, united to the pressure of the steam, has forced down the top and sides of the flue, and with fatal effect discharged the contents of the boiler into the ash-pit, and destroyed and scalded every thing before it. A circumstance of this kind occurred on the Thames on board the steamer Victoria, some years since, when a number of persons lost their lives, and serious injury was sustained in all parts of the vessel within reach of the steam. This accident could not, however, be called an explosion, but a collapse of the internal flues, which were of large dimensions, and the consequent discharge of large quantities of steam and water into the space occupied by the engines. "One or two cases which bear more directly on this point, are, however, on record, and one of them, which took place in the Mold mines in Flintshire, was attended with explosion. The particulars, as given by Mr. John Taylor, will be found circumstantially recorded in the first volume of the Philosophical Magazine. This occurrence seems to prove that rarefaction produced in the flues of a high pressure boiler may determine an explosion. The boiler which exploded belonged to a set of three feeding the same engifie; the fuel used was bituminous coal. The furnace doors of all three of the boilers had been opened, and the dampers of two had been closed, when a gust of flame was seen to issue from the mouth of the furnace of these latter, and was immediately followed by an explosion. The interior flue of this boiler was flattened from the sides, the flue and shell of the boiler remaining in their places, and the safety-valve upon the latter not being inju red. "Other similar cases of collapse might be stated, but as most of them have been at tended by a defective supply of water in the boiler, the plates over the fire having become heated, they can scarcely be included in the category of this class of accidents, and more properly belong to those of which we have just treated,-explosions from a deficiency of water in the boiler. " It is, nevertheless, necessary to observe, that cases of collapse should be carefully guarded against, as the great sourice of danger is in the escape of hot water, which, with the steam generated by it produces death in one of its worst and most painful forms. "The remedies for these accidents will be found in the vacuum valve, and careful construction in the form and strength of the flues, "44h. Explosions from defective construction. " This is, perhaps, one of the most important divisions that can possibly engage our attention, and on which it shall be my duty to enlarge. In a previous inquiry I have already shown the nature of the stanin and the ultimate resistance which the material used in the construction of boilers is able to bear. We have not, however, in all cases shown the distribution and position in which that material should be placed in order to attain the maximum of strength, and afford to the public greater security in the resisting powers of vessels subject to severe and sometimes ruinous pressure. This is a subject of such importance that I shall be under the necessity of trespassing upon youl time, in endeavoring to point out the advantages peculiar to form, and the use of a sound and perfect system of construction. "For a number of years the haycock, hemispherical, and wagon-shaped boilers were those generally in use; and it was not until high pressure steam was first intro )ILERS. 219 duced into Cornwall, that tho cylindrical form with hemispherical ends, and the furnace under the boiler, came into use. Subsequently this gave way to the introduction of a large internal flue extending the whole length of the boiler, and in this the furnace - was placed. For many years this was the best and most economical boiler in Cc rnwall, and its introduction into this country has effected great improvements in the economy of fuel as well as the strength of the boiler. Several attempts have been made to improve this boiler by cutting away one half of the end, in order to admit a larger furnace. Ti's was first done by the Butterley Company, and it since has gone by the name of the Butterley boiler. This construction has the same detects as the haycock or hemispherical and wagon-shaped boilers: it is weak over the fire-place, and cannot well be strengthened without injury to the part A,fig. 151, of the boiler, from 151 152 the vast number of stays necessary to suspend the.part which forms the canopy of th6 furnace. Of late years a much greater improvement has, however, been effected by the double flue, B B, fig. 152, and double furnace boiler, which is now in general use, and has nearly superseded all the other constructions. It consists of the cylindrical form, varying from five to seven feet in diameter, with two flues which extend the whole length of the boiler; they are perfectly cylindrical, and of sufficient magnitude to admit a furnace in each. This boiler is the simplest, and probably the most effective, that has yet been constructed. It presents a large flue surface as the recipient of heat, and the double flues, when riveted to the flat ends, add greatly to the security and strength of those parts. It, moreover, admits of the new process of alternate firing, so highly conducive to perfect combustion, and the prevention of the nuisance of smoke.-Fairbairn and Hetherington's patent of April 30, 1844. "Another boiler, into which a number of small tubes are introduced, exhibits a powerful generator of steam, from the extent of its flue surface, and the facility with which the repairs can be effected. It does not present any greater security against explosion than the boiler with two flues, but its construction on the tubular system effects a great saving in space, and is otherwise productive of all the advantages of economy in the consumption of fuel and the prevention of smoke. This boiler is constructed with a large internal flue, divided in the middle, which admits of two fire-places and alternate firing. In the space which I call the mixing chamber, the products of combustion amalgamate, and are thus ignited before they enter the tubes, and from which they issue into the end flues, and from thence to the chimney in the usual way. In this latter construction it will be observed that the boiler is of the same form as the last, and contains the same elements of strength as the double-flue boiler, the only difference being a combination of the locomotive and marine tubular system, which contains a large absorbent heating surface in a small space. "It will not be necessary to multiply examples of construction, as I have already described those which I consider best calculated to sustain severe pressure. At the same time, when the parts are judiciously and skilfully arranged, with a grate-bar surface well proportioned to the amount of flue-surface as the recipient, we may reasonably conclude that we are not far from the maximum of strength, including other important elements in the material and the consumption of fuel. "The means necessary to be employed for the prevention of accidents in this depart ment of the inquiry, are a knowledge of the principles of construction, and an acquaint. ance with the strength and properties of the materials used for that purpose. "5th. Explosions arising from mismanagement or ignorance. "To mismanagement, ignorance, and the misapplication of a few leading principles in connection with the use and application of steam, may be traced the great majority of accidents which from titne to time occur. Many of these accidents, so fruitful of the destruction of property and human life, might be prevented if we had well constructed vessels, judiciously united to skill and competency in the management. To convey a few practical instructions to engineers, stokers, and engine-men, would be an undertak ing of no great difficulty. A young man of ordinary capacity would learn all that is necessary in a few months; and if placed under competent instructors, he might be made acquainted with the properties of steam-its elastic force at different degrees of pressure-the advantages peculiar to sensitive and easy working safety valves —the 220 BOILERS. necessity of cleanliness and keeping them in good working condition-the use of water gauges, fusion plugs, indicators, signals, &c., &c., connected with the supply and height ot water in the boiler-the dangers to be apprehended from a scarcity of water-the danger of explosion when the engine is standing, or when the usual channels for relieving the boiler of its surplus steam are stoppod. All these are parts of elementary instruction which the stoker, as well a the engineer, should be acquainted with; and no proprietor of a mill, captain of a steamship, or superintendent of locomotives should give employment to any persons unless they can produce certificates of good behavior, and a knowledge of the elementary principles of their profession. "If these precautions were adopted, greater care observed in the selection of mer of skill and responsibility in the construction of boilers, and a more strict and rigid code of laws in the management, we might look forlward with greater certainty to a considerable diminution, if not a prevention, of those calamitous events which so frequently plunge whole families into mourning by unexpected and instantaneous death. "As an individual, I would cheerfully lend my best assistance to the development of a.principle of instruction calculated to relieve the country of the ignorance which pervades that part of the community on which the lives of so many depend. A resolution on the part of those who employ persons of this description, and whose interests are so much at stake, to take only those wlose knowledge and character come up to the requisite standard, and pay for it, would soon cau-e, fiom the economy of the management, and the increased security of their property, a very important change in all the requirements of the economy, as well as the application, of steam. How often do we find implements of danger, and vessels containing the elements of destruction, in the hands of the most ignorant and reckless practitioners, whose insensibility to danger, and total incompetency to judge of its presence, render them above all others the most unfit to be employed. And why? Because they are the very persons, from their defective knowledge, to increase the danger and aggravate the evils they were selected to prevent. It is not the first time that engineers, to secure (if I may use the expression) an insane pressure, have fastened the safety valves, and screwed down the steam valve, closing every outlet, without ever thinking of the fire that was blazing under the boiler. Under such circumstances what could be expected but a blow up? A madman rushing with a lighted match into a powder magazine could not act with greater insanity. Such, however, has been the case, and all arising from want of thought, or, what is worse, from the total absence of knowledge, which it was the duty of his employer as well as himself to have possessed. "I have on former occasions stated that I am not an advocate for legislative interference either in the construction or management of boilers; but, seeing the dangerous tendency of these vessels when placed under the control of ignorance and incapacity, I would forego many considerations to encourage a more judicious and intelligent class of men than has hitherto been employed in the care and management of steam and the steam engine. The reforms necessary to be introduced may be made by the owners of steam engines, steamboats, railways, and others engaged in the use and application of this important element. A desire to enforce more judicious and stringent regulations, to remunerate talent, and to employ only those whose good conduct and superior knowledge entitle them to confidence, is the only sure guarantee of public safety and the pros perity of the employer. "Lastly, The remedies applicable for the prevention of accidents arising from explosions. " Having noticed in the foregoing remarks most of the causes incident to boiler explo, sions, it now only remains to draw such inferences as will point out the circumstances which it is desirable to cultivate, and others which it is desirable to avoid. These circumstances I have endeavored to class in such a way as to bring the subject prominently forward, and to point out under each head, first, the causes which lead to accident; and, secondly, the means necessary to be observed in avoiding it. In a general summary, it may not be inexpedient briefly to recapitulate these statements, in order to impress more forcibly upon the mind of those concerned the necessity for care and consideration in the use of one of the most powerful agents ever placed at our disposal. "One of the most scientific nations of Europe places the greatest confidence, as a means of safety, on the use of a fusible metal plate over the furnace. These plates are allovs of tin and lead, with a small portion of bismuth, in such proportions as will ensure fusion at a temperature something below that of molten lead. In France the greatest importance is attached to these alloys, and, in order to ensure certainty as to the definite proportions, the plates are prepared at the royal mint, where they may be purchased duly prepared for use In this country these alloys are not generally in use, but in this respect I think we are wrong, as boiler explosions are not so frequent in France as ------- -- -------. —------------ ----- - --------- -" -------- J BOILERS. 221 m this country, and high-pressure steam, from its superior economy, is more extensively used in France than in England. In my own practice I invariably insert a lead rivet, one inch in diameter, immediately over the fireplace, and as common lead melts at 6200, I have invariably found these metallic plugs a great security in the event of a scarcity ol water in the boiler. I am persuaded many dangerous explosions may be avoided by the use of this simple and effective precaution; and as pure lead melts at 610~, we may infer from this circumstance that notice will be given and relief obtained before the internal pressure of the steam exceeds that of the resisting lowers of the heated plates. As this simple precaution is so easily accomplished, I would advise its general adoption. It can do no harm to the boiler, and may be the means of averting explosions and the destruction of many valuable lives. "The fusible metal plates, as used in France, are generally covered by a perforated metallic disc, which protects the alloy of which the plate is composed, and allows it to ooze through as soon as the steam has attained the temperature necessary to insure the fusion of the plate. The nature of the alloy is, however, somewhat curious, as the different equivalents have different degrees of fluidity, and the portion which is the first to melt is found out by the pressure of the steam causing the adhesion of the less fusible parts, but in a most imperfect state, and incapable of resisting the internal force of the steam. The result of these compounds is the fusion of one portion of the alloy and the fracture of the other, which is generally burst by pressure. "This latter'description of fusible plates is different from the lead plug over the fire, which is fused at 600~ by the heat of the furnace, and the other, by the temperature of the steam, when raised to the fusible point of the alloy, which varies from 280~ to 350~. "Another method is the bursting plate, fixed in a frame and attached to some convenient part of the upper side of the boiler; this plate is to be of such thickness and of such ductility as to cause rupture whenever the pressure exceeds that of the weight on the safety valve. There can be no doubt that such an apparatus, if made with a suffi ciently large opening, would relieve the boiler; but the objections to this and several other devices are the frequent bursting of those plates, and the effect every change of pressure has upon the material in reducing its powers of resistance, and thus increasing uncertainty as to the amount of pressure in the boiler, as well as the constant renewal of the plates. "It has already been noticed that one of the most important securities against explosions is a duly proportioned boiler, well constructed; and to this must be added ample means for the escape of the steam on every occasion when the usual channels have been suddenly stopped. Tie only legitimate outlets under these circumstances appear to me to be the safety-valves, which, connected with this inquiry, are indispensable to security. Every boiler should, therefore, have two safety-valves, of sufficient capacity to carry off the quantity of steam generated by the boiler. One of these valves should be of the common construction, and the other beyond the reach of the engineer or any other person. " Fig. 153 is a sketch of a lock-up safety-valve, as constructed by Mr. Fairbairn. A is the valve. B is a shell of thin brass, opening on an hinge and secured by a padlock; it is of such a diameter as to allow the waste steam to escape in the direction of the arrows. 163 c is the weight, which may be s B fixed at any part of the lever to give the desired amount of vu Jiaf V pressure, but which cannot be {I"^ ^N1^^ ~ g fixed or altered unless the boiler is opened to allow a man to get inside. D is a handle,' having a long slot, by which the valve may be re=_______. lieved or tried at any time, to obviate the liability of its corroding or beingjammed; the - ~i]: - --- H _ engineer cannot, however, put = ==3____ ___ -= - Si -s ~ ~ any additional weight upon ____2:~-~~ ~_ ~~_'* - ---- - the valve by this handle.* "Whilst tracing the causes of explosions from a deficiency of water in the boiler, I have recommended as the usual precautions, good pumps, selfacting feeders, water cocks, glass gauges, floats, alarms, and other indicators which mark the changes and variations in the height of the water. To these may be added the steam whistle, but chiefly the constant inspection of a careful, sober, and judicious engineer. Above all other means however ingeniously devised, this is the most 222 BOILERS essential to security, for on that official depends, not only the security of the property under his charge, but also the interests of his family, and the lives of all those within the immediate influence of his operations. One of the most important considerations in this and every other department of management is cleanliness and the careful attention of a good sober engineer. " Explosions produced fiom collapse have their origin in different causes to those arising from a deficiency of water, and the only remedy that can be applied is the vacuum valve and the cylindrical or spheroidal form of boiler. "Defective construction is unquestionably one of the greatest sources of the frightful accidents which we are so frequentiy called upon to witness. No man should be allowed unlimited exercise of judgment on a question of such vital importance as the construction of a boiler, unless duly qualified by matured experience in the theoretical and practical knowledge of form, strength of materials, and other requirements requisite to insure the maximum of sound construction. It appears to me equally important that we should have the same proofs and acknowledged system of operations in the construction of boilers, as we have in the strength and proportions of ordnance. In both cases we have to deal with a powerful and dangerous element; and 1 have yet to learn why the same security should not be given to the general public as we find so liberally extended to an important branch of the public service. In the ordnance department at Woolwich (with which I have been more or less connected for some years) the utmost care and precision is observed in the manufacture of guns; and the proofs are so carefully made under the superintendence of competent officers, as to render every gun perfectly safe to the extent of 1000 to 1200 rounds of shot. "Boilers and artillery are equally exposed to fracture, and it appears to me of little moment whether the one is burst by the discharge of gunpowder, or the other by the elastic force of steam. "Taking into consideration all the circumstances connected with the bursting of boilers and the bursting of guns, and looking at the active competition which exists, and is likely to be extended, in manufactories, railway traffic, and steam navigation, rendering it every day more desirable to reduce the cost by an extended use of steam at a much higher pressure, it surely becones a desideratum to secure the public safety by the introduction of some generally acknowledged system of construction that will bear the test of experience, and involve a maximum power of resistance. The most elaborate disquisitions have taken place, by the most distinguished men of all ages since the invention of gunpowder, to discover the strength and form of guns of every description. Surely boilers are equally if not more important, as the sacrifice of human life appears to me much greater in the one case than the other. It is therefore a subject of paramount importance to the public to know that the facts of scientific inquiry, and the knowledge of practical skill, have combined to give undeniable security as well as confidence, that boilers are properly constructed, and capable of bearing at least six times their working pressure. "On the question of explosions arising from mismanagement and ignorance, we have little further to add; and it now only remains to state, that the subject of security from boiler explosions is of such importance as to call for more able exponents than myself. I have endeavored to trace the causes of these lamentable occurrences, and to draw such deductions therefrom as I trust may be useful in at least mitigating, if not almost entirely averting, the danger. "I repeat the means of prevention and the precautions necessary to be observed in the construction and management of boilers. "1st. To avoid'explosions from internal pressure, cylindrical boilers of maximum forms and strength must be used,including all the necessary appendages of safety-valves, &c. " 2d. Explos;ons arising fromdeficiency of water may be prevented by the fusible alloys, bursting plates, good feed pumps, water gauges, alarms and other marks of indictation; but above all, the experienced eye and careful attention of the engineer is the greatest security. " 3d. Explosions from collapse are generally produced from imperfect construction, whicli can only be remedied by adopting the cylindrical form of boiler, and a valve to prevent the formation of vacuum in the boiler. "4th. Explosions from defective construction admit of only one simple remedy, and that is, the adoption of those forms which embody the maximum powers of resistance to internal pressure, and such as we have already recornmelded for general use. "Lastly. Good and efficient management, a respectable and considerate engineer, and the introduction of such improvements, precautions, and securities as we have been able to recommend, will not only ensure confidence, but create a better system of managemeiit in all the requirements necessary to be observed for the prevention of steam boilel explosions. (Fairbairn, in Lecture at Leeds.) BONES. 223 BOMBAZINE. A worsted stuff, sometimes mixed with silk. BONES. (Os, Fr.; Knochen, Germ.) They form the frame worx of animal bodies, commonly called the skeleton; upon which the soft parts are suspended, or in which they are enclosed. Bones are invested with a membrane styled the periosteum, which is composed of a dense tissue affording glue; whence it is convertible into jelly, by ebullition with water. Bones are not equally compact throughout their whole substance; the long ones have tubes in their centres lined with a kind of periosteum, of more importance to the life of the bones than even their external coat. The flat. as well as the short and thick bones, exhibit upon their surface an osseous mass of a dense nature, while their interior presents a cavity divided into small cellules by their bony partitions. In reference to the composition of bones, we have to consider two principal constituents; the living portion or the osseous cartilage, and the inorganic or the earthy salts of the bones. The osseous cartilage is obtained by suspending bones in a large vessel full of dilute muriatic acid, and leaving it in a cool place at about 50~ Fahr. for example. The acid dissolves the earthy salts of the bones without perceptibly attacking the cartilage, which, at the end of a short time, becomes soft and translucid, retaining the shape of the bones; whenever the acid is saturated, before it has dissolved all the earthy salts it should be renewed. The cartilage is to be next suspended in cold water, which is to be frequently changed till it has removed all the acidity. By drying, the cartilage shrinks a little, and assumes a darker hue, but without losing'ts translucency. It becomes, at the same time, hard and susceptible of breaking when bent, but it possesses great strength. This cartilage is composed entirely of a tissue passing into gelatine. By boiling with water, it is very reaily convertible into a glue, which passes clear and colorless through the filter, leaving only a small portion of fibrous matter insoluble by further boiling, This matter is produced by the vessels which penetrate the cartilage, and carry nourishment to the bone. We may observe all these phenomena in a very instructive manner, by macerating a bone in dilute muriatic acid, till it has lost about the half of its salts; then washing it with cold water, next pouring boiling water upon it, leaving the whole in repose for 24 hours, at a temperature a few degrees below 212~ Fahr. The cartilage, which has been stripped of its earthy salts, dissolves, but the small vessels which issue from the undecomposed portion of the bone remain under the form of white plumes, if the water has received no movement capable of crushing or breaking them. We may then easily recognise them with a lens, but the slightest touch tears them, and makes them fall to the bottom of the vessel in the form of a precipitate; if we digest bones with strong hot muriatic acid so as to accelerate their decomposition, a portion of the cartilage dissolves in the acid with a manifest disengagement of carbonic acid gas, which breaks the'interior mass, and causes the half-softened bone to begin to split into fibrous plates, separable in the direction of their length. According to Marx, these plates, when sufficiently thin, possess, like scales of mica, the property of polarizing light, a phenomenon which becomes more beautiful still when we soak them with the essential oil of the bark of the Laurus Cassia. The osseous cartilage is formed before the earthy part. The long bones are then solid, and they become hollow only in proportion as the earthy salts appear. In the new-born infant, a large portion of the bones is but partially filled with these salts, their deposition in cartilage takes place under certain invariable points of ossificalion, and begins at a certain period after conception, so that we may calculate the age of the feetus according to the progress whici ossification has made. The earthy parts of bones are composed principally of the phosphate and carbonate of lime in various proportions, variable in different animals, and mixed with small quantities, equally variable, of phosphate of magnesia and fluate of lime. The easiest means of procuring the earthy salts of bones consists in burning them to whiteness, but the earthy residuum procured in this manner, contains substances which did not exist beforehand in the bones, and which (lid not form a part of their earthy salts; as, for example, sulphate of soda, produced at the expense of the sulphur of tne bones and the alkaline carbonate, proceeding fiom the cartilage with which it was combined. On the other hana, the greater part of the lime has lost its carbonic acid. As the sulphuric acid is the product of combustion, it is obvious that an acidulous solution of a fresh bone can affird no precipitate with muriate of barytes. The phosphate of lime contained in the lhne-salts is a subphosphate, consisting, according to Berzelius, of three prime equivalents of the acid, and eight of the base; or of 2,677 parts of the formr.i, and 2,818 of the latter. It is always obtained when we precipitate the phosphate of lime by an excess of ammonia. When calcined bones are distilled in a retort with their own weight of sulphuric acid, a little fluoric acid is disengaged, and it acts on the surface of the glass. The following analyses of the bones of men and horned cattle, are given by Berzelius. They were dried after being stripped of their fat and periosteum till they lost no more weight. 224 BONES. Human bone. Ox bone. Cartilage completely soluble in water 32 17 Vessels - 1-13 33 Subphosphate with a little fluate of lime - 53'04 57'35 Carbonate of lime - - - - - - - 11-3 3'85 Phosphate of magnesia - - - 116 2'05 Soda with very,little muriate of soda - - - - 120 3.45 100-00 100-00 The most essential difference in the composition of these bones is that those of man contain three times as much carbonate of lime as those of the ox; and that the latter are richer in phosphate of lime and magnesia in the same proportion. Fernandez de Barros has established a comparison between the phosphate and carbonate of lime in the bones of different animals. He found in 100 parts of earthy salt of the bones of the following animals:Phosphate oflime Carb. lime. Lion - - - - - - - - - 950 25 Sheep - - - - - 80-0 19-3 Hen - - - - - 83'9 10-4 Frog - - - - - - 9532 2-4 Fish - - - - - - - - - - 91'9 5-3 The bones of fish are divided into those which contain earthy salts and those which have none, called cartilaginous fishes. The enamel of the teeth is composed as follows:Hluman enamel. Ox enamel. Phosphate of lime with fluate of lime 88-5 85-0 Carbonate of lime - -. 8-0 71 Phosphate of magnesia - - - - 15 3'0 Soda -. — - 0 0 1-4 Brown membranes attached to the tooth, alkali, water - 20 3-5 100-0 1000 _ __ _ - _____ I In the arts, the bones are employed by turners, cutlers, manufacturers of animal charcoal, and, when calcined, by assayers for making cupels. In agriculture, they are employed as a manure, for which purpose they should be ground in a mill, and the powder sowed along with the seeds in a drill. It is supposed, in many cases, to increase the crop in weight of grain and straw together, by from 40 to 50 per cent. In France, soup is extensively made by dissolving bones in a steam-heat of two or three days' continuance. The shavings of hartshorn, which is a species of bone, afbfrd an elegant jelly: the shavings of calves' bones may be used in their stead. Living bones acquire a red tinge when the animals receive madder with their food; but they lose it when the madder is discontinued for some time. The following analysis of the middle part of the thigh-bone of a man of 30 years of age by Marchand, merits confidence:1. Cartilage insoluble in muriatic acid.. 27'23 2. Do. soluble in do...... 502 3. Blood-vessels and nerves...... 101 4. Subphosphate of line...... 5226 5. Fluoride of calcium.... 1100 6. Carbonate of lime...... 1021 7. Phosphate of magnesia....... 105 8. Soda....... 092 9. Chlorsodium....... 0.25 10. Oxides of iron and mnanganese, and loss... 1.05 100-00 The human bones contain much more carbonate of lime than those of oxen; which are, however, richer in phosphate of lime and magnesia. The proportion of cartilaginous matter in bones is not uniform, but varies in the same species of animal with age, sex, and pasture. The quantity of bones imported in 1850 amounted to 27,198 tons, and in 1851 to 31.956 tons. BONE BLACK. 225 BONE BLACK (Noir d'os, Fr.; Knlochenschwartz, Germ.), or A.nimal charcoal, as it is less correctly called, is the black carbonaceous substance into which bones are converted by calcination in close vessels. This kind of charcaol has two principal applications: to deprive various solutions, particularly sirups, of their coloring matters, and to furnish a black pigment. The latter subject will be treated of under IvoRY BLACK. The discovery of the antiputrescent and decoloring properties of charcoal in general, is due to Lowitz, of Petersburg; but their modifications have occupied the attention of many chemists since his time. Kels published, in 1798, some essays on the discoloring of indigo, saffron, madder, sirup, &c. by means of charcoal, but he committed a mistake in supposing bone black to have less power than the charcoal of wood. The first useful application of charcoal to the purification of raw colonial sugar was made by M. Guillon, who brought into the French markets considerable quantilies of fine sirups, which he discolored by ground wood charcoal, and sold them to great advantage, as much superior to the cassonades of that time. In 1811, M. Figuier, an apothecary at Mcntpellier, published a note about animal charcoal, showin, hat it blanched vinegars and wines with much more energy than vegetable charcoal; and, lastly, in 1812, M. Derosnes proposed to employ animal charcoal in the purification at sirups and sugar refining. The quantities of bone black left in the retorts emp; yed by MM. Payen. for producing crude carbonate of ammonia, furnished abundant materials for making the most satisfactory experiments, and enabled these gentlemen soon to obtain ten per cent. more of refined sugar from the raw article than had been formerly extracted, and to improve, at the same time, the characters of the lumps, bastards, treacle, &c. The calcination of bones is effected by two different systems of apparatus; by heating them in a retort similar to that in which coal is decomposed in the gas works, or in small pots piled up in a kiln. For the description of the former, see GAS-LIGHT. On the second plan, the bones, broken into pieces, are put into small cast-iron pots of the form shown in fig. 154, about three eighths of an inch thick, two of which are dexterously placed with their mouths in contact, and then luted together with loam. The lip of the upper pot is made to slip inside of the under one. These double vessels, containing together about fifty pounds of bones, are arranged alongside, and over each other, in an oven, like a potter's kiln, till it be filled. The oven or kiln may be either oblong or upright. The latter is represented in figs. 155, 156, 157. A is the fireplace or grate for the fuel; c c are the openings in the dome of the furnace through which the flame flows; the divisions of these orifices are shown in fig. 157. B is the wall of orick-work. D the space in which the pots are distributed. E is the door by which the workman carries in the pots, which is afterwards built up with fire-bricks, and lastered over with loam. This door is seen in fig. 155. F F are the lateral flues for conveying the disengaged gases into the air. 158 155 156 154 15 OgeD71 d 19 I''::B " I-//'7 A S Fig. 158 is a longitudinal section, and fig. 159, a ground plan of a horizontal kiln foi calcining bones. a is the fire-chamber, lying upon a level with the sole of the kiln; it is separated by a pillar b, from the calcining hearth c. In the pillar or wall, several rows of holes d, are left at different heights; e is the entrance door; f, the outlet vents for the gases, vapors, and smoke, into the chimney g; h, a sliding damper-plate for regulating the admission of the air into the fire in the space a. By this arrangement the offensive emanations are partly consumed, and partly carried off with the smoke. To destroy the smell completely, the smoke should be made to pass through a second small furnace. The number of pots that may be put into a kiln of this kind depends, of course, upon its dimensions; but, in general, from 100 to 150 are piled up over each other, in columns, 16 226 BONE BLACK. at once; the greatest heat being nearest the roof of the kiln; which resembles, in many respects, that used for baking pottery ware. In both kilns the interior walls are built of fire-bricks. In the oblong one, the fiercest heat is near the vaulted roof; in the upright one, near the sole; and the pote, containing the larger lumps of bones, should be placed accordingly near the top of the former, and the bottom of the latter. Such a kiln may receive about seventy double pots, containing in the whole thirty-five cwt. of bones. After the earth is filled with the pots, and the entrance door is shut, the fire is applied at first moderately, but afterwards it must be raised and maintained, at a brisk heat, for eight or ten hours. The door of the ash-pit and the damper may now be nearly closed, to moderate the draught, and to keep up a steady ignition for six or eight hours longer, without additional firing; after which the doors must be all opened to cool the furnace. When this is done, the brick-work of the entrance door must be taken down, the kiln must be emptied, and immediately filled again with a set of pots previously filled with bones, and luted together; the pots which have been ignited may, in the course of a short time, be opened, and the contents put into the magazine. But in operating with the large decomposing cylinder retort, the bones being raked out hot, must be instantly tossed into a receiver, which can be covered in air-tight till they are cool. The bones lose upon the average about one half of their weight in the calcination. In reference to the quality of the black, experience has M"own that it is so much more powerful as a discoloring agent, as the bones from whioh t was made have been freer from adhering fatty, fleshy, and tendinous matters. The charcoal is ground in a mill, either to a fine powder and sifted, or into a coarse granular state, like gunpowder, for the preparation of which two sieves are required, one with moderately fine meshes, to allow the small dust to pass through, and one with large meshes, to separate the proper-sized grains from the coarser lumps. Either a corn-mill, an edgestone mill, or a steel cylinder mill, may be employed for grinding bone-black, and it is generally damped in the operation to keep down the fine dust. Bone-black, as found in commerce, is very variable in its discoloring power, which arises from its having been exposed either to too great a heat which has glazed its carbon, or too low a heat which has left its albumen imperfectly decomposed. A steady ignition of due continuance is the proper decomposing temperature. Its composition is generally as follows:Phosphate of lime, with carbonate of lime, and a little sulphuret of iron, or oxyde of iron, 88 parts; iron in the state of a silicated carburet, 2 parts; charcoal containing about one fifteenth of azote, 10 parts. None of the substances present, except the char. coal, possesses separately any discoloring power. The quality may be tested by a solution of brown sugar, or. molasses, or of indigo in sulphuric acid. The last is generally preferred by the French chemists, who have occupied themselves most with this subject, and it contains usually one thousandth part of its weight of this dye-drug of the best quality. Other animal substances yield a charcoal, possessed of very considerable discoloring properties. The following table by M. Bussy exhibits an interesting comparison of almost every kind of charcoal in this point of view. Table of the discoloring powers of different charcoals. li.dg,, test Molasses rest Blanching by Power by Species of Charcoal. Weight., ed. consnued. indigo. molasses. Gramme. jit res. Blood calcined with potash 1 1-60 0-18 50 20 Di'to with chalk - - 1 0-57 0.10 18 11 Ditto with phosphate lime 1 038 0'09 12 10 Gelatine ditto with potash 1 115 0-14 36 15'5 Albumen ditto ditto - 1 1-08 0-14 34 15'5 Starch ditto ditto - - 1 0-34 0'08 10-6 8-8 Charcoal from acet. potash 1 0'18 0-04 5-6 4-4 Ditto from carb. soda by phosphorus - - - - 1 0'38 0'08 12 8' 8 Calcined lamp black - 1 0-128 0-03 4 3-3 Ditto ditto potash - - - 1 055 0'09 15-2 10-6 Bone black treated with mur. acid and potash -. 1 1-45 0-18 45 20 Bone black ditto with mur. acid - - -- 1 0-06 0-015 1-87 1-6 Oil calcined with phosph. of lime - -- 1 0-064 0-017 2 1' 9 Crude bone black - - - 1 0032 0-009 1 1 BONE BLACK, 227,With regard to the mode of operation of bone black on colored liquids, M. Payen showed in his prize essay, 1. That the decoloring power of charcoal depends in general upon its state of division; 2. That in the various charcoals, the cerbonaceous matter acts only upon the coloring matters, combining with and precipitating Ihem; 3. That in the application of charcoal to the refining of sugar, it acts also upon the eluten, for it singularly promotes crystallization; 4. That according to the above principles, the decoloring action of charcoals may be so modified, as to make the most inert become the most active; 5. That the distinction between animal and vegetable charcoals is improper, and that we may substitute for it that of dull and brilliant charcoals; 6. That of the substances present in charcoal besides carbon, and particularly animal charcoal those which favor the decoloring action, have an influence relative only!o the carton; they serve as auxiliaries to it, by insulating its particles, and presenilng them more freely to the action of the coloring matter; 7. That animal charcoal, bes' les its decoloring power, has the valuable property of taking lime in solution fiom water and sirup; 8. That neither vegetable, nor other charcoals, besides the animal, have this power of abstracting lime; 9. That by the aid of the decolorimeter, or graduated tube charged with test solution of indigo or molasses, it is easy to appreciate exactly the de coloring properties of all kinds of charcoal. Different varieties of lignite (fossilized wood) or even pit coal, when well carbonizec in close vessels, afford a decoloring charcoal of considerable value. By reducing 10( parts of clay into a thin paste with water, kneading into it 20 parts of tar, and 500 of finely-ground pit coal, drying the mixed mass, and calcining it out of contact of air, E charcoally matter may be obtained not much inferior to bone-black in whitening sirups. The restoration of animal charcoal from burnt bones, for the purpose of sugar refining, has been long practised in France. Mr. W. Parker has lately made the following process the subject of a patent. The charcoal, when taken from the vessel in which it has been employed for the purposes of clarifying the sugar, is to be thoroughly waslhed with the purest water that can be obtained, in order to remove all the saccharine matter adhering toit. When the washing:;rocess has been completed, ihe charcoal is laid out to dry, either in the open air or in a suitable stove, and when perfectly free from moisture, it is to be separated into small pieces and sifted through a sieve, the wires or meshes of which are placed at distances of about two and a half in every inch. This sifting will not only divide the charcoal into small pieces, but will cause any bits of wood or other improper matters to be separated from it. The charcoal, thus prepared, is then to be packed lightly in cylindrical vessels called crucibles, with some small quantity of bones, oil, or other animal matter mixed with it. The crucibles are then to be closed by covers, and luted at the joints, leaving no other opening but one small hole in the centre of the cover, through which any gas, generated within the vessel when placed in the oven or furnace, may be allowed to escape. The crucibles are now to be ranged round the oven, and placed, one upon another, in vertical positions; and when the oven is properly heated, gas will be generated within each crucible, and issue out from the central hole. The gas thus emitted, being of an inflammable quality, will take fire, and assist in heating the crucibles; and the operation being carried on until the cruci60? ------ 1^ E j| m bles become of a red heat, the 160( c c 161 W c c " oven is then to be closed, and alIb, il f e _ lowed to cool; after which the crucibles are to be removed, 1a r I11 when the charcoal will be found - h11 to have become perfectly renol-<^ ^ (vated, and fit for use as before. a - iBONE BBLACK, or animal charcoal'Zi~~wlS~~ l' ~, /..restored. A process for this purto ~, * 1' I ^SE X //, ^Ie pose was made the subject of a, — t: ^i Pl,M^^ [~patent by Messrs. Bancroft and -lT l aIi? | | MacInnes of Liverpool, which,_.IZ d J.~', | X! consists in wasling'the granular X, d4 I d 1 charcoal, or digesting it when I,,- = I Ad finely ground, with a weak soluffT l.E"~ i l SXtion of potash or soda, of specific -,, - /;-lf- gravity 1'06. The bone black XLl g: 7i7 / which has been used in sugar re-,,,'t'' " 1' fining may thus be restored, but,';',i','''''"X'wr it should be first cleared from all I I' i\ I' I' 2 - the soluble filth by means of water:,',':,', l W Xl e Mr. F. Parker's method, patent-. II.III...........ed in June, 1839, for effecting a like purpose, is by a fresh calcination as follows: 228 BOOKBINDING. Fig. 160 represents a front section of the furnace and retort; and fig. 161 is a trans. verse vertical section of the same. a is a retort, surrounded by the flues of the furnace b; c is a hopper or chamber, to which a constant fresh supply of the black is furnished, as the preceding portion has been withdrawn, from the lower part of a. d is the cooling vessel, which is connected to the lower part of the retort a by a sand joint e. The cooler d is made of thin sheet iron, and is large; its bottom is closed with a slide plate f. The black after passing slowly through the retort a into the vessel d, gets so much cooled by the time it reachesf, that a portion of it may be safely withdrawn, so as to allow more to fall progressively down; g'is the charcoal meter, with a slide door. BOOKBINDING, is the art of sewing together the sheets of a book, and securing them with a back and side boards. Bookbinding, according to the present mode, is performed in the following manner: -The sheets are first folded into a certain number of leaves, according to the form in which the book is to appear; viz., two leaves for folios, four for quartos, eight for octavos, twelve for duodecimos, &c. This is done with a slip of ivory or boxwood, called a folding-stick; and in the arrangement of the sheets the workmen are directed by the catch-words and signatures at the bottom of the pages. When the leaves are thus folded and arranged in proper order, they are usually beaten upon a stone with a heavy hammer, to make them solid and smooth, and are then condensed in a press. After this preparation they are sewed in a sewing press, upon cords or packthreads called bands, which are kept at a proper distance from each other, by drawing a thread through the middle of each sheet, and turning it round each band, beginning with the first and proceeding to the last. The number of bands is generally six for folios, and five for quartos, or any smaller size. The backs are now glued, and the ends of the bands are opened, and scraped with a knife, that they may be more conveniently fixed to the pasteboard sides; after which the back is turned with a hammer, the book being fixed in a press between boards, called backing boards, in order to make a groove for admitting the pasteboard sides. When these sides are applied, holes are made in them for drawing the bands through, the superfluous ends are cut off, and the parts are hammered smooth. The book is next pressed for cutting; which is done by a particular machine called the plough, to which is attached a knife. See the figures and descriptions infra. It is then put into a press called the cutting press, betwixt two boards, one of which lies even with the press, for the knife to run upon; and the other above for the knife to cut against. After this the pasteboards are cut square with a pair of iron shears; and last of all, the colors are sprinkled on the edges of the leaves, with a brush made of hog's bristles; the brush being held in the one hand, and the hair moved with the other. A patent was obtained in 1799 by Messrs. John and Joseph Williams, stationers in London, for an improved method of binding books of every description. The improvement consists of a back, in any curved form, turned a little at the edges, and made of iron, steel, copper, brass, tin, or of ivory, bone, wood, vellum, or, in short, any material of sufficient firmness. This back is put on the book before it is bound, so as just to cover without pressing the edges; and the advantage of it is that it prevents the book, when opened, from spreading on either side, and causes it to rise in any part to nearly a level surface. In this method of binding the sheets are prepared in the usual manner, then sewed on vellum slips, glued, cut, clothed, and boarded, or half boarded; the firm back is then fastened to the sides by vellum drawn through holes, or secured by enclosing it in vellum or ferret wrappers, or other materials pasted down upon the boards, or drawn through them. A patent was likewise obtained in 1800 by Mr. Ebenezer Palmer, a London stationer, for an improved way of binding books, particularly merchants' account-books. This Improvement has been described as follows:-let several small bars of metal be provided, about the thickness of a shilling or more, according to the size and thickness of the book; the length of each bar being from half an inch to several inches, in proportion to the ttrength required in the back of the book. At each end of every bar let a pivot be rmade of different lengths, to correspond to the thickness of two links which they are to receive. Each link must be made in an oval form, and contain two holes proportioned to the size of the pivots, these links to be the same metal as the hinge, and each of them nearly equal in length to the width of two bars. The links are then to be riveted on the pivots, each pivot receiving two of them, and thus holding the hinge together; on the principle of a link-chain or hinge. There must be two holes or more of different sizes, as may be required, on each bar of the hinge or chain; by means of these holes each section of the book is strongly fastened to the hinge which operates with the back Df the book. when bound, in such a manner as to make the different sections paralle with each other, and thus admit writing without inconvenience on the ruled lines, close i'o the back. The leather used in covering books is prepared'and applied as follows: being firsl BOOKBINDING. 229 moistened in water, it is cut to the size of the book, and the thickness of the edge is paired off on a marble stone. It is next smeared over with paste made of wheat flour, stretched over the pasteboard on the outside, and doubled over the edges within. The book is then corded, that is, bound firmly betwixt two boards, to make the cover stick strongly to the pasteboard and the back; on the exact performance of which the neatness of the book in a great measure depends. The back is then warmed at the fire to soften the glue, and the leather is rubbed down with a bodkin or folding stick, to set and fix it close to the back of the book. It is now set to dry, and when dry, the boards are removed; the book is then washed or sprinkled over with a little paste and water, the edges and squares blacked with ink, and then sprinkled fine with a brush, by striking it against the hand or a stick; or with large spots, by being mixed with solution of green vitriol, which is called marbling. Two blank leaves are then pasted down to the cover, and the leaves, when dry, are burnished in the press, and the cover rolled on the edges. The cover is now glazed twice with the white of an egg, filleted, and, last of all, polished, by passing a hot iron over the glazed color. The employment in bookbinding of a rolling press for smoothing and condensing the leaves, instead of the hammering which books have usually received, is an improvement introduced several years ago into the trade by Mr. W. Burn. His press consists of two iron cylinders about a foot in diameter, adjustable in the usual way, by means of a screw, and put in motion by the power of one man or of two, if need be, applied to one or two winch-handles. In front of the press sits a boy who gathers the sheets into packets, by placing two, three, or four, upon a piece of tin plate of the same size, and covering them with another piece of tin plate, and thus proceeding by alternating tin plates and bundles of sheets till a sufficient quantity have been put together, which will depend on the stiffness and thickness of the paper. The packet is then passed between the rollers and received by the man who turns the winch, and who has time to lay the sheets on one side, and to hand over the tin plates by the time that the boy has prepared a second packet. A minion Bible may be passed through the press in one minute, whereas the time necessary to beat it would be twenty minutes. It is not, however, merely a saving of time that is gained by the use of the rolling-press; the paper is made smoother than it would have been by beating, and the compression is 3 162 R so much greater, that a rolled book will be reduced to about five sixths of the thickness of the same book if beaten. A shelf, therefore, that will hold fifty tE o n U IL- books bound in the usual way would hold nearly I- T.r Ir sixty of those bound in this manner, a circumstance | P D ~ p I of no small importance, when it is considered how large a space even a moderate library occupies, and that book-cases are an expensive article of furniture..A__j1 An 1 I _J The rolling-press is now substituted for the hammer,tzu _ t, ~ ~ s by several considerable bookbinders. Fig. 162 represents the sewing-press, as it stands |I tI A 1 1 upon the table, before which the bookbinder sits. A 1063 Fig. 163 is a ground plan, without the parts a and tio.. _______. nin in the former figure. A is the base-board, supf-.-*^'*V" EvI- ported upon the cross bars m n, marked with dotted lines in fig. 163. Upon the screw rods r r,fig. 162, the nuts t d serve to fix the flat upper bar n, at any desired distance from the base. That bar has a slit along its middle, through which the hooks below z z pass down for receiving the ends of the sewing cords p p, n __on _ fixed at y y, and stretched by the thumb-screws z z. Mom>~fg-.~ The bar y y is let into an oblong space cut out of the Ct I a front edge of the base-board, and fixed there by a l|~ ~ moveable pin a, and a fixed pin at its other end, round which it turns. COif ii a 1 _ Fig. 164 is the bookbinder's cutting-press, which is 164 cS set upright upon a sort of chest for the reception of the paper parings; and consists of three sides, being open above and to the left hand of the workman. The pressbar, or beam a, has two holes n n upon its c l t 10 ounder surface, for securing it to two pegs standing on \1! I! ZZ. Othe top of the chest. The screw rods t t pass through s - - ntwo.tapped holes in the bar, marked with b c at its upper end; their heads r r being held by the shoulders o o. The heads are pierced with holes into which lever pins are thrust for screwing the rods hard up. The heavy beam a remains immoveable, while the parallel bar with the book is brought home towards it by the two screws. The wvo rulers s s serve as guides to preserve the motions truly 230 BOOKBINDING. parallel; and the two parallel lath bars b c guide between them the end bar e, of the plough, whose knife is shown at i, with its clamping screw z. Mr. Oldham, printing engineer of the Bank of England, distinguished for mechanical ingenuity, has contrived a convenient machine for cutting the edges of books, banknotes. &c., either truly square or polygonal, with mathematical precision. Fig. 165, represents an end elevation of the machine. Fig. 166, a side view of the same, the letters of reference indicating the same parts of the machine in each of the figares. a, is the top cross bar with rectangular grooves b b; c c, are side posts; d d, cross feet to the same, with strengthening brackets; e e, a square box, in which the press stands for holding waste cuttings. Fig. 167, is a cross section of the upright posts, c c, taken horizontally. There are rectangular grooves in the upright posts, for the projecting ends of the cast iron cross bracketf, to slide up and down in. In the middle of the under-side of this piece f, there is a boss, within which is a round recess, to receive the top of the screw g, which works in the cast iron cross piece h, similarly made with the former, but bolted firmly to the posts c c. Upon the screw g, there is a circular handle or ring i, for 166 E4 -i! _1L_. partially turning the screw, and immediately over it cross holes for tightening the press by means of a lever bar. Upon the cross piece f, is bolted the be)ard j, and upon each end ot this board is made fast the rabbeted pieces k k, for another board 1, to slide in. 169 168 ArXI- 1774 ALin, _y, _167 171 n 175 174 Across the middle of this board, and parallel to the pieces k k, the tongue piece m is made fast, which fits into a groove in the bottom of board 1. A horizontal representation of this is seen at fig. 168, and immediately under this view is also seen an end view of I and f, connected together, and a side view off. by itself. In the middle of the board 1, is a pin for a circular board %, to turn upon, and upon this letter board is placed the "material to be cut," with a saving piece between it, and the circular piece which is to be divided upon its edge into any number of parte required, with a stationary index on the board 1, to point to each. It will now be understood that the " material to be cut," may be turned round upon the centre pin of the board n, and also that both it and the board can he shifted back. BOOKBINDING. 231 ward and forward under the top cross piece a, and between the side slide slips k k, the surfaces of which should also be divided into inches and tenths. The plough, fig. 169, shown in several positions, is made to receive two knives or cutters as the " material to be cut" may require, and which are situated in the plough as I now describe. The plough is composed of three principal parts, namely, the top, and its two sides. The top o, is made the breadth of the cross piece a, and with a handle made fast thereon. The sides p p, are bolted thereto, with bolts and nuts through corresponding holes in the top and sides. The figures below give inside views, and cross sections of the details of the manner in which the cutters and adjustments are mounted. A groove is cut down each cheek or side, in which are placed screws that are held at top and bottom from moving up and down, but by turning they cause the nuts upon them to do so; they are shown at q q. These nuts have each'a pin projecting inwards, that go into plain holes made in the top ends of cutters r r. The 169th and following figs. are t in scale. The cutters, and the work for causing them to go up and down, are sunk into the cheeks, so as to be quite level with their inner surfaces. Fig. 170 shows one of those screws apart, how fixed, and with moveable nut and projecting pin. The top of each screw terminates with a round split down, and above it a pinion "heel and boss thereon, also similarly split. This pinion fits upon the split pin. Above, there is & cross section of a hollow coupling cap with steel tongue across, that fits into both the cuts of the screw pin and pinion boss, so that when lowered upon each other, they must all turn together. In the middle and on the top of the upper piece o, the larger wheel s, runs loose upon its centre, and works into the two pinion-wheels t t. The wheel s has a fly-nut with wings mounted upon it. It will now be seen, when the plough is in its place as at fig. 171, that if it be pushed to and fro by the right hand, and the nut occasionally turned by the left, the knives or cutters will be protruded downwards at the same time, and these either will or will not advance as the coupling caps u are on or off The ribs vv, run in the grooves b b, fig. 165, and keep the cutters to their duty, working steadily. The top cross bar a, is the exact breadth of a bank-note, by which means both knives are made to cut at the same time. The paper is cut uniformly to one length, and accurately square. By the use of this machine, the air-pump paper-wetting apparatus, and appendant press, the paper of 45,000 notes is fully prepared in one hour and a half by one person, and may then be printed. It is not so much injured by this process as by the ordinary method of clipping by hand, soaking it, &c., which more or less opens and weakens the fabric, especially of bank-note paper. One of the greatest improvements ever made in the art of bookbinding is, apparently, that for which Mr. William Hancock has very recently obtained a patent. After folding the sheets in double leaves, he places them vertically, with the edges forming the back of the book downwards in a concave mould, of such rounded or semi-cylindrical shape as the back of the book is intended to have. The mould for this purpose consists of two parallel upright boards, set apart upon a cradle frame, each having a portion or portions cut out vertically, somewhat deeper than the breadth of the book, but of a width nearly equal to its thickness before it is pressed. One of these upright boards may be slidden nearer to or farther from its fellow, by means of a guide bar, attached to the sole of the cradle. Thus the distance between the concave bed of the two vertical slots in which the book rests, may be varied according to the length of the leaves. In all cases about one fourth of the length of the book at each end projects beyond the board, so that one half rests between the two boards. Two or three packthreads are now bound round the leaves thus arranged, from top to bottom of the page in different lines, in order to preserve the form given to the back of the mould in which it lay. The book is next subjected to the action of the press. The back, which is left projecting very slightly in front, is then smeared carefully by the fingers with a solution of caoutchouc, whereby each paper-edge receives a small portion of the cement. In a few hours it is sufficiently dry to take another coat of a somewhat stronger caoutchouc solution. In 48 hours, 4 applications of the caoutchouc may be made and dried. The back and the adjoining part of the sides are next covered with the usual band or fillet of cloth, glued on with caoutchouc; after which the book is ready to have the boards attached, and to be covered with leather -r parchment as may be desired. We thus see that Mr. Hancock dispenses entirely with the operations of stitching, sewing, sawing-in, hammering the back, or the use of paste and glue. Instead of leaves attached by thread stitches at 2 or 3 points, we have them agglutinated securely along their whole length. Books bound in this way open so perfectly flat tpon a table without strain or resilience, that they are equally comfortable to the student, the musician, l [ --........................................ 232 BORACIC ACID LAGOONS. and thl merchant. The caontchouc cement moreover being repulsive to insects, and not affected by humidity, gives this mode of binding a great superiority over the old method with paste or glue, which attracted the ravages of the moth, and in damp situa tions allowed the book to fall to pieces. For engravings, atlasses, and ledgers, this bind ing is admirably adapted, because it allows the pages to be displayed most freely with out the risk of dislocating the volume; but for security, 3 or 4 stitches should be made. The leaves of music books bound with caoutchouc, when turned over lie flat at their whole extent, as if in loose sheets, and do not torment the musician like the leaves or the ordinary bool;s, which are so ready to spring back again. Manuscripts and cbllections of letters which happen to have little or no margin left at the back for stitching them by, may be bound by Mr. Hancock's plan without the least encroachment upon the writing. The thickest ledgers thus bound, open as easily as paper in quire, and may be written on up to the innermost margin of the book without the least inconvenience. BOOKsBINING, Jlechanical.-An ingenious invention, for which Mr. Thomas Richards of Liverpool, bookbinder, obtained a patent in April 1842. He employs, first a mechanism to sew, weave, or bind a number of sheets together to form a book, instead of stitching them by hand; 2dly, a table which slides to and fro to feed or supply each sheet of paper separately into his machine; also needle bars. or holders, to present needles with the requisite threads, for stiching such sheets as they are supplied with in succession. He has, moreover, a series of holding fingers, or pincers, suitably provided with motions, to enable them to advance and clasp the needle. draw them through the sheets of paper, and return them into their respective holders, after threading or stitching the sheet; lastly, there are arms or levers for delivering each sheet regularly upon the top of the preceding sheets, in order to form a collection or book of such sheets, ready for boarding or finishing. A minute description of the whole apparatus, with plates, is given in Newton's Journal, C. S. xxiii. 157. BORACIC ACID. 1841. 184. 143. 34. Quantities imported. ts. - 7,833 14,986 15,060 Quantities exported.... cwts. - 1 22 620 Retained for consumption.. cwts. - 7,245 18,717 15,953 Nett revenue. 8,193 798 861 422 The duty was repealed in 1845. BORACIC ACID LAGOONS. Before the discovery of this acid in the time of tile Grand Duke Leopold I., by the chemist Hmefqr, the fetid odor developed by the sulphuretted hydrogen gas, and the disruptions of the ground occasioned by the appearance of new Sofioni or vents of vapor, had made the natives regard them as a diabolical scourge, which they sought to remove by priestly exorcisms; but since science has explained the phenomena, the fumachi have become a source of public prosperity, and, were they to cease would be prayed to return. The vapors which issue from these lakes keep the waters always at a boiling temperature; hence, after impregnation for 20 or 30 hours by the steams of the highest lake, they draw off the waters into a second lake to suffer a fresh impregnation. Thence they are drawn into a third, and so on till, they reach the lowest receptacle. In this passage, they get charged with one-half per cent. of boracic acid. They are then concentrated in leaden reservoirs, by the heat of the vapors themselves. The liquid, after having filled the first compartment, is diffused very gradually into the second, then into the third, and successively to the last, where it reaches such a state of concentration that it deposits the crystallized acid; the workmen remove it immediately by means of wooden scrapers. This mode of gradual concentration is very ingenious, and requires so few hands that it may almost be said that the acid is obtained without expense. From 1818 to 1845 the quantity of acid manufactured was 33,349,095 Tuscan pounds. From 1839 to 1845 the mean quantity has been 2,500,000 pounds. Thus in estimating the product at 7,500 pounds per day, the quantity of saturated water upon which they operate is 1,500,000 lbs. daily, and annually 547,500,000 lbs. This labor brings to Tuscany ten millions of francs: it is surprising that it should have remained unproductive for so many ages, and that it should have been reserved for the skill of M. Dardarel, now Count of Mote Corboli,-before 1818 a simple wandering merchant, ertirely unacquainted with scientific researches, to discover tl 3 nature of the fugitive vapors, and render them a source of inexhaustible wealth. The violence with which the scalding vapors escape gives rise to muddy explosion, when a lake has been drained by turning its waters into another lake. The mud is then thrown out, as solid matters are ejectedfrom volcanoes, and there is formed in the bottom of the lake a crowd of those little cones of eruption, whose activity and play are generally from 120~ to 145' Centigrade, and the clouds which they form in the lagoons constitute true natural barometers, whose greater or less density rarely disap points the predictions that they announce. BORAX. 233 BORAX. A native saline compound of boracic acid and soda, found abundantly in Thibet and in South America. The crude product from the foimer locality was impol ted into Europe under the name of tincal, and was purified from some adhering fatty matter by a process kept a lone time secret by the Venetians and the Dutch, and which consisted chiefly in boiling the substance in water with a little quicklime. Gmelin found borax, in prismatic crystals, to contain 46'6 per cent. of water; and Arvredson, in the calcined state, to consist of 68'9 of acid and 31'1 soda, in 100 parts M. Payen describes an octahedral borax, which contains only 30'64 per cent. of water, and is therefore preferred by the brasiers in their soldering processes. Borax has a sweetish, somewhat lixivial taste, and affects vegetable colors like an alkali; it is soluble in 12 parts of cold and 2 of boiling water. It effloresces and becomes opaque in a dry atmosphere, and appears luminous, by friction, in the dark. It melts at a heat a little above that of boilinn water, and gives out its water of crystallization, after which it forms a spongy mass, called calcined borax. The octahedral borax, which is prepared by crystallization, in a solution of 1'256 sp. gr., kept up at 145~ F., is not efflorescent. When borax is ignited, it fuses into a glassy-looking substance. The following is the improved mode of purifyina borax. The crude crystals are to be. broken into small lumps, and spread upon a filter lined with a lead grating, under which a piece of cloth is stretched upon a wooden frame. The lumps are piled up to the height of 12 inches, and washed with small quantities of a caustic soda ley of 5~ B. (sp. gr. 1-033) until the liquor comes off nearly colorless; they are then drained, and put into a large copper of boiling water, in such quantities that the resulting solution stands 20~ B. (sp. gr. 1'160.) Carbonate of soda, equivalent to 12 per cent. of the borax. must now be added; the mixed solution is allowed to settle, and the clear liquid syphoned off into crystallizing vessels. Whenever the mother waters get foul, they must be evaporated to dryness in cast-iron pots, and roasted, to burn away the viscid coloring matter. Borax is sometimes adulterated with alum and common salt; the former addition may be readily detected by a few drops of water of ammonia, which will throw down its hlumina; and the latter by nitrate of silver, which will give with it a precipitate insoluble in nitric acid. The native boracic acid obtained from the lakes of Tuscany, which has been manufactured in France into borax, has greatly lowered the price of this article of commerce. When MM. Payen and Cartier first began the business, they sold the crystals at the same price as the DBtch, viz., 7 francs the kilogramme (2.- lbs. avoird.); but, in a few years, they could obtain only 2 francs and 60 centimes, in consequence of the market getting overstocked. The annual consumption of France in 1823 was 25,000 kilos., and the quantity produced in M. Paven's works was 50,000. The mode of making borax from the acid is as follows:-The lake water is evaporated in graduation houses, and then concentrated in boilers till it crystallizes. In that state it is carried to Marseilles. About 500 kilogrammes of water are made to boil in a copper, and 600 kilo. grammes of crystallized carbonate of soda are dissolved in it by successive additions of 20 kilogrammes. The solution being maintained at nearly the boiling point, 500 kilogrammes of the crystallized boracic acid of Tuscany are introduced, in successive portions. At each addition of about 10 kilogrammes, a lively effervescence ensues, on which account the copper should be of much greater capacity than is sufficient to contain the liquors. When the whole acid has been added, the fire must be damped by being covered up with moist ashes, and the copper must be covered with a tight lid and blankets, to preserve the temperature uniform. The whole is left in this state during 30 hours; the clear liquor is then drawn off into shallow crystallizing vessels of lead, in which it should stand no higher than 10 or 12 inches, to favor its rapid cooling. At the end of three days in winter, and four in summer, the crystallization is usually finished. The mother' water is drawn off, and employed, instead of simple water, for the purpose of dissolving fresh crystals of soda. The above crystals are carefully detached with chisels, redissolved in boiling water, adding for each 100 kilos., 10 kilos. of carbonate of soda. This solution marks 20~ B. (sp. gr. 1'160); and, at least, one ton (1000 kilos.) of borax should be dissolved at once, in order to obtain crystals of a marketable size. Whenever this solution has become boiling hot, it must be run off into large crystallizing lead chests of the form of inverted truncated pyramids, furnished with lids, enclosed in wooden frames, and surrounded with mats to confine the heat. For a continuous business, there should be at least 18 vessels of this kind; as the solution takes a long time to complete its crystallization, by cooling to 30~ C. (86~ F.) The borax crystals are taken out with chisels, after the, liquor has been drawn off, and tlTe whole has become cold. One hundred parts of the purest acid, usually extracted from the lakes of Tuscany, contain only fifty parts of the real boracic acid, and yield no more, at the utmost, than 140 or 150 of good borax. 234 BORAX. According to Wittstein, the commercial boracic acid is composed as follows:Sulphate of manganese --- A trace iron - --- 0'365 alumina - - - - -- 0320 lime - - - - - -- 1018 magnesia - - - - - - - 2632 ammonia - - - -- - 8'508 soda - - - - - - - - 0917 potash - - - - - - - 0369 salammonia - - - -- - 0'298 silica (in solution) - - - 1200 sulphuric acid (combined with the boracic) - - 1-322 crystallizable boracic acid - - - - - 6494 Water - - - - - - - - - 6557 100'000 Dry borax acts on the metallic oxides at a high temperature, in a very remarkable manner, melting and vitrifying them into beautiful colored glasses. On this account it is a most useful reagent for the blowpipe..Oxide of chrome tinges it of an emerald green; oxide of cobalt, an intense blue; oxide of copper, a pale green; oxide of tin, opal;.oxide of iron, bottle green and yellow; oxide of manganese, violet; oxide of nickel, pale emerald green. The white oxides impart no color to it by themselves. In the fusion of metals borax protects their surface from oxidizement, and even dissolves away any oxides formed upon them; by which twofold agency it becomes an excellent flux, invaluable to the goldsmith in soldering the precious metals, and to the brazier in soldering copper and iron. Borax absorbs muriatic and sulpllureous acid gases, but no others, whereby it be comes, in this respect, a useful means of analysis. The strength or purity of borax may be tested by the quantity of sulphuric acid requisite to neutralize a given weight of it, as indicated by tincture of litmus. When mixed with shellac in the proportion of one part to five, borax renders that resinous body soluble in water, and forms with it a species of varnish. Boracic acid is a compound of 31'19 of boron and 68'81 oxygen, in 100 parts. Its prime equivalent referred to oxygen 100, is 871'96. The following process for refining the native Indian borax, or tincal, has been published by MM. Robiquet and Marchand:It is put into large tubs, covered with water for 3 or 4 inches above its surface, and stirred through it several times during six hours. For 400 lbs. of the tincal there must now be added 1 lb. of quicklime diffused through two quarts of water. Next day the whole is thrown upon a sieve, to drain off the water with the impurities, consisting, in some measure, of the fatty matter combined with the lime, as an insoluble soap. The borax, so far purified, is to be dissolved in 21 times its weight of boiling water, and 8 lbs. of muriate of lime are to be added for the above quantity of borax. The liquor is now filtered, evaporated to the deqsity of 18~ or 20~ B. (1'14 to 1'16 sp. grav.), and set to crystallize in vessels shaped like inverted pyramids, and lined with lead. At the end of a few days, the crystallization being completed, the mother waters are drawn off, and the crystals are detached and dried. The loss of weight in this operation is about 20 per cent. 1841. 1842. 1848. 1844. Quantities imported - - - - cwts. - 3581 847 1427 Quantities exported - - - - cwts. - 2435 2940 3637 Retained for consumption - - - cwts. - 7798 889 349 Nett revenue - - - - - 866 161 5 4 The duty on borax has been repealed. BORAX, DRY. A considerable saving of expense in manufacturing borax, and a more ready application of the borax to use, are proposed by Saulter, as follows:-Take about 38 parts of pure crystallized boracic acid, pounded and sifted; mix them well with 45 parts of crystals of carbonate of soda in powder; expose the mixture upon wooden shelves to heat in a stove room; and rake it up from time to time. The boracic acid and the alkali thus get combined, while the carbonic acid and water are ex pelled; and a perfect dry borax is obtained. BOUGIE. 235 ~~~~17'16 lBOTTLE MANUFACTURE. The fol. 1 n 6I I P lowing mechanism for moulding bottles ~ forms the subject of a patent obtained by a e _ I —-- a Henry Rickets of Bristol, in 1822. Fig. 176 X -it~~n X is a section of the apparatus, consisting of q X a square frame, a a, of iron or wood; this is fixed in a pit formed in the floor; b b *^a o is the base of the frame, with an aperk h X _ _ _k ture for knocking up the bottom of the.' i.... I bottle; c c are four legs secured to the mI - frame-floor b, upon which the mould is i I,~m -z l z supported. The platform or stand of the 1t v mould d d has an opening in its centre for the introduction of the bottom of the t h ~ ~ mould, which is raised against the bottom -!R i - ": of the bottle by the knocker-up; e e are [ jl;'* - g'5:5l C|; the sides of the mould; and ff is the top 7/ n unot be heated by ther The crucibles are 16 inches deep, i / 9 wide at the mouth, 6_ at the bottom; with a thickness in the sides of 1 inch and 1I below; they stand from 40 to 50 meltings. The old brass, which fills their whole capacity, is first put in and melted down; the crucibles are now taken out and are charged with the half of the zinc in pieces of from 1'o 3 cubic inches in size, covered over with coal ashes; then one-half of the copper ch[ rge is introduced, again coal-dust; and thus the layers of zinc and copper are distributed alternately with coal-ashes betwixt them, till the whole charge gets finally fused. Over all, a thicker layer of carbonaceous matter is laid, to prevent oxidizement of the brass. Eight crucibles filled in this way are put into the furnace between the 11 holes of the grate shelf; and over them two empty crucibles are laid to be heated for the casting operation. In from 31 to 4 hours the brass is ready to be poured out. Fifteen English bushels of coals are consumed in one operation; of which six are used at the introduction of the crucibles, and four gradually afterwards. When sheet brass is to be made the following process is pursued:An empty crucible, called a caster (giesser), is taken out of the furnace through the crown with a pair of tongs, and is kept red hot by placing it in a hollow hearth (mundal) surrounded with burning coals; into this crucible the contents of four of the melting pots are poured; the dross being raked out with an iron scraper. As soon as the melting pot is emptied, it is immediately re-charged in the manner above described, and replaced in the furnace. The surface of the melted brass in the caster is swept with the stump of a broom, then stirred about with the iron rake, to bring up any light foreign matter to the surface, which is then skimmed with a little scraper; the crucible is now seized with the casting tongs, and emptied in the following way:The mould orform for casting sheet brass consists of two slabs of granite, a a, figs 185, 186. They are 51 feet long; 3 feet broad, 1 foot thick, and for greater security, girt with iron banfds, b b, 2 inches broad, 11 thick, and joined at the four corners with bolts and nuts. The mould rests upon an oaken block, c, 36 feetlong, 2- broad, and 1 thick, which is suspended at each end upon gudgeons, in bearing blocks, placed under the foundry floor, dd, in the casting pit, e e. This is lined with bricks; and is 6-] feet long, 5- broad, and 2 deep; upon the two long side walls of the pit, the bearing blocks are laid which support the gudgeons. The swing-blocks are 10 inches long, 18 inches broad, 15 inches thick, and are somewhat rounded upon their back edge, so that the casting frame may slope a little to the horizon. To these blocks two cross wooden arms, 185 186 g iCL/ 7~k a e.............. 7-"/il,,,, - i/ o I/ r 242 BRASS. ff, are mortised, upon which the underslab rests freely, but so as to project about 5 inches backwards over the block, to secure an equipoise in the act of casting. g g are bars, placed at both of the long sides, and one of the ends, between the slabs, to determine the thickness of the brass-plate. Upon the other slab the gate h is fastened, a sheet of iron 6 inches broad, which has nearly the shape of a parallel trapezium (lozenge), and slopes a little towards the horizon. It serves for setting the casting pot upon in the act of pouring out, and renders its emptying more convenient. That gate (steinmaul) is coated with a mixture of loam and hair. The upper Flab is secured to the under one in its slanting position by an armor or binding. This c. nsists of the tension bars of wood, i k Im, of the iron bars n, (3 to 31 inches broad, 1 inch thick, see the top view, fig. 186,) of a rod with holes and pins at its upper end, and of the iron screw spindle o. The mode in which these parts act may be understood fromc inspection of the figure. In order to lift the upper slab from the under one, which is effected by turning it round its edge, a chain is employed, suspending two others, connected with the slab. The former passes over a pully, and may be pulled up and down by means of a wheel and axle, or with the aid of a counterweight. Upon each of the two long sides bf the slab there are two iron rings, to which the ends of the chains may be hooked. The casting faces of the slab must be coated with a layer of finely ground loam; the thinner the better. When calamine is employed, I cwt. of copper, I cwt. of calamine, and { the volume of both of charcoal mixed, are put into seven crucibles, and exposed to heat during 11 or 12 hours; the product being from 70 to 72 lbs. of brass. Brass-Plate Rolling.-At Hegermiihl there are two re-}reating or annealing fur, naces, one larger, 18 feet long, and another smaller, 81; the hot chamber is separated from the fire place by iron beams, in such a way that the brass castings are played upon by the flames on both their sides. After each passage through the laminating press (rolls) they are heated anew, then cooled and laminated afresh, till they have reached the proper length. The plates are besmeared with grease before rolling. 1 —l^7fl'A7 I I 1 188 — ^a I! fg' Fig. 187 shows the ground plan of the furnace and its railway;fig. 188 the cross section; andJ i. 189 the section lengthwise; a a, the iron way bars or rails upon the floor of the foundry, for enabling the wheels of the wagon-frame to move readily backwards and forwards; b b, the two grates; c c, the ash pits; d d, the fire beams; e e e, vInts in the roof of the hot chamberf; g g, two plates for shutting the hot chamber; h. the flue; i, the chimney. After the rolling, the sheets covered with a black oxide of copper, are plunged into a mother water of the alum works for a few minutes, then washed in clean water, and lastly, smeared with oil, and scraped with a blunt knife. In rough brass and brass wares, no less than 16,240 cwts. were manufactured in the Prussian States in the year 1832. For musical purposes. the brass wire made in Berlin, has acquired great and meritad celebrity, but that of Birmingham is now preferred even by foreigners. 3RAss COLOR, for staining glass, is prepared by exposing for several days thin plates af brass upon tiles in the leer or annealing arch of the glass-house, till it be oxidized BRASS. 243 into a black powder, aggregated in lumps. This being pulverized and sifted, is to be again well calcined for several days more, till no particles remain in the metallic state when it will form a fine powder of a russet brown colour. A third calcination must now be given, with a carefully regulated heat; its quality being tested from time to time by fusion with some glass. If it makes the glass swell, and intumesce, it is properly prepared; if not, it must be still farther calcined. Such a powder communicates to glass greens of various tints, passing into turquoise. When thin narrow strips of brass are stratified with sulphur in a crucible, and calcined a. a red heat, they become friable, and may be reduced to powder. This being sifted and exposed upon tiles in a reverberatory furnace for ten or twelve days becomes fit for use, and is capable of imparting a chalcedony, red or yellow tinge to glass by fusion, according to the mode and proportion of using it. The glass-maker's red colour may be prepared by exposing small plates of brass to a moderate heat in a reverberatory furnace, till they are thoroughly calcined, when the substance becomes pulverulent, and assumes a red colour. I1 is then ready for immediate use. BRASS COLOUR, as employed by the colourmen to imitate brass, is of two tints, the red or bronze, and the yellow like gilt brass. Copper filings mixed v-tch red ochle or bole, constitute the former; a powdered brass imported fiom Germany is used for the latter. Both must be worked up with varnish after being dried with heat, and then spread with a flat camel-hair brush evenly upon the surface of the object. The best varnish is composed of 20 ounces of spirits of wine, 2 ounces of shellac, and 2 ounces of sandarach, properly dissolved. (See VARNIsEI.) Only so much of the brass powder and varnish should be mixed at a time as is wanted for immediate use. (See BRONZE POWDER.) BRASS FOIL. Dutch leaf, called Knitter or Rauschgold in Germany, is made from a very thin sheet brass, beat out under a hammer worked by water power, which gives 300 or 400 strokes per minute; from 40 to 80 leaves being laid over each other. By this treatment it acquires its characteristic solidity and lustre. See above, the process for converting the copper superficially into brass by the fumes of zinc. BRASS, YELLOW. The following table exhibits the composition of several varieties of this species of brass. No. 1. is a cast brass of uncertain origin; 2. the brass of Jemappes; 3. the sheet brass of Stolberg, near Aix-la-Chapelle; 4. and 5. the brass for gilding, according to D'Arcet; 6. the sheet brass of ERomilly; 7. English brass wire; 8. Augsburg brass wire; 9. brass wire of Neustadt-Eberswald, in the neighbourhood of Berlin. 1: 2. 3. 4. 5. 6. 7. 8. 9. Copper - 61-6 646 64-8 6370 6445 70-1 7029 71'89 7016 Zinc - - 35-3 33-7 32-8 3355 32-44 299 I29-26 27-63 27-45 Lead - - 2-9 1-4 2-0 0-25 2-86 - - 28 - 0-20 Tin - - 2 -2 2 04 250 0-25 - 017 0'85 0-79 io 93911 00.0 999 1000 100 100 0 - - 100-00 10-37 9860 The mean proportion of the metals in yellow brass is 30 zinc to 70 copper. Tombak, or Red Brass, in the cast state, is an alloy of copper and zinc, containing not more than 20 per cent. of the latter constituent. The following varieties are distinguished:-1, 2, 3. toinbak for making gilt articles; 4. French tombak for swordhandles, &c.; 4. tombak of the Okar, near Goslar, in the Hartz; 5. yellow tombak of Paris for gilt ornaments; 6. tombak for the same purpose firom a factory in Hanover; 8. chrysochalk; 9. red tombak from Paris; 10. red torbak of Vienna. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Copper - 820 82 82-3 80 85 85-3 86 900 92 97-8 Zinc - -180 18 17-5 17 15 14-7 14 7,9 8 2-2 Lead - 15 3 - ----- 16 Tin - - 3'0 1 0.2 3 trace. 1 04-5 110 10:'0 100 100 0 100095 100 100 0 Pinchbeck is made of 2 parts copper and 1 yellow brass: Prince's metal... 3 1 zinc. Mannheim gold (semilor), 28 copper, 12 yellow brass, 3 tin. Cast white metal buttons are made of an alloy of 32 parts brass (yellow), 4 parts zinc, and 2 tin. The specific gravity of brass is greater than the mean density of its constituents, 244 BRAZIL-WOOD. varying from 7'82 to 8'73, according to the proportion of zinc to copper. Sheet brass varies from 8'52 to 8-62; brass wire from 8'49 to 8'73. Brass heated and ouickly cooled becomes somewhat less dense. The specific gravity of sheet tombak (81'25 copper + 18'75 zinc) is 8'788; of tombak wire (87'5 copper + 12'5 zinc) has been found so great as 9'00. BRASS, MALLEABLE. It is known that common brass containing from 27'4 to 31-8 per cent. of zinc, and from 71'9 to 65-8 per cent. of copper, is not malleable while hot, but that articles of it must be made by casting. As it would be of great advantage it many branches of industry to have an alloy of this kind that could be worked while hot, like malleable iron, the information that such an alloy exists must be welcome to artists. By melting together 33 parts of copper, and 25 parts of zinc, there was a loss of three parts; thus making 60 per cent. copper, and 40 per cent. zinc. It differs from the English specimens by containing a larger proportion of zinc, and possesses, according to M. Machts, the precious property of malleability in a higher degree than the English specimens. A piece of "yellow metal," similar in colour to this alloy, was found, on analysis, to contain 60'16 copper, and 39-71 zinc, which is the composition of malleable brass. It also showed great density or solidity. An alloy was prepared by melting together 60 parts copper and 40 parts zinc, which had the following properties:-The colour was between that of brass and tombak, it had a strong metallic lustre, a fine, close grained fracture, and great solidity (density). Its specific gravity at the temperature of 10~ Cent. was 8-44; by calculation it ought only to have been 8'08; thus sliowing that in the formation of the alloy a condensation must have taken place. Calculation shows that the alloy may be considered as a determinate chemical combination, for the results of the analysis very nearly accord with the assumption that it may be considered as composed of 3 atoms by weight of copper, and 2 atoms by weight of zinc (3 Cu + 2 Zn). The hardness of the alloy is the same as that of fluor spar; it can be scratched by apatite (glass), consequently its hardness is =4. The alloy is harder than copper, very tough, and is, in a properly managed fire, malleable; so much so that a key was forged out of a cast rod. These important properties of this alloy warrant an expectation of its application to many purposes in the arts, and it would appear that they depend on its definite chemica. proportions. Agreeably to the directions of M. Feyerabind, care must be taken in melting together the metals, not to permit too great a loss of zinc to take place, lest the proportions between the metals should be altered, which might not be without effect on the important properties of the alloy. With this view, it might be advantageous in practice, in place of zinc, to add, in melting, a proportionate mixture of brass to the proper proportions of copper. An alloy prepared in this way gave, on analysis, 61.44 copper, and 38'15 zinc. It is very probable that malleable brass will hereafter, in many cases, be made use of instead of the higher priced copper. BRAZING. (Braser, Fr.; Alessing-lothung, Germ.) The soldering together of edges of iron, copper, brass, &c., with an alloy consisting of brass and zinc, sometimes with a little tin or silver. The surfaces to be thus united must be filed perfectly bright, and not be soiled with the fingers or in any other way. The granular or nearly pulverulent alloy is usually wetted with a paste of ground borax and water, applied in this state, dried, and then exposed carefully to bright ignition at a clear forge fire. Some workmen enclose the part to be soldered in a clay lute, but others prefer leaving it uncovered, that they may see when the solder has flowed freely, and entered into all the seams. BRAZIL-WOOD. (Bois de Fernambouc, Fr.; Brasilienholz, Germ.) This dye-wood derives its name from the part of America whence it was first imported. It has also the names Fernambuca, wood of Saint Martha, and of Sapan, according to the places which produce it. Linnaeus distinguishes the tree which furnishes the Brazil-wood by the name of Ccesa.pinia crista. It commonly grows in dry places among rocks. Its trunk is very large, crooked, and full of knots. It is very hard, susceptible of a fine polish, and sinks in water. It is pale when newly cleft, but becomes red on exposure to the air. It has different shades of red and orange. Its goodness is determined particularly by its density. When chewed, a saccharine taste is perceived. It may be distinguished from red saunders wood, as the latter does not yield its color to water. Boiling water extracts the whole coloring matter of Brazil-wood. If'the ebullition be?ong enough continued, it assumes a fine red color. The residuum appears black. In this case, an alkali may still extract much coloring matter. The solution in alcohol or ammonia is still deeper than the preceding. The decoction of Brazil-wood, called juice of Brazil, is observed to be less fit for dyemg when recent, than when old or even fermented. By age, it takes a yellowish BRAZIL-WOOD. 245 red color. For making this decoction, Hellot recommends to use the hardest water; but it should be remarked, that this water deepens the color in proportion to the earthy salts which it contains. After boiling this wood reduced to chips, or, what is preferable, to powder, for three hours, this first decoction is poured into a cask. Fresh water is poured on the wood, which is then made to boil for three hours, and mixed with the former. When Brazil-wood is employed in a dyeing bath, it is proper to enclose it in a thin linen bag, as well as all the dye-woods in general. Wool immersed in the juice of Brazil takes but a feeble tint, which is speedily destroyed. It must receive some preparations. The wool is to be boiled in a solution of alum, to which a fourth or even less of tartar is added, for a larger proportion of tartar would make the color yellowish. The wool is kept impregnated with it for at least eight days, in a cool-place. After this, it is dyed in the Brazil juice with a slight boiling. But the first coloring particles that are deposited, afford a less beautiful color; hence it is proper to pass a coarser stuff previously through the bath. In this manner a lively red is procured, which resists pretty well the action of the air. Brazil-wood is made use of for dyeing silk what is called false crimson, to distinguish it from the crimson made by means of cochineal, which is much more permanent. The silk should be boiled at the rate of 20 parts of soap per cent., and then alumed. The aluming need not be so strong as for the fine crimson. The silk is refreshed at the river, and passed through a bath more or less charged with Brazil juice, according to the shade to be given. When W ater free from earthy salts is employed, the color is too red to imitate crimson; this quality is given it by passing the silk through a slight alkaline solution, or by adding a little alkali to the bath. It might, indeed, be washed in a hard water till it had taken the desired shade. To make deeper false crimsons of a dark red, juice of locwood is put into the Brazil bath after the silk has been impregnated with it. A little alkali may be added, according to the shade that is wanted. To imitate poppy or flame color, an annotto ground is given to the silk, deeper even than when it is dyed with carthamus. It is washed, alumed, and dyed with juice of Bratil, to which a little soap water is usually added. The coloring particles of Brazil-wood are easily affected, and made yellow by the action of acids. They thus become permanent colors. But what distinguishes them from madder and Kermes, and approximates them to cochineal, is their reappearing in their natural color, when they are thrown down in a state of combination with alumina, or with oxyde of tin. These two combinations seem to be the fittest for rendering them durable. It is requisite, therefore, to inquire what circumstances are best cale:'ated to promote the formation of hese combinations, according to the nature of t!e stuff. The astringent principle, likewise, seems to contribute to the permanence of the coloring matter of Brazil-wood; but it deepens its hue, and can only be employed for light shades. The coloring particles of Brazil-wood are very sensible to the action of alkalis which give them a purple hue; and there are several processes in which the alkalis, either fixed or volatile, are used for forming violets and purples. But the colors obtained by these methods, which may be easily varied according to the purpose, are perishable, and possess but a transient bloom. The alkalis appear not to injure the colors derived from madder, but they accelerate the destruction of most other colors. In England and Holland the dye-woods are reduced to powder by means of mills erected for the purpose. The bright fugitive red, called fancy red, is given to cotton by Nicaragua, or peachwood, a cheap kind of Brazil-wood. The cotton being scoured and'bleached, is boiled with sumach. It is then impregnated with a solution of tin (at 5~ Banme, according to Vitalis). It should now be washed slightly in a weak bath of the dyeing wood, and, lastly, worked in a somewhat stale infusion of the peach or Brazil wood. When the temperature of this is lukewarm, the dye is said to take better. Sometimes two successive immersions in the bath are given. It is now wrung out, aired, washed in water, and dried. M. Vitalis says, that his solution of tin is prepared with two ounces of tin and a pound pf aqua regia made with two parts of nitric acid at 24~ Baum6, and three parts of muriatic acid at 220. For a rose color, the cottotn.is alumed as usual, and washed from the alum. It then gets the tin mordant, and is again washed. It is now turned through the dye-bath, an ope'ation which is repeated if necessary. For purple, a little alum is added to the Brazil bath. 1. For amaranth, the cotton is strongly galled, dried, and washed. ___________I —------------------ 246 BREAD. 2. It is passed through the black cask (tonne au noir,) see BLACK DYE, till it has taker a strong gray shade. 3. It receives a bath of lime-,-ater. 4. Mordant of tin. 5. Dyeinc in the Brazil-wood bKth. 6. The two last eperations are repeated. Dingier has c-ndeavored to separate the coloring matter of the different sorts of Brazil. wood, so as to obtain the same ti'n from the coarser as from the best Pernambuco. His process consists in treating the wood with hot water or steam, in concentrating the de. coction so as to obtain 14 or 15 pounds of it from 4 pounds of wood, allowing it to cool, and pouring into it two pounds of skim milk; agitating, then boiling for a few minutes, and filtering. The dun coloring matters are precipitated by the coagulation of the caseous substance. For dyeing, the decoctions must be diluted with water; for printing they must be concentrated, so that 4 pounds of wood shall furnish only 5 or 6 pounds of decoction, and the liquor may be thickened in the ordinary way. These decoctions may be employed immediately, as by this treatment they have acquired the same property as they otherwise could get only by being long kept. A slight fermentation is said to improve the color of these decoctions; some ground woo.'s put into the decoction to favor this process. As gelatine produces no precipitate with these decoctions, they consequently contemn no tannin. Gall-nuts, however, sumach, the bark of birch or alder, render the color of Brazil-wood more durable, upon alumed linen and cotton goods, but the shade is a litle darker. In dyeing wool with Pernambuco, the temperature of the bath should never be above 150~ Fahr., since higher heats impair the color. According to Dingler and Kurrer, brieht and fast scarlet reds may be obtained upon wool, by preparing a decoction of 50 pounds of Brazil-wood in three successive boils, and setting the decoction aside for 3 or 4 weeks in a cool place; 100 pounds of the wool are then alumed in a bath of 22 pounds of alum and 11 pounds of tartar, and afterwards rinsed in cold water. Meanwhile we fill two thirds with water, a copper containing 30 pails, and heated to the temperature of 150~ or 160~ F. We pour in 3 pailfuls of the decoction, heat to the same point again, and introduce 30 pounds of wool, which does not take a scarlet, but rather a crimson tint. This being removed, 2 pails of decoction are put in, and 30 pounds of wool, which becomes scarlet, but not so fine as at the third dip. If the dyer strengthens the color a little at the first dip, a little more at the second, and adds at the third and fourth the quantity of decoction merely necessary, he will obtain a uniform scarlet tint. With 50 pounds of Pernambuco 1000 pounds of wool may be dyed scarlet in this way, and with the deposites another 100 may be dyed of a tile color. An addition of weld renders the color faster but less brilliant. Karkutsch says the dye may be improved by adding some ox-gall to the bath. In dyeing cotton the tannin and gallic acid are two necessary mordants, and the color is particularly bright and durable, when the cloth has been prepared with the oily process of Turkey red. It is said that stale urine heightens the color of the Brazil dye when the ground wood is moistened with it. The quantity of Brazil or Nicaragua wood imported into the United Kingdom in 1835, was 6,242 tons, whereof 1,811 were exported; of Brazilietto 230 tons. The duty upon the first art' le is 5s. per ton. BREAD (Pain, Fr.; Brod, Germ.) is the spongy mass produced by baking the leavened or fermented dough of wheat or rye flour, at a proper heat. It is the principal food of highly civilized nations. The skilful preparation of this indispensable article constitutes the art of the Baker. Dough baked without being fermented constitutes cakes or biscuits; but not bread strictly speaking. Pliny informs us, that barley was the only species of corn at first used for food; and even after the method of reducing it to flour had. been discovered, it was long before mankind learned the art of converting it into cakes. Ovens were first invented in the East. Their construction was understood by the Jews, the Greeks, and the Asiatics, among whom baking was practised as a distinct profession. In this art, the Cappadocians, Lydians, and Phoenicians, are said to have particularly excelled. It was not till about 580 years after the foundation of Rome, that these artisans passed into Europe. The Roman armies, on their return from Macedonia, brought Grecian bakers with them into Italy. As these bakers had handmills beside their ovens, they still continued to be called pistores, fiom the ancient practice of bruising the corn in a mortar; and their bakehouses were denominated pistorice. In the time of August is there were no fewer than 329 public bakehouses in Rome; almost the whole of which were in the hands of Greeks, who long continued the only persons in that city conuainted with the art of baking good bread. BREAD. 247 In nothing, perhaps, is the wise and cautious policy of the Roman government more remarkably displayed, than in the regulations which it imposed on the bakers within the city. To the foreign bakers who came to Rome with the army from Macedonia, a number of freedmen were associated, forming together an incorporation from which neither they nor their children could separate, and of which even those who married the daughters of bakers were obliged to become members. To this incorporation were intrusted all the mills, utensils, slaves, animals, every thing, in short, which belonged to the former bakehouses. In addition to these, they received considerable portions of land; and nothing was withheld, which could assist them in pursuing, to the best advantage, their highly prized labors and trade. The practice of condemning criminals and slaves, for petty offences, to work in the bakehouse, was still continued; and even the judges of Africa were bound to send thither, every five years, such persons as had incurred that kind of chastisement. The bakehouses were distributed throughout the fourteen divisions of the city, and no baker could pass from one into another without special permission. The public granaries were committed to their care; they paid nothing for the corn employed in baking bread that was to be given in largess to the citizens; and the price of the rest was regulated by the magistrates. No corn was given out of these granaries except for the bakehouses, and for the private use of the prince. The hakers had besides private granaries, in which they deposited the grain, which they had taken from the pub lic granaries for immediate use; and if any of them happened to be convicted of having diverted any portion of the grain to another purpose, he was condemned to a ruinous fine of five hundred pounds weight of gold. Most of these regulatiops were soon introduced among the Gauls; but it was long before they found their way into the more northern countries of Europe. Borrichius informs us that in Sweden and Norway, the only bread known; so late &s the middle of the 16th century, was unleavened cakes kneaded by the women. At what period in our own history the art of baking became a separate profession, we have not been able to ascertain; but this profession is now common to all the countries in Europe, and the process of baking is also nearly the same. The French, who particularly excel in the art of baking, have a great many different kinds of bread. Their pain bis, or brown bread, is the coarsest kind of all, and is made of coarse groats mixed with a portion of white flour. The pain bis blanc, is a kind of bread between white and brown, made of white flour and fine groats. The pain blanc, or white bread, is made of white flour, shaken through a sieve after the finest flour has been separated. The pain mollet, or soft bread, is made of the purest flour without any admixture. The pain chaland, or customers' bread, is a very white kind of bread, made of pounded paste. Pain chapele, is a small kind of bread, with a well-beaten and very light paste, seasoned with butter or milk. This name is also given to a small bread, from which the thickest crust has been removed by a knife. Pain cornu, is a name given by the French bakers to a kind of bread made with four corners, and sometimes more. Of all the kinds of small bread, this has the strongest and firmest paste. Pain a la reine, queen's bread, pain a la Sigovie, pain chapelS. and pain cornu, are all small kinds of bread, differing only in the lightness or thickness of the paste. Pain gruau is a small very white bread made now in Paris, from the flour separated after a slight grinding from the best wheat. Such flour is in hard granular particles. In this country we have fewer varieties of bread, and these differ chiefly in their degrees of purity. Our white or fine bread is made of the purest flour; our wheaten bread, of flour with a mixture of the finest bran; and our household bread, of the whole substance of the grain without the separation either of the fine flour or coarse bran. We have also symnel bread, manchet or roll bread, and French bread, which are all made of the purest flour from the finest wheat; the roll bread being improved by the addition of milk, and the French bread by the addition of eggs and butter. To these may be added gingerbread, a cake made of flour, wBth almonds, liquorice, aniseed, rose-water, and sugar or treacle; and mastlin bread, made o wheat and rye, or sometimes of wheat and barley. We have various kinds of small bread, having various names, according to their various forms. They are, in general, extremely light, and are sweetened with sugar, currants, and other palatable ingredients. In Scotland there is a cake called short bread, made from a pretty thick dough, enriched with butter, sweetened with sugar, and seasoned with orange peel, or other kinds of spices. The process of making bread is nearly the same in all the countries of modern Europe; though the materials of which it is Composed vary with the farinaceous productions of different climates and soils. The flour of wheat is most generally employed for this pur. pose, wherever that vegetable can be reared. This flour is composed of a small portion Df mucilaginous saccharine matter, soluble in cold water, from which it may be separated Dy evaporation; of a great quantity of starch, which is scarcely soluble in cold water, but capable of combining with that fluid by means of heat; and an adhesive gray substance salled gluten'nsoluble in water, ardent spirit, oil, or ether, and resembling an animal _I. 248 BREAD. substance in many of its properties. Flour kneaded with water, forms a tough and rather indigestible paste containing all the constituent parts which we have enumerated. Heat produces a considerable change on the glutinous part of this compound, and renders it more easy of mastication and digestion. Still, however, it continues heavy and tough, compared with bread which is raised by leaven or yeast. Leaven is nothing more than a piece of dough, kept in a warm place till it undergoes a process of fermentation; swelling, becoming spongy, or full of air bubbles, at length disengaging an acidulo-spirituous vapor, and contracting a sour taste. When this leaven is mingled in proper proportions with fresh-made dough, it makes it rise more readily and effectually than it would do alone, and gives it at the same time a greater decree of firmness. Upon the quality of the leaven employed, the quality of the bread materially depends. The principal improvement which has been made on bread in modern times, is the substitution of yeast or barm in place of common leaven. This yeast is the viscid froth that rises to the surface of beer, in the first stage of its fermentation. When mixed with the dough, it makes it rise much more speedily and effectually than ordinary leaven, and the bread is of course much lighter, and freer from that sour and disagreeable taste which may often be perceived in bread raised with leaven, either because too much is mingled with the paste, or because it has been allowed to advance too far in he process of fermentation. Bread properly raised and baked differs materially from unleavened cakes, rot only in being less compact and heavy, and more agreeable to the taste, but in losing its tenacious and glutinous qualities, and thus becoming more salutary and digestible. We possess several analyses of wheat flour. Ordinary wheat (triticum hybernum mixed with triticum turgidum) contains, according to the analyses made by Vadquelin of several species of wheat flour, the following substances:Water Species of Wheat. Water. Gluten Starch. Sugar. Gum. Bran. Total. of dough French wheat flour - - 10-0 10-96 71-49 4-72 3'32 - 100'49 50-3 Hard wheat of Odessa flour- ----- 12-0 14-55 56-50 8-48 4-90 2-3 98-73 51-2 Soft wheat of Odessa flour - - 10-0 12-00 62-00 7-56 5-80 1-2 98-42 54-8 Same sort of flour - 8-0 12-10 70-84 4-90 4-60 - 100-41 37-4 Same sort of flour - - 12-0 7'30 72'00 5-42 3-30 - 100-02 37'2 Wheat of the French bakers ----- 10-0 10-20 72-80 4-20 2-80 - 100-00 40'6 Flour of the Paris hospitals (2d quality) - 8-0 10-30 71-20 4-80 3-60 - 9790 37.8 Ditto (3d quality) - - 120 9-02 67-78 4-80 4-60 2-0 100-21 37-8 The following table of analyses merits also a place here. r Species of Flour. Water. Gluten. Starch. Sugar. Gummigluten. Albumen. Bran. Flour of the triticum spelta 1 22' 74- 5-50 1i 1-50 Ditto triticum hybernun 1 24- 68- 5'0 1' 1'50 Ditto common wheat - 12-5 74-5 12- 2' Ditto wheat and rye ) mixed (mastlin) - - b 9-80 75.50 4-22 3'28 - 12 The first two of the above analyses were made by Vogel, the third by Proust, and the fourth by Vauquelin. Analyses of the flour of some other corns. Species of Flour. Starch. Mucilage. Gluten. Albumen. Sugar. Husk. 1ordein Of a fat oil, Wh-te oatmeal - - - 59-00 2-5 - 4*30 8-25 2 Of resin, Barley meal - - - - 3200 9' 3. - 2 - 55 The first analysis is by Vogel, the second by Proust. It deserves to be remarked, that the flour of Odessa contains a much greater quantity 3f sugar than the French flour. The substance indicated in the preceding table by the name of gluten, is the gluten of Beccaria; that is to say, a mixture of gluten and vegetable BREAD. 249 albumen. The gum of wheat is not quite identical with ordinary gum. It is a browr arotized substance, a hich, when treated by nitric acid, affords no mucic acid, but oxalic acid and the bitter pi inciple of Welter. It contains besides superphosphate of lime. The last column of the first table exhibits the quantity of water necessary to convert the flour into dough of the ordinary consistence, and it is usually proportional to the quantity of gluten. The hard wheat of Odessa forms an exception in this respect; the reason of the difference being that the starch contained in this flour is not as in or. dinary flour in a fine powder, but in small transparent grains, which resemble pounded gum, and absorb less water than pulverulent starch. The trilicum monococcon, according to Zenneck, contains in its unsifted flour, 16'334 of gluten and vegetable albumen; 64*838 of starch; 11-347 of gum, sugar, and extractive; ^-481 of husks. The sifted flour affords 15'536 of gluten and vegetable albumen; 76*459 of starch; 7'198 of sugar, gum, and extractive; 0'807 of husky matter. It is difficult to conceive how such great quantities of gluten, albumen, and extractive matter could disappear in the sifting. The triticum spelta contains in 100 parts of the finest flour, 22-5 of a soft and humid gluten, mixed with vegetable albumen; 74 of starch, and 5*5 of sugar. Here we have an excess of 2 parts in the 100. Wheat furnishes very little ashes by incineration, not more than 0.15 per cent. of the weight; containing superphosphates of soda, lime, and magnesia. The object of baking is to combine the gluten and starch of the flour into a homogeneous substance, and to excite such a vinous fermentative action, ty means of its saccharine matter, as shall disengage abundance of carbonic acid gas in it for making an agreeable, soft, succulent, spongy, and easily digestible bread. The two evils to be avoided in baking are hardness on the one hand, and pastiness on the other. Well-made bread is a chemical compound, in which the gluten and starch cannot be recognised or separated, as before, by a stream of water. When flour is kneaded into a dough, and spread into a cake, this cake, when baked, will be horny if it be thin, or if thick, will be tough and clammy; whence we see the value of that fermentative process, which generates thousands of little cells in the mass or crumb, each of them dry, yet tender and succulent, through the intimate combination of the moisture. By this constitution it becomes easily soluble in the juices of the stomach, or, in other words, light of digestion. It is moreover much less liable to turn sour than cakes made from unfermented dough. Rye, which also forms a true spongy bread, though inferior to that of wheat, consists of similar ingredients; namely, 61'07 of starch; 9'48 of gluten; 3'28 of vegetable albumen; 3'28 of uncrystallizable sugar; 11-09 of gum; 6*38 of vegetable fibre; the loss upon the 100 parts amounted to 5-62, including an acid whose nature the analyst, M. Einhof, did not determine. Rye flour contains also several salts, principally the phosphates of lime and magnesia. This kind of grain forma a dark-colored bread reckoned very wholesome; comparatively little used in this country, but very much in France, Germany, and Belgium. Dough fermented with the aid either of leaven or yeast, contains little or none of the saccharine matter of the flour, but in its stead a certain portion, nearly half its weight, of spirit, which imparts to it a vinous smell, and is volatilized in the oven; whence it might be condensed into a crude weak alcohol, on the plan of Mr. Hick's patent, were it worth while. But the increased complexity of the baking apparatus will probably prove an effectual obstacle to the commercial success of this project, upon which already upwards of ~20,000 sterling have been squandered. That the sugar of the flour is the true elemen- of the fermentation preposterously called panary, which dough undergoes, and that the starch and gluten have nothing to do with it, may be proved by decisive experiments. The vinous fermentation continues till the whole suaar is decomposed, and no longer; when, if the process be not checked by the heat of baking, the acetous fermentation will supervene. Therefore, if a little sugar be added to a flour which contains little or none, its dough will become susceptible of fermenting, with extrication of gas, so as to make spongy succulent bread. But since this sponginess is produced solely by the extrication of gas, and its expansion in the heat of the oven, any substance capable of emitting gas, or of being converted into it under these circumstances, will answer the same purpose. Were a solution of bicarbonate ol ammonia obtained by exposing the common sesqui-carbonate in powder for a day to the air, incorporated with the dough, in the subsequent firing it will be converted into vapor, and in its extrication render the bread very porous. Nay, if water highly impregnated with carbonic acid eas be used for kneading the dough, the resulting bread will be somewhat spongy. Could a light article of food be prepared in this way, then as the sugar would remain undecomposed, the bread would be so much the sweeter, and the more nourishing. How far a change propitious to digestion takes place in the constitution of the starch and gluten, during the fermentative action of the dough, has not been hitherto ascertained by precise experiments. Medical practitioners, who 250 BREAD. derive an enormous revenue from dysl epsia, should take some pains to investigate this subject. Dr. Colquhoun, in his able essay upon the art of making bread, has shown that its text ure, when prepared by a sudden formation and disengagement of elastic fluid generated within the oven, differs remarkably from that of a loaf which has been made after the prepara. tory fermentation with yeast. Bread which has been raised with the common carbonate of ammonia, as used by the pastry-cooks, is porous no doubt, but not spongy with vesicu. lar spaces, like that made in the ordinary way. The former kind of bread never presents that air-cell stratification which is the boast of the Parisian baker, but which is almost un. known in London. I have found it, moreover, very difficult to expel bythe oven the last portion of the ammonia, which gives both a tinge and a taste to the bread. I believe, however, that the bicarbonate would be nearly free from this objection, which operates so much against the sesqui-carbonate of the shops. In opposition to Mr. Edhn's account of the excellent quality of bread made by im pregnating dough with carbonic acid gas,* Dr. Colquhoun adduces Vogel's experiments, which show that such dough, when baked, after having been kept in a warm situation during the usual time, afforded nothing better than a.lard cake, which had no resemblance to common bread. Vogel further states. as illustrative of the general necessity of providing a sufficient supply of disengaged elastic fluid within the dough, before baking it at all, that when he made various attempts to form a well-raised vesicular loaf within the oven, by mixing flour with carbonate of magnesia, or with zinc filings, ana then kneading it into a paste by means of water, acidulated with sulphuric acid, he always met with complete failure and disappointment. Dr. Colquhoun performed a series of well-devigsd experiments on this subject, which fully confirmed Vogel's results, and prove that a proper spongy bread cannot be made by the agency of either carbonic acid water, or of mixtures of sesqui-carbonate of soda, and tartaric acid. The bread proved doughy and dense in every case, though less so with the latter mixture than the former. No loaf bread can, indeed, be well made by any of these two extemporaneous systems, because they are inconsistent with the thorough kneading of the dough. It is this process which renders dough at once elastic enough to expand when carbonic acid gas is generated within it, and cohesive enough to confine the gas when it is generated. The whole gas of the loaf is disengaged in its interior by a continuous fermentation, after all the processes of kneading have been finished; for the loaf, after being kneaded, weighed out, and shaped, is set aside till it expands gradually to double its bulk, before it is put into the oven. But when a dough containing sesqui-carbonate of soda is mixed with one containing muriatic acid, in due proportions to form the just dose of culinary salt, the gas escapes during the necessary incorporation of the two, and the bread formed from it is dense and hard. Dr. Whiting has, however, made this old chemical process the subject of a new patent for baking bread. When the baker prepares his dough, he takes a portion of the water needed for the batch, having raised its temperature to from 70~ to 100~ F., dissolves a certain proportion of his salt in it, then adds the yeast, and a certain quantity of his flour. This mixture, called the sponge, is next covered up in the small kneading-trough, alongside of the large one, and let a'one for setting in a warm situation. In about an hour, signs of vinous fermentation appear, by the swelling and heaving up of the sponge, in consequence of the generation of carbonic acid; and if it be of a semi-liquid consistence, large air bubbles will force their way to the surface, break, and disappear in rapid succession. But when the sponge has the consistence of thin dough, it confines the gas, becomes thereby equably and progressively inflated to double its original volume; when no longer capable of containing the pent-up air, it bursts and subsides. This process of rising and falling alternately might be carried on during twenty-four hours, but the baker has learned by experience to guard against allowing full scope to the fermentative principle. He generally interferes after the first, or at furthest after the second or third dropping of the sponge; for were he not to do so, the bread formed with such dough would be invariably found sour to the taste and the smell. Therefore he adds at this stage to the sponge the reserved proportions of flour, salt, and water, which are requisite to make the dough of the desired consistence and size; and next incorporates the whole together by a long and laborious course of kneading. When this operation has been continued till the fermenting and the fresh dough have been intimately blended, and till the glutinous matter of both is worked into such union and consistence that the mass becomes so tough and elastic as to receive the smart pressure of the hand without adhering to it, the kneading is suspended for some time. The dough is now abandoned to itself for a few hours, during which it continues in a state of active fermentation throughout its entire mass. Then it is subjected to a second but much less labGoious kneading, in order to distribute the generated gas as evenly as possible * Treatise on the Art of Bread Making, p. 56 BREAD. 251 among its parts, so that they may all partake equally of the vesicular structure. Aftet this second kneading, the dough is weighed out into the portions suitable to the size of bread desired; which are of course shaped into the proper forms, and once more set aside in a warm situation. The continuance of the fermentation soon disengages a fresh quantity of carbonic acid gas, and expands the lumps to about double their pristine volume. These are now ready for the oven, and when they finally quit it in the baked state, are about twice the size they were when they went in. The generation of the due quantity of gas should be complete before the lumps are transferred to the oven; because whenever they encounter its heat, the process of fermentation is arrested; for it is only the previously existing air which gets expanded throughout every part of the loaf, swells out its volume, and gives it the piled and vesicular texture. Thus the well-baked loaf is composed of an infinite number of ceilules filled with carbonic acid gas, and apparently lined with a glutinous membrane of a silky softness. It is this which gives the light, elastic, porous constitution to bread. After suffering the fermentative process to exhaust itself in a mass of dough, and the dough to be brought into that state in which the addition of neither yeast, nor starch, nor gluten will produce any effect in restoring that action, if we mix in 4 per cent. of saccharine matter, of any kind, with a little yeast, the process of fermentation will immediately re-commence, and pursue a course as active and lengthened as at first, and cease about the same period.* This experiment, taken in connexion with the facts formerly stated, proves that what was called panary fermentation, is nothing but the ancient and well-known process of the vinous fermentation of sugar, which generates alcohol. There seems to be but one objection to the adoption of this theory. After the loaf is baked, there is found in its composition nearly as much saccharine matter as existed in the flour before fermentation. M. Vogel states that in the baked bread there remains 3-6 parts of sugar, out of the 5 parts which it originally contained. Thus, in 100 parts of loaf bread prepared with wheaten flour, distilled water, and yeast without the admixture of any common salt, he found the following ingredients:Sugar - - - 36 Torrefied or gummy starch - 18.0 Starch -53.5 Gluten, combined with a little starch, 20'75 Exclusive of carbonic acid, muriate of lime, phosphate of lime, &c. It must be borne in mind that in every loaf the process of fermentation has been prematurely checked by the baker's oven, and therefore the saccharine constituent can never be wholly decomposed. It seems certain, also, that by the action of gluten upon the starch in the early stage of the firing, a quantity of sugar will be formed by the saccharine fermentation; which we have explained in treating of BEER. Several masses of dough were prepared by Dr. Colquhoun in which pure wheat starch was mixed with common flour, in various proportions. In some of the lumps this starch had been gelatinized, with the minimum of hot water, before it was added to the flour. After introducing the usual dose of salt, the dough was thoroughly kneaded, set apart for the proper period, allowed to ferment in the accustomed way, and then baked in the oven. In outward appearance, increase of bulk, and vesicular texture, none of them differed materially from a common loaf, baked along with them for the sake of comparison; except that when the starch considerably exceeded the proportion of flour in the lump, the loaf, though whiter, had not risen so well, being somewhat less vesicular. But, on tasting the bread of each loaf, those which contained most gelatinized starch were unexpectedly found to be the sweetest. The other loaves, into which smaller quantities of the gelatinized starch had been introduced. or only some dry starch, had no sweetish taste whatever to distinguish them from ordinary bread. These facts seem to establish the conclusion, that the presence of gelatinous starch in bread put into the oven, is a means of Ibrming a certain portion of saccharine matter within the loaf, during the bak. inq nrocess. Now it is more than probable that gelatinized starch does exist, more or less, in all loaves which have been fermented by our usual methods, and hence a certain quantity of sugar will necessarily be generated at its expense, by the action of heat. Thus the difficulty started by M. Vogel is sufficiently solved; and there remains no doubt that, in the saccharine principle of flour, the fermentation has its origin and end, while dough is under fermentation. The source of the sourness which supervenes in bread, under careless or unskilful hands, had been formerly ascribed to each of all the constituents of flour; to its gluten, its starch, and its sugar; but erroneously, as we now see: for it is merely the result of the second fermentation which always succeeds the vinous, when pushed improperly too far. It las been universally taken for granted by authors, that the acid thus generated * Dr. Co;quhuun, in Annals of Philosophy for 1826, vol. xii. p. 171 252 BREAD. in dough s the acetic. But there appear good grounds to believe that it is frequently t less volatile acid, probably the lactic, particularly when the process has been tardy, from the imperfection of the yeast or the bad quality of the flour. The experiments of Vogel, Braconnot, and others, prove that the latter acid is generated very readily, and in considerable quantity during the spontaneous decomposition of a great many vegetable substances, when in a state of humidity. The presence of lactic acid would account for the curious fact, that the acidity of unbaked dough is much more perceptible to the taste Ihan to the smell; while the sourness of the same piece of bread, after coming out of the oven, is, on the contrary, much more obvious to the olfactory organs than to the palate. But this is exactly what ought to happen, if the lactic acid contributes, in coniunction with the acetic, to produce the acescence of the dough. At the ordinary temperature of a bakehouse, the former acid, though very perceptible in the mouth, is not distinguishable by the nostrils; but as it is easily decomposed by heat, no sooner is it ex posed to the high temperature of the oven, than it is resolved, in a great measure, into acetic acid,* and thus becomes more manifest to the sense of smell, and less to that of taste. This theory seems to explain satisfactorily all the phenomena accompanying the progress of fermentation in baker's dough, and Iso some of its results in the process of baking which do not easily admit of any other solution. There are extremely simple and effectual methods for enabling the baker to adopt measures either to prevent or correct the evil of acescence, and these are to neutralize the acid by the due exhibition of an alkali, such as soda; or an alkaline earth, suen as magnesia or chalk. And it affords a striking proof of how much the artisan has been accustomed to plod, uninquiring and uninformed, over the same ground, that a remedy so safe and so economical, should remain at this day unthought of and unemployed by most of the manufacturers of bread in the United Kingdom. The introduction of a small portion of carbonate of soda will rectify any occasional error in the result of the so called panary fermentation, and will, in fact, restore the dough to its pristine sweetness. The quantity of acetate of soda, which will be thus present in the bread, will be altogether inconsiderable; and as it has no disagreeable taste, and is merely aperient to the bowels in a very mild degree, it can form no objection in the eye of the public police. The restoration of dough thus tainted With acid, and its conversion into pleasant and wholesome bread, has been sufficiently verified by experiment. But, according to Mr. Edmund Davy, carbonate of magnesia may be used with still greater advantage, as during the slow action of the acid upon it, the carbonic acid evolved serves to open up and lighten bread which would otherwise be dense and doughy from the indifferent quality of the flour. Here, however, the dangerous temptation lies with a sorditl baker to use cheap or damaged flour, and to rectify the bread made of it by chemical agents, innocent in themselves, but injurious as masks of a bad raw material. When sour yeast must be used, as sometimes happens with the country bakers, or in private houses at a distance from beer breweries, there can be no harm, but, on the contrary, much propriety, in correcting its acidity, by the addition of as much carbonate of soda to it as will effect its neutralization, but nothing more. When sour yeast has.been thus corrected, it has been found, in practice, to possess its fermentative power unimpaired, and to be equally efficacious with fresh formed yeast, in making good palatable loaves. We have seen that, in baking, about one fourth of the starch is converted into a matter possessing the properties of British gum (see STARCH), and also that the gluten, though not decomposed, has its particles disunited, and is not so tough and adhesive as it is in the flour. This principle is also, as we have said, useful in cementing all the particles of the dough into a tenacious mass, capable of confining the elastic fluid gene. rated by the vinous fermentation of the sugar. Starch is the main constituent, the basis of nourishment in bread, as well as in all farinaceous articles of food. The albumen also of the wheat, being coagulated by the heat of the oven, contributes to the setting of the bread into a consistent elastic body. In the mills in the neighborhood of London, no less than seven distinct sorts cf flour are ground out of one quantity of wheat. These are for one quarterFine flour -- 5 bushels 3 pecks. Seconds 0 2 Fine middlings -- - - 0 1 Coarse middlings - - 0 05 Bran - - - - -3 0 Twenty-penny- -- 3 0 Pollard -- - - - - 2 11 2-5 * Berzelius. BREAD. 253 So that we have nearly a double bulk of flour, or 14 bushels and 21 pecks from 8 bushels of wheat. In the sifting of the flour through the bolter, there is a fine white angular meal obtained called sharps, which forms the central part of the grain. It is consumed partly by the fine bisbcit bakers. The bakers of this country were formerly bound by law to bake three kinds of bread, the wheaten, standard wheaten, and the household; marked respectively with a W, S W, and H, and if they omitted to make these marks on their bread they were liable to a penalty. The size of the loaves were usually peck, half-peck, quartern, and half-quartern; the weights of which, within 48 hours of their being baked, should have been respectively 17 lbs. 6 oz.; 8 lbs. 11 oz.; 4 lbs. 5 oz. 8 dr.; and 4 lbs. 2 oz. 14 dr. In general they weigh about one seventh more before they enter the oven, or they lose one seventh of their weight in baking. The French bread loses fully one sixth in the oven, owing chiefly to its more oblong thin shape, as compared to the cubical shape of the English bread. But this loss of weight is very variable, being dependant upon the quality of the wheaten flour, and the circumstances of baking. The present law in England defines the quartern' loaf at 4 lbs., and subjects the baker to a penalty if the bread be one ounce lighter than the standard. Hence it leaves the baker, ih self-defence, to leave it in rather a damp and doughy state. But there is much light bread sold in London. I have met with quartern loaves of 3 lbs. 10 oz. A sack of flour weighing 280 lbs. was presumed by the framers of our former parliamentary acts, for the assize of bread, to be capable of being baked into 80 loaves. If this proportion had been correct, one fifth part of our quartern loaf must consist of water and salt, and four fifths of flour. But in general, of good wheaten flour, three parts will take up one part of water; so that the sack of flour should have turned out, and actually did turn out, more than 80 loaves. At present with 4 lb. bread it may well yield 92 loaves. The following statement of the system of bakizg at Paris, I received in 1835 from a very competent judge of the business. 1,000 kilogrammes of wheat=5 quarters English, cost 200 fr., and yield C00 kilos. of flour of the best white quality, equivalent to 5-1L sacks French. Hence the sack of flour costs 40 francs at the mill, and including the carriage to Paris, it costs 45 or 46 francs. The profit of the flour dealer is about 3- francs, and the sale price becomes from 43 to 50 francs. Bread manufactured from the above. ~ s.d. ~ s. d. One day's work of an ordinary baker, who makes four batches in a day, consists of 3 sacks at 50 francs, or 21. sterling each 6 0 0 Salt 2V lbs. at 2d. per lb. -0- 00 5Yeast or leaven 3 lbs. at 5d -0 1 3 Total cost of materials - -6 1 84 Expenses of Baking. Three workmen at different rates of wages, 15 francs - 0 12 0 Fire-wood 0, as the charcoal produced pays for it - - - General expenses, such as rent, taxes, interest of capital, &c. 0 12 0 14 0= 1 4 0 7 5 8j For this sum 315 loaves are made, being 105 for every sack of flour weighing 156-66 kilos. or 344f lbs. avoird. One loaf contains therefore 3 4 46 = 3-282 lbs., and as 100 lbs. of flour in Parisian baking are reckoned to produce 127 lbs. of bread, each loaf will weigh 4-168 lbs., avoird., and will cost 71. 5s. 82d. divided by 315 = 5-d. very nearly. The value of 315 loaves at the sale price of 6d. will be 7 17 5 Upon this day's work the clear profit is therefore - - 0 11 61f A new baking establishment has been recently formed at the Royal Clarence Victualling Establishment at Weevil, near Portsmouth, upon a scale of magnitude nearly sufficient to supply the whole royal navy with biscuits, and that of a very superior description. The following account of it is taken from the United Service Journal. " It having been discovered that the flour supplied to government by contract, had in many instances been most shamefully adulterated, the corn is ground at mills comprised within the establishment, by which means the introduction of improper ingredients is prevented, and precisely the proportion of bran which is requisite in the composition of good sea-biscuit is retained, and no more. The flour-mill is furnished with ten pairs of 254 BREAD. stones, by which 40 bushels of flour may be ground and dressed ready for baking, in an hour. The baking establishment consists of 9 ovens, each 13 feet long by 11 feet wide, and 171 inches in height. These are each heated by separate furnaces, so constructed,hat a blast 9f hot air and fire sweeps through them, and gives to the interior the requisite dose of heat in an incredible short space of time. The first operation in making the biscuits consists in mixing the flour, or rather meal and water; 13 gallons of water are first introduced into a trough, and then a sack of the meal, weighing 280 lbs. When the whole has been poured in by a channel communicating with an upper room, a bell rings, and the trough is closed. An apparatus consisting of two sets of what are called knives, each set ten in number, are then made to revolve amongst the flour and water by means of machinery. This mixing operation lasts one minute and a half, during which time the double set of knives or stirrers makes twenty-six revolutions. The next process is to cast the lumps of dough under what are called the breaking-rollers,huge cylinders of iron, weighing 14 cwt. each, and moved horizontally by the machinery along stout tables. The dough is thus formed into large rude masses 6 feet long by 3 feet broad, and several inches thick. At this stage of t;e business, the kneading is still very imperfect, and traces of dry flour may still be detected. These great masses of dough are now drawn out, and cut into a number of smaller masses about a fio t and a half long by a foot wide, and again thrust under the rollers, which is repeated until the mixture is so complete that not the slightest trace of any inequahiiy is discoverable in any part of the mass. It should have been stated that two workmen stand one at each side of the rollers, and as the dough is flattened out they fold it up, or double one part upon another, so that the roller at its next passage squeezes these parts together, and forces them to mix. The dough is next cut into small portions, and being placed upon large flat boards, is, by the agency of machinery, conveyed from the centre to the extremity of the baking-room. Here it is received by a workman, who places it under what is called the sheet roller, but which, for size, color, and thickness, more nearly resembles a blanket. The kneading is thus complete, and the dough only requires to be cut into biscuits before it is committed to the oven. The cutting is effected by what is called the cutting-plate, consisting of a net-work of 52 sharp-edged hexagonal frames, each as large as a biscuit. This frame is moved slowly up and down by machinery, and the workman, watching his opportunity, slides under it the above-described blanket of dough, which is about the size of a leaf of a dining-table; and the cutting-frame in its descent indents the sheet, but does not actually cut it through, but leaves sufficient substance to enable the workman at the mouth of the oven to jerk the whole mass of biscuits unbroken into it. The dough is prevented sticking to the cutting-frame by the following ingenious device: between each of the cutter-frames is a small flat open frame, moveable up and down, and loaded with an iron ball, weighing several ounces. When the great frame comes down upon the dough, and cuts out 52 biscuits, each of these minor frames yields to the pressure, and is raised up; but as soon as the great frame rises, the weight of the balls, acting upon the little frames, thrusts the whole blanket off, and allows the workmen to pull it out. One quarter of an hour is sufficient Xo bake the biscuit, which is afterwards placed for three days in a drying room, heated to 85~ or 90~, which completes the process." The following statement of the performance of the machinery is taken from actual experiment; in 116 days, during 68 of which the work was continued for only 7- hours; and during 48, for only 5- hours each day, in all 769 working hours, equal to 77 days of 10 hours each; the following quantity of biscuit was baked in the 9 ovens, viz.: 12,307 cwt. = 1,378,400 lbs. The wages of the men employed in baking this quantity amounted to 2731. 10s. 91d.; if it had been made by hand, the wages would have been 9331. 9s. 10d.; saving in the wages cf labor, 6591. 7s. 0ld. In this, is not included any part of the interest of the sum laid out upon the machine, or expended in keeping it in order. But in a very few years, at such an immense rate of saving, the cost of the engine and other machinery will be repaid. This admirable apparatus is the invention of T. T. Grant, Esq., storekeeper ot the Royal Clarence Victualling Establishment, who, we believe, has been properly rewarded, by a grant of 2,0001. from government. The labor of incorporating the ingredients of bread, viz., flour, water, and salt, or kneading dough, is so great as to have led to the contrivance of various mechanical modes of producing the same effect. One of the most ingenious is that for which a patent was obtained in August, 1830, by Mr. Edwin Clayton. It consists of a rotatory kneading trough, or rather barrel, mounted in bearings with a hollow axle, and of an interior frame of cast iron made to revolve by a solid axle which passes through the hollow one; in the frame there are cutters diagonally placed for kneading the dough. The revolving frame and its barrel are made to turn in contrary directions, so as greatly to save time anl equalise the operation. This double action represents kneading by the two hands, in which the dough is inverted from time to time, torn asunder, and reunited in every litferent form. The mechanism will be readily understood from the following description BREAD. 255 Fig. 190 exhibits a front elevation of a rotatory kneading trough, constructed according to improvements specified by the patentee, the barrel being shown in section a is the which barrel is mounted in the frame-work b, with hollow axles c and d, which hollow axles turn in suitable bearings at e; f is the revolving frame which is mounted in the interior of the barrel a, by axles g and h. The ends of this revolving fiame are fasteaed, or braced together by means of the oblique cutters or braces i, which act upon the doueh when the machine is put in motion, and thus cause the operation of kneaJing. Either the barrel may be made to revolve without the rotator tframe, or the rotatory frame without the barrel, or both may be made to revolve together, but in opposite ways. These several motions may be obtained by means of the gear-work, shown at k, 1, and in, as will be presently described. If it be desired to have the revolving mo tion of the barrel and rotatory fram e together, but in contrary directions, that motion may be obtained by fastening the hollow axle of the wheel m, by msaeeans of a screw, to the axle h, of the rotatory frame f, tight, so as they will revolve t ogether, the other wheels k and be iing used for th e purpose of reversing the motion of the barrel. It will then be found that by turning t he handle o t he two motion s will be obtained. If it be desired to put the rotatory frame f, only, into motion, that action will be ob tained by loosening the screw o, upon the axle of the wheel m, when it will be found that the axle h will be made to revolve freely by means of the winch o, without giving motion to the w he els k, I, and, and thus the barrel will remain stationary. If the rotatory action of the barrel be wanted, it will be obtained by turning the handle p, at the reverse end of tite machine, which, although it puts the gear at the opposite end of the barrel into motion, yet as the hollow axle of the wheel m is not fastened to the axle gh, by the screw a, the se wheels will revolve with out carry ing round the frame f. M. Kuhlmann, Professor of Che mistry at Lille, having be en called upon several times by the courts of justice to examine by chemical processes bread suspected of containing substances injurious to health, collected some interesting facts upon the subject, which were published under te de on o the central council of salubrity of the department du Nord. For some e tim e public attention had been drawn to an odi ous fraudcommitted by a great many bakers in the north of Fran ce and in Belgium-the in troduction of a certain quantiy of sulph of a of copper into their bread. When the flour was made from bad gram this adulteration was very generaliy p)ractised, as was proved by many convictions and confessions of the guilty persons. Whenhe e dough does not rise well in the fermentation (e pain pousse ploa),x this inconvenience was found to be obviated by the additisn of blue vitriol, which was supposed also to cause the flour to retain more water. The quantity of blue water added is extremely small, and it is never done in presence of strangers, because it is reckoned a valuable secret. It occasions no economy of yeast, but rather the reverse. In a litre (about a quart) of water, an ounce of sulphate of copper is dissolved; and of this solution a wine-glass full is mixed with the water necesssry for 50 quartern or 4 pound loaves. M. Kuhlmann justly obser ves, that there can be no safety whatever to the public when such a practice is permitted, because igno rance a nd avarice are always apt to increase the quantity of the poisonous water. In analyses imade by him and his colleaeues, portions f bread werie several times found so impregnated with the above salt that they had acquired a blue color, and presented occasionally even small crystals of the sulphate. By acting on the poisoned bread with distilled water, and testing the water with ferro-cyanat e (pvrussiate) of potash, the reddish brown recip tate or int characteristic of copper will appear even withr small qantities. Should the noxious im pregnation b e still more minute, the bread should be treated with a very dilute nitric acid, either directly or after incineration in a platinum capsule, and th e solution, w hen concentrated by evaporation, should bc tested by the ferro-cyanat e of potash. In this way, a one seventy thousandth part of sulphate of copper m ay be detected. part of sulphate of copper may be detected. 256 BREAD. M. Kuhlmaia deduces from a series of experiments on baking with various smax. quantities of sulphate of copper, that this salt exercises an extremely energetic action upon the fermentation and rising of the dough, even when not above one seventy thousandth part of the weight of the bread is employed; or one grain of sulphate for ten pounds of bread. The proportion of the salt which makes the bread rise best is one twenty thousandth, or one grain in three pounds of bread. If much more of the sulphate be added, the bread becomes moist, less white, and acquires a peculiar disagreeable smell like that of leaver. The increase of weight by increased moisture may amount to one sixteenth without the bread appearing softer, in consequence of the solidifying quality of the copper; for the acid does not seem to have any influence; as neither sulphate of soda, sulphate of iron, nor sulphuric acid have any analogous power. Alum operates like blue vitriol on bread, but larger quantities of it are required. It keeps water, and raises well, to use the bakers' terms. When alum is present in bread it may be detected by treating the bread with Jistilled water, filtering the water first through calico, and next through filtering paper, till it becomes clear; then dividing it into two portions, and into the one pouring a few drops of nitrate or muriate of barytes, and into the other a few drops of water of ammonia. In the former a heavy white precipitate indicating sulphuric acid will appear, and in the latter a light precipitate of alumina, redissoluble by a few drops of solution of caustic potash. When chalk or Paris plaster is used to sophisticate flour, they may be best detected by incinerating the bread made of it, and examining the ashes with nitric acid, which will dissolve the chalk with effervescence, and the Paris plaster without. In both cases the calcareous matter may be demonstrated in the solution, by oxalic acid, or better by oxalate of ammonia. In baking puff-paste the dough is first kneaded along with a certain quantity of butter, then rolled out into a thin layer, which is coated over with butter, and folded face-wise many times together, the upper and under surfaces being made to correspond. This stratified mass is again rolled out into a thin layer, its surface is besmeared with butter, and then it is folded face-wise as before. When this process is repeated ten or a dozen times, the dough will consist of many hundred parallel laminae, with butter interposed between each pair of plates. When a moderately thick mass of this is put into the oven, the elastic vapor disengaged from the water and the butter, diffuses itself between each of the thin laminee, and causes them to swell into what is properly called puff-paste, being an assemblage of thin membranes, each dense in itself, but more or less distinct from the other, and therefore forming apparently, but not really, light bread. One of the most curious branches of the baker's craft is the manufacture of gingerbread, which contains such a proportion of molasses, that it cannot be fermented by means of yeast. Its ingredients are flour, molasses or treacle, butter, common potashes, and alum. After the butter is melted, and the potashes and alum are dissolved in a little hot water, these three ingredients, along with the treacle, are poured among the flour, which is to form the body of the bread. The whole is then incorporated by mixture and kneading into a stiff dough. Of these five -constituents the alum is thought to be the least essential, although it makes the bread lighter and crisper, and renders the process more rapid; for gingerbread dough requires to stand over several davs, sometimes 8 or 10, before it acquires that state of porosity which qualifies it for the oven. The action of the treacle and alum on the potashes in evolving carbonic acid, seems to be the gasefying principle of gingerbread; for if the carbonate of potash is withheld from the mixture, the bread, when baked, resembles in hardness a piece of wood. Treacle is always acidulous. Carbonate of magnesia and soda may be used as substitutes for the potashes. Dr. Colquhoun has found that carbonate of magnesia and tartaric acid may replace the potashes and the alum with great advantage, affording a gingerbread fully more agreeable to the taste, and much more wholesome than the common kind, which contains a notable quantity of potashes. His proportions are one pound of flour, a quarter of an ounce of carbonate of magnesia, and one eighth of an ounce of tartaric acid; in addition to the treacle, butter, and aromatics, as at present used. The acid and alkaline earth must be well diffused through the whole dough. The magnesia should, in fact, be first of all mixed with the flour. Pour the melted butter, the treacle, and the acid dissolved in a little water all at once among the flour, and knead into a consistent dough, which being set aside for half an hour or an hour will be ready for the oven, and should never be kept unbaked more than 2 or 3 hours. The following more complete recipe is given by Dr. Colquhoun, for making thin gingerbread cakes: Flour 1 lb. Treacle 0a Raw sugar 0} BREAD. 257 Butter 2 oz. Carbon. magnesia 01 Tartaric acid 0O Ginger 0o Cinnamon 0O Nutmeg 1 This compound has rather more butter than common thin gingerbread. I shall here insert a passage from my Dictionary of Chemistry, as published in,s21 as it inay prove interesting to many of my present readers. "Under Process of Baking, in the Supplement to the Encyclopedia Britannica, we have the following statement:-' An ounce of alum is then dissolved over the fire in a tin pot, and the solution poured into a large tub, called by the bakers the seasoningtub. Four pounds and a half of salt are likewise put into the tub, and a pailful of hot water.'-Foot note on this passage.-' In London, where the goodness of bread is esti-. mated enirely by its whiteness, it is usual with those bakers who employ flour of an in. ferior quality, to add as much alum as common salt to the dough; or, in other words, the quantity of salt added is dim.nished one half, and the deficiency supplied by an equal weight of alum. This improves the look of the bread very much, rendering it much whiter and firmer.'" In a passage which we shall presently quote, our author represents the bakers of London in a conspiracy to supply the citizens with bad bread. We may hence infer that the full allowance he assigns of 2- pounds of alum for every 2f rounds of salt, will be adopted in converting the sack of flour into loaves. But as a sack of flour weighs 280 pounds, and furnishes on an average 80 quartern loaves, we have 2! pounds divided by 80, or 15750 -rais _ 197 grains, for the quantity present, by this writec in a London 80 quartern loaf. Yet in the very same page (39th of vol. ii.) we have the following passage: "Alum is not added by all bakers. The writer of this article has been assured by several bakers of respectability, both in Edinburgh and Glasgow, on whose testimony he relies, and who made excellent bread, that they never employed any alum. The reason for adding it given by the London bakers is, that it renders the bread whiter, and enables them to separate readily the loaves fiom each other. This addition has been alleged by medical men, and is considered by the community at large, as injurious to the health, by occasioning constipation. But if we consider the small quantity of this salt added by the baker, not quite 51 grains to a quartern loaf, we will not readily admit these'allegations. Suppose an individual to eat the seventh part of a quartern loaf a day, he would only swallow eight tenths of a grain of alum, or, in reality, not quite so much as half a grain; for one half of this salt consists of water. It seems absurd to suppose that half a grain of alum, swallowed at different times during the course of a day, should occasion constipation.'" Is it not more absurd to state 2' pounds or 36 ounces, as the alum adulteration of a sack of flour by the London bakers, and within a few periods to reduce the adulteration to one ounce? That this voluntary abstraction of -35 of the alum, and substitution of superior and more expensive flour, is not expected by him from the London bakers, is sufficiently evident from the following story. It would appear that one of his friends had invented a new yeast for fermenting dough, by mixing a quart of beer harm with a paste made of ten pounds of flour and two gallons of boiling water, and keeping this mixture warm for six or eight hours. "Yeast made in this way," says he, " answers the purposes of the baker much better than brewers' yeast, because it is clearer, and free from the hop mixture which sometimes injures the yeast of the brewer. Some years ago the bakers of London, sensible of the superiority of this artificial yeast, invited a company of manufacturers from Glasgow to establish a manufactory of it in London, and promised to use no other. About 5,0001. accordingly was laid out on buildings and materials, and the manufactory was begun on a considerable scale. The ale-brewers, finding their yeast, for which they had drawn a good price, lie heavy on their hands, invited all the journeymen bakers to their cellars, gave them their fill of ale, and promised to regale them in that manner every day, provided they would force their masters to take all their yeast from the ale-brewers. The journeymen accordingly declared, in a body, that they would work no more for their masters unless they gave up taking any more yeast from the manufactory. The masters were obliged to comply; the new manufactory was stopped, and the inhabitants of London were obliged to continue to eat worse bread, because it was the interest of the alebrewers to sell the yeast. Such is the influence of journeymen bakers in the metropolis of England!" This doleful diatribe seems rather extravagant; for surely beer yeast can derive nothing noxious to a porter drinking people, from a slight impregnation of hops; while it must form probably a more energetic ferment than the fermented paste of the new company, which at any rate could be prepared in six or eight hours by any baker who 18 258 BREAD. found it to answer his purpose of making a pleasant eating bread. But it is a very serious thing for a lady or gentleman of sedentary habits, or infirm constitution, to have their di. gestive process daily vitiated by damaged flour, whitened with 197 grains of alum pei quartern loaf. Acidity of stomach, indigestion, flatulence, headaches, palpitation, costive. ness, and urinary calculi may be the probable consequences of the habitual introduction of so much acidulous and acescent matter. I have made many experiments upon bread, and have found the proportion of alum very variable. Its quantity seems to be proportional to the badness of the flour; and hence when the best flour is used no alum need be introduced. That alum is not necessary for giving bread its utmost beauty, sponginess, and agreeableness of taste, is undoubted; since the bread baked at a very extensive establishment in Glasgow, in which about 20 tons of flour were regularly converted into loaves in the course of a week, united every quality of appearance with an absolute freedom from that acido-astringent drug. Six pounds of salt were used for every sack of flour; which, from its good quality, generally afforded 83 or 84 quartern loaves of the legal weight of four pounds five ounces and a half each. The loaves lost nine ounces in the oven. Every baker ought to be able to analyze his flour. He may proceed as follows:-A ductile paste is to be made with a pound of the flour and a sufficient quantity of water, and left at rest for an hour; then having tiel across a bowl a piece of silken sieve-stuff, a little below the surface of the water in the bowl, the paste is to be laid upon the sieve on a level with the water, and kneaded tenderly with the hand, so as merely to wash the starchy particles out of it. This portion of the flour gets immediately diffused through the water, some of the other constituents diss Jv e, and the gluten alone remains upon the filter. The water must be several times renewed till it ceases to become milky. The' last washings of the gluten are made out of the sieve. The whole of the turbid washings are to be put into a tall conical glass or stoneware vessel, and allowed to remain at rest, in a cool place, till they deposite the starch. The clear supernatant liquor is then decanted off. The deposite consists of starch, with a little gluten. It must be washed till the water settles over it quite clear, and then it is to be dried. The filtered waters being evaporated at a boiling heat, discover flocks floating through them, which have been supposed by some to be albumen, and by others gluten. At last, phosphate of lime precipitates. When the residuum has assumed a sirupy consistence in the cold, it is to be mixed with alcohol, in order to dissolve out its sugar. Cold water being added to what remains, effects a solution of the mucilage, and leaves the insoluble azotized matter with the LXspnate of lime. By this mode of analysis a minute portion of resin may remain in the gluten and in the washing water; the gluten retains also a small proportion of a fixed oil, and a volatile principle, which may be removed by alcohol. If we wish to procure the resin alone, we must first of all treat the flour, well dried, with alcohol. When corn flour, poor in gluten, is to be analyzed, the dough must be enclosed in a linen bag, kneaded with water, and washed in that state. In analyzing barley-meal by the above process, hordeile, mixed with common starch, is obtained: they may be separated by boiling water, which dissolves the starch, and leaves;he hordeine und r the aspect of saw-dust. Fig. 191 is th- I'an of a London baker's oven, fired with coal fuel. Fig. 192 is the longitudinal section. 192 [ Ah, 191 \//, m %W////// A _ lSfa I __' 1 E?//////// V ~ \ \ X x 5, 1 i a, the body of the oven; b, the door; c, the fire-grate and furnace; d, the smoke flue; e, the flue above the door, to carry off the steam and hot air, when taking out the bread; f, recess below the door, for receiving the dust; g, damper plate to shut off' the steam flue; h, damper plate to shut off smoke flue, after the oven has come to its propel BREAD. 259 1d' 193 heat; i, a small iron pan ever the fire-place c I' for heating water; k, ash-pit below the fur ^^^fi^ ^^^ B\\\|>\\nace. -w-..... 1 5\ — \ - Fi. 193 is the front view; the same letters re- h'~=_'.=+.....fSl - fer to the same objects in all the figures. r r - The flame and burnt air of the fire at c, sweep J j i _jj ^ -I C along the bottom of the oven by the right hand, L_ —~1- -.__.- ~ side, are reflected from the back to the left hand!f r' [ —'I side, and thence escape by the flue d; (see plan f jk fig. 193.) Whenever the oven has acquired the 1. I t _. 1 proper degree of heat, the fire is withdrawn, the E||~i ~ ~ J {^_ _ _ _ flues are closed by the damper plates, and the lumps %~'~' ~%~%%~"~~~^x\ w. f X. m m of fermented dounh are introduced. I believe it may be safely asserted that the art of baking bread, pastry, and confectionery, is carried in Paris to a pitch of refinement which it has never reached in London. I have never seen here any bread which, in flavour, colour and texture, rivalled the French pain de gruau. In fact, our corn monopoly laws, till they were of late happily repealed, prevented us from getting the proper wheat for preparing, at a moderate price, the genuine sernoule out of which that bread is baked. Hence, the plebeian bourgeois can daily grace his table with a more beautiful piece of bread than the most affluent English nobleman. The French process of baking has been recently described, with some minuteness, by tleir distinguished chemist, M. Dumas*, and it merits to be known in this country. At each operation, the workman (petrisseur) pours into the kneading trough the residuary leaven of a former kneading, adding the proportion of water which practice enjoins, and diffuses the leaven through it with his hands. He then introduces into the liquid mass the quantity of flour destined to form the sponge (pate). This flour is let down from a chamber above, through a linen hose (manche), which may be shut by folding it up at the end. The workman now introduces the rest of the flour by degrees, diffusing and mingling it, in a direction from the right to the left end of the trough. When he has thus treated the whole mass successively, he repeats the same manipulation from left to right. These operations require no little art for their dextrous performance; hence they have the proper name assigned respectively to each, of frasaye and contrefrasage. The workman next subjects the dough to three different kinds of movement, in the kneading process. He malaxates it; that is, works it with his hands and fingers, in order to mix very exactly its component parts, while he adds the requisite quantity of flour. He divides it into six or seven lumps (pdtons), each of which he works successively in the same manner. Then he seizes portions of each, to draw them out, taking only as much as he can readily grasp in his hands. When he has thus kneaded the different lumps, he unites them into one mass, which he extends and folds repeatedly back upon itself. He then lifts up the whole at several times, and dashes it forcibly against the kneading trough, collecting it finally at its left end. The object of these operations is to effect an intimate mixture of the flour, the water, and the leaven. No. y powdery spots called marrons, should be left in any part of the dough. The kneader has now completed his work; and after leaving the dough for some time at rest, he turns it upside down. He lays the lumps, of a proper weight, upon a table, rolls them out, and dusts them with a little flour. He next turns over each lump, and puts it in its panneton, where he leaves it to swell. If the flour be of good quality, the dough be well made, and the temperature be suitable, the lumps will swell much and uniformly. If after the surface has risen, it falls to a considerable extents the flour must be bad, or it must contain other substances, as potato starch, bean meal, &c. Whenever the oven is hot enough, and the dough sufficiently fermented, it is subjected to the baking process. Ovens, as at present constructed, are not equally heated throughout, and are particularly liable to be chilled near the door, in conseque,,ce of its being occasionally opened and shut. To this cause M. Dumas ascribes many of the defects of ordinary bread; but he adds, that by adopting the patent invention of M. Mouchot these may be obviated. This is called the improved bakery, boulangerie perfectionnee. Fig. 194. is a ground plan of the aerothermal bake-house, the granaries being in the upper stories, and not shown here. b b are the ovens; c, the kneading machine; d, the place where the machinery is mounted for hoisting up the bread into the store * Traite de Chimie appliquee aux Arts, vi. p. 400. 260 BREAD. room above; e, a space common to the two oven-, into which the hot air passes; f, tih place of a wheel driven by dogs, for giving moticn to the kneading machine. 194 zig. 195. is a longitudinal section of the oven; A, the grate where coke or even pita coals may be burned; B, B, void spaces which, becoming heated, serve for warming small pieces of dough in; c, c are flues for conducting the smoke, &c., from the fireplace; D, seen in fig. 196., is the chimney for carrying off the smoke transmitted by the flues; E, E, void spaces immediately over the flues, and beneath the sole, F, F, of the oven. By this arrangement the air, previously heated, which arrives from the void spaces B through the flues, c, c, gets the benefit of the heat of the flame which circulates in these flues, and, after getting more heated in the spaces E, E, ascends through channels into the oven F, F, upon the sole of which the loaves to be baked are laid..,. X\\\\\\\X X S\t The hot air is admitted into it through the passages a, a, being drawn from the reservoirs B, B, B, and also by the passage d, d, drawn from the reservoirs E E. The sole is likewise heated by contact with the hot air contained in the space E, t, placed immediately below it. The hot air, loaded with moisture, issues by the passage b, b, and returns directly into the reservoir B, B. G, G, an enclosed space directly ovei BREAD. 261 ihe oven, to obstruct the dissipation of its heat; g, vault of the fire-place. Fig. 196., a transverse section through the middle of the oven. Fig. 197., the kneading machine, a longitudinal section passing through its axis; P, P, the contour of the machine, made 196 f of wood, and divided into three compartments fdr the reception of the dough. The wooden bars, o, o, are so placed in the interior of the compartments, as to divide the 4ough whenever the cylinder is made to revolve. One portion, D, of the cylinder may be opened and laid over upon the other by means of a hinge joint, when the dough and flour are introduced. A, B, C, the three compartments of the machine, two for making the dough, and one for preparing the sponge, called levain, or leaven, by the French. a, a, is the pulley which receives its motion from the engine, and transmits it to the cylinder through the pinion b, and the spur-wheel e; d d, the fly-wheel to regulate the motion; g, a brake to act upon the fly d, by means of a lever h; i, the pillar of the fly-wheel. There is a ratchet wheel counter for numbering the turns of the kneading machine, but it cannot be shown in this view; n, cross bars of wood, which are easily removed when the cylinder is opened; they divide the dough. Each of Ahe three compartments of the kneader (fig. 197.) is furnished at pleasure with two'ars fixed crosswise, but which may be easily removed, whenever the cylinder is opened. These bars c, nstitute the sole agents for drawing ont the dough. 197 a P P In a continuous operation, the leaven is constantly prepared in the compartment A; with which view there is put into it125 kilogrammes of ordinary leaven or yeast. 67 - -- flour. 33 - - - - - - water. In all 225 kilogrammes. The person in charge of the mechanical kneader shuts down its lid, and setv it 262 BREAD. a-going. At the end of about seven minutes he hears the bell of the counter sound, announcing that the number of revolutions has been sufficient to call for an inspection of the sponge, in regard to its consistence. The cylinder is therefore opened, and after verifying the right state of the leaven, and adding water to soften, or flour to stiffen it, he closes the lid, and sets the machine once more in motion. In ten minutes more the counter sounds again, and the kneading is completed. The 450 kilo. grammes of leaven obtained from the two compartments are adequate to prepare dough enough to supply alternately each of the two ovens. For this purpose 75 kilogrammes of leaven are taken from each of the two compartments A and A', and placed in the intermediate compartment B. The whole leaven is then 75+75=150 kilogrammes; to which are added 100 kilogs. of flour and 50 of water=150, so that the chest contains 300 kilogrammes. There is now replaced in each of the cavities A and A' the primitive quantity, by adding 50 kilogrammes of flour and 25 of water= 75. The cylinder is again set a-going, and from the nature of the apparatus, it is obvious that the kneading takes place at once on the leavens A end A' and on the paste B; which last is examined after 7 minutes, and completed it 10 more=17, at the second sound of the counter-bell. The kneader is opened, the paste on the side and on the bars is gathered to the bottom by means of a scraper. The whole paste of the chest B being removed, 150 kilogs. of the leaven are taken, to which 150 kilogs. of flour and water are added to prepare the 300 kilogs. of paste destined for the supply of the oven No. 2. These 75 kilogs. of leaven from each compartment are replaced as before, and so on in succession. The water used in this operation is raised to the proper temperature, viz. 25~ or 30~ C. (77~ or 86~ F.) in cold weather, and to about 68~ F. in the hot season, by mixing common cold water with the due proportion of water maintained at the temperature of about 160~ F., in the basin F placed above the ovens. Through the water poured at each operation upon the flour in the compartment B, there is previously diffused from 200 to 250 grammes of fresh leaven, as obtained from the brewery, after being drained and pressed (German yeast). This quantity is sufficient to raise properly 300 kilogs. of dough. As soon as this dough is taken out of the kneader, as stated above, and while the machine goes on to work, the quantity rc:lisite for each loaf is weighed, turned about on the table D, to give it its round or oblong form, and there is impressed upon it with the fore-arm or roller, the cavity which characterizes cleft loaves. All the lots of dough of the size of one kilog., called cleft loaves (pains fendus) are placed upon a cloth a fold of which is raised between two loaves, the cloth being first spread upon a board; which thus charged with 10 or 15 loaves is transferred to the wooden shelves G G in front of the oven. The whole of them rise easily under the influence of the gentle temperature of this antechamber or fou'il,. Whenever the dough loaves are sufficiently raised here, they are put into the oven, a process called enfournement in France; which consists in setting each loaf on a wooden shovel dusted with coarse flour, and placing it thereby on the sole of the oven, close to its fellow, without touching it. This operation is made easy, in conse;:ence of the introduction of a long jointed gas-pipe and burner int the interior of the oven, by the light of which all parts of it may be minutely examined' The oven is first kept moderately hot, by shutting the dampers; but whenever the thermometer attached to it indicates a temperature of from 300~ to 290~ C. (572~ to 554~ F.), the dampers or registers, are opened, to restore the heat to its original degree, by allowing of the circulation of the hot air, which rises from the lower cavities around the fire-place into the interior of the oven. When the baking is completed, the gaslight, which had been withdrawn, is again introduced into the oven, and the bread is taken out; called the pro'ess of difournement. If the temperature have been maintained at about 300~ C., the 300 kilogs. of dough divided into loaves of one kilog. (2} lbs. avoirdupois) will be baked in 27 minutes. The charging having lasted 10 minutes, and the discharging as long, the baking of each batch will take up 47 minutes. But on account of accidental interruptions, an hour may be assigned for each charge of 260 loaves of 1 kilog. each; being at the rate of 6240 kilogs. (or 6-75 tons) of bread in 24 hours. Although the outer parts of the loaves be exposed to the radiation of the walls, heated to 280~ or 300~ C., and undergo therefore that kind of caramelization (charring) which produces the colour, the taste, and the other special characters of the crust, yet the inner substance of the loaves, or the crumb, never attains to nearly so high a temperature; for a thermometer, whose bulb is inserted into the heart of a loaf, does not indicate more than 100~ C. (212~ F.). The theory of panification (bread-baking) is easy of comprehension. The flour owes this valuable quality to the gluten, which it contains in greater abundance thar BREAD. 263 any of the other cerealia (kinds of corn). This substance does not constitute, as had been heretofore imagined, the membranes of the tissue of the perisperm of the wheat; but is enclosed in cells of that tissue under the epidermic coats, even to the centre of the grain. In this respect the gluten lies in a situation analogous to that of the starch, and of most of the immediate principles of vegetables. The other immediate principles which play a part in panification are particularly the starch and the sugar; and they all operate as follows:The diffusion of the flour through the water, hydrates the starch and dissolves the sugar, the albumen, and some other soluble matters. The kneading of the dough, by completing these reactions through a more intimate union, favors also the fermentation of the sugar, by bringing its particles into close contact with those of the leaven or yeast; and the drawing out and malaxating the dough softens and stratifies it, introducing at the same time oxygen to aid the fermentation. The dough, when distributed and formed into loaves, is kept some time in a gentle warmth, in the folds of the cloth, pans, &c., a circumstance propitious to the development of their volume by fermentation. The dimensions of all the lumps of dough now gradually enlarge, from the disengagement of carbonic acid in the decomposition of the sugar; which gas is imprisoned by the glutinous paste. Were these phenomena to continue too long, the dough would become too vesicular; they must, therefore be stopped at the proper point of sponginess, by placing the loaf lumps in the oven. Though this causes a sudden expansion of the enclosed gaseous globules, it puts an end to the fermentation, and to their growth; as also evaporates a portion of the water. The fermentation of a small dose of sugar is, therefore, essential to true breadbaking; but the quantity actually fermented is so small as to be almost inappreciable. It seems probable that in well-made dough the whole carbonic acid that is generated remains in it; amounting to one half the volume of the loaf itself at its baking tempera. ture, or 212~. It thence results that less than one hundredth part of the weight of the flour is all the sugar requisite to produce well-raised bread. What egregious folly was it, therefore, to mount the bakery in Chelsea, twelve years ago, at an expense of 20,0001., for the purpose of catching the volatile spirits in their escape from the loaves in the oven-or, as it was vulgarly terried, " taking the gin out of the bread!" whereas it was nothing but taking the cash out of the pockets of the pseudo-chemical visionaries who swarm in this metropolis. The richness or nutritive powers of sound flour and also of bread are proportional to the quantity of gluten they contain. It is of great importance t6 determine this point, for both of these objects are of enormous value and consumption; and it may be accomplished most easily and exactly by digesting in a water-bath, at the temperature of 167' F., 1,000 grains of bread (or flour) with 1,000 grains of bruised barley-malt, in 5,000 grains, or in a little more than half a pint, of water. When this mixture ceases to take a blue color from iodine (that is, when all the starch is converted into soluble dextrine) the gluten left unchanged may be collected on a filter cloth, washed, dried at a heat of 2120, and weighed. The color, texture, and taste of the gluten, ought also to be examined, in forming a judgment of good flour, or bread. Independently of the skill of the baker, bread varies in quality according to the quantity of water and gluten it contains. A patent of German or French origin wu obtained here a few years ago, for manufacturing loaf-bread by using thin boiled flour. paste instead of water for setting the sponge, that is, for the preliminary dough fermentation. By this artifice, 104 loaves of 4 lbs. each could be made out of a sack of flour, instead of 94, as in ordinary baking; because the boiled paste gave a water-keeping faculty to the bread in that proportion. But this hydrated bread was apt to spoil in warm weather, and became an unprofitable speculation to all concerned. Bread and flour are often adulterated in France with potato staich, brt almost never, I believe, in this country. The sophistication is easily detected by the microscope, on account of the peculiar ovoid shape and the large size of the particles of the potato fecula. Horse-bean flour gives to wheaten bread a pinkish tint. In spoiled flour (such as is too often used, partially at least, by our inferior bakers) the gluten sometimes disappears altogether, and is replaced by ammoniacal salts.* In this case quicklime separates ammonia from the flour without beat; in flour slightly damaged, or ground from damaged wheat, the gluten present is deprived of its elasticity, and is softer than in the natural state. On this account the gluten test of M. Ioland is valuable. It consists in putting some gluten into the bottom of a copper tube, and heating that tube in an oven, or in oil at a vemperature of 284~ F..The length to which the cylinder of gluten expands is proportional to and indicates its quality. It appears that a French sack of flour, which weighs 159 kilogrammes, affords from 102 to 106 loaves of 2 kilogrammes each: and therefore, 159. 52-0:: 280: 91'6; that is, if 159 kilogs. or lbs. afford 52 loaves of 4 kilogs. ar lbs., 280 lbs., a sack English, should afford 91'6 loaves of 4 lbs. each; but oui * Dumas, Chimie Appliquee, vi. 425. 264 BREWING. bakers usually make out 94 loaves, which are rated at 4 pounds, though they seldom weigh so much. The loaves of a baker in my neighbourhood, who supplied my family with bread for some time, were found on trial to be fiom 6 to 8 oz. deficient in weight: when challenged for this fraud, he had the effrontery to palliate it by alleging that all his neighbour bakers did the same. It must be borne in mind that a Paris loaf of 2 lbs. or 2 kilogs. contains more dry farina than a London loaf of like weight; for it contains, from its form and texture, more crust. The crumb is to the crust in the Paris long loaves, as 25 to 75, or 1 to 3; in our quartern loaves it is as 18 or 20 to 100 M. Dumas gives the following Table:Weight of a Number of Weight of the Increase of Ratio of dry Flour Sack of Flour. Loaves. Bread. Weight of Flour. = 1. to Bread. 159 Kilogs. 102 202 Kilogs. 1-283 159 do. 104 208 do. 1'300 1: 1-60 159 do. 106 212 do. 1-333 Thus it would appear that the mean yield would corresp.rd to 130 kilogs. of bread for 100 of the flour employed: and admitting that common flour contains 0-17 of water, the product would be equivalent to 150 of bread for 100 of flour absolutely dry, The whole loaf contains 66 per cent. of dry substance, and the crumb only 44. BRECCIA, an Italian term, used by mineralogists and architects to designate such compound stony masses, natural or artificial, as consist of hard rocky fragments of considerable size, united by a common cement. When these masses are formed of small rounded pebbles, the conglomerate is called a pudding-stone, from a fancied resemblance to plum pudding. Concrete, now so much used for the foundation of large buildings, is a factitious breccia, or pudding-stone. See CONCRETE. BREWING. (Brasser, Fr.; Brauen, Germ.) The art of making BEER, which see. The peculiar properties contained in wort, do not exist ready formed in malt, but are the result of the direct action of heat and water upon that substance. Hence it follows that the composition of beer-wort depends more upon the process of mashing than upon the malt employed,-for it would be quite practicable to obtain from 1 part of malt and 8 parts of barley, a wort precisely similar to that procured from 9 parts of pure malt alone. But, of course, this could not be done without modifying considerably the process of mashing; and it happens, unfortunately, that the practice of the present day, amongst brewers, is to maintain, as closely as possible, one uniform system of mashing, whatever may be the nature or quality of the malt employed. Thus a difference in the malt is made to produce a difference in the wort, and all the energy and skill of the practical brewer are sometimes insufficient to compensate for the alterations which this difference induces in the subsequent working of the beer. With a regular and certain composition, as to the constituents of his wort, the operations of the brewer would assume a fixed and definite character, which, at present, they are very far indeed from possessing; and by which he not unfequently suffers the most severe pecuniary loss and mental anxiety. With the exception of a trifling quantity of vegetable albumen, the only solid ingredients of beer-wort are dextrine and sugar; the latter of which ferments with great ease and rapidity, whilst the dextrine, though capable of fermentation, enters into the process only with difficulty, and requires, for its successful termination, not only much more yeast, but also a much higher temperature in the fermenting fat. At the same time, it is this very sluggishness in the fermentative quality of dextrine which is essential to the production of good beer; for, with sugar alone, the fermentation cannot be checked at ordinary temperatures, until the full measure of its decomposition has taken place, and it has become either a vapid admixture of alcohol and water, or, by the absorption of oxygen, is resolved into vinegar. It is indeed a notorious fact, that beer made with sugar will not keep so well as that mande from malt; though, for rapid consumption, the use of sugar is, under some circumstances, to be commended, more especially on the small scale and in cold weather. The peculiarity of dextrine is, however, as we have stated, to undergo fermentation only with difficulty and by slow degrees; hence its decomposition spreads over a long space of time, and, in very cold weather, amounts to nothing; so that for months, or even years, after all the sugar of the wort has been destroyed, the evolution of carbonic acid gas from the still fermentiug dextrine, keeps up a briskness and vitality in the beer; and, by excluding oxygen, all chance of acidification is shut off. A perfect beer-wort should therefore have reference to the period of its consumption: if this be speedy and pressing, the proportion of sugar ought to be large; if remote, the dextrine should greatly predominate. Under the first condition, the attenuation would proceed quickly and, provided the temperature of the fermenting vat was not allowed to exceed 78~, the beer would soon cleanse and become ripe and bright; under the second, the attenuation in BREWING. 265 the vat would be slow and trifling, and require, perhaps, several years for its completion in the cask. Nevertheless, if the attenuation in the vat had gone on to the complete destruction of all the sugar, this kind of beer would prove in the end both the better and more healthy beverage of the two; for by the mode of its formation tht presence of senantllic ether or fusel oil is avoided. The importance therefore of placing in the hands of the brewer a means of determining the relative amounts of sugar and dextrine in his wort is sufficiently obvious. Now, this may be done in two ways; either by ascertaining, in wort of a determinate strength, the proportion of the one or the other of these substances. The dextrine is easier of calculation than the sugar, in a rough or approximate way; but the sugar can be determined with much more minute accuracy than the dextrine. Yet, in practice, the former plan is preferable, from its simplicity, as we shall proceed to show. If, to a certain volune of strong wort (say of 30 lbs. per barrel), we add an equal amount of alcohol or spirits of wine, the whole of the dextrine will precipitate as a dense coagulum; and by examining the bulk of this deposit in the tnbe, its weight may be inferred pretty nearly if the tube has been previously graduated so as to indicate, from actual experiment, the weight of the different measures of the coagulated dextrine. With weaker wort, more alcohol must be used, and with a denser wort, less alcohol,-the relations of which to each other may easily be kept recorded on a small card or scale affixed to the tube. This instrument:s very easy of application, and has been found extremely useful to more than one practical brewer of the present day; and the accompanying record of brewing operations has reference to this mode of analysing wort. The determination of sugar in wort is best effected by boiling 100 grs. of it with about half a pint of the following solution, and collecting and weighing the red-coloured precipitate which ensues,-every three grains of which indicate one grain of grape-sugar in the wort. Grap. sugar Test Solution. Sulphate of copper in crystals 100 grains Bitartrate of potash - - - - - 200 do Carbonate of soda in crystals - - - - 800 do Boiling water, one pint, or - - - - 8750 do First dissolve the sulphate of copper, then the bitartrate of potash, after which add the carbonate of soda, and filter if necessary. This solution is not affected when boiled with cane-sugar, dextrine, gum, or starch. We now proceed to lay before our readers the result of two brewings taken from one mash at two different periods, and analyzed to determine their relative contents of dextrine and sugar, according to the tube or alcohol process:-March 28th, 1851, proceeded to mash for experimental brewings; weather clear and open; thermometer outside at 510, -in fermenting room 58~; difference between wet and dry bulb 5'750~; barometer 39'4 inches. Composition of the malt:-Moisture 6'1; insoluble matter 27; extract 66-9. Quantity of malt employed 70 bushels; of water at 180~ F., 700 gallons; made the mixture with a common mashing-oar, and finished in fifteen minutes. One hour afterwards, drew off 200 gallons of wort; and three hours from commencing to mash, drew off 200 gallons more,-continuing the mash for table-beer-wort. The first-drawn wort contained 7-5 parts of dextrine to 1 of sugar; the second, 6'3 parts of dextrine 2-2 of sugar;-their densities were, respectively, 30 and 36'5 lbs. per barrel. They were each boiled separately, with relative amount of hop,-the first having 30 and the second 36+ lbs. added; and the boiling in each case was kept up for three hours. At the end of this time both were cooled and diluted with water to a gravity of 27~ lbs. per barrel, and 250 gallons of each let down into separate fermenting-vats placed side by side; after which, they both received three quarts of good yeast,-the temperature being at 68~ F. Two hours afterwards, the following observations commenced:-No. 1. being the wort containing 7'5 parts of dextrine to 1 of sugar, and No. 2. the wert having 6-3 of dextrine to 2-2 of sugar. 1851. No. 1. Temp. March 28. 5 P. ir. No action - 67'5 " " 10 P. Mi. Light thin cream - - - 67'5 29. 9 A. M. White head 70 " 6 P. M. Fine white head - - - 71. " 80. 9 A. M. Thick tough head - - - - 74 " 6 P. M. Tough brown head - - - - 76 31. 2 P. M. Ferment well roused up - - - 75 Deg. Attenuation of No. 1. - - - April 2. 2 P. M. (Skimmed off yeast) - - - 10 " 11. 2 P. - - - - 15' " 13. 2 Pr.. " " - - - - 16 [~~~~~~~~~~~~~~~~~~~~~~~~ 266 BREWING. No. 2. Deg No action - - -. - 68' Fine white head - - 70 Thick yellow head - - - -. 74 Fine tough brown head - - 77 High roused up rocky head - - - - 77 In rapid fermentation - 765 Throws up much yeast (skimmed off yeast) - 76' Ditto of Nro. 2. - -- - 12-7..- - - - - - 15'5.... — -.. 17-5 "- - - - - 18-2 The temperature of both had now fallen to 69~ F., though each had been roused re peatedly; the yeast was, therefore, again skimmed off, and the beer run into barreld, ana filled up with reserved wort three times a day as it worked over. On April tLe 18th the barrels were closed, having then lost, by attenuation,-No. 1. 16-2 lbs., and No. 2. 19'6 Ibs. Six weeks afterwards these ales were examined;-No 1. was found muddy and unpleasant; whilst No. 2. had a finn fragrant aroma, a brisk, lively appearance, and was perfectly bright. On January 2nd, 1852, the casks were again exaxnined; No. 1. had now lost 17'9 lbs., and was bright, rich, and fine flavoured; whilst N. 2., though bright and pleasant, had contracted a little acidity, and was becoming flat; it had lost, in all, 21J lbs. Two similar experiments, made about the same time in another quarter, gave almost exactly the same results; and, consequently, there can be little doubt that, where a quick sale and rapid consumption of beer can be ensured, the great object of the bre wer should be to convert as much of the dextrine of his wort into sugar as is proportional to the rapidity of that consumption; whereas, for beer intended to keep, the opposite practice should be followed. The conversion of any given amount of the dextrine wort into sugar may be effected either by keeping up the temperature of the mash-tun, and prolonging the operation of mashing: or, which is better and simpler, by merely preserving the wort for a few hours at a heat of 170~ F., either in the underback or any other convenient vessel. We have found from experiment that a wort which when run out from the mash-tun had only 3 parts of sugar to 16 of dextrine, became by 10 hours' exposure to a heat of 165~ converted almost altogether into sugar,-the proportions then being 17'8 of sugar to 1-2 of dextrine. A very important part of the duty of a brewer should therefore be, first, the deter mination of the relative amounts of dextrine and sugar required to suit the taste of his customers, or the circumstances of the market, and next, the continued careful examination of his wort, so as to insure that these proportions are regularly maintained; for by no other plan is it possible to insure that certainty of result, and uniformity of quality which are essential to the proper conducting of an expensive business like brewing. It seems to us that far too little attention has hitherto been given to the fluctuating qualities of beer-wort. In warm weather, this wort should probably contain at least twice as much dextrine as in winter; yet this is the very period when from the increased temperature of the air and materials, the largest quantity of sugar must be formed by those who mash upon a fixed and unvarying principle. Hence the proneness of the wort to ferment violently in summer is still further increased by the presence of an extra proportion of sugar;-whereas prudence would suggest, under such circumstances, a predorninance of dextrine, and seek to effect this purpose by a low temperature in the mash-tun, and by shortening the period of mashing. We are not, however, aware that this custom prevails, except in one or two solitary instances, in the north of England, where it is well appreciated. As a general rule, in the management of wort, more sugar is requisite where small quantities are brewed at a time, than where large operations are conducted, for the loss of heat is relatively larger in small masses than in large ones; and, from what has been stated, it must be apparent, that, as the fermentation of dextrine is more easily checked by cold than that of sugar, the beer brewed in trifling quantities could not preserve a fermentative temperature, but would become chilled and dead from the excessive radiation of caloric, unless a principle existed in it capable of fermentation at the most ordinary temperatures of this country. If, therefore, beer-wort consisting chiefly of dextrine be fermented in very cold weather, or with an insufficiency of yeast, or if the temperature happen to rise too high, so as to destroy or impair the fermentative power of the yeast, then a dull languid action will ensue, accompanied by what has been called the viscous fermentation, and the beer becomes permanently ropy, and is spoiled. Although, clearly, it would be impossible to lay down any specific rule for the proper proportion of dextrine and sugar in beer-wort, yet there could be no difficulty in each BREWING. 267 brewer determining for himself, and for the conditions of size, time of sale, time of year, and other contingencies, the requisite ratio to be established in his own case; and, as we have shown, nothing can be simpler than the means proposed for ascertaining the composition of wort. The advance of the arts is gradually assuming a character which will no longer permit any manufacturer to neglect the assistance of science; and those who first take advantage of the power of knowledge, will assuredly leave their fellow-labourers behind. From being an uncertain and hazardous operation, brewing must ere long become a fixed and definite principle based upon facts well understood, and capable of perpetual repetition and reproduction at will. To sum up briefly the general details of ale brewing, we may state, that, for most kinds of ale, the attenuation in the first instance should be finished in from 6 to 21 days, according to the strength of the wort; that this attenuation should approach to two-thirds of the whole weight; and that after tunning and cleansing, the ale itself should weigh about one-fourth of the original gravity of the wort. Thus, if the fermenting tun be set with wort of 27 lbs., then the attenuation should bring it down to 9 or 10 lbs., and the subsequent operations produce an ale weighing from 6 to 7 lbs. When these conditions are fulfilled, without much extra trouble or attention, the ale is pretty certain to turn out well, though, in some localities, ale is never attenuated to more than one-half its original gravity; this kind of ale is, however, very apt to become sour in hot weather and ropy in cold. We will now proceed to describe the brewing of porter, which differs from that of ale both in the nature of the materials used and in the mode of finishing the fermentation. Porter owes its peculiar colour and flavour to burnt saccharine or starchy matter; and this was formerly obtained by burning sugar until it exhaled the odour called by French writers "caramel." At present, however, nothing but highly-torrefied malt is used; and of this there are several kinds, as brown malt, imperial malt, and black malt; all of which are used by some brewers, whilst others employ only the brown and black, and a few the black alone, for giving colour and flavour. The fermentative quality is saccharine, is, however, the same as that of ale, and is derived from pale or amber malt. As a general rule, the ratio of the colouring and flavouring malts are to the saccharine, as about 1 to 5, or 1 to 4; but where black malt only is used, the pronortion does not exceed 1 to 10. The employment of these burnt malts permits a singular act of injustice on the part of the Excise, as regards the drawback on exportation. By the Excise regulations, it is assumed that a quarter of malt will produce four barrels of ale brewed from wort of the sp. gr. 1'054, or 19'4 lbs. per barrel; but, although this is hopeless even with pale malt, yet with an admixture of brown and black malt the assumption becomes absurd in the extreme. Admitting that, by good management, on the average, four barrels of. wort, weighing 20 lbs., can be obtained from one quarter of fine pale malt, yet in the operations of cooling, fermenting, tunning, skimming, and cleansing, a loss of fully 10 per cent. occurs under the most vigilant superintendence; and, taking the great bulk of our metropolitan breweries, it would be nearer the truth to estimate this loss at 12 per cent. In plain words, 100 gallons of wort will not, by any management, produce more than about 88 gallons of saleable beer, though no allowance is made for this by the Excise; and the brewer who has paid duty upon 100 gallons gets a drawback upon but 88. This, however, is the most favourable view of the case; and we solicit attention to the force with which the argument returns in the instance, of porter. If a quarter of pale malt be assumed at 84 lbs. of saccharine strength, then such an admixture of brown and black malt as is usually employed by brewers of porter, will not give more than about 24 lbs.; and as this constitutes at least one-fifth of the whole bulk used in porter brewing, we see that a quarter of such mixed malt can never give more than 70 lbs.; that is to say, 80 parts of pale malt, mixed with 20 of brown and black, instead of giving at the rate of 84 lbs., as pale malt alone does, would give but 70 lbs., or produce a difference between the actual return and that taken for granted by the Excise authorities, of no less than 16'6 per cent; to which, if we add the loss previously mentioned as arising from fermentation, yeast, &c., and which we have called 1z per cent., a total difference ensues of 28'6 per cent. between the duty paid by the brewer and the drawback allowed by act of parliament. But the grievance does not stop here; for the only return allowed by act of parliament is based upon the malt duty, and nothing whatever is said of the duty on hops. This, however, is at the rate of 19s. 7d. per cwt.:; and since hops yield only about 35 per cent. of their weight of soluble matter, it would require 168 lbs. of hops to produce a barrel of fluid or wort weighing 19'4 lbs., or having the requisite parliamentary specific gravity of 1'054. Upon this barrel, when exported, the drawback is 5s.; but as may easily be seen, on calculation, the duty paid by the brewer has been 29s. 3d. In fact, upon every 168 lbs. of hops consumed by the export brewer, he suffers a dead loss of 24s. 3d., independently of the waste'icidental to his various processes. These things may seem startling, yet I challenge 268 BREWING. the whole Board and Staff of the Excise to prove that they are in the least over-esti, mated. At the same time the intelligent reader will gather that the profits of brewing are not by any means so large as a cursory glance at the subject might warrant; and we say this rather as having reference to schemes now in progress for reducing the price of beer, than from its connection with our general arrangements. No doubt the brewing business has been of late singularly prosperous; and if the price of malt con tinues as low this year as it was last, the public have a right to look for some reduction in the price of ale and porter; but it must not be forgotten that the capital required is large, and invested in very perishable materials, such as casks and other wooden utensils, the wear and tear upon which is a very large item; nor again, as we have shown, must a speculator begin by assuming, with the Excise authorities, that a quarter ol ma t will produce four barrels of beer, for he will be much nearer the truth if he estimates his saleable produce at three barrels. As, however, it forms no part of our present task to enter into the financial statistics of brewing, we return to the object more immediately in view, merely throwing out, en passant, the above hints for the benefit of those whom they may concern. If the analyses of malt and malt-wort are requisite to enable the brewer to perform his operations with safety and success, the analysis of beer is not less indispensable to qualify him for the harassing labour of competition with his neighbours, and for the protection of his interest against Excise confiscation. Although beer may have been brewed of the requisite gravity for justifying a drawback on exportation, yet this is very far indeed from ensuring a return of the malt duty, even to the limited extent awarded by law. The question is, how are'the Excise officials to know the real weight of the wort from which the beer was brewed. This may be ascertained by the following method, which should take the place of the present indefinite system:-Having agitated a portion of the ale or beer, so as to dissipate its carbonic acid gas, measure out exactly 3600 grain measreles of it, and pour these into a retort; then distil, with great care, into a receiver, surrounded by ice-cold water, about one-third of the whole fluid, or rather more than this if the ale or beer is known to be highly alcoholic. Next weigh the distilled fluid, and then ascertain its specific gravity; from whence, by any of the proper tables of alcohol (which see), the total quantity of absolute alcohol in the distilled fluid may be known. This alcohol is to be converted, by calculation, into its equivalent of sugar, at the rate of 171 parts of sugar for every 92 of alcohol found: after which, this sugar must be brought into pounds per barrel, by the rule given in our article BEER, which is 52] lbs. of sugar for every 20 lbs. of gravity. The amount of vinegar is next to be determined, by any of the known forms of alkalimetry. (See ACETIC ACID..) This vinegar or acetic acid must, like the alcohol, be also converted into its representative of sugar, by assigning 171 of sugar to every 102 of anhydrous acetic acid present in the beer,-this sugar being, as before, converted into pounds per barrel. To the beer remaining in the retort, sufficient distilled water is then to be added, that the entire bulk of fluid may once more be equal to 3600 grain measures; and the temperature of the mixture having fallen to 60~ Fahr., its specific gravity must be determined in the usual way, and this reduced to pounds per barrel, by multiplying the excess above 1000 by 360, and dividing the product by 1000. The whole of these weights, added together, gives the original weight of the wort. Thus, for example, we will suppose that 3600 grs. of a particular beer'have given 1300 gr. of a dilute alcohol, of specific gravity'9731, and consequently containing about 17 per cent., by weight, of alcohol; again, that the same quantity of beer, when tested by ammonia, has indicated 30 grs. of acetic acid; and, lastly, that the spent wash, when filled up with distilled water to its primary bulk, has, at 60~, a specific gravity of 1-016;-then the total alcohol would be in 360 grs., or the representative of a barrel, 22) grs., and the acetic acid in the same quantity, 3 grs.: hence we have the following results: - Grs. of sugar. Brewer's libs. Alcohol, 22, grs., equal to - - - - 42-2 or 16* Acetic acid, 3 grs. - - - - - 5 19 Spent wash, of sp. grav. 1-016 - - - - 576 Total weight - - 23-66 It might be thought that the proper kind of sugar to select in this instance, as the representative of alcohol and acetic acid, should be grape sugar, whose atomic weight is 180; but it has long ago been shown by lAr. Ure, that the kind of sugar actually employed in the construction of our saccharometer tables must have been cane sugar, the atom of which is 171; and hence the reason why it must be employed in this calculation. We may now turn our attention to the business of the distiller, which is a kind of BREWING. 269 supplemertary operation to that of the brewer. There are, however, some ilnmortant differences, both in mashing and fermenting, between these two methods of producing alcohol; for the principal object of the brewer is to secure flavour and transparency to the fermented product, whilst the sole care of the distiller is to ensure the complete alcoholisation of all the saccharine and gummy constituents of this wort. We have seen that to the brewer the presence of dextrine was essential; whereas, in distillation, the more purely saccharine the wort the better. On this account, although malt is much dearer than raw grain, many eminent distillers continue to employ it alone, from the simple circumstance that its relatively large contents of diastase furnishes, in the limited period assigned for mashing, an infinitely more saccharine wort than can be pioduced in the same space of time from a mixture of one part of malt and seven or eight of barley meal. Nevertheless by maintaining the wort from the latter at a sufficient temperature for a few hours, as indicated with respect to beer-wort, the diastase in it would exert its specific action upon the dextrine, and, in the end, give as saccharine a wort from mixed grain as from pure malt. This subject is peculiarly worthy of the attention of distillers; for the sluggish fermentative qualities of dextrine are such, that very frequently a considerable quantity of this substance remains in the wash unacted on, and passes away with the residue as a waste product. It is, indeed, customary for the distiller to seek a remedy for this, in the employment of large and frequently repeated additions of yeast; and there can be no doubt as to the propriety of this measure. Still, however, the true solution of this difficulty must be referred to a period anterior to fermentation, and it is in the under-back where it should be grappled with and vanquished. If we examine with care the catalytic effect of diastase upon starch, we shall find that the time employed by the distiller is far too short to achieve the object which it is his interest to bring about. In the case of the brewer, many conditions, as we have pointed out, require to be foreseen and provided for; and hence a uniform system of mashing is to be condemned in brewing; but the distiller has only one single circumstance to bear in mDJA and that is, if possible, the total conversion of all the hordeine, starch, dextrine, and other constituents of his grain and wort into sugar. In fact, lie can scarcely by any chance mash too long or keep his wort at 170~ for too many hours;-at all events, the following observations demonstrate that the time now employed is barely one-fourth of that necessary for success, under the most favourable circumstances:-A mixture, composed of 1 part of very fine malt and 7 parts of barley-meal, was mashed with great care in a vessel capable of having its temperature kept at any required degree for many consecutive hours. The heat of the water was 180~; and it was found, after thorough mixing, that this had fallen to 168~, at which point it was accordingly decided to maintain it, and a series of experimental essays were made upon each sample of the wort, with the view of illustrating the progressive formation of sugar. The results were as follows:Sugar. Dextrine. 2 hours after mashing - - - - 13 18'7 3 ditto ditto - - - - 41 15-9 4 ditto ditto - - - - 63 13-7 5 ditto ditto - - - - 8- 12' 6 ditto ditto - - - - 9-2 10.8 7 ditto ditto - - - - 107 93 8 ditto ditto - - - - 12 8 9 ditto ditto - - - - 13-3 6-7 10 ditto ditto - - - 14-5 5-5 11 ditto ditto - - - 15 7 4-3 12 ditto ditto - - - - 169 3-1 Hence, instead of three hours, which is the period commonly used for mashing, the distiller would be warranted in continuing this operation for twelve hours. II reality, however, it is only the wort which requires this treatment; for, after the third hour, all the starch and nearly the whole of the hordeine have become soluble, and nothing but continued heat is required to complete the saccharification of the wort. The working of the mash-tun need not therefore be varied, as it will suffice to maintain the underback for 6 or 8 hours at a temperature of 170~. The advantage of converting all the dextrine into sugar is not limited to the mere saving of material, or the production of more alcohol, for there is another and most important object gained. Sugar ferments more freely and at a lower temperature than dextrine, consequently the heat of the fermenting vat need never rise so high, nor require the large quantity of yeast now employed for the purpose of forcing a rapid and hot fermentation. Thus the tendency to generate fusel oil would be destroyed, as there is not the slightest doubt that the formation of this oil is due to an excess of temperature in the fermenting-vat, 270 BRICK. and constantly bears a relation to the amount of dextrine in the wort; for this, as wV have before stated, necessitates the employment of a higher fermenting heat than sugar, by which the elements of the decomposing materials take on new and unusual arrangements. The presence of fusel oil in spirit is a serious impediment to the distiller, and either retards the sale of his produce, or diminishes its value in the market. As usual, the Excise regulations interfere much with the progress of this, as of every other manufacture under fiscal superintendence. Careful to prevent fraud, they cripple industry, and seek, as it were, to secure the honesty of the labourer by cutting off his hand:-ignorant or careless, meanwhile, of the permanent mischief which they inflict. Yet, we know of no more fitting subject for fiscal burdens, than the manufacture of ardent spirits; and had Excise interference been limited to this branch of industry, we should have deemed it a matter for congratulation, rather than otherwise. Nevertheless, consistency is a kind of virtue in politics; and we cannot imagine why the quasi superior, moral, and intellectual status of Ireland is continually tempted to err, by a low duty of but 2s. 8d. per gallon, whilst nearly three times this amount is needed to repress thebad habits of the people of England. The duty now charged is, for England 7s. 1cd., for Scotland 3s. 8d., and for Ireland 2s. 8d. per gallon of proof spirits: but on what principle this graduated scale of temptation to drunkenness has been co fixed, we are quite unable to conceive. To return, however, to the question of distillation, the duty can be charged the distiller in any one of three ways,viz. according to the gravity of the wort he uses: the attenuation of that wort by fermentation; or lastly, the actual quantity of spirit which he produces; the latter being, of course, the only just mode of charge. The restrictions and penalties are excessive, as our courts of law too frequently testify;'nd the notorious prevalence of smuggling seems to prove that the present rates of duty are too high, and offer a premium for fraud greater than the terror of a temporary imprisonment. The greatest improvement in modern times, as regards distillation, is that brought about by the invention of the apparatus, now well known under the name of "Coffey's still." It would be foreign to our task to give a minute description of this contrivance here (see STILL); its principle is similar to that of the "cascade chimique" of Clement Desormes. The wort, or other fluid to be distilled, is made to flow over a very extensive surface in contact with a current of steam passing in an opposite direction; by which means the steam is condensed, and giving up its latent heat to the more volatile spirit, this latter is driven on into the condenser in a state of great purity; whilst the residuary wort and the condensed steam flow out of the vessel fiom beneath in a continual stream. Mr. Coffey had many impediments to contend with, from the opposition of the Excise authorities, in his first attempt to introduce this ingenious invention into public use; but prejudice and ignorance have at length given way, and the Coffey's still may be now seen in operation at almost every large distillery in the kingdom. After the distiller has paid duty on the spirit which he has manufactured, it is transmitted to the rectifier, whose premises must be at a considerable distance from the distillery, according to act of parliament. The business of the rectifier is to purify the spirit by separating its fusel oil; and this he commonly effects through the agency of caustic potash. The impure spirit being mixed with a portion of potash, and carbonate of potash, is carefully distilled or rectified, until it ceases to possess any disagreeable odour, when it is again distilled in contact with certain aromatic substances, to give it the requisite qualities of the particular spirit or liquor desired. There is, however, too much reason to fear that the necessary measures of purification are neglected in the case of common gin,-the defect being merely covered or concealed beneath more powerful odours. This practice cannot be too strongly reprobated; for experiments made purposely on dogs have convinced us that fusel oil is a highly poisonous substance, and possesses acro-narcotic powers of no ordinary energy. Its removal from an article of universal consumption, like spirits, ought therefore to be deemed an ilmportant subject for sanitary leg:slation, and not left to the casual skill or dubious honesty of any class of manufacturers whatever. There is more or less fusel oil in all the gin we have examined. BRICK. (Brique, Fr.; Backsteine, ziegelsteine, Germ.) A solid, commonly rectangular, composed of clay hardened by heat, and intended for building purposes. The natural mixture of clay and sand, called loam, as well as marl, which consists of lime and clay, with little or no sand, constitutes also a good material for making bricks. The poorer the marl is in lime, the worse adapted it is for agricultural purposes, and the better for the brick manufacturer, being less liable to fuse in his kiln. When a natural compound of silica and clay can be got nearly free from lime and magnesia, it forms a kind of bricks very refractory in the furnace, hence termedfire-bricks. Such a material is the slate-clay, schieferthon, of our coal measures, found abundantly, and of excellent quality, at Stourbridge, and in the neighbourhood of Newcastle and Glasgow. The London brick-makers add to the clay about one-third of coal ashes obtained from.he kitchen dust-holes; so that when the bricks are put into the kiln, the quantity of BRICK. 271 coaly matter attached to their surface serves to economise fuel, and makes them less apt to shrink in the fire; though they are less compact, and probably less durable than the bricks made in the coal districts of England. The general process of brick-making consists in digging up the clay in autumn; exposing it, during the whole winter, to the frost, and the action of the air, turning it repeatedly, and working it with the spade; breaking down the clay lumps in spring, throwing them into shallow pits, to be watered and soaked for several days. The next step is to temper the clay, which is generally done by the treading of men or oxen. In the neighbourhood of London, however, this process is performed in a horse-mill. The kneading of the clay is, in fact, the most laborious but indispensable part of the whole business; and that on which, in a great measure, the quality of the bricks depends. All the stones, particularly the ferruginous, calcareous, and pyritous kinds, should be removed, and the clay worked into a homogeneous paste with as little water as possible. The earth, being sufficiently kneaded, is brought to the bench of the moulder, who works the clay into a mould made of wood or iron, and strikes off the superfluous matter. The bricks are next delivered from the mould, and ranged on the ground; and when they have acquired sufficient firmness to bear handling, they are dressed with a knife, and staked or built up in long dwarf walls, thatched over, and left to dry. An able workman will make, by hand, 5000 bricks in a day. The different kinds of bricks made in England are principally place bricks, gray and red stocks, marl facing bricks, and cutting bricks. The place bricks and stocks are used in common walling. The marls are made in the neighbourhood of London, and used in the outside of buildings; they are very beautiful bricks, of a fine yellow colour, hard, and well burnt, and, in every respect, superior to the stocks. The finest kind of marl and red bricks, called cutting bricks, are used in the arches over windows and doors, being rubbed to a centre, and gauged to a height. In France attempts were long ago made to substitute animals and machines for the treading of men's feet in the clay kneading pit; but it was found that their schemes could not replace, with advantage, human labour where it is so cheap, particularly for separating the stones and heterogeneous matter from the loam. The more it is worked, the denser, more uniform, and more durable, the bricks which are made of it. A good French workman, in a day's labour of 12 or 13 hours, it has been said, is able to mould from 9000 to 10,000 bricks, 9 inches long, 41 inches broad, and 2~ thick; but he must nave good assistants under him. In many brickworks near Paris, screw-presses are now used for consolidating the bricks and paving tiles in their moulds. M. Mollerat employed the hydraulic press for the purpose of condensing pulverized clay, which, after baking, formed beautiful bricks; but the process was too tedious and costly. An ingenious contrivance for moulding bricks mechanically, is said to be employed near Washington, in America. This machine moulds 30,000 in a day's work of 12 hours, with the help of one horse, yoked to a gin wheel, and the bricks are so dry when discharged from their moulds, as to be ready for immediate burning. The machine is described, with figures, in the Bulletin de la Societe d'Encouragement for 1819, p. 361. See further on, an account of our recent patents. Bricks, in this country, are generally baked either in a clamp or in a kiln. The latter is the preferable method, as less waste arises, less fuel is consumed, and the bricks are sooner burnt. The kiln is usually 13 feet long, by 10- feet wide, and about 12 feet in height. The walls are one foot two inches thick, carried up a little out of the perpendicular, inclining towards each other at the top. The bricks are placed on flat arches, having holes left in them resembling lattice-work; the kiln is then covered with pieces of tiles and bricks, and some wood put in, to dry them with a gentle fire. This continues two or three days before they are ready for burning, which is known by the smoke turning from a darkish color to transparent. The mouth or mouths of the kiln are now dammed up with a shinlog, which consists of pieces of bricks piled one upon another, and closed with wet brick earth, leaving above it just room sufficient to receive a fagot. The fagots are made of furze, heath, brake, fern, &c., and the kiln is supplied with these until its arches look white, and the fire appears at the top; upon which the fire is slackened for an hour, and the kiln allowed gradually to cool. This heating and cooling is repeated until the bricks be thoroughly burnt, which is generally done in 48 hours. One of these kilns will hold about 20,000 bricks. Clamps are also in common use. They are made of the bricks themselves, and generally of an oblong form. The foundation is laid with place brick, or the driest of those just made, and then the bricks to be burnt are built up, tier upon tier, as high as the clamp is meant to be, with two or three inches of breeze or cinders strewed between each layer of bricks, and the whole covered with a thick stratum of breeze. The fireplace is perpendicular, about three feet high, and generally placed at the west end; and the flues are formed by gathering or arching the bricks over, so as to leave a space 272 BRICK. between each of nearly a brick wide. The flues run straight through the clamp, and are filled with wood, coals, and breeze, pressed closely together. If the bricks are to be burnt off quickly, which may be done in 20 or 30 days, according as the weather may suit, the flues should be only at about six feet distance; but if there be no immediate hurry, they may be placed nine feet asunder, and the clamp left to burn off slowly. Floating bricks are a very ancient invention: they are so lizht as to swim in water; and Pliny tells us, that they were made at Marseilles; at Colento, in Spain; and at Pittane, in Asia. This invention, however, was completely lost, until M. Fabbroni published a discovery of a method to imitate the floating bricks of the ancients. AccordiJn to Posidonius, these bricks are made of a kind of argillaceous earth, which was employed to clean silver plate. But as it could not be our tripoli, which is too heavy to float in water, M. Fabbroni tried several experiments with mineral argaric, guhr, lac-lunee, and fossil meal, which last was found to be the very substance of which he was in search. This earth is abundant in Tuscany, and is found near Casteldelpiano, in the territories of Sienna. According to the analysis of M. Fabbroni, it consists of 55 parts of silicious earth, 15 of magnesia, 14 of water, 12 of alumina, 3 of lime, and 1 of iron. It exhales an argillaceous odor, and, when sprinkled with water, throws out a light whitish smoke. It is infusible in the fire; and, though it loses about an eighth part of its weight, its bulk is scarcely diminished. Bricks composed of this substance, either baked or unbaked, float in water; and a twentieth part of clay may be added to their composition without taking away their property of swimming. These bricks resist water, unite perfectly with lime, are subject to no alteration from heat or cold, and the baked differ from the unbaked only in the sonorous quality which they have acquired from the fire. Their strength is little inferior to that of common bricks, but much greater in proportion to their weight; for M. Fabbroni found, that a floating brick, measuring 7 inches in length, 41 in breadth, and one inch eight lines in thickness, weighed only 14 ounces; whereas a common brick weighed 5 pounds 6i ounces. The use of these bricks may be very important in the construction of powder magazines and reverberatory furnaces, as they are such bad conductors of heat, that one end may be made red hot while the other is held in the hand. They may also be employed for buildings that require to be light; such as cooking-places in ships, and floating batteries, the parapets of which would be proof against red-hot bullets. The following plan of a furnace or kiln for burning tiles has been found very convenient: Fig. 198., front view, A A, B B, the solid walls of the furnace; a a a, openings to the ash-pit, and the draught hole; b b b, openings for the supply of fuel, furnished with a sheet-iron door. Fig. 199. Plan of the nsh-pits and air channels c c c. The principal B & $ / DDE D D, A a a a A 7 198 199 200 branch of the ash-pit D D D, is also the opening for taking out the tiles, after removing the grate; E, the smoke flue. Fei. 200. Plan of the kiln seen from above. The _ -_ —- - grates H H H. The tiles to be fired are arranged upon the spaces f f f. Fig. 201. is the plan and section of one of the grates upon a much larger scale than in the preceding figures. Mechanical brick moulding.-Messrs. Lyne and Stainford obtained in August, 1825, a patent for a machine for making a considerable number of bricks at one operation. It consists, in the first place, of a cylindrical pug-mill of the kind usually employed for comminuting clay for bricks and tiles, furnished with --....- rotatory knives, or cutters, for breaking the lumps and mixing _-T- Y -- - the clay with the other materials of which bricks are commonly ~f<^ made. Secondly, of two movable moulds, in each of which 201 fifteen bricks are made at once; these moulds being made to travel to and fro in the machine for the purpose of being alternately brought under the pug-mill to be fitted with the clay, BRICK. 273 and then removed to situations where plungers are enabled to act upon them. Thirdly, w a contrivance by which the plungers are made to descend, for tile purpose of compressing the material and discharging it fiom the mould in the form of bricks. Fourthly, in the method of constructing and working trucks which carry the receiving boards, and conduct the bricks away as they are formed. Fig. 202. exhibits the general construction of the apparatus; both ends of which being exactly similar, little more than half of the machine is represented. a is the cylindrical pug-mill, shown partly in section, which is supplied with the clay and other 202 X^.1 P Fiti. 1i, I' III ~ -i II [- II' l i iiiii 1'lll'1 1 I Nill n fill= }4 J X I li~'..........el...... dll materials from a hopper above; b b, are the rotatory knives or cutters, which are at tached to the vertical shaft, and, being placed obliquely, press the clay down towards the bottom of the cylinder, in the act of breaking and mixing it as the shaft revolves. The lower part of the cylinder is open; and immediately under it the mould is placed in which the bricks are to be formed. These moulds run to and fro upon ledges in the side frames of the machine; one of the moulds only can be shown by dots in the figure, the side rail intervening; they are situated at c c, and are formed of bars of iron crossing each other, and encompassed with a frame. The mould resembles an ordinary sash window in its form, being divided into rectangular compartments (fifteen are proposed in each) of the dimensions of the intended bricks, but sufficiently deep to allow the material, after being considerably pressed in the mould, to leave it, when discharged, of the usual thickness of a common brick. The mould being open at top and bottom, the material is allowed to pass into it, when situated exactly under the cylinder; and the lower side of the mould, when so placed, is to be closed by a flat board d, supported by the trunk e, which is raised by a lever and roller beneath, running upon a plane rail with inclined ends. The central shaft, f, is kept in continual rotatory motion, by the revolution of the upper horizontal wheel g, of which it is the axis; and this wheel may be turned by a horse yoked to a radiating arm, or by any other means. A part of the circumference of the wheel g, has teeth which are intended at certain periods of its revolution to take into a toothed pinion, fixed upon the top of a vertical shaft h h. At the lower part of this vertical shaft, there is a pulley i, over which a chain is passed that is connected to the two mnoulds c, and to the frame in which the trucks are supported; by the rotation of the vertical shaft, the pulley winds a chain, and draws the moulds and truck frames along. The clay and other material having been forced down firom the cylinder into the mould, the teeth of the horizontal wheel g now come into geer with the pinion upon 19 274 BRICK. k, and turn it and the shaft and pulley i, by which the chain is wound, and the mould at the right hand of the machine brought into the situation shown in the figure; a scraper or edge-bar under the pug-mill having levelled the upper face of the clay in the mould, and the board d, supported by the truck e, formed the flat under side. The mould being brought into this position, it is now necessary to compress the materials, which is done by the descent of the plungers k k. A friction-roller 1, pendant from the under side of the horizontal wheel, as that wheel revolves, comes in contact with an inclined plane, at the top of the shaft of the plungers; and, as the frictionroller passes over this inclined plane, the plungers are made to descend into the mould, and to compress the material; the resistance of the board beneath causing the clay to be squeezed into a compact state. When this has been effectually tccomplished, the further descent of the plungers brings a pin m, against the upper end of a quadrant catch-lever n, and, by depressing this quadrant, causes the balance-lever upon which the truck is now supported to rise at that end, and to allow the truck with the board d to descend, as shown by dots; the plungers at the same time forcing out the bricks from the moulds, whereby they are deposited upon the board d; when, by drawing the truck forward out of the machine, the board with the bricks may be removed and replaced by another board. The truck may then be again introduced into the machine, ready to receive the next parcel of bricks. By the time that the discharge of the bricks from this mould has been effected, the other mould under the pug cylinder has become filled with the clay, when the teeth of the horizontal wheel coming round, take into a pinion upon the top of a vertical shaft, exactly similar to that at h, but at the reverse end of the machine, and cause the moulds and the frame supporting the trucks to be slidden to the left end of the machine; the upper'surface of the mould being scraped level in its progress, in the way already described. This movement brings the friction-wheel o, up the inclined plane, and thereby raises the truck, with the board to the under side of the mould, ready to receive another supply of clay; and the mould at the left hand side of the machine being now in its proper situation under the plungers, the clay becomes compressed, and the bricks discharged from the mould in the way described in the former instance; when this truck being drawn out, the bricks are removed to be dried and baked, and another board is placed in the same situation. There are boxes, p, upon each side of the pug cylinder containing sand, at the lower parts of which small sliders are to be opened (by contrivances not shown in the figure) as the mould passes under them, for the purpose of scattering sand upon the clay in the mould to prevent its adhering to the plungers. There is also a rack and toothed sector, with a balance-weight connected to the inclined plane at the top of the plunger-rods, for the purpose of raising the plunger after the friction-roller has passed over it. And there is a spring acting against the back of the quadrant-catch for the purpose of throwing it into its former situation, after the pin of the plunger has risen. One of the-latest, and apparently most effective machines for brick-making, is that patented by Mr. EdLward Jones, of Birmingham, in August, 1835. His improvements are described under four heads; the first applies to a machiae for moulding the earth into bricks in a circular frame-plate horizontally, containing a series of moulds or rectangular boxes, standing radially round the circumference of the circular frame, into which boxes successively the clay is expressed from a stationary hopper'Os the frame revolves, and after being so formed, the bricks afe successively pushed out of their boxes, each by a piston, acted upon by an inclined plane below. The second head of the specification describes a rectangular horizontal frame, having a series of moulding boxes placed in a straight range, which are acted upon for pressing the clay by a corresponding range of pistons fixed in a horizontal frame, worked up and down by rods extending from a rotatory crank shaft. the moulding boxes being allowed to rise for the purpose of enabling the pistons to force out the bricks when moulded, and leave them upon the bed or board below. The third head applies particularly to the making of tiles, for the flooring of kilns in which malt or grain is to be dried. There is in this contrivance a rectangular mould, with pointed pieces standing up for the purpose of producing airholes through the tiles as they are moulded, which is done by pressing the clay into the moulds upon the points, and scraping off the superfluous matter at top by hand. The fourth or last head applies to moulding chimney pots in double moulds, which take to pieces for the purpose of withdrawing the pot when the edges of the slabs or sides are sufficiently brought into contact. "The drawing which accompanies the specification very mperfectly represents some parts of the apparatus, and the description is still more defedtive; but as we are acquainted with the machinery, we will endeavor to give it an intelligible form, and quote those parts of the specification which point the particular features of novelty proposed to De claimed by the patentee as his invention, under the several heads." * * Mr Newton, in his London Journal, February, 1837. BRICK. 275 Fig. 205 represents, in eievation, the first-mentioned machine for moulding bricks. The v^^r^';203 * moulds are formed in the face 203 i 0orf a circular plate or wheel, - S =-esa a, a portion of the upper surl[ ] [ -- l" ^ [ face of which is represented in the horizontal view, fig. 201. Any convenient number of' these _.. —.-........ i li moulds are set radially in the Hgif ] I___I____ [___! ll{ ^Iiff ii wheel, which is mounted upon 1illlllll I I I l llllB a central pivot, supported by ^ * -l —-1111 —11!',l I —i'lll I I!! I 1 the masonry b b. There is a rim of teeth round the outer 2or~)~~~04 Aedle of the wheel a a, which L t ^ l _ __, i,_____ take into a pinion c, on a shaft l\ B^ G" \ l< / ^ | connected to the first mover, and by these means the wheel a, with the moulding boxes, is made to revolve horizontally guided by arms with anti-fiictior rollers, which run round a hori.zontal plate a a, fixed upon the masonry. A hopper, e, filled with the brick earth shown with one of the moulding boxes in section, is fixed above the face of the wheel in such a way that the earth may descend from the hopper into the several moulding boxes as the wheel passes round under it; the earth being pressed into the moulds, and its surface -scraped off smooth by a conical rollerf, in the bottom of the hopper. Through the bottom of each moulding box there is a hole for the passage of a piston rod g, the upper end of which rod carries a piston with a wooden pallet upon it, acting withlin the moulding box; and the lower end of this rod has a small anti-friction roller, which. as the wheel a revolves, runs round upon the face of an oblique ring or inclined way, h h, fixed upon the masonry. The clay is intrcduced into the moulding boxes from the hopper. fixed over the lowest part of the inclined way h, and it will be perceived that as the wheel revolves, the piston rods g, in passing up the inclined way, will cause the pistons to force the new-moulded bricks, with their pallet or board under them, severally up the mould, into the situation shown at i, in fig. 203, from whence they are to be removed by hand. Fresh pallets being then placed upon the several, pistons, they, with the mouldls, will be ready for moulding fresh bricks, when, by the rotation of the wheel a, they are severally brought under the hopper, the pistons having sunk to the bottoms of their boxes, as the piston rods passed down the other side of the inclined way h. The patentee says, after having described the first head of his invention, he would have it understood that the same may be varied without departing from the main object of the invention; viz., that of arranging a series of moulds when worked by means of an inclined track, and in such manner that bricks, tiles, or other articles made of brick earth, may be capable of being formed in a mould with pallets or boards laid within the moulds, and constituting the bottom thereof, the bricks being removed from out c~ the moulds, with the pallets or boards under them, as above described. "I do not, therefore, confine myself to the precise arrangement of the machine here shown, though it is the best with which I am acquainted for the purpose." The second head of the invention is another construction of apparatus,or moulding bricks, in this instance, in a rectangular frame. Fig. 205 is a front elevation of the machine; fig. 206, a section of the same taken transversely. a a is the standard frame-work and bed on which the bricks are to be moulded. Near the corners of this standard frame-work, four vertical pillars b b are-erected, upon which pillars the frame of the moulding boxes c, slides up and down, and also the bar d. carrying the rods of the pistsns eee. These pistons are for the purpose of compressing the clay in the moulding box, and therefore must stand exactly over and correspond with the respective moulds in the frame c beneath. The sliding frame c, constituting the sides and ends of the moulding boxes, is supported at each end by an upright sliding rod f, which rods pass through guides fixed to the sides of the standard frame a a, and at the lower end of each there is a roller, bearing upon the levers g, on each side of the machine, but seen only in fig. 206, which levers 276 BRICKS. when depressed, allow the moulding boxes to descend, and rest upon the bed or table o, the machine h h. 205 206 - E I I c i a i i iX r'I flo Cz In this position of the machine resting upon the bed or table, the brick-earth is to be placed upon, and spread over, the top of the frame c, by the hands of workmen, when the descent of the plunger or pistons e e e, will cause the earth to be forced into the moulds, and the bricks to be formed therein. To effect this, rotatory power is to be applied to the toothed wheel i, fixed on the end of the main driving crank shaft k k, which on revolving will, by means of the crank rods I 1, bring down the bar a, with the pistons or plungers e e e, and compress the earth compactly into the moulds, and thereby form the bricks. When this has been done, the bricks are to be released from the moulds by the moulding frame c rising up from the bed, as shown in fig. 205., the pistons still remaining depressed, and bearing upon the upper surfaces of the bricks. The moulding frame is raised by means of cams m, upon the crank shaft, which at this part of the operation are brought under the leversg, for the purpose of raising the cams and the sliding rods f, into the position shown infig. 206. The bricks having been thus formed and released from their moulds, they are to be removed from the bed of the machine by pushing forward, on the front side, fresh boards or pallets, which of course will drive the bricks out upon the other side, whence they are to be removed by hand. There is to be a small hole in the centre of each pallet, and also in the bed, for the purpose of allowing any superfluous earth to be pressed through the moulding boxes when the pistons descend. And in order to cut off the projecting piece of clay which would be thus formed on the bottom of the brick, a knife-edge is in some way connected to the bed of the machine; and as the brick slides over it, the knife separates the protuberant lump; but the particular construction of this part of the apparatus is considered to be of little importance; and the manner of effecting the object is not clearly stated in the specification. The patentee proposes a variation in this construction, which he describes in these words: "It will be evident that in place of having the moulds to rise, they may, by suitable arrangements, be made to descend below the bricks. In this case, in place ot the boards, stationary blocks to receive the pallets must be fixed on the bed of the machine, and these blocks must be shaped in such a manner as to allow of the moul'tpassing over them: and then it will be desirable to use the first part of my improvements, that of having the pallets within the moulds at the time of moulding the bricks; or in case of working with exceedingly stiff brick-earth, the pallets may be dispensed with." In 1849, 1,503,961,106 bricks paid duty in the United Kingdom; the revenue from which was 461,5821. 6s. Id. BRICKS. Mr. F. W. Simms, C. E., communicated to the Institution of Civil Engineers, in April and May, 1843, an account of the process of brick-making for the Dover railway. The plan adopted is called slop-moulding, because the mould is dipped into water before receiving the clay, instead of being sanded as in making sand-stock bricks. The workman throws the proper lump of clay with some force into the mould, presses it down with his hands to fill the cavities, and then strikes off the surplus clay with a stick. An attendant boy, who has previously placed another mould in a Water trough by the side of the moulding table, takes the mould just filled, and carries it to the floor, where he carefully drops the brick from the mould on its flat side, and leaves t to dry; by the time he has:eturned to the moulding table, and deposited the empty BRICKS. 277 mould in the water trough, the brickmaker will have filled the other mrou d, for th< boy to convey to the floor, where they are allowed to dry, and are then stacked in readiness for being burned in clamps or kilns. The average product is shown in the fol lowing table:Force employed. Area of land. Duration of season Produce per week. Produce per season. Roods. Perches. Weeks. Bricks. Bricks. 1 moulder - 1 temperer - 1 wheeler - 1 22 16,100 354,200 1 carrier boy - 1 picker boy - It appears that while the produce in sand-stock bricks is to that of slop-bricks in the same time as 30 to 16, the amount of labor is as 7 to 4; while the quantity of land, and the cost of labor per thousand, is nearly the same in both processes. The quantity of coal consumed in the kiln was at the rate of 10 cwt. 81bs. per thousand bricks. The cost of the bricks was 21. Is. 6d. per thousand. The slop-made bricks are fully 1 pound heavier than the sand-stock. Mr. Bennett stated to the meeting, that at his brick-field at Cowley, the average number of sand-stock bricks moulded was 32,000; but that fiequently so many as 37,000, or even 50,000, were formed. The total amount in the shrinkage of his bricks was 1 3 of an inch upon 10 inches in length; but this differed with the different clays. Mr. Simms objected to the use of machinery in brick-making, because it caused economy only in the moulding, which constituted no more than about one eighth of the total expense. The principal varieties of bricks are called malm,paviors, stocks, grizzles, places, and shuffs. For the first and best kind, the clay was washed and selected with care; stocks were good enough for ordinary building purposes; the rest are inferior. The difference in price between malms, paviors, and stocks, was 15s. or 20s. per 1,000; between stocks and places, 10s. The average weight of a sand-stock brick is fully 5 pounds, that of a slop is 1 pound more. I believe that the siliceous sand on the surface of the sand-stocks is useful in favoring adhesion of mortar, by the production of a silicate of lime. To smooth aluminous bricks, mortar sometimes forms no stony adhesion. Mr. Prosser, of Birmingham, makes bricks by pressure. The clay is first ground upon a slip kiln, as if for making pottery, then ground to a fine powder, and in that dry state it is subjected to the heavy pressure of about 250 tons, in strong metal moulds, by which means it is reduced to about one third of its original thickness. The clay seems to have retained sufficient moisture to give it cohesion, and the tiles are perfectly sharp at the edges. They being then baked within seggars by the heat of a kiln, seldom crack in the baking. The brrcks thus formed are denser than usual, and weigh 6- lbs., with a specific gravity of 2-5. Fig. 207., represents Mr. Hunt's brick-making machine. The principal working 207 parts consist of 2 cylinders, each covered by an endless web, and so placed as to form the front and back of a hopper, the two sides being iron plates, placed so that when the hopper is filled with tempered clay from the pug-mill, the lower part of the hopper, and consequently the mass of clay within it, has exactly the dimensions of a brick. Beneath the hopper an endless chain traverses simultaneously with the movement of the cylinders. The pallet-boards are laid at given intervals upon the chain, and being thus placed under the hopper, while the clay is brought down with a slight pressure, a frame with a wire stretched across it is projected throug the 278 BRICKS. mass of clay, cutting off exactly the thickness of the brick, which is removed at the same moment by the forward movement of the endless chain. This operation is repeated each time that a pallet-board comes under the hopper. The chief object of this machine, which is worked by hand, is to produce good square compact bricks of uniform quality, using only a slight pressure. It has been found to be very difficult to dry bricks made by machinery, where a considerable pressure has been employed, because, before the evaporation from the centre of the clay is completed, the surfaces have become hard and peel off. The present machine is in operation in several parts of England, producing usually about 1200 bricks per hour, while each machine requires only 2 men and 3 boys to tend it, and to take off the bricks. The clot-moulders are dispensed with, and the workmen are common labourers, so that professed bri.,k-makers at higher wages are not needed. Fig. 208. shows Mr. Hunt's machine for making tiles, and it is on the same principle. It consists of two iron cylinders, round which webs or bands of cloth revolve, whereby the clay is pressed into a slab of uniform thickness, without adhering to the cylhndtes. It is then carried over a covered wheel, curved on the rim, which gives the tile the semi-cylindrical or other required form; after which the tiles are polished and finished 20_ by passing through three iron moulds of a horse-shoe form, as shown in the centre of the cut; while they are at the same time moistened from a water cylinder placed above them. The tiles are next cut off to such lengths as are wanted, and carried away by an endless web, whence they are transferred by boys to the drying shelves. Flat tiles, for sole pieces t6 draining tiles, are formed in nearly the same manner, being divided into two portions while passing through the moulds; the quantity of clay used for one draining tile being as much as for two soles. The method of making bricks in the vicinity of London differed from that of almost all other places, because the material there employed is not pure clay, but a loam of a slightly cohesive nature, which will not admit of its being used in the natural state and burned in close kilns with coal; but with an admixture of ashes it becomes sufficiently tenacious to be formed into bricks, by inducing a slight semi-fusion. But the coal-ashes are also of advantage in the process of burning, because they enable the fire to spread gradually from the lower tiers, through the whole mass in the kiln or clamp, and thus obviate the effect of an intense partial heat, where distinct coal fires are trusted to alone, whereby the bricks nearest it get vitrified and glazed. The brick kilns and clamps round London, and other large cities, which are fired with the breeze-rubbish collected from dust holes, that contain the refuse of kitchens, &c., emit, in consequence, most unpleasant effluvia; but brick-kilns fired with clean coke or coals, give out no gases of a more noxious nature than common household fires. The consideration of this subject was closely pressed upon my attention on being consulted concerning an injunction issued by the chancellor against a brick clamp in the Isle of Wight, fired with clean coke cinders from the steam-engine furnace at Portsmouth Dock Yard. The bricks being of the description called sand-stock, were of course made in moulds very slightly dusted with sand, to make them fall freely out. The sand was brought from Portsmouth harbor, and on being subjected to a degree of heat, more intense certainly than it would suffer in the clamp, was discovered by two chemical witnesses to give out traces of hydrochloric acid. Not content with this trivial indication, the said chemists, in their evidence before the courts of law, paraded a train of goblin gases, as the probable products of the pre-adjudicated clamp. As it is well known to the chemist that common salt strongly ignited in contact with mcnist sand will emit hydrochloric acid, there was nothing remarkable in the above i"-~~~~ —--— ~~~~ —-— =i~ ~ ___i BRITANNIA TUBULAR BRIDGE. 279 observation, but I ascertained that the sand with which the moulds were strewed would give out no hydrochloric acid, at a heat equal at least to what the bricks were exposed to in a clamp 10 or 12 feet high, and fired at its bottom only with a layer of cinders 3 or 4 inches thick. But I further demonstrated that the entire substance of the brick with its scanty film of sand, on being exposed to ignition in a suitable apparatus, gave out-not hydrochloric or any other corrosive acid, but ammonia gas. Hence, the allegations that the clamp set forth a host of acid gases to blight the neighbouring trees, were shown to be utterly groundless; on the contrary, the ammonia evolved from the heated clay would act beneficially upon vegetation, while it was too small in quantity to annoy any human being. A few yards to leeward of a similar clamp, in full activity, I could perceive no offensive odour. All ferruginous clay, when exposed to the atmosphere, absorbs ammonia from it, and of course emits it again on being gently ignited. It is a reproach to science when, as in the above case, it lends itself to judicial prejudice and oppression. Messrs. Whalley and Lighloller have patented apps&atus for manufacturing bricks and tiles, which combines the pug mill, iressing cylinder, screens and die-plate all in one machine; thereby effecting great economy in time and labour, and also in the cost of the machinery itself. The combination alone is claimed. BRIMSTONE. (Soufre, Fr.; Schwefel, Germ.) Sulphur, which see. BRITANNIA TUBULAR BRIDGE (opening of the). The opening of this magnificent structure, looked forward to with so much interest, came off on the 5th of March, 1849, at dawn with the grandest success. At precisely seven o'clock, the adventurous convoy, progressing at a speed of seven miles an hour, was lost sight of in the recess of the vast iron corridor. Instead of being driven through with a dispatch indicative of a desire on the part of those who manned it to get in and out with the utmost expedition, the locomotives were propelled at a slow and stately pace, with a view of boldly proving by means of a dead weight the calibre of the bridge at every hazard. The total weight of the locomotives was 90 tons. The appearance of the interior of the tube during the experiment was of a novel and remarkable character. The locomotives were brought to a standstill in the centre of each of the great spans, without causing the slightest strain or deflection. The first process, that of going through the tube and returning, occupied altogether 10 minutes. The second experimental convoy that went through consisted of 24 heavily laden waggons filled with huge blocks of Brymbo coal, in all, engines included, an aggregate weight of 300 tons. This was drawn deliberately through, at the rate of from eight to ten miles an hour, the steam working at quarter power. During the passage of this experimental train through the tube, a breathless silence prevailed until the train rushed out exultingly, and with colours flying, on the other side of the tube, when loud acclamations arose, followed at intervals by the rattle of artillery down the Straits. Upon the return, which occupied about seven minutes, similar demonstrations ensued, and during the progress of the train those who stood upon its top to ascertain any possible vibration, reported they could detect no sensible deflection. An ordeal stronger still was then resorted to; a train of 200 tons of coals was allowed to rest with all its weight for two hours in the centre of the Carmarthenshire tube,.and at the end of the time, on the load being removed, it was found to have caused a deflection of only four-tenths of an inch. It is remarkable that this amount of deflection is not so much as one half hour of sunshine would produce upon the structure, it being moreover calculated with confidence that the whole bridge might with safety, and without injury to itself, be deflected to the extent of 13 inches. These loads, it is most material to remember, are immensely more than the bridge will ever be called on to bear in the ordinary run of traffic, though the engineers are of opinion that it would support with ease, and without much show of deflection, a dead weight on its centre of 1,000 tons. Twelve miles an hour is the limit of speed at which Mr. Stephenson intends that trains shall at first go through, more particularly as there are sharp curves at the.termini of the tube. The effect of the recent hurricane on the calibre of the tube has proved that its lateral surface strength is sufficient, and far more than sufficient, to resist the strongest wind. It is calculated that, taking the force of the wind at 50 Ibs. on thesquare foot, an excessive supposition, the resistance offered by the bridge would be 300 tons X 2 = 600 tons, which is not two thirds of its own weight. The wind going at 80 miles an hour, the rush of a hurricane would only press in the ratio of 128 tons on the side. It is intended, when both tubes are up, to brace them together with stays, so as to counteract any possible oscillation. The great work has now been four years in hand, and is nearly complete, while Telford's suspension bridge took eight years. The floating and actual transference of the tubes have occupied since June last, a short period, when the bulk of the fabric is taken into consideration Great fears wers 280 BRONZE. entertained for its safety during the late gales, from the recollection in this part o) the country of the damage done to Telford's suspension bridge. BRITISH GUM. The trivial name given to starch, altered by a slight calcination in an oven, whereby it assumes the appearance and acquires the properties of gum, being soluble in cold water, and forming in that state a paste well adapted to tiicken the colours of the calico printer. See DEXTRINE and STARCH. BROMINE, one of the archieal elements, which being developed from its combinations at the positive pole of the voltaic circuit, has been therefore deemed to be idio-electropositive like oxygen and chlorine. It derives its name from its nauseous smell, Bpoon, fietor. It occurs il various saline springs on the continent of Europe, in those of Ashby de la Zouche, and some others in England; in the lake Asphaltites, in sponges, in some marine plants, in an ore of zinc, and in the cadmium of Silesia. At ordinary tempera tures it is liquid, of a dark brown colour in mass, but of a hyacinth-red in thin layers, Its smell is rank and disagreeable, somewhat like that of chlorine. It has a very caustic taste. Its specific gravity is 2'966. Applied to the skin it colours it deep yellow and corrodes it. One drop put within the bill of a bird suffices to kill it. It combines with oxygen with feeble affinity, forming bromic acid. Its attraction for hydrogen being far more energetic, it forms therewith a strong acid, the hydrobromic. Bromine dissolves very sparingly in water, but it is very so,'le in alcohol and ether. It combines with carbon, phosphorus, sulplhur, and chlorine, as well as with most of the metals. Front its scarcity it has not hitherto been applied to any purpose in the arts, except photography; but it is supposed to possess powerful discutient effects upon scrofulous and other glandular tullours, whence the waters containing it are prescribed as an internal and external remedy in such forms of disease. BRONZE. A compound metal consisting of copper and tin, to which sometimes a little zinc and lead are added. This alloy is much harder than copper, and was employed by the ancients to make swords, hatchets, &c., before the method of working iron was generally understood. The art of casting bronze statues may be traced to the most remote antiquity, but it was first brought to a certain degree of refinement by Theodoros and Rcecus of Samos, about 700 years before the Christian era, to whom the invention of modelling is ascribed by Pliny. The ancients were well aware that by alloying copper with tin, a more fusible metal was obtained, that the process of casting was therefore rendered easier, and that the statue was harder and more durable; and yet they frequently made them of copper nearly lure, because they possessed no means of determining the proportions of their alloys, and becauseeby their mode of managing the fire, the copper became refined in the course of melting, as has happened to many founders in our own days. It was during the reign of Alexander that bronze statuary received its greatest extension, when the celebrated artist Lysippus succeeded by new processes of moulding and melting to multiply groups of statues to such a degree that Pliny called him the mob of Alexander. Soon afterwards enormous bronze colossuses were made, to the height of towers, of which the isle of Rhodes possessed no less than one hundred. The Roman consul Mutianus found 3,000 bronze statues at Athens, 3,000 at Rhodes, as many at Olympia and at Delphi, although a great number had been previously carried off from the last town. In forming such statues, the alloy should be capable of flowing readily into all the parts of the mould, however minute; it should be hard, in order to resist accidental blows, be proof against the influence of the weather, and be of such a nature as to acquire that greenish oxidized coat upon the surface which is so much admired in the antique bronzes called patina antiqua. The chemical composition of the bronze alloy is a matter therefore of the first moment. The brothers Keller, celebrated founders in the time of Louis XIV., whose chefs-d'oeuvre are well known, directed their attention towards this point, to which too little importance is attached at the present day. The statue of Desaix in the place Dauphine, and the column in the Place Vend6me, are noted specimens of most defective workmanship from mismanagement of the alloys of which they are composed. On analysing separately specimens taken from the basreliefs of the pedestal of this column, from the shaft, and from the capital, it was found that the first contained only 6 per cent. of alloy, and 94 of copper, the second much less, and the third only 0-21. It was therefore obvious that the founder, unskilful in the melting of bronze, had gone on progressively refining his alloy, by the oxidizement oi the tin, till he had exhausted the copper, and that he had then worked up the refuse scoria in the upper part of the column. The cannons which the government furnished him for casting the monument consisted ofCopper - - - 89-360 Tin - - - 10l00 Lead - - - 0102 Silver, zinc, iron, and loss 0-498 100-000 BRONZE. 281 The moulding of the several bas-reliefs was so ill-executed, that the chiselers employed to repair the faults removed no less than 70 tons of bronze, which was given them, besides 300,000 francs for their work. The statues made by the Kellers at Versailles were found on chemical analysis to consist ofNo. 1. No. 2. No. 3. The mean. Copper 91-30 91-68 91-22 91-40 Tin 1'00 2-32 1-78 1-70 Zinc 6-09 4-93 5'57 5-53 Lead 1-61 1-07 1-43 1'37 100-00 100-00 100-00 100-00 The analysis of the bronze of the statue of Louis XV. was as follows:Copper 82-45 Its specific gravity was 8'482 Zinc 10'30 Tin 4-10 Lead 3'15 100-00 The alloy most proper for bronze medals which are to e s:iterward struck, is composec of from 8 to 12 parts of tin, and from 92 to 88 of copper; to which if two or three parts in the hundred of zinc be added, they will make it assume a finer bronze tint. The alloy of the Kellers is famous for this effect. The me, al should be subjected to three or four successive stamps of the press, and be softened between each blow by being heated and plunged into cold water. The bronze of bells or bell metal is composed in 100 parts of copper 78, tin 22. This alloy has a fine compact grain, is very fusible and sonorous. The other metals sometimes added are rather prejudicial, and merely increase the profit of the founders. Some of the English bells consist of 80 copper, 10.1 tin, 5'6 zinc, and 4'3 lead; the latter metal when in such large quantity is apt to cause insolated drops, hurtful to the uniformity of the alloy. The fam-tams and cymbals of bronze.-The Chinese make use of bronze instrument% forged by the hammer, which are very thin, and raised up in the middle; they are called gongs, from the word tshoulg, which signifies a bell. Klaproth has shown that they contain nothing but popper and tin; in the proportions of 78 of the former metal and 22 of the latter. Their specific gravity is 8-815. This alloy when newly cast is as brittle as glass, but by being plunged at a cherry-red heat into cold water, and confined between two discs of iron to keep it in shape, it becomes tough and malleable. The cymbals consist of 80 parts copper and 20 tin. Bronze vessels naturally brittle may be made tenacious by the same ingenious process, for which the world is indebted to M. Darcet. Bronze mortars for pounding have their lips tempered in the same way. Ancient warlike weapons of bronze were variously compounded; swords were formed of 87| copper, and 12' tin in 100 parts;.the springs of balistEe consisted of 97 copper, and 3 tin. Cannon metal consists of about 90 or 91 copper, and 10 or 9 of tin. From the experiments of Papacino-d'Antony, made at Turin. in 1770, it appears that the most proper alloy for great guns is from 12 to 14 parts of tin to 100 of copper; but the Comte Lamar tilliere concluded from his experiments made at Douay, in 1786, that never less than 8. nor more than 11 of tin should be employed in 100 parts of bronze. Gilt ornaments of bronze.-This kind of bronze should be easy of fusion, and take perfectly the impression of the mould. The alloy of copper and zinc is when fused of a pasty consistence, does not make a sharp cast, is apt to absorb too much amalgam, is iiable to crack in cooling, and is too tough or too soft for the chaser or the turner. Were the quantity of zinc increased to make the metal harder, it would lose the yellow color suitalle to the gilder. A fourfold combination of copper, zinc, tin, and lead is preferable for making such ornamental bronze articles; and the following proportions are probably the best, as they unite closeness of grain with the other good qualities. Copper 82, zinc 18, tin 3 or 1, lead 1. or 3. In the alloy which contains most lead, the tenacity is diminished and the density is increased, which is preferable for pieces of small dimensions Another alloy, which is said to require for its gilding only two thirds of the ordinary quantity of gold, has the following composition: copper, 82-257; zinc, 17-481; tin, 0-238; lead, 0-024. The antique bronze color is given to figures and other objects made from these alloys by the following process:-Two drachms of sal-ammoniac, and half a drachm of salt of sorrel (binoxalate of potash) are to be dissolved in fourteen ounce measures (English) of color less vinegar. A hair pencil being dipped into this solution, and pressed gently between 282 BRONZE. the fingers, is to be rubbed equally over the clean surface of the object, slightly warmed in the sun or at a stove; and the operation is to be repeated till the wished-for shade is obtained. (See GILDING.) The bronze founder ought to melt his metals rapidly, in order to prevent the loss of tin, einc, and lead, by their oxydizement. Reverberatory furnaces have been long used for this operation; the best being of an elliptical form. The furnaces with dome tops are employed by the bell-founders, because their alloy being more fusible, they do not require so intense a heat; but they also would find their advantage in using the most rapid mode of fusion. The surface of the melting metals should be covered with small charcoal, o0 coke; and when the zinc is added, it should be dexterously thrust to the bottom of the melted copper. Immediately after stirring the melted mass so as to incorporate its ingredients, it should be poured out into the moulds. In general, the metals most easily altered by the fire, as the tin, should be put in last. The cooling should be as quick as possible in the moulds, to prevent the risk of the metals separating from each other in the order of their density, as they are very apt to do. The addition of a little iron, in the form of tin-p ate, to bronze, is reckoned to be advantageous. One part of tin, and two parts of copper (nearly one atom of tin and four of copper, or more exactly, 100 parts of tin, and 215 copper), form the ordinary speculum metal of reflecting telescopes, which is of all the alloys the whitest, the most brilliant, the hardest, and the most brittle. The alloy of I part of tin, and 10 of copper (or nearly one atom of the former to eighteen of the latter), is the strongest of the whole series. Ornamental objects of bronze, after being cast, are commonly laid upon red-hot coals till they take a dull red heat, and are then exposed for some time to the air. The surface is thereby freed from any greasy matter, some portion of the zinc is dissipated, the alloy assumes more of a coppery hue, which prepares for the subsequent gilding. The black tinge which it sometimes gets from the fire may be removed by washing it with a weak acid. It may be made very clean by acting upon it with nitric acid, of specific gravity 1-324, to which a little common salt and soot have been added, the latter being of doubtful utility; after which it must be well washed in water, and dried with rags or saw-dust. BRONZING is the art of giving to objects of wood, plaster, &c., such a surface as makes them appear as if made of bronze. The term is sometimes extended to signify the production of a metallic appearance of any kind upon such objects. They ought first to be smeared over smoothly with a coat of size or oil varnish, and when nearly dry, the metallic powder made from Dutch foil, gold leaf, mosaic gold, or precipitated copper, is to b' applied with a dusting bag, and then rubbed over the surface with a linen pad; or the metallic powders may be mixed with the drying oil beforehand, and then applied with a br'uth. Sometimes fine copper, or brass filings, or mosaic gold, are mixed previously with some pulverized bone-ash, and then applied in either way. A mixture of these powders with mucilaoe of gum arabic is used to give paper or wood a bronze appearance. The surface must be afterward burnished. Copper powder precipitated by clean plates of iron, from a solution of nitrate of copper, after being well washed and dried, has been employed in this way, either alone or mixed with pulverized bone-ash. A finish is given tn works of this nature by a coat of spirit varnish. A white metallic appearance is given to plaster figures by rubbing over them an anal. eam of equal parts of mercury, bismuth, and tin, and applying a coat of varnish over it. The iron-colored bronzing is given by black lead or plumbago, finely pulverized and washed. Busts and other objects made of cast iron acquire a bronze aspect by being well cleaned and plunged in solution of sulphate of copper, whereby a thin film of this metal is left upon the iron. Copper acquires by a certain treatment a reddish or yellowish hue, in consequence oi a little oxide being formed upon its surface. Coins and medals may be handsomely b1ronzed as follows: 2 parts of verdigris and 1 part of sal ammoniac are to be dissolved in vinegar; the solution is to be boiled, skimmed, and diluted with water till it has only a weak metallic taste, and upon further dilution lets fall no white precipitate. This solution is made to boil briskly, and is poured upon the objects to be bronzed, which are previously made quite clean, particularly fiee from grease, and set in another copper pan. Tliis pan is to be lut upon the fire, that the boiling may be renewed. The pieces under operation must be so laid that the solution has free access to every point of their surface. The copper hereby acquires an agreeable reddish brown hue, without losing its lustre. But if the process be too long continued, the coat of oxide becomes thick, and makes the objects appear scaly and dull. Ience they must be inspected every five minutes, and be taken out of the solution the moment their colour arrives at the desired shade. It the solution be too strong, the bronzing comes off with fiiction, or the copper gets coveted with a white powder, which becomes green by exposure to air, and the labour is conoequently lost. The bronzed pieces are to be washed with many repeated waters, and carefully dried, otherwise they would infallibly turn green. To give fresh-made bronze BRONZE. 283 objects an antique appearance, three quarters of an ounce of sal ammoniac, and a drachm and a half of binoxalate of potash (salt of sorrel) are to be dissolved in a quart of vinegar and a soft rag or brush moistened with this solution is to be rubbed over the clean bright metal, till its surface becomes entirely dry by the friction. This process must be repeated several times to produce the full effect; and the object should be kept a litle warm. Copper acquires very readily a brown color by rubbing it with a solution of the common liver of sulphur, or sulphuret of potash. The Chinese are said to bronze their copper vessels by taking 2 ounces of verdigris, 2 ounces of cinnabar, 5 ounces of sal ammoniac, and 5 ounces of alum, all in powder, making them into a paste with vinegar, and spreading this pretty thick like a pigment on the surfaces previously brightened. The piece is then to be held a little while over a fire, till it becomes uniformly heated. It is next cooled, washed, and dried; after which it is treated in the same way once and again till the wished for color is obtained. An addition of sulphate of copper makes the color incline more to chestnut brown, and of borax more to yellow. It is obvious that the cinnabar produces a thin coat of sulphuret of copper upon the surface of the vessel, and might probably be used with advantage by itself. To give the appearance of antique bronze to modern articles, we should dissolve 1 part of sal ammoniac, 3 parts of cream of tartar, and 6 parts of common salt in 12 parts of hot water, and mix with the solution 8 parts of a solution of nitrate of copper of specific gravity 1-160. This compound, when applied repeatedly in a moderately damp place to bronze, gives it in a short time a durable green coat, which becomes by degrees very beautiful. More salt gives it a yellowish tinge, less salt a blueish cast. A large addition of sal ammoniac accelerates the operation of the mordant. BRONZE POWDERS, an article much used of late in the decorative painting of houses, &c. They are prepared of every various shade, from that of bright gold to orange, dark copper, emerald green, &c. Pale gold is produced from an alloy of 13} of copper, and 21 of zinc: crimson metallic lustre-from copper: do. paler, copper and a very little zinc: green bronze with a proportion of verdigris: another fine orange by 14J copper and 1 i zinc: another do. 131 copper and 2: zinc: a beautiful pale gold from an alloy of the two metals in atomic proportions. See ATOMIC WEIGHTS. The alloy is laminated into very fine leaves with careful annealing, and these are levigated into impalpable powders along with a film of fine oil to prevent oxidizement, and to favour the levigation. This Nuremberg manufacture. has been successfully introduced here by Mr. Bessemer. BROWNING of gun-barrels and other arms.-By this process, the surface of several articles of iron acquires a shining brown color. This preparation, which protects the iron from rust, and also improves its appearance, is chiefly employed for the barrels of fowling-pieces and soldiers' rifles, to conceal the fire-arms from the game and the enemy. The finest kind of browning is the Damascus, in which dark and bright lines run through the brown ground. This operation consists in producing a very thin uniform film of oxyde or rust upon the iron, and giving a gloss to its surface by rubbing wax over it, or coating it with a shellac varnish. Several means may be employed to produce this rust speedily and well. The effect nay be obtained by enclosing the barrels in a space filled with the vapor of muriatie acid. Moistening their surface with dilute muriatic or nitric acid, will answer the same purpose. But the most common material used for browning, is tha butter or chloride of antimony, which, on account of its being subservient to this porpose, has been called bronzing salt. It is mixed uniformly with olive oil, and rubbed upon the iron slightly heated; which is afterwards exposed to the air, till the wished-for degree of browning is produced. A little aquafortis is rubbed on after the antimony, to quicken its operation. The brown barrel must be then carefully cleaned, washed with water, dried, and finally polished, either by the steel burnisher, or rubbed with white way, or varnished with a solution of 2 ounces of shellac, and three drachms of dragon's blood, in 2 quarts of spirit of wine. The following process may also be recommended: Make a solution with half an ounce of aquafortis, half an ounce of sweet spirit of nitre, 1 ounce of spirit of wine, 2 ounces of sulphate of copper, and 1 ounce of tincture of iron, in so much water as will fill altogether a quart measure. The gun barrel to be browned must first of all be filed and polished bright, and then rubbed with unslaked lime and water to clear away all the grease. Its two ends must now be stopped with wooden rods, which may serve as handles, and the touch-hole must be filled with wax. The barrel is then to be rubbed with that solution, applied to linen rags or a sponge, till the whole surface be equally moistened; it is allowed to stand 24 hours, and is then scrubbed with a stiff brush. The application of the liquid and tne brushing may be repeated twice or oftenea 284 BRONZE. till the iron acquires a fine brown colour. After the last brushing, the barrel must be washed with plenty of boiling water, containing a little potash; then washed with clean water, dried, rubbed with polishing hard wood, and coated with shell-lac varnish, for which purpose the barrel must be heated to the boiling point of water. It is finally polished with a piece of hard wood. Storch recommends to make a browning solution with 1 part of sulphate of copper, one third of a part of sulphuric ether, and 4 parts of distilled water. To give the damask appearance, the barrel must be rubbed over first with very dilute aquafortis and vinegar, mixed with a solution of blue vitriol; washed and dried, and rubbed with a hard brush to remove any scales of copper which may be precipitated upon it from the sulphate. Statues, vases, bas-reliefs, and other objects made of gypsum, may be durably bronzed, and bear exposure to the weather better than after the ordinary oil-varnish, by the following process:-Prepare a soap fromi linseed oil, boiled with caustic soda ley, to which add a solution of common salt, and concentrate it by boiling, till it becomes somewhat granular upon the surface. It is then thrown upon a piece of linen cloth, and strained with moderate pressure. What passes through is to be diluted with boiling water, and again filtered. On the other hand, 4 parts of blue vitriol and 1 part of copperas are to be dissolved separately in hot water. This solution is to be poured slowly into the solution of soap, as long as it occasions any precipitate. This flocculent matter is a mixture of cupreous soap and ferruginous soap, that is, a combination of the oxides of copper and iron with the margaric acid of the soda soap. The copper soap is green, the iron soap is reddish brown, and both together resemble that green rust which is characteristic of the antique bronzes. When the precipitate is comrn pletely separated, a fiesh portion of the vitriol solution is to be poured upon it in a copper pan, and is made to boil, in order to wash it. After some time, the liquid part must be decanted, and replaced by warm water for the purpose of washing the metallic soaps. They are finally treated with cold water, pressed in a linen bag, drained and dried. In this state the compound is ready for use in the following way:Three pounds of pure linseed oil are to be boiled with 12 ounces of finely-powdered litharge, then strained through a coarse canvass cloth, and allowed to stand in a warm place till the soap turns clear. Fifteen ounces of this soap-varnish, mixed with 12 ounces of the above metallic soaps, and 5 ounces of fine white wax, are to be melted together at a gentle heat in a porcelain basin, by means of a water bath. The mixture must be kept for some time in a melted state, to expel any moisture which it may contain. It must be then applied, by means of a painter's brush, to the surface of the gypsum previously heated to the temperature of about 200~ F. By skilful management of the heat the colour may be evenly and smoothly laid on without filling up the minute lineaments of the butts. When after remaining in the cool air for a few days, the smell of the pigment has gone off, the surface is to be rubbed with cotton wool, or a fine linen rag, and variegated with a few streaks of metal powder or shell gold. Small objects may be dipped in the melted mixture, and then exposed to the heat of a fire till they are thoroughly penetrated and evenly coated with it. The patina antica (XErugo nobilis) of the Italian antiquaries is said to be imitated by plunging the copper medals in a boiling-hot solution of 2 parts of verdigris and 1 oi sal ammoniac, so much diluted as to be nearly tasteless. They are allowed to remain in the solution till they take an agreeable reddish or yellowish brown colour, when the fluid is to be poured off, and the medals washed and dried. BRONZE POWDER consists of a metallic alloy reduced to thin laminme by beating between skins or membranes in the ordinary way, and then triturated into fine powder along with oil, to prevent oxidation by the atmosphere. The leaves are put first into an iron wire sieve of ten meshes to the inch; olive oil is then allowed to flow freely from a stopcock over the centre of the sieve on to the leaf metal, which is briskly moved over the surface of the sieve with a wire brush, until the whole is forced through into a vessel below. This mixture of metal and oil is then introduced through a funnel hopper of the triturating machine, and spreading among the rods is caused by their rotation to approach the periphery of the steel bed beneath, and escape into a circular trough, whence they are conducted by a spout into another vessel. In this progress the metal is acted upon by polished hemispherical bottom ends of upright rods, as they ascend and descend the corrugated surface of the steel bed, and which, by a tearing and burnishing operation, separate the coarse pieces of leaf into a multitude of polished particles. By being passed three times through the machine, the metal is reduced to the quality of a coarse bronze powder; and is then subjected to a similar machine conaaining smaller rods, tossed up and down by the revolution of the corrugated angular bed on which they rapidly dance till the requisite fineness be produced. The contents of the vessel, which are usually 10 pounds of metal and 10 pounds of oil, are then put into a strong bag, made of three thicknesses of fustian, with their respective seams at different parts of the circumference, so as to'prevent the metallic particles from passing BROWN DYE. 285 through. This bag is subjected to the action of a hydraulic press, of abo It 30() tons upon a bag of one foot diameter, nearly all the oil is expelled. The empty bag is filled with boiling water, and again squeezed; and after two or three repetitions ofthis washing, all the oil comes out in the form of an emulsion. The bag now contains only a dense lump of bright metallic particles of nearly the gravity of the original metal. This lump is cut with a knife into slices about half an inch thick, and exposed to the air of a warm room, where the moisture evaporates, and the slices may then be crumbled into powder. (Newton's Journal, xxiv. 321.) BRONZING (of Objects in Imitation of Metallic Bronze). Plaster of Paris, paper, wood, and pasteboard, may be made to resemble pretty closely the appearance of articles of real bronze, modern or antique. The simplest way of giving a brilliant aspect of this kind is with a varnish made of the waste gold leaf of the beater, ground up on a porphyry slab with honey or gum-water. A coat of drying linseed-oil should be first applied, and then the metallic powder is put on with a linen dossil. Mosaic gold ground up with six parts of bone-ashes has been used in the same way. When it is to be put on paper, it should be ground up alone with white of eggs or spirit varnish, applied with a brush, and burnished when dry. When a plate of iron is plunged into a hot solution of sulphate of copper, it throws down fine scales of copper, which being repeatedly washed with water, and ground along with six times its weight of boneashes, forms a tolerable bronzing. Powdered and sifted tin may be mixed with a clear solution of isinglass, applied with a brush, and burnished or not, according as a bright or dead surface is desired. Gypsum casts are commonly bronzed by rubbing brilliant black-lead, graphite, upon them with a cloth or brush. Real-bronze long exposed to the air gets covered with a thin film of carbonate of copper, called by virtuosi antique cerugo (patine antique, Fr.). This may be imitated in a certain degree by several applications skilfully made. The new bronze being turned or filed into a bright surface, and rubbed over with dilute aquafortis by a linen rag or brush, will become at first greyish, and afterwards take a greenish blue tint; or we may pass repeatedly over the surface a liquor composed of 1 part of sal ammoniac, 3 parts of carbonate of potash, and 6 of sea-salt dissolved in 12 parts of boiling water, to which 8 parts of nitrate of copper are to be added; the tint thereby produced is at first unequal and crude, but it becomes more uniform and softer by time. A fine green-blue bronze may be obtained with very strong water of ammonia alone, rubbing it' at intervals several times upon the metal. The base of most of the secret compositions for giving the antique appearance is vinegar with sal ammoniac. Skilful workmen use a solution of 2 ounces of that salt in an English quart of French vinegar. Another compound which gives good results is made with an ounce of sal ammoniac, and a quarter of an ounce of salt of sorrel (binoxalate of potash) dissolved in vinegar. One eminent Parisian sculptor makes use of a mixture of half an ounce of sal ammoniac, half an ounce of common salt, an ounce of spirits of hartshorn, and an English quart of vinegar. A good result will also be obtained by adding half an ounce of sal ammoniac, instead of the spirits of hartshorn. The piece of metal being well cleaned, is to, be rubbed with one of these solutions, and then dried by friction with a fresh brush. If the hue be found too pale at the end of two or three days, the operation may be repeated. It is found to be more advantageous to operate in the sunshine than in the shade. BROWN DYE. Upon this subject some general views are given in the article DYEING, explanatory of the nature of this colour, to which I may in the first place refer. This dye presents a vast variety of tints, from yellow and red to black brown, and ia produced either by mixtures of red, yellow, and blue with each other, or of yellow or red with black, or by substantive colours, such as catechu or oxide of manganese, alone. We shall here notice only the principal shades; leaving their modifications to the caprice or skill of the dyer. 1. Brown from mixture of other colours. Wool and woollen cloths must be boiled with one eighth their weight of alum and sulpho-tartrate of iron (see this article); afterwards washed, and winced through the madder bath, which dyes the portion of the stuff imbued with the alum red, and that with the salt of iron black; the tint depending upon the proportion of each, and the duration of the madder bath. A similar brown is produced by boiling every pound of the stuff with two ounces of alum, and one ounce of common salt, and then dyeing it in a bath of logwood containing eitner sulphotartrate, acetate, or sulphate of iron. Or the stuff may be boiled with alum and tartar, dyed up in a madder bath, and then run through a black bath of iron mordant and galls or sumach. Here the black tint is added to the red till the proper hue be hit. The brown may be produced also by adding some iron liquor to the madder bath, after the stuff has been dyed up in it with alum and tartar. A better brown of this kind is obtained by boiling every pound of wool with 2 ounces of alum, dyeing it up in.ochineal, then changing the crimson thus given into brown, by turning the stuff through 286 BROWN DYE. the bath after acetate of iron has been added to it. Instead of the cochineal, archil, or cutbear, with a little galls or sumach, may be used. Wool or silk may also receive a light blue ground from the indigo vat, then be morlanted with alum, washed, and turned through a madder bath till the wished-for brown be brought out. For the deeper shades, galls or sumach may be added to the paler Brazilwood, with more or less iron mordant. Instead of the indigo vat, Saxon blue may be employed to ground the stuff before dyeing it with madder, or 5 pounds of madder, with I poundl of alum, a solution of one tenth of a pound of indigo in sulphuric acid, may be used with the proper quantity of water for 2n pounds of wool; for dark shades, some iron mordant may be added. Or we may combine i bath of cochineal or cutbear, fustic, and galls, and add to it sulphate of iron and sulphate of indigo, blunted with a little ot ash. If we boil woollen cloth with alum and tartar, then pass it through a madder bath, and afterward through one of well or fustic, containing more or less iron mordant, we obtain shades variable, according to the proportions of the materials, from rnordore and cinnamon to chestnut brown. After the same manner, bronze colors may be obtained from the union of olive dyes with red. For 25 pounds of cloth, we take 4 poundsof fustic chips, boil them for 2 hours, turn the cloth in this bath for an hour, and drain it; then add to the bath from 4 to 6 ounces of sulphate of iron, and 1 pound of ordinary madder, or 2 pounds of sandal-wood; put the cloth again in this compound bath, and turn it through, i.11 the desired shade be obtained. By changing the proportions, and adding an iron mordant, other tints may be produced. This mode of dyeing is suitable for silk, but with three difierlet baths; one, of logwood, one of Brazil-wood, and one of fustic. The silk, after being boiled with soap, is to be alumed, and then dyed up in a bath compounded of these three decoctions, mixed in the requisite proportions. By the addition of walnut peels, sulphate of copper, and a little sulphate of iron, or by passing the silk through a bath of annotto, a variety of brown shades may be had. Or the silk may receive an annotto ground, and then he passed through a bath of logwood or Brazil-wood. For 10 pounds of silk, 6 ounces of annotto are to be taken, and dissolved with 18 ounces of potashes in boiling water. The silk must be winced through this solution for 2 hours, then wrung out, dried, next alumed, passed through a bath of Brazil-wood, and finally through a bath of logwood, containing some sulphate of iron It is to be wrung out and dried. Brown of different shades is imparted to cotton and linen, by impregnating them with a nixed mordant of acetates of alumina and iron, and then dyeing them up, either with madder alone, or with madder and fustic. When the aluminous mordant predominates, the madder gives an amaranth tint. For horse-chestnut brown, the cotton must be gallet, pltinned into a black bath, then into a bath of sulphate of copper, next dyed up in a decoction of fustic, wrung out, passed through a strong madder bath, then through the sulphate of copper solution, and finished with a soap boil. Different shades of cinnamon are obtained, when cottons first dyed up with madder get an olive cast with iron liquor in a fustic bath. These cinnamon and mordore shades are also produced by dyeing them first in a bath o' weld and verdigris, passing them through a solution of sulphate of iron, wringinz and dryina them; nextputting them through a bath containing 1 pound of galls for 10 pounds of stuff, arain drying, next aluming, and maddering. They must be brightened by a boil in soap water. A superior brown is produced by like means upon cotton goods, which have undergone the oiling process of the Turkey red dye. Such stuffs must be galled, mordanted with alum (see MADDER), sulphate of iron, and acetate of lead (equal to } of the alum); aftet washing and drying, dyed in a madder bath, and cleared with a soap boil. The tint of brown varies with the proportion of alum and sulphate of iron. We perceive from these examples, in how many ways the browning of dyes may be modified, upon what principles they are founded, and how we have it in cur power to turn the shade more or less toward red, black, yellow, blue, &c. Brown may be produced by direct dyes. The decoction of oak bark dyes wool a fast brown of different shades, according to the concentration of the bath. The color is more lively with the addition of alum. The decoction of bastard marjoram (Origanum vulgare) dyes cotton and linen a reddish brown, with acetate of alumina. Wool takes from it a dark brown. The bark of the mangrove tree (Rizophora mangle) affords to wool boiled with alum and tartar a fine red brown colour, which, with the addition of sulphate of iron, passes into a fast chocolate. The Bablah, the pods of the East Indian JMimosa cineraria, and the African Miimosa nilotica, gives cotton a brown with acetate or sulphate of copper. The root of the white sea rose (Nymphcea alba) gives to cotton and wool beautifiu BUTTER. 287 shades of brown. A mordant of sulphate of iron and zinc is first given, and then the wool is turned through the decoction of the root, till the wished-for shade is obtained. The cotton must be mordanted with a mixture of the acetates of iron and zinc. Walnut peels (Juglans regia), when ripe, contain a dark brown dye stuff, which communicates a permanent color to wool. The older the infusion or decoction of the peels, the better dye does it make. The stuff is dyed in the lukewarm bath, and needs no mordant, though it becomes brighter with alum. Or this dye may be combined with the madder or fustic bath, to give varieties of shade. For dyeing silk, this bath should be hardly lukewarm, for fear of causing inequality of color. The peelings of horse-chestnuts may be used for the same purpose. With muriate of tin they give a bronze color, and with acetate of lead a reddish brown. Catecnu gives cotton a permanent brown dye, as also a bronze, and mordore, when its solution in hot water is combined with acetate or sulphate of copper, or when the stuff is previously mordanted with the acetates of copper and alumina mixedl, sometimes with a little iron liquor, rinsed, dried, and dyed up, the bath being at a boiling heat. Ferrocyanate of copper gives a yellow brown or a bronze to cotton and silk. The brown color called carmelite by the French is oroduced by one pound of catechu to four ounces of verdigris, with five ounces of muriate of ammonia. The bronze (solitaire) is given by passing the stuff through a solution of muriate or sulphate of manganese, with a little tartaric acid, drying, passing through a potash ley at 4~ Baume, brightening and fixing with solution of chloride of lime. BRUSHES. (Brosses, Fr.; Bursten, Germ.) Mr. T. Mason obtained a patent in October, 1830, for an improvement in the manufacture of this article. It consists in a firmer mode of fixing the knots or small bundles of hair into the stock or the handle of.the brush. This is done by forming grooves in the stocks of the brushes, for the purpose of receiving the ends of the knots of hair, instead of the holes drilled into the wood, as in brushes of the common constructions. These grooves are to be formed like a dovetail, or wider at the bottom than the top; and when the ends of the knots of hair have been dipped into cement, they are to be placed in the grooves and compressed into an oval form, by which the ends of the hair will be pressed outwards into the recess or wider part of the dovetailed groove, or the grooves may be formed with threads or teeth on the sides, instead of being dovetailed; and the cement and hairs being pressed into the teeth or threads, will cause them to adhere firmly to tile stock or handle of the brush. A metal ferrule may be placed on the outside of the stock of the brush, if necessary, and secured by pins or rivets, or in any other convenient manner, which ferrule may 209 c c also form one side of the outer groove. Fig. 209 is -09 e a plan view of the stock of a round brush; fig. 210 is a section of the same; a a are the dovetailed grooves, / which are turned out of the wood; b is the metal ferrule; c c are knots or small bundles of hair, to form 210 ne the brush. After a number of the knots of hair are prepared, the ends are to be dipped into proper cement, { ~/~////////[ and then placed into the grooves, when their ends are to be sueezed by a pair of pliers, or other means, which } r r ]si^ - will compress them into the oval shape, as shown in fig. 211 and cause the ends of the hairs to extend outward under the dovetailed part of the recess. JThe knots of hair are to be successively placed in the 21 /ffi grooves, and forced up by a tool against the last knot ~~211'' pput in, and so on, until the grooves are filled; fi,. 211 is a section taken through a brush with teeth or threads of a screw formed upon the sides of the groove; into these teeth or threads the cement and hairs will be forced by the compression, by which means they will he held firmly in the stock of the brush. BUTTER. (Beurre, Fr.; Butter, Germ.) Milk contains a fatty matter of more or less consistency, modified very much according to the nature of the animals which afford it. This substance is butter, held suspended in the milk by means of the caseous matter and whey, with which it is intimately blended. Milk is a true emulsion resulting from the mixture of these three ingredients, owing its opacity and white color to the diffusion through it of that butyraceous oil. When any circumstance dissolves this union, each component becomes insulated, and manifests its peculiar properties. Milk, even left to itself, at a temperature of from 50~ to 60~ F., separates spontaneously into several products. > A layer of a fatter, more consistent, but lighter nature floats on its surface, while the subjacent liquid forms a white magma, which retains among its curdy flocks all the whey of the milk. The upper layer or cream contains nearly the whole of the butter; but a portion remains entangled with the curd and whey below. 288 BUTTON MANUFACTURE. It belongs to a work on husbandry or rural economy to treat fully of the operations of the dairy: one of the principal of which is the extraction of butter from milk. The Tartars and French have been long in the habit of preserving butter, by melting it with a moderate heat, whereby are coagulated the albuminous and curdy matters remaining in it, which are very putrescible. This fusion should be made by a heat of a water bath, about 176~ F., continued for some time to effect the more complete purification of the butter. If in this settled liquefied state it be carefully decanted, strained through a tammy cloth, and slightly salted, it may be kept for a long time nearly fresh, without becoming in any degree rancid, more especially if it be put up in small jars closely covered. Butter is the fatty matter of milk, usually of that of the cow. Milk is composed of butter, caseine, sugar of milk, several salts, and water. The butter exists in the form of very small globules of nearly uniform size, quite transparent, and strongly refractive of light. Milk left in repose throws up the lighter particles of butter to the surface as cream. It was imagined that the butter was separated in the process of churning, in consequence of the milk becoming sour; but this is not the case, for milk rendered alkaline by bicarbonate of potash affords its butter fully more readily than acidulous milk. The best temperature for churning milk or cream is 53~ F.; that of 60~ is too high; and under 50~ it is too low. By the churning action the heat rises from 3 to 4 degrees F. All the particles of butter are never separated by churning; many remain diffused through the butter-milk, and are easily discoverable by the microscope. These are more numerous in proportion to the bulk of the liquid; and hence it is more economical to churn cream than the whole milk which affords it. It is computed that a cow which gives 1800 quarts (old English) of milk per annum eats in that time 8000 lbs. of hay, and produces 140 lbs. of butter.* Analysis shows that this weight of hay contains 168 pounds of fat. The finest flavoured butter is obtained from milk churned not long after it is drawn; but the largest proportion is derived from the cream thrown up by milk after standing 24 hours, in a temperature of about 50~ F. The butter-milk, which contains the very fermentable substance, caseine, should be well separated from the butter by washing with cold water, and by beating with the hands, or preferably, without water, for the sake of fine flavour, by the action of a press. The French purify their butter by melting it in pots, plunged into water heated to 200~ or 212~; and sometimes they mix a pure brine with the melting butter, whereby they favour the subsidence of the coagulated caseine and other impurities. The supernatant clear butter should be drawn or poured off, and rapidly cooled, to prevent the crystallization of its stearine and separation of its oleine, which injure its flavour and appearance. BUTTER OF CACAO. See CACAO, CHOCOLATE, and OIs. BUTTON MANUFACTURE. This art is divided into several branches, con stituting so many distinct trades. Horn, leather, bone, and wood, are the substances frequently employed for buttons, which are either plain, or covered with silk, mohair, thread, or other ornamental materials. The most durable and ornamental buttons are made of various metals, polished, or covered with an exceedingly thin wash, as it is termed, some more valuable metal, chiefly tin, silver, and gold. Those buttons intended to be covered with silk, &c., are termed in general moulds. They are small circles, perforated in the centre, and made from those refuse chips of bone which are too small for other purposes. These chips, which for the large and coarser buttons, are pieces of hard wood, are sawn into thin flakes, of an equal thickness; from which, by a machine, the button moulds are cut out at two operations. The shavings, sawdust and more minute fragments are used by manufacturers of cutlery and iron toys, in the operations of case-hardening; so that not the smallest waste takes place. Metal buttons are formed of an inferior kind of brass, pewter, and other metallic compositions: the shanks are made of brass or iron-wire, the formation of which is a distinct trade. The buttons are made by casting them round the shank. For this purpose the workman has a pattern of metal, consisting of a great number of circular buttons, connected together in one plane by very small bars from one to the next; and the pattern contains from four to twelve dozen of buttons of the same size. An impression from this pattern is taken in sand in the usual manner; and shanks are pressed into the sand in the centre of each impression, the part which is to enter the metal being left projecting above the surface of the sand. The buttons are now cast from a mixture of brass and tin; sometimes a small proportion of zinc is added, which is found useful in causing the metal to flow freely into the mould, and makes a sharp casting. When the buttons are cast, they are cleaned from the sand by brushing; they are then broken asunder, and carried to a second workman at the lathe, who inserts the shank of a button into a chuck of a proper figure, in which it is retained by * Two pounds and a quarter of hay correspond to one quart of good milk; and a cow which eats 6.500 Ibs. of hav will produce 300 lbs. of butter ner annum. BUTTON MANUFACTURE. 289 the back centre of the lathe being pressed against the button with a spring. The circumference is now, by filing it as it turns around, reduced to a true circle; and the outton is instantly released by the workman's holding back the centre, and is replaced by another. A third workman now turns the back of the button smooth, in a chuck lathe, and makes the projecting part round the shank true; and a fourth renders the face of the button smooth, by placing it in a chuck, and applying the edge of a squal e bar of steel across its centre. Gilt buttons are stamped out from copper (having sometimes a small alloy of zinc), laminated in the flatting mill to the proper thickness. The stamp is urged by a flypress, which cuts them out at one stroke. These circular pieces, called blanks, are annealed in a furnace to soften them; and the maker's name, &c. is struck on the back by a monkey, which is a machine very similar to a pile engine. This stamp also renders the face very slightly convex, that the buttons may not stick together in the gilding process. The shanks are next soldered on. The burnishing is performed by a piece of hematites or blood-stone, fixed into a handle, and applied to the button as it revolves by the motion of the lathe. A great number of the buttons, thus prepared for gilding, are put into an earthen pan, with the proper quantity of gold to cover them,- amalgamated with mercury in the following manner:- The gold is put into an iron iadle, and a small quantity of mercury added to it; the ladle is held over the fire, till the gold and mercury are perfectly united. This amalgam being put into the pan with the buttons, as much aquafortis, diluted with water, as will wet them all over, is thrown in, and they are stirred up with a brush, till the acid, by its affinity to the copper, carries the amalgam to every part of its surface, covering it with the appearance of silver. When this is perfected, the acid.is washed away with clean water. This process by the workman is called quicking. The old process in gilding buttons, called the drying off, was exceedingly pernicious to the operator, as he inhaled the vapour of the mercury, which is well known to be a violent poison. In order to obviate this, the following plan of apparatus has been employed with success. The vapour, as it rises from the pan of buttons heated by a charcoal fire, is conducted into an oblong iron flue or gallery, gently sloped downwards, having at its end a small vertical tube dipping into a water cistern, for condensing the mercury, and a large vertical pipe for promoting the draught of the products of the combustion. Plated buttons are stamped by the fly-press, out of copper-plate, covered on one side with silver at the flatting mill. The copper side is placed upwards in stamping, and the die or hole through which they are stamped, is rather chamfered at its edge, to make the silver turn over the edge of the button. The backs are stamped in the same manner as the gilt buttons. The shanks are soldered on with silver solder, and heated one by one in the flame of a lamp, with a blow-pipe urged by bellows. The edges are now filed smooth in the lathe, care being taken not to remove any of the silver which is turned over the edge. They are next dipped in acid, to clean tie backs, and boiled in cream of tartar and silver, to whiten them; after which they are burnished, the backs being first brushed clean by a brush held against them as they revolve in the lathe. The mode of burnishing is the same as for gilt buttons. Button shanks are made by hand from brass or iron wire, bent and cut by the following means:The wire is lapped spirally round a piece of steel bar. The steel is turned round by screwing it intc the end of the spindle of a lathe, and the wire by this means lapped close round it till it is covered. The coil of wire thus formed is slipped off, and a wire fork or staple witl parallel legs put into it. It is now laid upon an anvil, and by a punch the coil of wire is struck down between the two prongs of the fork, so as to form a figure 8, alittle open in the middle. The punch has an edge which marks the middle of the 8, and the coil being cut open by a pair of shears along this mark, aivides each turn of the coil into two perfect button shanks or eyes. Mr. Holmes, of Birmingham, obtained in May, 1833, a patent for an improved construction of buttons. Fiq. 212. represents the outside appearance of one of his improved shanks, as raised or formed out of the disc of metal which is to constitute the back of the button; fig. 213, an edge view, looking through the shank or loop; fig. 214. is another edge view, looking at the raised shank or loop endways; fig. 215. is a section taken through the shank and disc in the direction of the dotted line A B, in fig. 212.; and fig. 216. another section taken in the direction of the dotted line c D, in fig. 212. All these figures of his improved shanks, as well as those hereinafter described, together with the tools used to form the same, are drawn at about half the real size, to show the parts more distinctly. It will be seen that the shanks or loops a a are formed * By act of parliament 5 grains of gold are allotted for the purpose of gilding 144 buttons, though they may be tolerably well gilt by half that quantity. In this last:ase, the thickness would be about the 214,000th part of an inch. 20 290 BUTTON MANUFACTURE. by partially cutting and raising, or forcing up a portion of the metal disc or back b, and are compressed or formed by the action of the tools, or punches and dies, so as to have __._ _-~'~~ 224 65 i~.~ 218 217 24 28 "'f16281 ___ __. A912 213 (-KjT ^221 220 219 IDf...... [ (23235 (:D23 3 231 r r 28e227........ 232Q 230 a rounded figure on the inside of the top part of the shank, as at c, the edges of the metal being turned so as to prevent them cutting the threads by which the button is fastened to the cloth or garment. It will be observed that, there being but one passage or way through which the thread can be passed to sew on the button, and that opening being rounded on all edges, will ctuse the threads to keep in the centre of the shanks, the form of the shank allowing a much neater attachment to the garment, and keeping the threads from the edges of the metal. The ends of the shank or portions e e, which rise up from the disc or back b, are made nearly circular, in order to avoid presenting any edges of the metal to the sides of the button-hole; and when the shank is sewed on the cloth, it forms, in conjunction with the threads, a round attachment, thereby preventing the shank from cutting or wearing the button-hole: the threads, when the shank is properly sewed to the garment, nearly f'ling up the opening through the shank, and completing that portion of the circle which has been taken out of the shank by the dies in forming the crescented parts of the loop. It will be therefore understood that the intention is, that the inside edges of the shank should be turned as much as possible away from the threads by which the button is sewed on the cloth, and that the outside of the shank should be formed so as to present rounded surfaces to the button-hole, and that the thread should fill up the opening through the shank, so as to produce a rdund attachment to the garment. It should here be observed, that the backs of the buttons shown in these figures are of the shape generally used for buttons covered with Florentine or other fabric, or faced with plates of thin metal, and art intended.to have the edges of a disc, or what is termed a shell, forming the face, to be closed in upon the inclined or bevelled edges of the backs. Having now described the peculiar form of the improved shanks which he prefers, for buttons to be covered with Florentine or other fabric, or shells of thin metal plate, he proceeds to describe some of the different variations from the same. Fig. 217. is a representation of a shank, the cut through the disc or back being effected by a parallel rib on the die, and corresponding groove in the shaping punch, instead of the semi-circular or crescented cut shown in fig. 212; fig. 218. is a view of another shaAk, the separation of the sides of the loop being performed by straight edges in both punch and die. He prefers finishing this shaped shank (that is, giving it the rounded form, to prevent its cutting the threads), by detached punches, and dies, or pincers, as will be herein. after described. Fig. 219. is a representation of one of the improved shanks, which has merely portions, f f, of the back of the button connected to its ends. This shank may be used for buttons which have a metal shell to be closed in upon the bevelled edges of the ends, or the shank piece may be otherwise connected to the face part of the button. Fig. 220. is a representation of a shank raised out of a small disc of metal g g, intended to be soldered to the disc of metal forming the button, or it may be otherwise fixed to the tack; fig. 221. is a representation of another shank for the same purpose, having only BUTTON MANUFACTURE. 291 portions of metal h h, for soldering or otherwise attaching it to the back of the button, as by placing a ring or annular piece over it forming the back, which shall be confined to the face, as before described;fig. 222. is a representation of a shank raised upon a dish or bevelled piece of metal, and is intended to be used for buttons made from pearl-shell, horn, wood, paper, or other substances. The back part of the button has a dovetailed recess formed in it to receive the dish-shaped back, which is pressed into the recess, the edges of the dish being expanded in the dovetailed parts of the recess by the ordinary means, and thereby firmly fixing it to the button, as shown in fig. 223. laving now explained the peculiar form of his inproved shanks,he proceeds to describe the tools,or punches and dies,by which he cuts the disc or back fiom out of a sheet of metal, and at the same operation produces and forms the shank complete. Fig. 224. is a longitudinal section taken through a pair of dies and punches when separated;fig. 225. is a similar section, taken when they are put together, and in the act of forming a shank after cutting out the disc or back of the button from a sheet of metal; fig. 226. is a face view of the punch; and fig. 227. is a similar representation of the counter die,with the tools complete; a is the puncher or cutter, and b the counter bed, by the circular edges of which the disc of metal is cut out of the sheet; c is a die, fixed in the cutter a, (upon which the name of the button maker may be engraved.) Fig. 228. is a face view of this die when removed out of the punch; d is the counter die to the die c. It will be perceived that these dies c and d, together with the punch and bed, compress the disc of metal into the form required for the back of the button; that shown in the figures, as before stated, is of the shape used for buttons to be covered with Florentine or thin plate metal, in a round shell closed in upon the inclined or bevelled edge of the back; e is the cutting and shaping punch of the shank, which is fixed within the counter die; this punch cuts through the metal of the disc, and forms the shank as the dies approach nearer together, by raising or forcing it up into the recess or opening in the die c, where it is met by the end of another shaping punch f, fixed in the punch a, which compresses the upper part of the shank into the recess g, in the end of the punch e, thereby giving the shank its rounded figure, and at the same time forming the other part of the shank into the re(uired shape, as described at figs. 212. to 216. The ends of these shaping punches fit into and over each other, as will be seen by the detached figures of the punches designed for forming the shank first described. Fig. 229. is a representation of the punches when apart and removed out of the dies: fig. 230. is a longitudinal section of the same; fig. 231. is another view of the punches as seen on the top. Tlie sharp edge of the recess I, in the punch e, comes in contact with the cutting edges of the projecting rib i, of the die c, and thereby cuts through so much of the metal as is required. The edge k of this die keeps the outside ends of the shank of a spherical figure, as before explained,while the punches forc'e up the metal, and form the elevated loop or shank: u u are holes made through the counter die d, for the passage of clearing pins, which force out the shank or back piece firom the counter die when finished; the operation of which will be shown when describing the machinery hereafter. There are adjusting screws at the back of the punches and dies, by which they can be regulated and brought to their proper position one to the other. Although he has shown the punches which form his improved shanks, fixed into and working in conjunction with the punch and dies which cut out and shape the discs of metal for the back of the button, yet he does not intend to confine himself to that mode of using them, as flat blanks or discs for the backs of buttons may be cut out in a separate stamping press, and afterwards shaped in the same press or in another, and then brought under the operation of the punches which form his improved shanks, fixed in any suitable press. Tiis last-mentioned mode of producing button shanks and backs he prefers when such metals are employed as require annealing between the operations of shaping the backs and forming the shank. Fig. 23'. is a section taken through a pair of dies, in which the operation only of forming the shank is to be performed, the backs being previously shaped in another press. In this instance the punches e andf are mounted in guide-pieces m and n, which keep them in the proper position towards each other, the die c being mounted in the piece n, and acting against the face of the guide m. The blanks or backs of the buttons may be fed into these dies by hand or any other means; and after the shank is formed, the finished back can be pushed out of the lower die by clearing rods passed through the holes u u, and removed by hand, or in any convenient manner. When his improved shanks are formed out of iron or other metal which is too brittle to allow of the shank being forced up and finished at one operation in the dies and punches, he prefers cutting out and shaping the blank or back of the button first, and after annealing it, to raise or force up the portion of metal to form the shank into the shape shown in fig. 233., that is, without the edges of the metal being turned to prevent their cutting the threads, and after again annealing it, to bend or turn the edges into the shape shown in fig. 218. by means of suitable punches in another press, or by a pair of pincers and punch as shown infig. 234, which is a side view of a small apparatus to be 292 BUTTON. used for turning the cages of the shank by hand, with a partly formed shank seen undei operation. a, is the upper jaw of a pair of pincers, this jaw being fixed on to the head of the standard b; the under jaw c, is formed by the end of the lever or handle d, which has its fulcrum in the standard b. e, is a small punch, passed through a guide hole in the head of the standard, one end projecting into the jaws of the pincers, the other against a piecef, attached by a joint to the lever d, and working through a slot in the head of the standard; this piece f, has an inclined plane on the side next the end ot the punch, which, in its descent, projects the punch forward against the top of the loop of the shank, (placed at g,) as the pincers are closed by forcing down the lever d, and, in conjunction with the jaws of the pincers, compresses the shank into the required form, as shown at h, and in the enlargedfig. 218. A spring, i, acts against a pin fixed into the punch e, for the purpose of bringing it back as the jaws open after forming a shank. Figs. 235. and 236. represent the face and section of the dies mentioned before, for cutting the slits in the discs, as atfig. 217. Having explained the peculiar forms of his improved metallic shanks for buttons, and the tools employed in making the same, he proceeds to describe the machinery or apparatus by which he intends to carry his invention into effect. He proposes to take a sheet of metal, say about 30 or 40 feet long, and of the proper width and thickness, which thin sheet is to be wound upon a roller, and placed above the machine, so that it can be easily drawn down into the machine as required for feeding the punches and dies. Fig. 237. is a plan view of a machine, intended to work any convenient number of sets of punches and dies placed in rows. Eleven sets of punches and dies are represented, each set being J^^!,l,,l ii-impllW -|| constructed as described _,~I237 IFox___ ^ l under figs. 224. to 231.; 23_7 — == i fig. 238. is a side view,.....i...' _ andfig. 239. alongitudinal section, taken through ~____ __ L the machine; figs. 240. a v ___-_ B -T ~ and 241. are transverse 1....h-^._^ _ _.i... ~=.. r _ sections taken through'I~ii I the machine between the punches and counter;~~il~.C1 ~~dies, fig. 240. representd-11~32 111~3~ ~ face of the punches, and fig. 241. the opposite view ___^.^___/ ^,:___ — ]L inst ts appears af the r1 2 P11 1 3t dof the counter dies. a a, - I- are the punches; b b,; |-i.............-._.ii... the counter dies; each I_ -- ----.':being mounted in rows _...... i=.': _____ ( Twiin the steel plates c c, r - — P —-—' l...... - fixed upon two strong bars d and e, by countersunk screws and nuts, -'E --— / z' QQthe punches and dies _ ) n \ othibsTbeing retained in their proper position by the plates, which are screwed ___ ___ _r _ _ ___ A on to the front of the pins g g, fixed in the heads h h of the frame,._,,_......-: -__ which guide-pins pass -- through the bosses on the ends of the bars The bar d is stationary mupon the guide-pins being fixed to the heads h h, by nuts and screws passed through ears cast 239 ~~~tron their bosses. The bar e slides freely upon the guide-pins g g, as it is BUTTON. 293 moved backwards and forwards by the crank i i, and connecting-rods jj, as the crank shaft revolves. The sheet of thin iron to be operated upon is placed, as before stated, above the machine; its end being brought down as at a a, and passed between the guide-rod and clearing plate k, and between the pair of feeding-rollers 1, which, by revolving, draw down a further portion of the sheet of metal between the punches and dies, after each operation of the punches. As the counter dies advance towards the Tunches, they first come in contact with the sheet of metal to be operated upon; and after having produced the pressure which cuts out the discs, the perforations of the sheet are pushed on to the ends of the punches by the counter dies; and in order that the sheet may be allowed to advance, the carriage which supports the axles of the feeding-rollers, with the guide-rod and clearingplate, are made to slide by means of the pin m, which works in a slot in the slidingpiece n, bearing the axis of the feeding-roller I 1, the slide n being kept in its place on the framework by dovetailed guides, shown in fig. 241. When the counter dies have advanced near to the sheet of metal, the pin vm, comes in contact with that end of the slot in the piece n, which is next to the punches, and forces the carriage with feed-rollers and clearing plate, and also the sheet of metal, onwards, as the dies are advanced by the reaction of the cranks; and after they have cut out the discs, and raised the shanks, the sheet of metal will remain upon the punches; and when the bar e returns, the finished backs and shanks are forced out of the counter dies, by the clearing-pins and rods o o, which project through the bar e, and through the holes before mentioned in the counter dies; these clearing-pins being stationary between the bars p p, mounted upon the standard q q, on the cross bar of the frame, as shown in figs. 237. 239. 240. Immediately after this is done, the pins m come in contact with the other ends of the slots in the pieces n, and draw back the feeding-rollers 11, together with the clearing-plate k, and the sheet of metal, away from the punches into the position represented in the figures. At this time the feeding of the metal into the machine is effected by a crank-pin r, on the end of the crank-shafts coming in contact with the bent end of the sliding-bar s, supported in standards t t; and as the crank-shaft revolves, this pin r forces the bar a forward, and causes the tooth or pall u, on its reverse end, to drive the racket-wheel v, one or more teeth; and as the racket-wheel v is fixed on to the end of the axle of one of the rollers I, it will cause that roller to revolve; and by means of the pair of spurpinions on the other ends of the axles of the feeding-rollers, they will both revolve simultaneously, and thereby draw down the sheet of metal into the machine. It will be perceived that the standards which support the clearing-plate and guide-bar are carried by the axles of the feeding-rollers, and partake of their sliding motion: also that the clearing-pins o, are made adjustable between the bars p, to correspond with the counter dies. There is an adjustable sliding-stop x upon the bar s, which comes in contact with the back standard t, and prevents the bar s sliding back too far, and consequently regulates the quantity of sheet metal to be fed into the machine by the pall and ratchet-wheel, in order to suit different sizes of punches and dies. In case the weight of the bar c, carrying the counter dies, should wear upon its bearings, the guide-pins g g, have small friction-rollers y y, shown under thq bosses of this bar, which friction-rollers run upon adjustable beds or planes z z, by which means the guide-pins may be partially relieved from the weight of the bar c, and the friction consequently diminished. BUTTONS OF HORN..-Mr. Thomas Harris obtained in April, 1841, a patent for improvements in the manufacture of horn buttons, and in their dies. His invention relates, first, to a mode of applying flexible shanks to horn buttons; secondly, to a mode of ornamenting horn buttons, by inlaying the front surface thereof; thirdly, to a mode of ornamenting what are called horn buttons, by gilding or silvering their surfaces; fourthly, to a mode of constructing dies, by applying separate boundary circles to each engraved surface of a die, by which the process of engraving, as well as the forming of accurate di3s, will be facilitated; fifthly, to a mode of constructing dies, used in the I-~. 294 BUTTON. manufacture of horn buttons, whereby the horn or hoof employed will not be per mitted to be expressed beyond the circumference of the button. Fig. 242. represents, in section, a pair of dies, A and B, used in producing the 242 245 250 254 257 252258 z Z', 2489. D 3 256 2 244 A,~~, ~~253 C259 improved horn buttons, according to the first improvement; the upper die A is made to produce the back surfaces of the buttons, and the recess or groove for receiving the flexible shank. Fig. 243. shows, in section and back view, the form of a button produced by the dies. Buttons thus formed are now ready to receive flexible shanks; and if the buttons are to have plain smooth front surfaces, then, in fixing the flexible shanks, the same kind of under die B may be used; but if the front surface of the button is to be embossed or ornamented, then, in place of that die a similar one having engraved or suitably ornamented surfaces, is to be used. When fixing the shanks to buttons, the lower or face die, containing the previously formed buttons, is to be heated till a drop of water will nearly boil upon it. The shank is applied as follows:-a metal shell or collet a (see fig. 244.) is placed over the flexible shank b, and a plats of metal c is laid under the shank; these are placed in the groove or recess of the button, which had been previously heated in the lower die; the upper die A, fig. 245., is then to be placed on the lower die B, and the two submitted to pressure, until they become cool, when the shank will be firmly attached, as shown atfig. 246., and the bottom may be finished in the usual way. The second part of the invention, which relates to a mode of ornamenting horn buttons, by inlaying the front surface thereof,is performed in a manner similar to what has been above described, for fixing flexible shanks, and consists in first forming the front face or surface of a button, in suitable dies, for providing a recess; and then, by a second pressure in dies, to fix the ornamental surface; and, when desired, the surrounding front su-rface of the button may be embossed. Fig. 247. is a longitudinal section of a pair of dies, for forming a recess in the face of a button. Fiq. 248. shows, in front view and section, a horn button, produced by these dies. Fig. 249. shows a metal ornament, to be inlaid or fixed in the front surface of the button, but it should be stated that the ornamenting surface, to be fixed in the front surface of the button may be of pearl or other material; and the size and device varied according to taste. Fig. 250. shows in section a pair of dies, for giving the second pressure for affixing the ornamental surface; and, if desired, the remaining front surface of the button may be ornamented, by having the lower die engraved, or otherwise suitably ornamented. Fig. 251. shows in front view and section a button made according to this part of the invention. The third part of the invention relates to a mode of ornamenting horn buttons, by gilding or silvering their surfaces. This is effected by applying a suitable cementing or adhesive material with a soft brush to the button, in order that gold or silver leal may be attached to its surface. The cementing or adhesive material preferred to be used is dressing varnish rendered sufficiently liquid by essence of turpentine; and when the varnish is nearly dry, gold or silver leaf is applied thereto, and pressed in the same manner as practised when gilding and silvering other surfaces; by thus treating horn buttons, a very novel manufacture of that description of buttons may be produced. The fourth part of this invention relates to the construction of dies used in the manufacture of horn buttons. Fig. 252. is a section of a die, constructed according to BUTTON. 295 this part of the invention andfig. 253. is a section showing the die without the bound..ng circles, which confine the pattern; f is the die engraved at the parts g, g; around each of which engraved surfaces are circular grooves or recesses to receive the bounding circles, h, h, which fit accurately. By the after insertion of these circles, the workman is not confined to move his graver within the bounding line, as that line is not present when engraving the plate; and the graver may pass beyond, and the grooves and the bounding circles may readily be made with great accuracy to each of the engraved surtaces. The fifth part of the invention also relates to a mode of constructing dies, for the manufacture of horn buttons, and consists in forming the dies, so that the bounding circle shall be of a sufficient depth for the counter die to slide within it, and fit accurately in order that the circumference of each button shall be smoothly and accurately formed. Fig. 254. represents in section two dies, and one counter die, made according to this part of the invention; fig. 255. shows one of the dies, in plan and section; and fig. 256. a plan and section of a counter die, suitable for flexible shank buttons. h, h, are the dies, having the engraved surfaces i, i, on separate circular discs of metal, such as have heretofore been used; j, is a counter die, and k, a tube, within which the counter die is held, the object of this tube being to guide the projecting edges I, 1, of the dies as shown, and thus keep the dies and counter dies correct to each other. Fig 257. is a section of two dies A, And a counter die j; but in this case the tube k is dispensed with, the dies being deeper sunk, and thus guiding the counter die correctly. By the use of these dies, the edges of horn buttons will be more accurately formed, and consequently require less finishing. This description of dies may be made according to the mode described in the fourth part of this invention; that is, by forming the boundary circle separately, as will be understood by referring to fig. 258., which is a side section of a die complete, with its boundary circle formed in a similar manner to that described above. 1ig. 259. represents, in plan and section, a variation in the means of affixing a separate bounding circle to each engraved surface; and it is suitable for working without the tube. In using these dies they are to be heated but slightly, whether for buttons with metal shanks, or to receive flexible shanks, and are to be pressed as heretofore. The patentee claims, firstly, the mode of manufacturing horn buttons with flexible shanks, by first forming buttons by pressure and heat, and then by a second pressure in dies, to affix flexible shanks thereto, as above described. Secondly, the mode of ornamenting horn buttons, by causing suitable surfaces to be affixed in the front surfaces, by pressing the buttons with the ornaments in dies, as above described. Thirdly, the mode of ornamenting horn buttons by gilding and silvering their surfaces as described. Fourthly, the mode of constructing dies used in the manufacture of horn buttons, by applying separate bounding circles to each engraved surface for a button; and fifthly, the mode of manufacturing horn buttons in dies, wherein the horn or hoof is prevented from being expressed at the circumference of the buttons as described. BUTTONS, COVERED. Mr. Joseph Parkes obtained, in 1840, a patent for improve ments in the manufacture of covered buttons made by dies and pressure, by the application of horn as a covering material. The process resorted to by the patentees for carrying out this invention, is very similar to that pursued in manufacturing Florentine buttons; such modifications being applied as are rendered necessary for adapting such process V the peculiar nature of the material employed for covering the face of each button. a, fig. 260. shows a plan of a disc of iron plate, with four projecting points, which is formed by suitable dies in a fly-press, as is well understood; the points are then turned down, and the disc a, is sunk into the shape shown at fig. 261., and two such sunk discs are applied to the internal core of the button-board of each button; b, fig. 262., shows a plan and edge view of a circular dise of button-board, suitable for forming the internal core of a button. The dies being placed in suitable presses, as is well understood in using similar dies in manufacturing Florentine or other covered buttons, one of the sunk dies a is placed in the under die, with the points cpwards, having a disc of button-board placed on the points, as shown at fig. 263.; the upper die or punch is then caused to descend and press the button board b into the shape shown atfig. 264.; which, when thus formed, is to have a die a, applied on the other side, as shown at fig. 265. The disc a, to be next fixed to the button-board, is placed in a suitable die, the disc which has al'eady been fixed being upwards; the die or punch is now to be pressed down, which will produce the button-board, with the discs a a on either side, into the shape shown atfig. 266.; and it will be seen, that one of the discs will, by the shape of the die, be sunk concave, whilst the other disc a, on the other side, will be formed convex, or according to the figure of the face of the intended button. The core of button-board, fig. 266., is now ready for being inserted into the fabric which is to become the flexible shank of the button, and which flexible shanlkis formed by sink'.ng a portion of falric in suitable dies, as is well understood when making 296 BUTTON. similar shanks for Florentine or other covered buttons; and the shank being so sunk, the button-board or core, fig. 266., is to be placed thereon, with the concave surface 63 6 267 ~~~260 M ~ 4~ 2270 271 27274 264 b 261 26 2C69 u 4 275 2 7677 272 towards the protruding shank; and the edges of the fabric are then to be pressed over the core, (as is well understood,) which will produce the partly formed button, fig. 267., which is a side view, and consists of the shank containing the core, which is next inserted into the metal shell c, fig. 268., and these parts being placed in a suitable die, are pressed together, and the partly manufactured button, fig. 269., will be produced, consisting of the shank containing the core, covered on the front surface with the metal shell c, which, by the die, has its edges bent down on the fabric of the flexible shank. The button, thus far formed, is now in a condition to be covered with a thin plate of horn, which is performed in the following manner:-d, fig. 270., shows a disc of horn, cut out by suitable dies, the circumference being scolloped, in order that in folding over the mould, fig. 269., the horn may not be puckered. e e, fig. 271., shows a collet, for affixing the covering of horn to the button, the collet being similar to that used in what is called "Sandar's plan of making Florentine and other covered buttons." The method of covering the mould of the button with horn is described as follows: Fig. 272. represents, in section, a lower covering die, and also a proper punch for pressing the parts into the lower die; these dies being in a suitable press, as is well understood. The lower die is to be kept heated to such an extent that the workman can just bear his hand to rest, for a very short time, on the upper surface of the die; the heating is preferred to be accomplished by means of a flame of gas below the die; and it will be seen that there are holes f, f, in the die, through which the heat of the flame may pass; and g is an opening, to allow of atmospheric air flowing under the lower die. The disc, of horn d is placed in the lower die g. The shape or mould, fig. 269., is then placed on the horn, and the punch or die v:s caused to descend, and press the parts into the die g; the punch h is then raised, in order to allow of the introduction of the parts shown at figs. 273 and 274., which consist of the tube I, and the punch or die j. The lower edge of the tube i is made bell-mouthed, so as to cause the scolloped edges to be pressed on the back of the buttons, and the die or punch j is to cause the collet to be forced through the horn in the button; and, in using these parts, the collet is placed in the tube i, which with its punch is inserted into the die s, as shown at fig. 275., which figure represents the die g, and punch h, in the condition just described, after having forced the parts into the die G; and this figure also shows the tube i, with a collet d and the punch or die J, placed in the tube I; and all things are in a condition to receive the pressure of the punch u. In order to prevent the pressure coming on the punch or die J, before the horn has been folded down by the tube i, the hollow block K is placed over the die or punch J; consequently when the punch H is caused to descend, it will force down the tube r, and cause it to gather the edges of the horn, and press them on the back of the mould of the button, when the punch H will be raised again, and the block K removed, which will leave all things in the position shown at fig. 276.; and then again, the bringing down of the punch in will cause the die or punch J to descend and force the collet into the button, the die J being retained in the tube i by means of the pin z, passing through a slit formed therein, which allows of the die J rising and falling in the tube I, but prevents its coming out of that tube. The button, thus far formed, is now in.a condition to be completed in the finishing dies, fig. 277.; the lower dies being kept heated in a similar manner to the die G. The dies being fixed in a suitable press the button to be finished is inserted into the die L, (which may be ornamented or plain,) CABLE. 297 with the shank upwards, and the punch or die M is caused to descend and press the Dutton into shape. When the front of the button is to be plain, the disc of horn should be polished before being used for covering; but when used to cover a button, and finished by an engraved or ornamented die, the polishing is not necessary. The button being thus made is to be finished by placing it in a lathe to be " edged," as is commonly practised in finishing horn buttons. The patentee does not claim the means of making the mould or shape shown atfig. 269., nor the dies employed when separately considered, very similar dies having been before used in the manufacture of other covered buttons; nor does he confine himself thereto, so long as the peculiar character and essence of the invention be retained; viz. that of manufacturing covered buttons, made by dies and pressure by the application of thin sheet horn as the covering material. He claims the mode herein described, of manufacturing covered buttons by the application of horn as a covering material, as above described. C. CABLE. (Cable, Fr.; Ankertau, Germ.) A strong rope or chain connecting the ship with the anchor for the purpose of mooring it to the ground. The sheet anchor cable is the strongest, and is used at sea; the stream cable is more slender, being used chiefly in rivers. A cable's length is 120 fathoms. The greatest improvement in mooring vessels has been the introduction of the chain cable, which, when duly let out, affords in the weight of its long catenary curve, an elastic tension and play to the ship under the pressure of the wind. The dead strain upon the anchor is thus greatly reduced, and the sudden pull by which the flukes or arms are readily snapped is in a great measure obviated. The best iron cables are chains made of links, bound and braced by rods across their middle. Experience has taught that the ends of these links wear out much sooner than the sides. To remedy this evil, Mr. Hawkes, iron manufacturer, obtained a patent in July, 1828, for constructing these anchor chains with links considerably stouter at the ends than in the middle. With this view he forms the short rods of iron, of which the links are to be made, with swells or protuberances about one-third of-their length from each of their ends, so that when these are welded together, the slenderer parts are at the sides, and the thicker at the ends of the elliptical links. Such rods as the above are formed at once by rolling, swagging, or any other means. When the link is welded, it may be strengthened, by a brace or stretcher fixed across the middle. The first avowed proposal to substitute iron cables for cordage in the sea service was made by Mr. Slater, surgeon of the navy, who obtained a patent for the plan in 1808, though le does not seem to have had the means of carrying it into effect; a'very general misfortune with ingenious projectors. It was Captain Brown, of the West India merchant service, who, in 1811, first employed chain cables in the vessel Penelope, of 400 tons burden, of which he was captain. He made a voyage in this ship from England to Martinique and Guadaloupe and home again, in the course of four months, having anchored many times in every variety of ground without any accident. lie multiplied his trials, and acquired certain proofs that iron might be substituted for hemp in making cables, not only for mooring vessels, but for the standing rigging. Since this period chain cables have been universally introduced into all the ships of the royal navy, bui the twisted links employed at first by Brown have been replaced by straight ones, stayed in the middle with a cross rod, the contrivance of Mr. Brunton, which was secured by patent in this country and in France; but the latter patent was suffered to fall from not being acted upon within the' two years specified by law. The first thing to be considered in the manufacture of iron cable is, to procure a material of the best quality, and, in using it, always to keep in view the direction of the strain, in order to oppose the maximum strength of the iron to it. The best form of,he links may be deduced from the following investigation. 278 M Let A B, fig. 278., be a circular link or ring, of one inch rod iron, the outer circumference of the ring being 15 inches, and the inner 9. I equal opposite forces be applied to the two points of the link 1 i a c D, pulling c towards E, and D towards F, the result will be, when the forces are sufficiently intense, that the circular form of the link will be changed into another form with two round ends and two 7P 0 ~ parallel sides, as seen in fig. 279. The ratio of the exterior to the 279 interior periphery, which was originally as 15 to 9, or 5 to 3, is no longer the same infig. 279. Hence there will be a derangement in t( (P)jthe relative position of the component particles, and consequently _ -_ - their cohesion will be progressively impaired, and eventually de Y /55 stroyed. Infig. 278. the segment Mr N of the outside periphery being 298 CABLE.:qual to 3 inches, the corresponding inside segment will be 3 of it, or 14 inches. If Ahis portion of the link, in consequence of the stretching force, comes to be extended into a straight line, as shown in fig. 279, the corresponding segments, interior ana exterior, must both be reduced to an equal length. The matter contained in the 3 inches of the outside periphery must therefore be either compressed, that is, condensed into 14 inches, or the inside periphery, which is only 1 inches already, must be extended tc 3 inches; that is to say, the exterior condensation and the interior expansion must take place in a reciprocal proportion. But, in every case, it is impossible to effect this con. traction of one side of the rod, and extension of the other, without disrupture of the link. Let us imagine the outside periphery divided into an infinity of points, upon each of which equal opposite forces act to straighten the curvature: they must undoubtedly occasion the rupture of the corresponding part of the internal periphery. This is not the sole injury which must result; others will occur, as we shall perceive in considering what passes in the portion of the link Which surrounds c uD,fig. 279, whose length is 4{ inches outside, and 21L inside. The segments M P and N o, fig. 278 are actually reduced tc semi-circumferences, which are inside no more than half an inch, and outside as before. There is thus contraction in the interior, with a quicker curvature or one of shorter radius in the exterior. The derangement of the particles takes place here, in an order inverse to that of the preceding case, but it no less tends to diminish the strength of that portion of the link; whence we may certainly conclude that the circular form of cable links it an extremely faulty one. Leaving matters as we have supposed in fig. 278, but suppose that G is a rod introduced into the mai, I.ndering its two opposite points A B from approximating. This circum280 sstance makes a remarkable change in the results. The link pulled as A \^^B^S. above described, must assume the quadrilateral form shown in fig. 280. It offers more resistance to deformation than before; but as it may still sulffer change of shape, it will lose strength in so doing, and cannot therefore be recommended for the construction of cables which are to be exposed to very severe strains. Supposing still the link to be circular, if the ends of the stay comprehended a larger portion of the internal periphery, so as to leave merely the space necessary for the plan of the next link, there can be no doubt of its opposing more effectively the change of form, and thus rendering the chain stronger. But, notwithstanding, the circular portions which remain between the points of application of the strain and the stay, would tend always to be straightened, and of consequence to be destroyed. Besides, though we could construct circular links of sufficient strength to hear all strains, we ought still to reject them, because they would consume more materials than links of a more suitable ftrm, as we shall presently see. The effect of two opposite forces applied to the links of a chain, is, as we have seen, to reduce to a straight line or a straight plane every curved part which is not stayed: whence it is obvious that twisted links, such as Brown first employed, even with a stay in their middle, must of necessity be straightened out, because there is no resistance in the direction opposed to the twist. A cable formed of twisted links, for a vessel of 400 tons, stretches 30 feet, when put to the trial strain, and draws back only 10 feet. This elongation of 20 feet proceeds evidently from the straightening of the twist in each link, which can take place only by impairing the strength of the cable. From the preceding remarks, it appears that the strongest links are such as present, in their original form, straight portions between the points of tension; whence it is clear that links with parallel sides and round ends would be preferable to all others, did not a good cable require to be able to resist a lateral force, as well as one in the direction of its length. Let us suppose that by some accident the linkfig. 279. should have its two extremities 281 A pulled towards Y and z, whilst an obstacle x, placed right opposite to --,\'~ its middle, resisted the effort. The side of the link which touches x /':/,, would be bent inwards; but if, as in fig. 281., there is a stay A G B, the..J.. )two sides would be bent at the same time; the link would notwithstanding assume a faulty shape. In thus rejecting all the vicious forms, we are naturally directed to that which deserves the preference. It is shown infig. 282. This link has a cast-iron stay with large ends; it presents in all directions a great resistance to every \'^1 A d'<^^^ ^change of form; for let it be pulled in the direction a 6, ) (against an obstacle c, it is evident that the portions d e and d f, which are supported by the parts g e and g,'283 g8 2 cannot get deformed or be broken without the whole link c 282 giving way. As the matter composing g e and gf cannot be shortened, or that which composes d e and df be lengthened, these four sides will CABLE. 299 remain necessarily in their relative positions, by virtue of the large-ended stay 71 whose profile is shown in ig. 283. We have examined the strength of a link in every direction, except that perpendicular to its plane. Fig. 284. //\ \' represents the assemblage of three links in the above A ]3\ I~ predicament; but we ought to observe, that the obstacle c, placed between the links A B, must be necessarily very small, and could not therefore resist the 2\\/ 284 t^J pressure or impact of the two lateral links. Process of manufacturing iron cables.-The implements and operations are arranged in the following order:1. A reverberatory furnace (see IRON), in which a number of rods or round bars of the best possible wrought-iron and of proper dimensions, are heated to bright ignition. 2. The cutting by a machine of these bars, in equal lengths, but with opposite bevels, to allow of the requisite crossing and slicing of the ends in the act of welding. S. The bending of each of these pieces by a machine, so as to form the links; the last two operations are done rapidly while the iron is red-hot. 4. The welding of the links at small forge fires, fitted with tools for this express pur pose, and the immediate introduction of the stay, by means of a compound lever press 5. Proving the strength of the cables by an hydraulic press, worked by two mel turning a winch furnished with a fly wheel. The furnace is like those used in the sheet-iron works, but somewhat larger, and needs no particular description here. Aigs. 285. and 286. are a plan and elevation of the shears with which the rods are cut into 285 |E^ L_ =d equal pieces for forming each a link. It is moved at Mr. Brunton's factory by a smal steam engine, but, for the sake of simplicity, it is here represented worked by foul or more labourers, as it may be in any establishment. These must be relieved however frequently by others, for I believe each shears' machine is calculated to require nearly one horse in steam power. It is portable and must be placed in the neighbourhood of both the furnace and bending machine. A and B are the two cast-iron limbs of the shears. The first is fixed and th' vecond 300 CABLE. is moveable by means of a crank shaft c, driven by a l}eavy fly-wheel weighing 7 or 8 cwt. The cutting jaws G are mounted with pieces of steel which are made fast by bolts, and may be changed at pleasure. E, the bar of iron to be cut. It is subjected, immediately upon being taken out of the fire, to the shears, under a determinate uniform angle, care being taken not to let it turn round upon its axis, lest the planes of the successive incisions should become unequal. F is a stop which serves to determine, for the same kind of chain, the equality of length in the link pieces. Figs. 287, 288, 289, plan and elevations of the machine for bending the links into an elliptic form. It is represented at the moment when a link is getting bent upon it. 2s87 -:... 289 A is an elliptic mandrel of cast-iron; it is fixed upon the top of a wooden pillar B, solidly supported in the ground. c is the jaw of the vice, pressed by a squareheaded screw against the mandrel A. n part of the mandrel comprehended between x and Y, formed as an inclined plane, so as to preserve an interval equal to the diameter of the rod between the two surfaces that are to be welded together. E rectangular slots (shears) passing through the centre of the nut of the mandrel, in which each of the pins F may be freely slidden. G horizontal lever of wrought-iron six feet long. It carries at H a pulley or frictionroller of steel, whose position may be altered according to the diameter of the links. It is obvious that as many mandrels are required as there are sizes and shapes of links. The piece of iron intended to form a link being cut, is carried, while red-hot, to the bending machine, where it is seized with the jaw of the vice c, by one of its ends, the slant of the cut being turned upwards; this piece of iron has now the horizontal direction m n; on pushing the lever G in the line of the arrow, the roller H will force m n to be applied successively in the elliptic groove of the mandrel: thus finally the two faces that are to be welded together will be placed right opposite each other. The length of the small diameter of the ellipse ought to exceed by a little the length of the stay-piece, to allow of this being readi y introduced. The difference between the points F, E, is equal to the difference of the radii vectores of the ellipse. Hence it will be always easy to find the eccentricity of the ellipse. Fig. 290 is a lever press for squeezing the links t.pon their stays, after the links are 290\/' u~E... welded. This machine consists of a strong cast-iron piece A, in the form of a square, of which one of the.branches is laid horizontally, and fixed to a solid bed by means of bolts; the other branch, composed of two cheeks, leaving between them a space of two CABLE. 301 inenes, stands upright. These two cheeks are united at top, and on the back of their plane by a cross piece B. c, a rectangular staple, placed to the riuht and left of the cheeks through which is passed the mandrel D, which represents and keeps the place of the following link. F, is a press lever, 6 feet long. F, clamp and counterclamp, between which the link is pressed at the moment when the stay is properly placed. There are other clamps, as well as staples c, for chancing with each changed dimension of links. The links bent, as we have seen, are carried to the forge hearth to be welded, and to receive their stay; two operations performed at one heating. Whenever the welding is finished, while the iron is still red-hot, the link is placed upright between the clamps F; then a workman introduces into the staple the mandrel D, and now applies the stay Wlil a-pair of tongs or pincers, while another workman strikes down the lever E forcibly upon it. This mechanical compression first of all joins perfectly the sides of the link against the concave ends of the stay, and afterwards the retraction of the iron on cooling increases still more this compression. If each link be made with the same care, the cable must be sound throughout. It is not delivered for use, however, till it be proved by the hydraulic press, at a draw-bench made on purpose. The press is a horizontal one, having the axis of its ram in the middle line of the drawv-ench, which is about 60 feet long, and is secured to the body of the press by strong bolts. The portion of chain under trial, being attached at the one end to the end of the ram of the press, and at the other to a cross-bar at the extremity of the draw-bench, two men put the press in action, by turning the winch, which works by a triple crank three forcing pumps alternately; the action being equalized by means of a heavy fly-wheel. As long as the resistance does not exceed the force of two men, the whole three pumps are kept in play. After a while one pump is thrown out of gear and next another, only one being worked towards the conclusion. The velocity of the ram being retarded first one third and next two thirds, gives the men a proportional increase of mechanical power. The strength of two average men thus applied being computed, enables us to know at every instant the resistance opposed by the chain to the pressure of the ram. The strain usually applied to the stronger cables is about 500 tons. The side beams of the draw-bench are of cast-iron, 6 inches in diameter; the different pieces composing it are adjusted to each other endwise by turned joints. Props also of cast-iron support the beams two feet asunder, and at the height of 30 inches above the ground. The space between them is filled with an oak plank on which the trial chain is laid. btrength of iron cables compared to hemp cables:Iron Cables. Helimp Cables. Resistance Diameter of Iron Rod. Circunifeience of Rope. Inches. Inches. Tons. 0o 9 12 1 10 18 Iit 11 26 li 12 32 1k 13 35 l|5 14 to 15 38 la 16 44 15 17 52 1- 18 60 l1 20 70 2 22 to 24 80 It would be imprudent to put hemp cables to severer strains than those indicated in the preceding table, drawn up from Brunton's experiments; but the iron cables of the above sizes will support a double strain without breaking. The) aoght never in common cases, however, to be exposed to a greater stress. A cable destined for ships of a certain tonnage, should not be employed in those of greater burden. Thus treated it may be always trusted to do its duty, and will last longer than the ship to which it belongs. A considerable part of this decided superiority which iron cables have over hemp ones, is undoubtedly due to the admirable form contrived by Brunton. Repeated experiments have proved that his cables possess double the strength of the iron rods with which they are made-a fact which demonstrates that no stronger form can be devised or is in fact possible. One of the most valuable qualities of iron cables is their resisting lateral as well as longitudinal strains, as explained under figs. 282 and 284. Vessels furnished with such cables have been saved by them froni the most imminent 302 CADMIUM. peril. The Henry, sent out with army stores during the peninsular war, was caught on the northern coast of Spain in a furious storm. She run for shelter into the Ba) of Biscay among the rocks, where she was exposed for three days to the hurricane. She possessed fortunately one of Brunton's 70 fathom chain cables, which held good all the time, but it was found afterwards to have had the links of its lower portion polished bright by attrition against the rocky bottom. A hemp cable would have been speedily tern to pieces in such a predicament. In the contracts of the Admiralty for chain cables for the British navy, it is stipulated that " the iron shall have been manufactured in the best manner from pig iron, smelted from iron-stone only, and selected of the best quality for the purpose, and shall not have received, in any process whatever subsequent to the smelting, the admixture of either the cinuct or oxydes produced in the manufacture of iron; and shall also have been puddled in the best manner upon iron bottoms, and at least three times sufficiently drawn out at three distinct welding heats, and at least twice properly fagoted." The following is a table of the breaking proof (1 chain cables, and of the iron for the purpose of making them, also of the proofs required by her majesty's navy for chains. Size of Polt. Proof of Bolt. Proof of Chain. Navy Proof of Chain. Inches. Tons. Cwt. Tons. Cwt. Tons. B 5 7 8 11. 4t _ 8 7 13 4 52 4 12 1 19 5 108 78 16 4 26 5 13: 1 21 8 34 5 18 1- 27 2 48 15 224 1 33 10 53 11 2813 40 10 65 0 34 11 48 4 77 0 401 1| 56 11 90 10 47, 4 65 12 105 0 55~ 11 75 6 120 10 634 2 85 14 137 0 72 2 _ 96 15 155 0 81l in Brmnton's cable the matter in the link is thrown very much into one plane; the link being of an oval form, and provided with a stay. As there are emergencies in which the cable must be severed, this is accomplished in those of iron by means of a bolt and sheckle (shackle), at every fathom or two fathoms; so that by striking out this bolt or pin, this cable is parted with more ease than a hempen one can be cut. CACAO, BUTTER OF. See CocoA, and OILS, UNCTUOUS. CADMIUM is a metal discovered about the beginning of the year 1818. It occurs chiefly in Silesia in several ores of zinc; and may be readily recognised by means of the blowpipe; for at the first impression of the reducing or smoky part of the flame, the ores containing cadmium stain the charcoal all round them with a reddish yellow'ircle of oxyde of calmium. The Silesian native oxyde of zinc contains from 12 to 11 per cent. of cadmium. The cadmium may be extracted by dissolving the ore in sulphuric acid, leaving the solution acidulous, and diluting it with water, then transmitting through it a stream of sulphureted hydrogen, till the yellow precipitate ceases to fall. This powder, which is sulphuret of cadmium, is to be dissolved in concentrated muriatic acid, the excess of which is to be expelled by evaporation; and the muriatic salt being dissolved in water, carbonate of ammonia is to be added in excess, whereby the cadmium separates as a carbonate, while the small portion of adhering copper or zinc is retained in solution by the ammonia. Herapath has shown, that in distilling zinc per descensum (see ZINC), the first portions of gaseous metal which are disengaged burn with a brown flame and deposite the brown oxyde of cadmium. Cadmium has the color and lustre of tin, and is susceptible of a fine polish. Its fracture is fibrous; it crystallizes readily in regular octahedrons, and when it suddenly solidifies, its surface gets covered with fine mossy vegetations. It is soft, easily bent, filed, and cut, soils like lead any surface rubbed with it. It is harder and more tenacious than tin, and emits a creaking sound when bent, like that metal. It is very ductile, and may be drawn out into fine wire, and hammered into thin leaves without eracking at the edges. Its specific gravity, after being merely melted, is 8*604; and 8-6944 after it has been hammered. It is very fusible, melting at a heat much under redness; indeed, at a temperature little exceeding that of boiling mercury, it boils and iistils over in drops. Its vapors have no smell. It is but slightly altered by exposure CALCIUM. 303 to air. When heated in the atmosphere, it readily takes fire, and burns with a brownish yellow smoke which is destitute of smell. In strong acids it dissolves with disengagement of hydrogen, and forms colourless solutions. Chromate of potash causes no precipitate in them, unless zinc or lead be present. There is only one oxide of cadmium, the brown above mentioned. Its specific gravity is 8-183. It is neither fusible nor volatile at a very high temperature. When in the state of a hydrate it is white. The oxide of cadmium consists of 87'45 parts of metal, and 12'55 oxygen in 100 parts. Berzelius states its atomic weight to be 55'883 to hydrogen 1'000. Its sulphuret has a fine orange yellow colour, and would form a beautiful pigment, could the metal be found in sufficient quantity for the purposes of art. The sulphate is applied to the eyes by surgeons for removing specks of the cornea. CAFFEINE. A chemical principle discovered in coffee, remarkable for containing much azote. See COFFEE. According to Robiquet the proportion of caffeine in 1000 of coffee is as follows: Martinique 6'4, Alexandrian 4'4, Java 4'4, Mocha 4, Cayenne 3'8, St. Domingo 3'2. It is probable that 0'64 per cent. is an ordinary proportion. According to Liebig, the proportions are per lb., Martinique 32 gr., Alexandrian 22, Java 22, Mocha 20, Cayenne 19, St. Domingo 16. H. J. Versman of Lubeck mixes 10 lbs. of bruised raw coffee with 2 of caustic lime, made previously into hydrate; treats the mixture in a displacement apparatus with alcohol of 80~ till the fluid which passes through no longer furnishes evidence of the presence of caffeine. The coffee is then roughly ground and brought nearly to the state of a powder, and the refuse of the once digested mixture from the displacement apparatus, dried and ground again, and mixed with hydrate of lime, is once more macerated. The grinding is more easily effected after the coffee has been subjected to the operation of alcohol, having lost its horny quality, and the caffeine is thus more certainly extracted. The clear alcoholic liquid thus obtained is then to be distilled, and the refuse in the retort to be washed with warm water, to separate the oil. The fluid is now evaporated into a crystalline mass, filtered and expressed. The impure caffeine is freed from oil by pressure between folds of blotting paper, purified by solution in water with animal charcoal, and is thus obtained in shining white silky crystals. In general not more than 3 drams were procured from 5 pounds of coffee, from 10 pounds 7 drams, and from 100 pounds the largest quantity, viz. 6 ounces and 4 scruples of caffeine; a proof that a large quantity must be operated upon, if in a quantitative respect a satisfactory result is to be obtained. Thus it is seen that good Brazilian coffee contains 0'57 per cent. of caffeine. At the same time it may be observed that it contains about 10 per cent. of a green liquid oil, and 2 per cent. of a yellow solid fat. CAJEPUT OIL is obtained from the leaves of the tree called Melaleuca Leucadendron by Linneus, which grows upon the mountains of Amboyna, and in other of the Molucca islands. It is procured by distillation of the dried leaves along with water, is prepared in great quantities in the island of Banda, and sent to Holland in copper flasks. Hence as it comes to us, it has a green colour. It is very limpid, lighter than water, of a strong smell resembling camphor, and pungent taste like cardamoms. When rectified the copper remains in the retort, and the oil comes over colourless. It is used in medicine as a stimulant. See OILS, ETHEREOUS. CALAMANCO. A sort of woollen stuff of a shining appearance, chequered in the warp, so that the checks are seen only upon one side. CALAMINE. A native carbonate of zinc. See ZINC. CALCAREOUS EARTH. (Terre calcaire, Fr.; Kalkerde, Germ.) Commonly denotes lime, in any form; but, properly speaking, it is pure lime. CALCAREOUS SPAR. Crystallized native carbonate of lime. CALCEDONY. A hard mineral of the siliceous family, often cut into seals. Under it may be grouped common calcedony, heliotrope, chrysoprase, plasma, onyx, sardonyx, and sard. CALCHANTUM. The ancient name of native copperas or sulphate of iron. CALCINATION, is the chemical process of subjecting metallic bodies to heat with access of air, whereby they are converted into a pulverulent matter, somewhat like lime in appearance, called calx in Latin. The term calcination, however, is now used when any substance whatever is exposed to a roasting heat. CALCIUM. The metallic basis of lime. See LIME. The atomic weight of this element being an important point, both as to pure chemistry and the chemical arts, has been the subject of innumerable researches. Very lately Berzelius, in the Annalen der Chemie und Pharmacie, xLvI. p. 241., has collated the most recent results of the analysis of otherphilosophers with his own; and while Dumas, Marchand, and Erdmann estimate the weight at 20, that of hydrogen = 1, or 2506 oxygen -= 100, he finds it ought to be, as compared with the latter, 2519; and to the former, 20,152. 304 CALENDER. CALC-SINTER. The incrustations of carbonate of lime upon the ground, or the pendulous conical pieces called stalactites, attached to the roofs of caverns, ait so called. CALC-TUFF. A semi-hard, irregular deposite of carbonate of lime, formed from the waters of calcareous springs. CALCULUS. The stony-looking morbid concretion, occasionally formed in the bladder of urine, gall-bladder, cystic duct, kidneys, and other parts of living animals, Its examination belongs to medical chemistry. CALENDER (Calandre, Fr.; Kalander, Germ.), a word derived from the Greek kalindros ( cylinder), is the name of a machine, consisting of two or more cylinders, revolving so nearly in contact with each other that cloth passed through between them is smoothed, and even glazed, by their powerful pressure. It is employed either to finish goods for the market, or to prepare cotton and linen webs for the calico-printer, by rendering their surfaces level compact, and uniform. This condensation and polish, or satinage, as the French call it, differ in degree according to the object in view, and may be arranged into three distinct series. 1. For goods which are to receive the first impression by the block, a very strong pressure is required; for, upon the uniformity of the polish, the neatness and regularity of the printing, and the. correspondence of its members, depend. In many establishments the calico is passed twice through the calender before being sent to the tables. 2. The pieces already dyed up at the madder bath, or otherwise, and whichi remain to be filled in with other colors, or grounded-in, as it is technically styled, must receive a much less considerable gloss. This is a principle everywhere admitted and acted upon, because the outline of the figured design being deranged by the washing, and sometimes in consequence of the peculiar texture of the cloth, the printer, in order to apply his grounding blocks properly, and to fit them to the contours of the figures already impressed, is obliged to stretch the piece sometimes in the direction of the warp, and sometimes of the weft, which would be impossible if they had been hard glazed by the calender. 3. The degree of glazing given to finished goods depends upon the taste of purchasers, and the nature of the article; but it is, in general much less than for the first course of block-printing. The most complete calender probably in existence is that used by some of the eminent calico-printers of Alsace, as contrived by M. Charles Dollfus, and constructed by MM. Witz, Blech, and Co. 1. It passes two pieces at once, and thus does double the work of any ordinary machine. 2. It supersedes the necessity of having a workman to fold up the goods, as they emerge from the calender, with the aid of a self-acting folder. 3. It receives, at pleasure, the finished pieces upon a roller, instead of laying them in folds; and, by a very simple arrangement, it hinders the hands of the workmen from being caught by the rollers. Calenders, in consequence of the irregular demand for foreign orders and shipments, are worked very irregularly, being sometimes overloaded with duty, and at others altogether unemployed. A machine which can, when required, turn out a double quantity of goods, must, therefore, be a desirable possession. For the first course of the printers, where high calendering is necessary, the goods are usually passed twice through be tween two paper cylinders, to give that equality of surface which could not be obtained by one passage, however strong the pressure; and therefore the simplification of this calen der will prove no economy. Besides, in order to increase the pressure to the requisite degree, the cylinders would need to be made bulging at their middle part, and with such cylinders common smoothing could not be given; for the pieces would be glazed in the central line, and rough towards the edges. For pieces already printed in part, and requiring only to be grounded-in for other colors, the system of double effect has fewer objections, as a single passage through the excellent calender described under BLEACHING, page 140, is found to answer very well. The mest remarkable feature of M. Dollfus's machine is its being managed by a single workman.'x or eight pieces are coiled upon the feed-roller, and they are neither pasted nor stitched together, but the ends are merely overlapped half a yard or so. The workman is careful not to enter the second piece till one third or one half of the first one has passed through on the other side, to prevent his being engrossed with two ends at a time. He must, no doubt, go sometimes to the one side, and sometimes to the other of the machine, to see that no folds or creases occur, and to be ready for supplying a fresh piece as the preceding one has gone through. The mechanism of the folder in the Alsace machine is truly ingenious: it performs extremely well, really saves the attendance of an extra workman, and is worthy the attention of manufacturers intent upon economizing hand labor. The lapping-roller works by friction, and does its duty fully better than similar machines guided by the hand. The numerous accidents which have happened to the hands of workmen engaged in calenders should direct the attention towards its effective contrivance for preventing such misfortunes. These various improvements in the Alsace machine may be easily adapted'o the ordinary calenders of almost every construction. CALENDER. 305 The folder is a kind of cage, in the shape of an inverted pyramid, shut on the tout sides, and open at top and bottom; the top orifice is about five inches, the bottom one an inch and a half; the front and the back, which are about four feet broad, are made of tin-plate or smooth pasteboard, and the two sides are made of strong sheet-iron; the whole oeing bolted together by small bars of iron. Upon the sheet-iron of the sides, iron up. l troduced into it by two pipes, a b c, d ef. Then -- 3808 l= l two ends, d c, are shut; but their sides are all along perforated with small holes. The frames E F G H, E F G i, are moveable, and run upon l ICY #.7I rollers: they are taken out by front doors, which;= ): l^~ L~ are made of strong p)anks, shut by sliding in C1- ---- H — a slots, and are secured by strong iron bars and pressure screws. The cross rods, E F G H, are provided with hooks for hanging up the pieces. There is a safety-valve in the top of this laree chamber. The dimensions of the frame are ten feet long, 3 feet wide, and 7 high. Three feet and a half from the upper part of the frame, a row of hooks is fixed for hanging on a double row of pieces, as showa in the figure. Over the frame, woollen blankets are laid to protect it from drops of wa. ter that might fall from the roof of the chamber. When the hooks are two thirds of an inch apart, 24 pieces, of 28 yards each, may be suspended at once. The period of steam. ing is from 45 to 60 minutes. Muslins and silks do not require so high a temperature as woollen goods. When the stuffs are padded with color, like merinoes and chalys, they must not be folded together, for fear of stains, which are sometimes occasioned by the column in steam calico-printing, where the end which receives the first impression of the steam is seldom of the same shade as the rest of the roll of goods. The duration of the steaming depends upon the quantity of acid in the mordant, and of saline solution in the topical color; the more of which are present the shorter should be the steaming period. A dry vapor is requisite in ail cases; for when it becomes moist, from a feeble supply or external condensation, the goods become streaky or stained by the spreading of the colors. 1. Black figures are given by decoction of logwood thickened with starch, to which a little oxalic acid is added while hot, and, after it is cold, neutralized solution of nitrate pf iron. 2. Dark blue for a ground.-Decoction of logwood, and archil thickened w:th starch to which, while the paste is hot, a little soluble Prussian blue is added; and, when it is cold, neutralized nitrate of iron; see supra. 634 CALICO-PRINTING. 3. Deep popTry or ponceau color.-Cochineal boiled in starch water, with oxalic acid (or tartaric), and perchloride of tin. 4. Rose.-Cochineal infusion; oxalic acid; perchloride of tin; thickened with gum. 5. Dark anmaranth. —Decoctions of archil and cochineal, thickened with starch: to the paste, alum and perchloride of tin are added. A. Capuchin color.-Quercitron and cochineal thickened with starch; to the paste add axallc aclt and perchloride of tin. 7..Jlnotto orange.-Dissolve the annotto in soda ley, of spec. grav. 1'07, at a boiling heat; add aluminate of soda, and thicken with gum. 8. Golden yellow.-Decoction of Persian berries thickened with starch; to which some alum and murlate of tin are added, with a little perchloride of tin and oxalic acid. L. Lemon yellow.-Persian berries; starch; alum. 10. An ammoniacal solution of cochineal is used for making many violet and mallow colors. It is prepared by infusing cochineal in water of ammonia for 24 hours; then diluting with water, heating to ebullition, and straining. 11. FiCne violet is given by ammoniacal cochineal, with alum and oxalic acid; to which a little aceto-sulphate of indig,) is added, and gum for thickening. The following blue may be used instead of the solution of indigo. The mallow tint is given by adding a little perchloride of tin to the above formula, and leaving out the blue. 12. Dark blue.-Soluble Prussian blue; tartaric acid; alum; thicken with gum. 13. Emerald green.-One quart of decoction, equivalent to 1 pound of Persian berries; 1 quart of infusion of quercitron, of spec. grav. 1027; in which dissolve 12 ounces of alum in powder; and add 6 ounces of the following blue bath fxr greens; thicken with 20 ounces of gum. 14. Blue bath for greens. Half a gallon of water at 140~ F., one pound of soluble Prussian blue, 3 ounces of tartaric acid, and 2 ounces of alum. I. Priningg of Silks.-1. Of the madder style. This is one of the most difficult to execute, requiring both much skill and experience. The first step is the removal of the gum. A copper being nearly filled with water, the pieces, tied up in a linen bag, are put into it, with a quarter of a pound of soap for every pound of silk, and are boiled for 3 hours. If tie silk be Indian, half an ounce of soda crystals must be added. When the goods are taken out, they are rinsed in the river, then passed through water at 140~ F., holding 8 ounces of crystallized soda in solution, as a scourer. They are'next rinsed in cold water, and steeped in water very faintly acidulated with sulphuric acid, during 4 hours, then rinsed, and dried. Preparation of Mordants.-1 gallon of boiling water; 2 pounds of alum; dissolve: 1 pound of acetate of lead; 4 ounces of sal-ammoniac; 1 of chalk; mix well together; after decomposition and subsidence, draw off clear. 1. Red. —l gallon of the above mordant, thickened with 14 ounces of starch, and tinged with decoction of Brazil-wood. If dark red.be wanted, dissolve, in a gallon of the above red, 4 ounces of sulphate of copper. 2. Black.-1 gallon of iron liquor, of 1-056 spec. grav.; thicken with 14 ounces of starch; and dissolve in the hot paste 2 ounces of sulphate of copper. 3. Violet —Take 1 gallon of iron liquor of 1'04 spec. grav.; 2 ounces of cream of tartar; 2 ounces of nitre; 2 ounces of copperas; 1 ounce of alum: dissolve, and mix the solution with 1 gallon of gum water, containing 6 lbs. of gum. 4. Puce.-Half a gallon of red mordant; half a gallon of iron liquor of 1*07; 7 ounces of starch for thickening; color with logwood. Manipulation of the above colors.-Print-on the black, then the puze, next the violet, and lastly the red. Dry in the hot flue, and 48 hours after the impression, wash away the paste. The copper employed for dyeing is of a square form: a boil is given with bran, at the rate of 4 lbs. per piecQ of the foulards: cold water is added to lower the temperature to 130~ F. The pieces must be entered with the printed surface undermost, and winced for half an hour, taking care to keep them expanded and well covered with the liquor: they are then taken out and rinsed. When grounds are to be made on the foulards, 2 ounces of sumach must be added per piece. Maddering.-Suppose 48 pieces are to be grounded with madder. 12 pounds of madder must be put into the copper, 1 pound of sumach, and 6 pounds of bran; the bath must be tepid when the pieces are entered: it must be heated to 104~ F. in 20 minutes, and to the boiling point in an hour and a half. The goods must be briskly winced all the time, and finally turned out into cold water. When they come out of the madder bath they are much loaded with color. They are cleared by a boil of half an hour in bran, then turned out into cold water, and rinsed. A copper must be now mounted with 3 pounds of soap, 1 ounce of solution of tin, and 2 pailsful of bran, in which the goods are to be boiled for half an hour, then rinsed, and passed through a very dilute sulphuric acid bath. Then rinse, and dry. By following,his process, a light salmon ground is obtained. CALICO-PRINTING. 335 TT. Steam colors upon silk.-The same plan of operations may be adcpted here as A described for calico-printing; the main difference being in the method of mordanting the stuffs. After boiling in soap water, in the proportion of 4 ounces per pound of silk, the goods are washed in cold water, and then in hot water at 140~; they are next rinsed, passed through weak sulphuric acid, rinsed, squeezed between rollers, and afterwards steeped.1 a bath containing 8 ounces of alum per gallon, where they remain for four hours, with occasionally wincing. They are now rinsed and dried. The subsequent treatment resembles that of steam-color printed cottons. /Wack.-Take a gallon of decoction, made with 4 lbs. of logwood, with which 14 ounces of starch are to be combine *~ mix in 2 ounces of powdered nut-galls: boil, and pour the color into a pipkin con taining 2 ounces of tartaric acid; 2 ounces of oxalic, both in powder, and 2 ounces of olive oil. Stir the color till it is cold, and add 8 ounces of nitrate of iron, and 4 ounces of nitrate of copper. The red, violet, lilach, yellow colors, &c. are the same as for steam colors upon cotton. Topical colors are also applied without mordanting the silk beforehand. In this case a little muriate of tin is introduced. Thus, for Yellow.-Take 1 gallon of a decoction, made with 4 lbs. of Persian bellies: dissolve in it 8 ounces of salt of tin (muriate), and 4 ounces of the nitro-muriatic solution of tin. Thicken with 2 pounds of gum. Printing offoulard pieces. The tables which serve for the impression of silk goods are so constructed as to receive them in their full breadth. Towards the part between the color or sieve tub and the table, the roller is mounted upon which the piece is wound. 309 ___ This roller, A B, fig. 309, has a groove, c, cut out parallel to its axis. Into this a bar is pressed, which fixes the end n -- c. 5 of the piece. The head, B, of the roller is pierced with 310 several holes, in which an iron pin passes for stopping its j'"1if~1"!fi~""!'f"~'1'""''""" "!L rotation at any point, as is shown at n. At the other end Ak —— a']-J of the table there is placed a comb, fig. 310, which is supported by pivots A B at its ends. The teeth of the comb are on a level with the cloth. The piece is arranged for printing as follows:-It is unwound, and its end is brought upon the teeth of the comb, and made to pass into them by slight taps with a brush. It is now stretched, by turning round the roller, and fixing it by the pin-handle. After tracing the outline, the printing blocks are applied. Care should be taken, in the course of printing, always to fix the teeth of the comb in the middle line between two handkerchiefs. The operation of grounding-in is much facilitated by this plan of extension. The pieces are washed in running water, and must be rapidly dried. The subsequent dressing is given by gum tragacanth: they are dried upon a stretching frame, and then folded up for the market. III. Mandarining of silk stuffs and chalys.-This style of printing depends upon the property which nitric acid possesses of giving to silk and woollen stuffs a yellow color. The first step is the scouring with a soap boil, as already described. The designs are printed-on as also above described. The swimming or color tub is usually double, and serves for two tables; instead of being placed, therefore, at the end of the table, it is put between two, and, consequently, behind the printer. It is formed of a -A. 7.,-copper chest, fig. 311, A B c D, in which steam [][Lii.l _:f_/may circulate, introduced by the pipe I; the exc Il..X... — l!,-I, cess being allowed to escape by the tube j, as also =-': jl l-"1 the water of condensation. The frame is placed 311 in the hollow box K K. Between two such frames _^::::: Lthere is a plate of copper, L, which closes the box; it serves for laying the plates in order to keep them hot. At E and H are prolongations of the box, in which are set the vessels F G for holding the reserve paste. Preparation of the reserve or resist paste.-Melt in a kettle 21 lbs. of rosin; 1 b. of suet; mix well, and put it into the basins F G'. By means of steam the reserve is kept melted, as well as the false color upon which the sieve floats. The piece of silk being laid upon the table, and the reserve spread upon the frame, the printer heats his block, which should be mounted with lead, if the pattern will permit, upon the little table L. He takes up the color from the frame, and transfers it instantly to the piece. He must strike the block lightly, and then lift it, lest, by its cooling, it might stick to the silk. When the table pattern is completed, he dusts it ever with sand, and proceeds to another portion of the silk. The piece must not be 336 C ALICO-PRINTING. taken out of the stretch till it is luite dry, which requires usually 6 hours. Let us con sider first the most common case, that of a white upon an orange ground. We shaL afterwards describe the other styles, which may be obtained by this process. The piece, being printed and dry, must next be subjected to the nanduariling operation. 312 The apparatus here employed consists of a sandstone trougl. iF_ _G A B C D, fig. 812. Upon the two sides, A c, B D, of this trough ----- are fixed two wooden planks, pierced with a hole an inch from the bottom to.receive the roller E, under which the piece passes. In this trough the acid mixture is put. That trough is put into a wooden or copper trough, F G H i. Into the latter, water is put, which is heated by means of steam, or a convenient furl E l~ ~ hnace. Before and behind are placed two winces, or reels, K L; one serves to guide the piece in entering into the trough, and the other in its leaving it. The piece falls immediately into a stream of cold water, or, failing that,'nto a large back, conC-..lD j; [ taining a mixture of chalk and water. rhe two winces are moved by handles: the velocity is proportioned to the action of H r I l = the acid. The wince i. ought to be higher t.an K, to allow the acid to drain off. h tg. 313 shows a section of the apparatus. 8 ogf, 313 --."i The temperature of the acid mixture ought to be maintained between 95~ and 100~ F.; for if it be raised higher, the resist.iq I1 T Ii~ a would run the risk of melting, and the impression would be-'j II \ k /1 j, come irregular and blotty. The proportions of the acid mixture are the following:1 gallon of water; and 1 gallon of nitric acid, of spec. grav. 1-288, which may be increased with the strength of the silk. It should be a little weaker for chalys. For the strong greens it may be 2 measures of acid of 1'288 to 1 measure of water. The duration of the passage through the acid should be 1 minute at most. Mixture of orange color, antd clearing a-way of the resist.-The goods, on conming out of the mandarining apparatus, are rinsed in running water; then boiled in soap water, quickened with a little soda, at the rate of 2 lbs. of the former and 4 oz. of the latter for a piece of 30 yards. They must be worked by the wince for half an hour. They are now rinsed in cold water, then passed through hot, again rinsed, and dried. I shall give some examples of the mode of manufacture, which is undoubtedly one of the most curious applications of chemical ingenuity. 1. Orange ground with white figures. (1.) Print-on the fat reserve; (2.) mandarine; (3.) brighten the orange, and clear. 2. Orange ground with blue figures. (1.) Dip in the indigo vat as for calico; (2.) print-on the fat resist to preserve the blue; (3.) mandarine; (4.) clear, and brighten the orange by the boil. 3. Orange ground, with blue and white figures. (1.) Print-on the resist to preserve the white; (2.) dip in the vat, rinse, and dry; (3.) ground-in the fat resist to preserve the blue; (4.) mandarine; (5.) cleanse, and brighten. 4. Full green ground, and white figures. (1.) Print-on the resist; (2.) mandarine, and rinse without drying; (3.) dip in the blue vat; (4.) cleanse, and brighten. 5. Full green ground, and blue figures. (1.) Dip a pale blue, rinse, and dry; (2.) print-on the fat resist; (3.) mandarine, wash and dry; (4.) dip full blue; (5.) clean, and brighten. 6. Full green ground, with white and blae figures. (1.) Print on the resist; (2.) dip a pale blue, and dry; (3.) ground-in the fat resist; (4.) mandarine and rinse; (5.) dip a full blue; (6.) clean, and brighten. 7. Full green ground, with white, blue, and orange figures. (1.) Print-on the fat reserve; (2.) dip a pale blue, and dry; (3.) ground-in the re serve; (4.) mandarine, rinse, and dry; (5.) ground-in the reserve; (6.) dip a full blue; (7.) clean, and brighten. If blue grounds with white figures be wanted, the resist must be applied, and then the goods must be dipped in the blue vat: the resist is afterwards removed by a boil in soap-water. The above processes are applicable to chalys. The property which nitric acid possesses of staining animal matters yellow, such as wae skin, wool, and silk, is here applied to a very elegant purpose. Of th4e bronze or solitaire style by mandarining.-The mandarining mixture is 1 gallon of nitric acid, of 1'17 spec. crav.; mixed with 3 pints of solution of nitrate of iron, of spec. grav. 1]F5. If the quantity of nitrate of iron be increased, a darker tint will be obtained. The temperature of the mixture should be 94~ F. The piecer, after mandarining, are let fall nmt: water, anu steeped for an hour, CALI(CO-PRINTING. 337 In order to raise the bronze, and clear away the fat resist, the goods muJt be boiled in a bath of soap and soda, as described for orange. 1. Bronze ground, with white figures. (1.) Print-on the fat resist; (2.) dip in the blue vat, and dry; (3.) pad in a decoction of logwood, of 4 lbs. per gallon; dry, taking care to turn over the selvages; (4.) nmaplarine, and steep in water for an hour; (5.) cleanse, and pass through soap. 2. Bronze ground, with blue figures. (1.) Dip in the blue vat, and dry; (2.) print-on the fat resist; (3.) pad in tile abovs decoction of logwood, and dry; (4.) mandarine, and steep an hour; (5.) cl(anse, and brighten. 3. Bronze ground, with white and blue. (1.) Print-on the fat resist; (2.) dip in the blue vat. and dry; (3.) ground-in the fat resist; (4.) pad in the logwood liquor, and dry; (5.) nandarine, and steep for an hour; (6.) cleanse, and give the brightening boil with soap. This style of manufacture may be executed on chalys; and is capable of producing beautiful effects, which will in vain be nought for by other means. With silks, advantage may be derived from various metallic solutions which possess the property of staining animal substances; among which are nitrate of silver, nitrate of mercury, and muriate of iron. The solutions of these salts may be thickened with gum, and printed-on..An orange upon an indigo vat ground. —After the blue ground has been dyed, orange figures may be produced by printing-on the ftllowing discharge paste:1 gallon of water, made into a paste with 1 pound of starch; when cold, add to it from 16 to 24 ounces of nitric acid, of spec. grav. 1'288. After fixing the color by steam, the orange is brightened with a soap boil..n orange upon a Prussian-blue ground.-The dye is first given by Prussian blue in the ordinary way, and then the following discharge is printed-on:A caustic ley being prepared, of 1-086 specific gravity, dissolve in a eallon of it 2 pounds of annotto, and thicken with 3 pounds and a quarter of gum. Two days after the impression of this paste, pass the goods through steam, and wash then in running water. With these two designs, the logwood and gall-black, formerly described, may be associated, to produce a rich effect. To the preceding practical instructions for printing calicoes, silks, woollens, and mixed fabrics, made of the two latter, a few annotations may he added. When a uniform color is to be applied to both sides of the cloth, the padding process is employed; but, when only one side is to be thus colored, diagonal lines are cut very.closely to each other upon the cylinder, which transfer so much color from the trough to the cloth passed under it as to make the surface appear uniformly stained. This process is called mattage by the French. Mordants or topical dyes, to be applied in this way, should not be much thickened. The doubler is the piece of felt or blanket stuff placed between the cloth to be printed, and the block printing-table, or the cylinders. It should be kept very clean; because, were it soiled with acetate of iron, it would spoil all the light shades made with acetate of alumina. Filters for the color shop of a print-house are best made of wool, formed into a substantial conical cap by felting. A filter ought to be set apart for each different dye-stuff. When the goods after dyeing are washed, by being held by the selvage, dipped, and shaken in a stream of water, the process is called giving a list by the French (donner une lisicre). The piece is transferred alternately from one hand to another. Stains. When we observe stains produced by mordants upon spots where no color is to come, we must, before dunging the goods, apply a little of the lime-juice, or tartarooxalic acid discharge paste, to the place. If, on the contrary, the stains are not perceived till after the maddering, we must then apply to it first a strong solution of chloride of lime with a pencil, next a solution of oxalic acid mixed with a little muriatic with another pencil, and immediately afterward wash with water. Every madder stain will be effaced by this means. Rust stains are removeable by a mixture of oxalic and muriatic acids. Indigo stains by the combined action of chloride of lime and muriatic acid. Topical yellow stains, or yellow dyes, by the same combination. Metallic greens and Scheele's green by the acid alone, Chrome green, and Prussian blue. The blue may be taken out by a caustic alkali; after which the goods must be washed: the residuary rust stain may be removed by the mixture of oxalic and muriatic acids. The above methods refer to cotton and linen. The stains on silk and woollen stuffs should be removed before fixing the colors by the soap boil; which may generally be done by scratching with the finger, with the aid of a little water. For a direct calicc green, see oxyde of CIROTTiE. 23 338 CALICO PRINTING. Mr. Hudson, of Gale, near Rochdale, obtained a patent, in December, 1834, for a me chanism which furnishes a continual and regular supply of color to the sieve or teal (tire, Fr.), into which the printer has to dip his block, for the purpose of receiving the color about to be transferred to the fabric in the operations of printing calicoes or paper hangings. The contrivance consists in a travelling endless web, moved by power, which, by passing progressively from the color vat over the diaphragm, brings forward continunasly an equable supply of the colored paste for the workman's block. 314 - Fig. 314 represents the construction of this ingenious apparatus, shown e _ partly in section. a a is a e O _h__-._ d- [ A,~,~~S vessel of iron, supported ___________ i', — - upon wooden standards b b, over the upper surface of \T which vessel a sheet or diaphragm, c c, of oiled i/~~b/ f I'^j ~cloth, or other suitable _ elastic material, is'distended and made fast at its edges by being bent over a flange, and packed or cemented to render the joints water-tight. A vertical pipe d is intended to conduct water to the interior of the vessel a, and, by a small elevation of the column, to create such upward pressure as shall give to the diaphragm a slight bulge like the swimming tub. An endless web, e e e, passing over the surface of the diaphragm, is distended over three rollers,fg h, the lower of which,f, is in contact with the color-roller i in the colortrough lr. On the axle of the roller i a pulley wheel is fixed, which allows the roller to be turned by a band from any first mover; or the roller may receive rotatory motion by a winch fixed on its axle. On this said axle there is also a toothed wheel, taking into a another toothed wheel on the axle of the rollerf; hence, the rotation of the color-roller i in the one direction will cause the roller f to revolve in the opposite, and to, carry forward the endless web e e e, over the elastic diaphragm, the web taking with it a stratum of color received from the roller i, evenly distributed over its surface, and ready for the printer to dip his block into. The axles of the rollersf and g turn in stationary bearings; but the axle of h is mounted in sliding nuts, which may be moved by turning the screws m, for the purpose of tightening the endless web. The axle of the color-roller i turns in mortises, and may be raised by screws n in order to bring its surface into contact with the endless web. To prevent too great a quantity of color being taken up, the endless web passes through a long slit, or parallel aperture, in a frame o, which acts as a scraper or doctor, and is adjustable by a screw p, to regulate the quantity of color carried up. The contents of the vessel a, and of the color-trough k, may be discharged when required by a cock in the bottom of eacn. See PAPER HANGINGS, for the Fotdu style. Tne outside working gear of the four-colour calico printing machine, is shown in fig. 315., where A, A is a part of the two strong iron frames or cheeks in which the various rollers are mounted. They are bound together by the rods and bolts a, a, a. B is the large iron pressure cylinder, which rests with its gudgeons in bearings or bushes, which can be shifted up and down in slots of the side cheeks A, A. These bushes are suspended from powerful screws, b, which turn in brass nuts, made fast to the top of the frame A, as is plainly shown in the figure. These screws serve to counteract the strong pressure applied beneath that cylinder by the engraved cylinders D, E. C, D, E, F, (see fig. 297.) are four printing cylinders; named in the order of their operation. They consist of strong tubes of copper or gun metal, forcibly thrust by a screw press upon the iron mandrels, round which, as shafts, they revolve. The first and last cylinders, c and F, are mounted in brass bearings, which may be shifted in horizontal slots of the frame A. The pressure roller B, against whose surface they bear with a very little obliquity downwards, may be nicely adjusted to that pressure by its elevating and depressing screws. By this means c and F can be adjusted to B with geometrical precision, and made to press it in truly opposite directions. The bearings of the cylinders D and E are lodged also in slots of the frame A, which point obliquely upwards towards the centre of B. The pressure of these two Drint cylinders, c and F, is produced by two screws, c and d, which work in brass nuts made fast to the frame, and very visible in the figure. The framework in which these bearings and screws are placed has a curvilinear form, in order to permit the cylinders to be readily removed and replaced, and also to introduce a certain degree of elasticity. Hence the prcuseure applied to the cylinders c and F partakes of the nature of a spring, CALICO PRINTIN G. 339 315,; \^ A Scale r I - 4 eet a circumstance essential to their working smoothly, notwithstanding the occasional inequalities in the thickness of the felt web and the calico. The pressure upon the other two print cylinders, D and E, is produced by weights acting with levers against the bearings. The bearings of D are, at each of their ends, acted upon by cylindrical rods, which slide in long tubular bosses of the frame, and press with their nuts g, at their under end upon the smaller arms of two strong levers G, which lie on each side of the machine, and whose fulcrum is at h (in the lower corner at the left hand). The longer arms of these levers, G, are loaded with weights, Hi, whereby they are made to press up against the bearings of the roller D, with any desired degree of force, by screwing up the nut g, and hanging on the requisite weights. The manner in which the cylinder E is pressed up against B is by a similar construction to that just described. With each of its bearings there is connected, by the link k, a curved lever i, whose fulcrum or centre of motion is at o. By turning, therefore, the screw rm, the weight L, laid upon the end of the longer arm of the lever K (of which there is one on each side of the machine), may be made to act or not at pleasure upon the bearings of the cylinder E. The operation of this exquisite machine is minutely described in pp. 315, 316. A patent was obtained in August, 1829. by Mr. J. C. Miller of Manchester, for cer tain improvements in priL ing calicoes, consisting of a modified mechanism, by which the same effect can be produced as by block printing. Figs. 316, 317, 318, are several views of thisnlachine, calculated to print two pieces, or two different patterns (on the same block) of calico, side by side, or four pieces, the carriage printing both ways, the intended device consisting of four colours to be printed from blocks. Fig. 316. represents a side elevation, fig. 317. a front view, and fig. 318. a transVerse section, taken nearly through the middle of the machine. The side or main framing is shown at a, a, supporting the colour boxes b, b, 6, with their doctors; the furnishing tables or beds, c, c, c, (substitutes for the sieves in ordinary." ~~Ji~~~~~.)) S~ ~ ~~~~~~~' "'. ~~~~~~~~~~~~1 1 11""' g K bi~~~~~t~~j H~ ~~' their doctors; the furnishing tables or beds, c, c, e, (substitutes for the sieves in ordinary 840 CALICO PRINTING. block printing); the printing table, d, d; and the feeding, drying, and colourinl rollers, f, f, g, g, h,. 0 0 316,,,, — The machine is also provided with a carriage, i, i, for the printing blocks, j, j, j. This carriage, i, i, travels in and out at suitable ihtervals upon rails, k, k, attached to the main framing. The operation of the machine is effected by passing a driving strap, 1, round the driving pulley m, fixed at the extremity of the main driving shaft, n, n. At the other end of this shaft, the bevil pinion, o, is keyed, gearing at suitable intervals with the bevil wheel p,which is mounted upon the end of the cross shaft q; at about the middle of this shaft, the mitre wheels r, r, driving the upright shaft s, s, and mitre wheels t, t, above, actuate, by means of the spur pinions u, %, the feeding rollers f, f, and thus draw the pieces of goods into the machine. Simultaneously with the progress of the cloth, the mitre wheels v, v, at the other end of the cross shaft q, drive the furnishing rollers w, w, w, by means of the spur gearing x, x, x. The furnishing rollers, revolving in their respective color-boxes, spread or apply the colors upon the travelling endless blankets, y y, y, y, which pass round the top roller and the furnishing tables or beds, c, c, c, in order to supply the colors to the surfac es of the printing blocks, j, j, j. Either beds or the backs of the printing blocks may be made slightly elastic, to insure the perfect taking up of the colors. Supposing the carriage, i, i, to be run out upon its railway s, at t t he far st point fro the beds c, c, it is drawn inwar is efed the furnishing beds c, c, by means of the spur-wheely, upon the driving-shaft n, taking into a smainnion, 1 (shown by dots n fig. 17), upon th e shaft, 2. On the end of this shaft is also keyed the mangle pinion, 3, gearing in the mangle wheel, 4, which is keyed upon the end of the shaft, This shaft drives the spur-wheel, 6, in gear with the pinion, 7, made fast to the shaft, (see fig. 19). Upon either end of the shaft, 5, is a rack pinion, 9, taking into the horizontal rack 10, made fast to the carriage-frame,,; and thus the blocks j, j, are presented to the furnishing tblanke s y, y y, and take a supply of colour ready for printing. The travellingarriage e and blo cks now retire, by the agency of the mangle-wheel and pinion, 3 and 4, the pinion being fixed upon the end of the shaft, 2, and the wheel upon the other shaft in a l ine with the shaft 2. At this tim e anot her operati on of the machine takes place CALICO PRINTING. 341 Upon the reverse end of the shaft 5, is a pinion, 11, gearing with the spur-wheel 12; and by means of the spur gearing, 6 and 13, and counter-shaft, 14, the pinion 14 317 v' J. Z $ [ drives the spur-wheel, 16, which corresponds to the wheel, 12, on the other side of tha machine. To one of these spur-wheels are attached by bolts two quadrant levers, 17, 17; and as these wheels revolve by means of the gearing just described, the levers, 17, 17, draw down the chains, 18, 18, actuate the levers, 19 and 20, and thus elevate the whole series of printing blocks in the parallel grooves, 21, 21; at the same time pressing or closing them into one mass or block by expanding the springs, 22, 22; and at the nest of the carriage caused at a proper interval by the agency of the mangle-wheel, the blocks are made to impress the patterns upon the surface of the goods at once, in four or more different colours, and in one, two, or more widths of cloth at one operation. The cloth is now drawn forward for the space of the exact width of one of the blocks, Or sketch of the design, by means of the spur-wheels and pinions, 23, 23, and passed a.tound heated cylinders, g I, if necessary, and between the delivering rollers out of the i:taehine. These operations are to be repeated by the continuous rotation of the main diiving-shaft, until the printing is completed; the colours making a single advance lion the pattern at every presentation of the blocks, until the whole number of blocks I;as been presented to the same space or portion of the goods successively. The steam pipes, 24, are to be in connection with the printing table and drying cylinders, in order to supply a degree of heat during the operation, which may be renulated at pleasure. To give suitable intervals of rest and motion to the various parts of the drivinggear, an ordinary clutched box, 25 (shown in fig. 318.), and regulated by suitable stops fixed to the travelling carriage, is used for throwing the wheel p, in and out of gear with the pinion, o; this is to prevent clots of colour from being dragged upon the blocks or cloth.-Newton's Journal, xxi. C. S. p. 242. General Observations.-The cotton of Pernambuco takes a more lively Turkey red dye than that of Georgia, and both are preferable to the Macedonian cotton. Goods woven of dead wool cannot be well dyed. Cloth of mixed cotton and wool yarns require a peculiar treatment from the calico printer. Blues do not take well on cotton. Indigotine, carthamine, curcumine, oxide of iron, oxide of chrome, arseniuret of sulrlulr and of antimony, are all substantive colours, and need no mordant to fix them 342 CALICO PRINTING. out they must be presented to the stuff in a soluble state, or rendered so by some solN ent. This proposition is well illustrated in the indigo dye. 318 (8L i211 o o y a a a aa a The ferruginous mordants for good dyes, applied by the plate, have almost always a little of a copper salt added to facilitate the peroxidation of the iron, and its combination with the stuff. The empyreumatical oil of pyrolignous acid has the power of retarding the oxidation, and preventing the corrosive action of the ferric acid upon the fibres. The arsenious acid is employed for the violets and lilacs; it combines with the iron-oxide in its normal state, and stops its peroxidation. The chlor-zinc used in the black mordant has no tinctorial operation, but it counteracts the tendency of the starch thickeners to coagulate. Sal-ammoniac and nitre are also in many cases of great service in mordants; as well as the muriates of potash and soda. When pyrolignite of iron alone is used, the dyes are not so rich as when some purer acetate of iron is added to it; to favour the more ready oxidizement of the metal, which should be always introduced into the stuff in the state of black oxide. The basic pyrophosphate of iron being soluble in alkalis makes thus an excellent mordant, especially with ammonia, which may be dyed immediately after impression. When a solution of sulphate of iron is mixed with one of pyrophosphate of soda, the whitish precipitate may be dissolved (after being washed) in water of ammonia. Such a mordant serves well for a madder bath, and also for many others. Tin crystals (chloretin) dissolved in the sulphuric acid of Nordhausen to saturation, have at first the consistence of syrup, but become afterwards solid; and being kept out of contact of air, make the best of all tin mordants. For some purposes, however, the peroxide of tin is preferable. Generalities of Calico Printing.-I. Of the colours fixed in the humid way, or in the water-bath, and with concourse of mordants; the simple genera are derived from the application of indigo, carthamus, curcuma, catechu, and the oxides of iron and chrome; the peroxides of manganese, and lead; with the sulphide of antimony. 1. From indigo, there are the following species:(1.) The blue vat or blue ground; such as pencil blue, china blue, blue of solid appli. cation. Indigo is reduced into a soluble state by grinding in the moist condition and mixing 100 parts of it with from 75 to 95 parts of green sulphate of iron, and 100 of quicklime, in the vat along with 8000 parts of water, and stirring vigorously from time to time. The vat is best heated by transmitting steam into it through pipes. By this means the indigo vat may be prepared for action in the course of 12 hours. The liquid CALICO PRINTING. 343 should be transparent and of a fine yellow hue; and should have a coppery looking pellicle on its surface. To insure complete oxidizement to the indigo in the substance of the stuff, it may be padded through a weak solution of sulphate of copper, mixed with a little boiled starch and glue. See INDIGO. Resist pastes for indigo may consist of solutions of the copper salts, which act on chemical principles by furnishing oxygen to the indigo and thus rendering it insoluble and incapable of entering the fibres of the stuff; or they are composed of pipe clay, sulphate of lead, and such articles as act mechanically. A resist paste with sulphate of zinc and alum answers well for brief immersions in the vat, and it washes easily away. The arseniates and phosphates are sometimes used along with the salts of copper to prevent the fixation of this metal reduced upon the cloth. The following are some receipts for reserve pastes. No. 1. For deep blues. In 9 quarts of water dissolve, 12 pounds of sulphate of copper 5 - acetate of copper 6 - nitrate of copper, at 15~ B. 5 - gum arabic 2 - pipe clay; the latter two being thickeners, No. 2. In 9 quarts of water dissolve, 8 pounds of sulphate of copper 4 - acetate of copper 61 - nitrate of copper, at 55~ B. thickened w th 4 - gum arabic 8 - pipe clay No. 3. For cravats. In 9 quarts of water dissolve 8 pounds of sulphate of copper 4 - acetate of copper 4 - nitrate of copper, at 55~ B., thickened with 4 - of gum arabic 8 - of pipe clay. In other formulae, a little alum is used; in others, verdigris dissolved in vinegar is added to the mixture; in some a little cream of tartar is introduced, also a very small quantity of sulphuric acid for handkerchiefs to be printed on both sides. In 9 quarts of water, 3 pounds of sulphate of copper, I pound acetate, to be thickened with l pound of starch and 7 pounds of gum, 6~ pounds of pipe clay; the whole being coloured with I pound of acetate of indigo. By another formula a resist paste is made by dissolving in 8 pints of water, 20 pounds of sulphate of zinc, incorporated with 4~ pounds of pipe clay 5 - of soft soap 1 - of lard 14 - olive oil - oil of turpentine 12 - of mucilage at 2 pounds per quart. All the above pastes should not be thicker than what is absolutely necessary, and the cloth to be printed should be highly calendered; in printing with blocks the workmen should strike them with their hand and not with a mallet. It is advisable to dip the frame with its stretched piece of cloth in milk of lime before plunging it in the vat; in which it should receive 4 or more immersions, with airing intervals for the oxidizement of the indigo. Pencil blue, as applied by hand.-To 35 quarts of water, add 12 pounds of carbonate of potash, 10 of quicklime, 10 of indigo, 12 of realgar. This mixture is to be boiled for 2, hours, then poured into a tub to settle, when the clear part is to be thickened with gum arabic in the proportion of 1 pound to 4. The insoluble matter is treated with a fresh quantity of water, and boiled repeatedly till it be quite exhausted, and it then serves ulterior purposes. For this prescription may be substituted with advantage a solution of the realgar in caustic potash, so as to avoid the annoyance introduced by the lime. This pencil blue has been of late successfully applied by the cylinder press, working in an atmosphere of coal gas, to prevent the oxidizement by the atmospheric oxygen, till the web was all uniformly printed. Of the styles of colour derived from Carthanus (safflower).-Safflower being washed in pure water, is to be immersed in solution of carbonate of soda, of which the weight 344 CALICO PRINTING. should in no case exceed that of the safflower; for an excess of it, or too long digestion or at too high a temperature, must be avoided. The alkaline compound, called cartha mate of soda, is to be poured into an oval tub, having a discharge pipe at its bottom and two supports at each end of the tub, for bearing the pivots of the reel round which the cloth is coiled, and which is turned by means of a handle. The liquid being slightly super-saturated with lemon juice, passes from orange to a lively pink hue, and becoming carthamine is ready to be deposited upon the cloth as it revolves in the tub. Silks, which have been sulphured, are to be previously passed through a soda bath. But brighter colours are obtained upon cotton. Of the styles of colour derived from curcuma (turmeric). This drug is employed chiefly to modify the tints produced by other dyes: into a decoction of it any kind of goods, cotton, silk, wool, or linen, being immersed, take a yellow stain without any mordant. This substance has been associated with Brazil-wood for printing certain kinds of silk handkerchiefs with a mordant of iron and al&snina. The colours derived from annotto.-To dye cloth with anrt tto, an alkaline decoction is to be made of it, along with a solution of dextrine, into which the cloth is to be plunged. It needs no mordant, and affords an orange brownr ye, after the alkali has been neutralized by an acid bath. A solution of peroxide ct tin 3rightens the dye. Of the styles of printing by elans of catechu.-1. This dye stuff, combined with the blue vat, produces very fine blacks. Catelhu is prepared for dyeing by dissolving in 9 quarts of water, 7' pounds of it. along with 1 pound of acetate of copper, 2 pounds of sal ammoniac, and 10 pounds of gum arabic. 2. To 9 quarts of pyrolignous acid, put three pounds of catechu in fine powder, which has been steeped in 12 quarts of water. The mixture is to be evaporated at a gentle heat, till it be reduced by one tenth, allowed to settle, and set aside for use. To 9 quarts of the above prepared catechu, there are to be added 2- pounds of sal ammoniac, 4 of gum arabic, 5 of pipe clay, and 1 of nitrate of copper. Introducing into this preparation salts which promote oxidation, the shade may be modified, and other colours produced. Thus, in adding to 6 quarts of the above 6 quarts of acetate of protoxide of iron, at 12~ B. and 9 pounds of gum arabic; or adding to 9 quarts of the above catechu preparation, 14 quarts of water, 18 of mucilage, con. taining 2 pounds of gum per quart, and 9 of protacetate of iron of 9~ B. This colour, which is employed for cylinder printing, may be extensively modified; the acetate of iron may be replaced by a mixture of acetate and sulphate, or even by the nitrate, if the proportions of the other soluble matters be changed. If the preparations are to be rendered more oxidable, a little corrosive sublimate or chloride of tin may be added. Catechu with manganese (acetate of) either alone, or with acetate of copper, forms an excellent dye. Catechu is also united with alkalis, and with sulphate of chrome, or tartaro-acetate of copper; chlor-calcium and acetate of lime are likewise introduced into the formule by some printers, for the purpose of keeping the mordants moist, as the colours of catechu are thereby rendered richer. After having exposed the goods printed with one or other of the mixtures for some days to a humid atmosphere, from a hazel nut tint they become of a marron hue. The colours are then fixed by steaming, or by means of a chromate or of lime, as a milk or water. Alkaline catechu gives a brown red impression. 9 quarts of the decoction of catechu, at 1 pound per quart, are to be thickened with 2~ pounds of flour, and when it is boiled, 4~ quarts of solution of caustic soda at a density of 10~ B. By varying the proportion of catechu without changing the ratios which exist among the other substances, stronger or fainter shades may be obtained, but only after several days' digestion. Lime is used for fixing such colours. Of the colours derivedfrom the application of the peroxide of iron.-One of the ferruginous preparations here employed is the nitro-sulphate of iron (protoxide). It is made by adding to 10 quarts of nitric acid, about three times its weight of sulphate of iron by very slow degrees in a large vitriol bottle; and by the mutual action of these ingredients a portion of ammonia is formed. Six days are required to complete this compound. Towards the conclusion the sulphate must be added very slowly, otherwise frothing will ensue in the thickening liquor. It is liquid at the temperature of 59~ Fahr. and has a density of 56~ to 57~ B. When cooled below that point it has a tendency to crystallize. It should always be diluted to a strength of from 18~ to 22~ B. before being used. To dye with this preparation it is to be diluted to the desired degree, and put into the padding trough, where it serves to impregnate the goods uniformly. They are then transferred to the stove, where they are to be dried, but not to hardness, for fear of torroding the fibres by the red oxide of iron; they are next passed through a peculiar dadding machine containing a weak solution of carbonate of soda mixed with a little quicklime. In proportic n as the cloth is passed through the bath, and its alkaline matter CALICO PRINTING. 34t gets neutralized, it must be refreshed with fresh solution of soda. The cloth may b( supplied by a soap-bath; and lastly by the dash-wheel. If the iron orange tint is not sufficiently deep by one operation, it may be increased by another, and also rendered more uniform. A mixture of red muriate of iron and sal ammonia gives a good iron dye, and with perfect safety; or one of red sulphate and sal ammoniac. Goods padded in iron liquor, dried, and then padded in a solution of chlorine containing a little freelime, acquire a good rust ground. The following prescriptions serve as resist pastes for these dyes. In 9 quarts of hot water dissolve 5 lbs. of the biarsenate of potash, and add to the solution as much carbonate of potash as to give it a slight alkaline reaction. Dividing this liquor into two equal parts, there is to be incorporated with the first, 10 lbs. of pipe-clay, and to be dissolved in the second 41 lbs. of gum senegal, with 3 of a pound of soft soap; the two are to be united. This resist is to a certain degree of a mechanical quality, for the ferruginous preparation cannot touch it, without setting the fat acid of the soap at liberty and preventing the entrance of the liquor into the pores of the web. White resists on rust grounds are also made with a mixture of tartaric and oxalic acids; as also of lime juice. When the iron oxide is fixed, as in the genus avanturine, muriate of tin is a preferable discharge; as for example: In 9 quarts of water diffuse 31 lbs. of flour, 1 lb. of starch, and boil into a paste; and add to 2 lbs. of this paste, 2 lbs. of acid muriate of tin at 65~ B. (solution of salt of tin in muriatic acid.) This for printing with the block. For printing on the discharge paste by the cylinder, to 2 lbs. of the paste are to be added 4 lbs. of the acid muriate of tin at 65~ B. In these preparations the combined action of the muriatic acid and muriate of tin is sufficient to displace the oxide of iron; but the paste must not be left long exposed to the air, otherwise the iron may become fixed by peroxidizement. White discharge upon chamois (a faint rust colour) is produced by 11 lbs. of gum arabic, 2- lbs. of oxalic acid, 2 lbs. of tartaric acid, ~ lb. of oil of vitriol. After applying this discharge the goods should not be exposed to a high heat to dry them. The first of these two receipts tends to crystallize, the second to deliquesce. It deserves to be remarked, that when soda is employed to precipitate rust of iron upon goods, the tint is much deeper than it is by lime. Of the colours produced by the oxide of chrome.-A preparation for this purpose is made by boiling together 2 lbs. of bichromate of potash, and 4 lbs. of muriatic acid. The muriatic acid excess is to be evaporated off. For obtaining deeper shades, arsenic acid is introduced in determinate proportions; as for example: To 9 quarts of water, there are added 9 lbs. of bichromate of potash, 12 of arsenious acid, and 20 or 22 lbs. of muriatic acid, in order to destroy all the chromic acid, and that the chlorine set at liberty in contact with the water and the arsenious acid may transform the last into arsenic acid by the oxygen of the decomposed water. When the reaction has ceased, a fine green liquor results, which is to be evaporated to the density of 60~ or 65~ B. to dissipate the fiee acid; care should be taken to get rid of the acid excess either by a regulated heat or by soda. Many pieces of calico are dyed a fine green by the oxide of chrome, and are very fast. The solution of muriate of chrome, just described, at a density of 45~ B., is to be thickened slightly with gum, poured into a padding machine, then dried carefully to aid the fixation of the colour, and finally passed through a weak bath of soda: to complete the deposition of the oxide of chrome, ammonia may be substituted for the carbonate of soda. The colours thus produced are pale green, or grey, but may be deepened by passing the cloth through a weak bath of sulphate of copper; it may be deepened also by mixing with arsenic acid, and after some days' repose, precipitating the arseniate of chrome on the stuff by passing it through a bath of carbonate of soda. Of the simple genera derived from oxide of mnanganese.-This colour is generally known by the name of solitaire bistre, and sometimes turks-head. By impregnating the cloth with a neutral solution of acetate of manganese, then precipitating the oxide with an alkali, exposing the goods to the air to favour the oxidation, or passing them through a bath of chlorite of lime, the process of the manganese dye may be executed. After passing the goods through the manganese bath over 8 rollers, to secure uniformity of impression, they should be dried immediately in a stove. The dye-bath should contain a small quantity of mucilage of gum arabic. The alkali for precipitating the oxide of manganese in the padding machine should be caustic, strong, and heated by a steam pipe to the boiling point. The strength of the alkaline solution should in all cases be 14~ B.: and for some purposes even 22~ B. This alkaline strength is requisite to seize the fibre the instant of the tissue entering the alkaline bath, and to force, by the contraction which it causes, the oxide of manganese to remain within it till the oxidation is completed. It is obvious that the bath must be kept up by fresh alkali. The two last cylinders of the frame should be heavily loaded, so as to render the goods as dry as possible. A passage through solution of chlorine is in general advantageous to complete the 346 CALICO PRINTING. oxidation of the manganese. A more economical process would be to add an equivb lent of sal ammoniac to an equivalent of chlormanganese, and to make the solution alkaline with a little ammonia. The goods padded in this liquor might be dried with. out risk of injury, and be then finished in the baths, first, of milk of lime, and next or chlorine: or at once in a mixture of the two. The shades with a foundation of manganese are often modified in various ways; ae by adding to the mixture a certain quantity of acetate of lead, whence results chlorlead; while in passing into the solution of chlorlime, the lead is transformed into peroxide, whose brownish yellow added to the tint of the manganese produces a yellowish cast and a velvety aspect. Sometimes some salts of iron are added, which decomposed and peroxidized along with the salts of manganese give shades which resemble aventurine, the more closely the larger the proportion of iron. Prussian blue.-Its white discharge is effected upon calico, by preparing a rust ground of a proper tint for producing with acidulated ferrocyanure of potash the desired blue shade. Into either the mordant or into the ferrocyanide put the quantity of muriate of tin necessary to give the blue its purest tint. The discharge is performed usually at two operations, by the first the ferrocyanure is decomposed by a powerful base (potash), which forms a yellow cyanure, and liberates the iron oxide; by the second, we remove the iron, by the intervention of an acid. But the success of this second operation depends on the energy of the first, and especially upon the washings which follow it, and which ought to have carried off the whole of the ferrocyanure; otherwise the presence of the acid would regenerate the blue upon the points which should remain clear of it. The pieces, after being dried and calendered, receive an impression with caustic potash ley (thickened with gum), and which in every case should mark at least 14~ B., in order to make the texture contract or shrink suitably, and furnish a precise or sharp print. It is then to be rinsed and washed in the dash-wheel so as to clear away every thing but the oxide of iron from the cloth upon all points touched by the alkali. The piece is then immersed in water acidulated with muriatic or sulphuric acid, till the oxide of iron has entirely disappeared. By adding to the potash a little tartrate of potash, the oxide of iron from the Prussian blue enters into combination with the tartaric acid, and goes off in a great measure with the subsequent washings. This style may also be executed upon silk and woollen goods, but great precaution must be used to avoid injuring the texture by the strong alkaline ley. Silk handkerchiefs are first passed for about thirty minutes through a bath of nitrate of iron of 4~ B., then through running water, next through the dash-wheels. They are next put in a bath of clear and cold lime water, in order to decompose the salt of iron, and to fix the oxide upon the stuff. It is now rinsed, and sent through the dash-wheel before proceeding to dye it; which is done by passing it through a tub sharpened with a little sulphuric acid, and containing a small quantity of ferrocyanure of potash. After working the cloth fifteen or twenty minutes in this bath, a little more acid and ferrocyanure are introduced, and the passage of the cloth is resumed during fifteen minutes more, which time is usually sufficient to produce the desired tint. It might be better to decompose previously in a separate vessel the ferrocyanure by adding to one equivalent of it in solution two equivalents of sulphuric acid. The mixture of sulphate of potash and ferrocyanic acid thence resulting, should be poured by degrees into the dyeing bath, till the due tint is produced, or the oxide of iron on the clot'hbecomes saturated. When the ground has been thus dyed, the discharge-printing may be proceeded with as already directed. Muriate of tin may sometimes be substituted for acid, for acidifying the ferrocyanure of potash in the act of dyeing. By substituting oxide of copper for oxide of iron, a crimson colour is obtained with the ferrocyanure. Saxon blue; solution of indigo in sulphuric acid. This blue dye is given by passing the cloth mordanted with base of alumina through the indigo solution of a proper degree of strength. It enters also as an ingredient in tertain pistachio green dyes. The genera of styles derived from madder are numerous. rbhre are, 1. Plain grounds upon ordinary cloth; albuminous mordant. 2. do.; iron mordant, 3. do.; mordant of alumina and iron, 4. do.; mordant of chrome, 5. Plain printing; white reserve with mordants of alumina, iron, o0 chrome, 6. do. white discharge upon common madder dye.'7. do. white discharge on oiled cloth, with madder dye mordants of iron (violet and lilac) upon the cy linder. CALICO PRINTING. 347 White ground; printing with alumina mordant for red and pink upon the cylinder White ground; printing on mordants of alumina and iron. White ground; printing on mordants; for red, violet, puce, black; a binary, three. fold, and fourfold union of these colours. IWhite ground; printing on mordants, for red, violet, or puce; separate or combined; by the block or Perrotine. Plain ground upon oiled mordanted cloth: with alumina or iron. Turkey red, or violet oiled. White ground; printing with mordant of iron and alumina upon oiled cloth. The colours obtained directly by madder are red and its gradations, pale red and pink, which have always all aluminous mordant for their base; black and its gradations: deep violet, light violet, and lilac, of which the base is pyrolignite of iron, or the common acetate; red and deep puce, whose mordant is a mixture of aluminous and iron liquors; lastly, the ventre de biche fixed by means of the oxide of chrome. In every print wort, three principal mordants are prepared beforehand in a certain state of concentration, which are diluted when wanted with water, but more frequently with gum-w ater, and vinegar. A. Mord nt for red is made with 100 quarts of boiling water in'which are dissolved 150 pounds of alum; and then 150 pounds of pyrolignite of lead added. B. Mordant for red, 100 quarts of water, in which are dissolved,'70 pounds of alum, 48 pounds of acetate or pyrolignite of lead, 2i pounds of carbonate of soda (crystals), 4 pounds of muriate of soda. C. Mordant for red. In 100 quarts of boiling water are to be dissolved, 66 pounds of alum; and then to be added, 56 pounds of pyrolignite of lime, and 5 pounds of soda carbonate in crystals. Red Mordant. To 66 quarts of decoction of logwood, add 100 quarts of boiling water; and dissolve in this mixture 67 pounds of alum, 56 pounds of pyrolignite of lead, and 6 pounds ol soda: Other mordants are made of like quantity in which decoction of quercitron is put along with chlorzinc; some into which an admixture of chalk is made, others with an admixture of acetate of lead, and some chalk. The blacks are made by strong mordants, with some salt of copper. Cochineal is used much in the same way as for the madder printing and discharges, and the mordants are much the same; Brazil wood printing is of like nature: as also logwood dyes. The styles of printing derived from mixed colours are innumerable; but all proceed on the principles already laid down. Calico Printing by Steam.-All textile fibres do not attract colouring matters to them with an equal power, but they may be rendered capable of acting with more or less force by adventitious aids, of which the use of steam conjoined with the salts or oxides of tin forms two of the most remarkable. The nuriate or chloride of tin is decomposed by the action of water into muriatic acid and oxide of tin, the first of which is expelled by the heat of steam, or it.may be neutralized by the intervention of a saturating substance; while the second is never set at liberty in presence of cloth without making such a body with it, as to resist all the means of discharge employed for the removal of the other substances, and without fixing at the same time on the fibres the colouring matter previously mixed with it. The same reasoning may be applied to the muriate of alumina. Oxalic acid fulfils at once the functions of these two saline compounds. It is an agent employed to remove the oxides or the mordants; and this application is based upon the affinity which it has for alumina and iron. When deposited upon a mordanted cloth, it may either make the whole of the oxide disappear, if used in sufficient quantity, or it may restore it in whole or in part eventually, if the contact be prolonged at the ordinary temperature, or immediately when exposed to steam. It is thereby easy to explain certain phenomena, since by its energetically dissolving the oxides, it preserves them in solution during the whole period of printing them, and then quits them under the influence of a steam heat; and leaves them on the cloth in all their properties when alone. It is to this peculiar property of the oxalic acid that we must ascribe the solidity of esrtain topical blacks, for which it has been long employed. The tartrates and tartaric acid concur also to the same end; but the affinity of this acid for the bases, and the force with which it masks them, render its application more limited than the oxalic acid. It is useful for effecting displacements, and for preserving oxides in solution, so as to insure homogeneity to colours. Acetic acid enters also as an ingredient into steam printing; possessing a solvent 948 CALOMEL. power different from the other acids, and being applicable in a state of concenltration without corroding the tissues, it is applied in circumstances where substances of a more or less resinous nature need to be kept in solution in order to being printed on; whilst quitting under the influence of heat the bases with which it is associated, it allows them to contract an intimate union with the stuffs. The salts of copper and chromate of potash are employed to perform the oxidizing power of the absent air. The colours fixable by steam, after having been suitably thickened, are to be printed with the nicety appropriate to each, and the goods covered with them should be previously exposed for some time to a damp atmosphere. In the steaming process, the goods are coiled round a perforated hollow cylinder charged with steam by a central pipe, or they are exposed on frames in single pieces without mutual contact in wooden cases filled vith steam. Care must be had to prevent the dropping down of condensed steam upon the Foods. When rolled up in a cylindrical form, they are wrapped in blanket stuff. Of late years contrivances have been made to keep the cloth moving in the steam so as to receive the equal benefit of its actidn. A great variety of other forms of this steam-bath are in use, according to the fancy of the operators. But in all cases there should be a redundance of highly elastic steam, of vesicular quality, which is secured by causing it to bubble up through a stratum of water lying on the bottom of the case. CALOMEL. (Chlorure de Mercure, Fr.; Versusstes Qitecksilber, Germ.) The mild protochloride of mercury. The manufacture of this substance upon the great scale may be performed in two ways. The cheapest and most direct consists in mixing 1 part of pure quicksilver with 1 part of pure nitric acid, of sp. grav. from 1'2 to 1'25; and in digesting the mixture till no more metal can be dissolved, or till the liquid has assumed a yellow colour. At the same time a solution of 1 part of common salt is made in 32 parts of distilled water, to which a little muriatic acid is added: and, when heated to nearly the boiling point, it is mixed with the mercurial solution. The two salts exchange bases, and a protochloride of mercury precipitates in a white powder, which after being digested for some time in the acidulous supernatanJ liquor, is to be washed with the greatest care in boiling water. The circumstances which may injure the process are the following:-1. When less mercury is employed than the acid can dissolve, there is formed a deuto-nitrate of mercury, which forms some corrosive sublimate with the common salt, and causes a proportional defalcation of calomel. 2. If the liquors are perfectly neutral at the moment of mixing them, some subnitrate of mercury is thrown down, which cannot be removed by washing, and which gives a noxious contamination to the bland calomel. The acid prescribed in the above formula obviates this danger. The second manner of manufacturing calomel is to grind very carefully 4 parts of corrosive sublimate (bichloride of mercury) with 3 parts of quicksilver, adding a little water or spirits to repress the noxious dust during the trituration.'The mass is then introduced into a glass globe, and sublimed at a temperature gradually raised. The quicksilver combines with the deutochloride, and converts it into the protochloride, or calomnel. The following formula, upon the same principle, was recommended to the chemical manufacturer in Brande's Journal, for July, 1818:" Prepare an oxysulphate of mercury, by boiling 25 pounds of mercury with 35 pounds of sulphuric acid to dryness. Triturate 31 pounds of this dry salt with 20 pounds 4 ounces of mercury, until the globules disappear, and then add 17 pounds of common salt. The whole is to be thoroughly mixed, and sublimed in earthen vessels. Between 46 and 48 pounds of pure calomel are thus produced: it is to be washed and levigated in the usual way." The above is the process used at Apothecaries' Hall, London. The oxysulphate is made in an iron pot; and the sublimation is performed in earthen vessels. The crystalline crust or cake of calomel should be separated from the accompanying grey powder, which is nearest the glass, and consists of mercury mixed with corrosive sublimate. An ingenious modification of the latter process, for which a patent, now expired, was obtained by Mr. Jewell, consists in conducting the sublimed vapours over an extensive surface of water contained in a covered cistern. The calomel thus obtained is a supe rior article, in an impalpable powder, propitious to its medical efficacy. The presence of corrosive sublimate in calomel is easily detected by digesting alcohol upon it, and testing the decanted alcohol with a drop of caustic potash, when the characteristic brick-coloured precipitate will fall, if any of the poisonous salt be present. To detect subnitrate of mercury in calomel, digest dilute nitric acid on it, and test the acid with potash, when a precipitate will fall in case of that contamination. As it is medicine so extensively administered to children at a very tender age, its purity ought o be scrupulously watched. 118 parts of calomel contain 100 of quicksilver A patent was obtained in September, 1841, by Anthony Todd Thomson, 1M D., CALORIFERE OF WATER. 349 for an improved method of manufacturing calomel and corrosive subllniate, as follows:This invention consists in combining chlorine in the state of gas with the vapour of mercury or quicksilver, in order to produce calomel and corrosive sublimate. The apparatus employed consists of a glass, earthenware, or other suitable vessel, mounted in brick-work, and communicating at one end with a large air-tight chamber, and at the other end, by means of a bent tube, with an alembic, such as is generally used in generating chlorine gas. The alembic is charged with a mixture of common salt, binoxide of manganese and sulphuric acid, or of binoxide of manganese and muriatic acid, in order to produce chlorine gas. The mode of operating with this apparatus is as follows:-A quantity of mercury or quicksilver is placed in the glass vessel, and the temperature of the same is raised to between 350~ and 660~ Fahr., by means of an open fire beneath. The chlorine gas, as't is generated, passes from the alembic through the bent tube into the glass vessel, and there combining with the vapour of the mercury, forms either corrosive sublimate or calomel, according to the quantity of chlorine gas employed. The product is found at the bottom of the air-tight chamber, and may be removed irom the same through a door, when the operation is finished. According to the patent of Mr. Josiah Jewell, the vapour of calomel was to be transmitted into a vessel containing water, in order to condense it at once into an impalpable powder. But this process was beset with many difficulties. The vapour of the calomel was afterwards introduced into a large receiver, into which steam was simultaneously admitted; but this plan has also been found to be precarious in the execution. The best way is to sublime the calomel into a very large chamber from an iron pot, in the same way as the flowers of sulphur are formed. The great body of cool air serves to cause the precipitation of the calomel in a finely comminuted state. It is afterwards washed with water, till this is no longer coloured by sulphuretted hydrogen. CALORIC. The chemical name of the power or matter of heat. CALORIFERE OF WATER. (Calorifere d'eau, Fr.; Wasser-Heitzung, Germ.) In the Dictionnaire Technologique, vol. iv., published in 1823, we find the following description of this apparatus, of late years so much employed in Great Britain for heating conservatories, &c., by hot water circulating in pipes:"This mode of heating is analogous to that by stove-pipes: it is effected by the circulation of water, which, like air, is a bad conductor, but may serve as a carrier of caloric by its mobility. We may readily form an idea of the apparatus which has been employed for this purpose. We adapt to the upper part of either a close kettle, or of an ordinary cylindric boiler A, fig. 819, a tube B, which rises to a certain height, then descends, making several sinuosities with a gentle J7 319 slope till it reaches the level of the bottom of the boiler, to whose lowest part, as that which is least heated, it is fitted at c. At the highest point of the tube F we adapt a vertical pipe, des. EIjC-~-^2 _ tined to serve as an outlet to the steam which may be formed if the temperature be too much raised: it serves also for the escape of the air expelled from the water by the heat: and it per. mits the boiler to be replenished from time to time as the water is dissipated by evaporation; lastly, it is a tube of safety. "The apparatus being thus arranged, and all the tubes as well as the boiler filled with water, if we kindle fire in the grate H A p^ J D, the first portions of water heated, having become specifically lighter, will tend to rise: they will actually mount into the upper part of the boiler, and, of course, enter the tube B F: at /g the same time an equivalent quantity of water will re-enter the boiler by the other extremity c of the tube. We perceive that these simultaneous movements will determine a circulation in the whole mass of the liquid, which will continue as long as heat is generated in the fireplace; and if we suppose that the tubes, throughout their different windings, are applied against the walls of a chamber, or a stove-room, the air will get warmed by contact with tle hot surfaces; and we may accelerate the warming by multiplying these contacts in the mode indicated. "This calorifere cannot be employed so usefully as those with heated air, when tt is wished to heat large apartments. In fact, the passage of heat through metallic plates is in the ratio of the difference of temperature and quantity of the heating surfaces. In the present case, the temperature of the water, without pressure, in the tubes, must be always under 100~ C. (2120,F.), even in those points where it is most heated, and less still in all the other points, while the temperature of the flues in air stoves, heated directly by the products of combustion, may be greatly higher. In these stoves, also, the pipes 350 CALOTYPE. may without inconvenience have a large diameter, and present consequentlya large heaf ing surface; whereas, with the water calorifere, the pressure exercised by liquid upon the sides of the tubes being in the ratio of the surfaces, we are obliged, in order to avoid too great pressure, to employ a multitude of small tubes, which is expensive. Lastly, if the hot-water circulation is to be carried high, as may be often necessary in lofty buildings, the pressure resulting from the great elevation would call for proportional thickness in the tubes and the boiler: for these reasons, and others which we shall state in treating of heating by steam, it appears that water cannot be advantageously substituted for ail or steam in the applications above stated; yet this mode of heating presents very decided advantages where it is useful to raise the temperature a small number of degrees in a unnorm manner." See INCUBATION, ARTIFICIAL. " M. Bonnemain applied, with much success, these ingenious processes of heating by the circulation of water, to maintain a very equal temperature in hot-houses (serreschaudes), in stoves adapted to artificial incubation, and in preserving or quickening vegetation within hot-houses, or outside of their walls, during seasons unpropitious to horticultu re. " Since the capacity of water for heat is very great, if the mass of it in a circulationapparatus be very considerable, and the circulation he accelerated by proper arrangements, as by cooling the descending tube exterior to the stove-room, we may easily obtain by such means a moderately high and uniform temperature, provided the heat generated in the fire-place be tolerably regular We may easily secure this essential point by the aid of the fire-regulator, an instrument invented by M. Bonnemain, and which is described under the article INCUBATION, because there its use seems to be indispensable." From the above quotation, and, more especially, from the evidence adduced in the ar. tide INCUBATION, we see how little claim the Marquis de Chabannes, or any of his f1o lowers, can have to invention in their arrangements for heating apartments by the caiorific motions of the particles of'water, enc'osed in pipes of any kind. CALOTYPE is the name given by Mr. Fox Talbot to the art invented by him, of making pictures on paper or other such surfaces by the agency of light. It is merely a modified kind of photography. The processs is as follows:-Dissolve 100 grains of crystallized nitrate of silver in 6 ounces of distilled water, and brush over the paper (Whatman's sized post answers well) with a soft brush on one side only with this solution, and mark the side. When nearly dry, dip it into the solution of iodide of potassium (for only a few minutes), containing 500 grains of that salt dissolved in a pint of water. As soon as the paper is completely imbued with this solution, it should be immediately washed in distilled water, drained, and hung up to dry. This paper is to he kept for subsequent use in a portfolio, and carefully secluded from light. Next dissolve 100 grains of silver-nitrate in 2 ounces of distilled water, and add to the solution one-sixth of its volume of strong acetic acid. Keep this solution in the dark. Make a saturated solution of gallic acid in distilled water. When it is required to make a calotype picture, the two liquids last described are to be mixed in equal quantities, but only so much as is needed for the operation. With this gallonitrate of silver a sheet of the silver iodide paper is to be washed over upon its marked side with a soft brush, an operation to be performed by candle-light. After half a minute, the paper being dipped in water, and dried lightly by pressure between folds of blotting paper, becomes so exceedingly sensitive to light as to take a pictorial impression in the camera in a space varying from one second to five minutes, according to the brightness of illumination. The camera should be mounted with a meniscus lens, in an adjustable tube, so as to throw the image of the object to be calotyped upon a vertical plate of roughened glass, in the posterior side or wall of the wooden box. Whenever the focus is correctly adjusted, the glass is withdrawn, and replaced by sliding in a groove a frame with the prepared sheet of paper fixed flat upon it, the prepared side towards the lens, but screened from light by a card or thin board. The telescope, which has been invented for calotype purposes, by Dr. Petzval and M. Voigtlander, of Vienna, is recommended, in preference to all others, by Mr. Talbot, especially for taking portraits. The paper, after exposure for the due time in the camera, is to be again covered from the light, taken out, and subjected to another process; for as yet it has no pictorial appearance. To bring out this effect, it must be washed with the gallo-nitrate of silver, and then be gently warmed. In a few seconds thee portions of the paper upon which the light has acted will begin to darken, and eventually grow quite black, while the rest of the paper retains its original hue. Even though the pictorial impression be very faint, it may be brought out by a second application of the same solution. The operator should watch the gradual development of the tints; and when it is sufficient, he should fix them by dipping the paper in water, drying it slightly with blotting paper, then washing it over with a solution of bromide of potassium CAMPHOR. 351 containing 100 grains of that salt, dissolved in 8 or 10 ounces of water. Strong brine will also answer, but not so well. Similar calotype pictures may be made by using the bright light emitted from lime ignited by the oxy-hydrogen lame; as is practised in making the Daguerreotype portraits at night. In all the photographic pictures the lights and shades of the object are reversed, but they may be made conformable to nature by rendering the paper transparent witt white wax scraped upon its back, melting this in by rubbing it with a hot smoothing iron, after it is placed between two sheets of common paper, then laying it upon paper imbued with bromide of potassium, and exposing it to sunshine. Portraits are best taken by means of a lens, whose focal length is 3 or 4 times only greater than the diameter of the aperture. (See PHIOTOGRAPHY.) CAMBRIC. (Batiste, Fr.; Kammertuch, Germ.) A sort of very fine and rather thin linen fabric, first made at Cambray. An excellent imitation of this fabric is made in Lancashire, woven from fine cotton yarn hard twisted. Linen cambric of a good quality is also now manufactured in the United Kingdom from power-spun flax. CAMLET, or CAMBLET. A light stuff much used for female apparel. It is made of long wool hard spun, sometimes mixed in the loom with cotton or linen yarn. CAMPHOR, OR CAMPHIRE. This immediate product of vegetation was known tc the Arabs under the names of kamphur and kaphur, whence the Greek and Latin namt can.mp'ora. It is found in a great many plants, and is secreted, in purity, by several laurels; it occurs combined with the essential oils of many of tte labiacce; but it is extract. ed, for manufacturing purposes only, from the Laurus camphora, which abounds in China and Japan, as well as from a tree which grows in Sumatra and Borneo, called, in the country, Kapour barros, from the name of the place where it is most common. The camphor exists, ready formed, in these vegetables, between the wood and the bark; but it does not exude spontaneously. On cleaving the tree Laurus sumatrensis, masses of pure camphor are found in the pith. The wood of the laurus is cut into small pieces, and put, with plenty of water, into large iron boilers, which are covered with an earthen capital or dome, lined within with rice straw. As the water boils, the camphor rises with the steam, and attaches itself as a sublimate to the stalks, under the form of granulations of a gray color. In this state, it is picked off the straw, and packed up for exportation to Europe. Formerly Venice held the monopoly of refining camphor, but now France, England, Holland, and Germany refine it for their own markets. All the purifying processes proceed on the principle that camphor is volatile at the temperature of 400~ F. The substance is mixed, as intimately as possible, with 2 per cent. of quicklime, and the mixture is introduced into a large bottle made of thin uniform glass, sunk in a sand bath. The fire is slowly raised till the whole vessel becomes heated, and then its upper part is gradu. ally laid bare in proportion as the sublimation goes on. Much attention and experience are required to make this operation succeed. If the temperature be raised too slowly, the neck of the bottle might be filled with camphor before the heat had acquired the proper subliming pitch; and, if too quickly, the whole contents might be exploded. If the operation be carried on lanmgidly, and the heat of the upper part of the bottle be somewhat under the melting point of camphor, that is to say, a little under 350~ F., the condensed camphor would be snowy, and not sufficiently compact and transparent to be saleable. Occasionally, sudden alternations of temperature cause little jets to be thrown up out of the liquid camphor at the bottom upon the cake formed above, which soil it, and render its re-sublimation necessary. If, to the mixture of 100 parts of crude camphor and 2 of quicklime, 2 parts of boneblack, in fine powder, be added, the small quantity of coloring matter in the camphor will be retained at the bottom, and whiter cakes will be produced. A spiral slip of platina foil immersed in the liquid may tend to equalize its ebullition. By exposing some volatile oils to spontaneous evaporation, at the heat of about 70~ F., Proust obtained a residuum of camphor; from oil of lavender, 25 per cent. of its weight from oil of sage, 12'; from oil of marjoram, 10. Refined camphor is a white translucid solid, possessing a peculiar taste and smell It may be obtained, from the slow cooling of its alcoholic solution, in octahedral crystals. It may be scratched by the nail, is very flexible, and can be reduced into powder merely by mixing it with a few drops of alcohol. Its specific gravity varies fromn 0".85 to 0'996. Mixed and distilled with six times its weight of clay, it is decomposed, and yields a golden yellow aromatic oil, which has a flavour analogous to that of a mixture of thyme and rosemary: along with a small quantity of acidulous water tinged with that oil, charcoal remains in the retort. In the air, camphor takes fire on contact of an ignited body, and burns all away with a bright fuliginous flame. Camphor is little soluble in water; one part being capable of communicating smell and taste to 1000 of the fluid. 100 parts of alcohol, spec, grav. 0806, dissolve 120 parts of camphor, at ordinary temperatures. It is separated, inl a pulverulent state, by water. Ether and oils, both expressed and volatile, also dissolve it. 352 CANDLES. When distilled with eight parts of aquafortis, camphor is converted into camphoi ic acid. Camphor absorbs 144 times its volume of muriatic acid gas, and is transformed into a col, criess transparent liquid, which becomes solid in the air, because the acid attract humidity, which precipitates the camphor. One part of strong acetic acid disso. es two parts of camphor. By my analysis, camphor consists of 77-38 carbon, 11-14 hydrogen, and 11*48 oxygen. Berzelius's numbers are certainly erroneous. CAMWOOD. An article imported from Sierra Leone, which seems to possess similar dyeing powers with Brazil or Nicai agua wood. CANDLE. (Chandelle, Fr.; Kerze, Licht, Germ.) I shall first briefly describe the ordinary manufacture of candles. They are either dipped or moulded. But the first part of the process is the sorting of the tallow. Mutton suet with a proportion of oxtallow is selected for mould candles, because it gives them gloss and consistence. Coarsei tallow is reserved for the dipped candles. After being sorted, it is cut into small pieces, preparatory to being melted or rendered; and the sooner this is done after the fat is taken from the carcass the better, because the fibrous and fleshy matters mixed with it promote its putrefaction. Tallow is too commonly melted by a naked fire applied to the bottom of the vessel, whereas it should be done either in a cold set pan, where the flame plays only round the sides a little way above the bottom, or in a steam-cased pan. After being fused a considerable time, the membraneous matters collect at the surface, constituting the cracklings used sometimes for feeding dogs, after the fat has been squeezed out of it by a press. The liquid tallow is strained through a sieve into another copper, where it is treated with water at a boiling temperature in order to wash it. Al ter a while, when the foul water has settled to the bottom, the purified tallow is lifted out, by means of tinned iron buckets, into tubs of a moderate size, where it concretes, and is ready for use. It is a remarkable circumstance, that the wicks for the best candles are still cotton rovings imported fiom Turkey, notwithstanding the vast extension and perfection of cotton-spinning in this country. Four or more of these Turkey skeins, according to the intended thickness of the wick, are wound off at once into bottoms or clews, and after ward cut by a simple machine into lengths corresponding to those of the candles to be made. Mr. Colebank obtained a patent, in June, 1822, for a machine for cutting, twisting, and spreading wicks, which, though convenient, does not seem to have come into general use. The operations are performed upon a series of threads at once. The apparatus is placed in a box, in fiont of which the operator sits. A reel extends across the box, at the hinder part, upon which the cotton threads have been previously wound: from this reel they are drawn off in proper lengths, doubled, and cut by an ingenious mechanism. By dipping the wicks into the melted tallow, rubbing them between the palms of the hands, and allowing the tallow which adheres to harden, they may be arranged with facility upon the broaches for the purpose of dipping. The dipping-room is furnished with a boiler for melting the tallow, the dipping-mould, or cistern, and a large wheel for supporting the broaches. From the ceiling of the workshop a long balanceshaped beam is suspended, to one end of which a wooden frame is attached for holding the broaches with the wicks arranged at proper distances. The opposite arm is loaded with a weight to counterbalance the wooden frame, and to enable the workman to ascer. tain the proper size of the candles. The end of the lever which supports the frame is placed immediately above the dipping-cistern; and the whole machine is so balanced that by a gentle pressure of the hand, the wicks ale let down into the melted tallow as oftel es may be required. The following convenient apparatus for dipping candles has been long in use at Edin bnrgh. In the centre of the dipping-room a strong ulpright post A A, fig. 320, is erected with turning iron pivots at its two ends. Near its middle, six mortises are cut at small distances from one another, into each of which is inserted a long bar of wood n B, which moves vertically upon an icon pin, also passing through the middle of the shaft. The whole presents the appearance of a large horizontal wheel with twelve arms. A complete view of two of them only is given in the figure. From the extremity of each arm is suspended a frame, or port, as the workmen call it, containing 6 rods, on each of which are hung 18 wicks, making the whole number of wicks upon the wheel 1296. The machine, though apparently heavy, turns round by the smallest effort of the workman; and each port, as it comes in succession over the dipping-mould, is gently pressed downwards, by which means the wicks are regularly immersed in melted tallow. As the arms of the lever are all of the same length, and as each is loaded with nearly the same weight, it is obvious that they will all naturally assume a horizontal position. In order, however, to prevent any oscillation of the machine in turning round, the levers are kept in a horizontal position by means of small chains a a, one end of which is fixed to the top of the upright shaft, and the other terminates in a small square piece of wood, b, which exactly fills the notch c in the lever. As one end of the lever must be depressed at each dip, the square piece of wood is thrown out of the notch CANDLES. 358 by the workmen pressing down the handle D, which communicates with the small lever e inserted into a groove in the bar B. In order that the square piece of wood fixed in one extremity of the chain may recover its position upon the workman's raising the port, a small cord is attached a^320 / l t \ to it, which passes over a pulley inserted in a groove near c, and comdX/ A \ e municates with another pulley and. D l \ z~weight, which draws it forward to the notch. In this way the operation of dipping may be conducted by a single workman with perfect ease and regularity, and even dispatch. No time is lost, and no unnecessary labour expended, in removing the oX^^u ~'turning round back-wards by the tension ) ^^^^SII f ""^ of the'wb. D, the lay, with its reed, its under and upper shell, its two lateral /1jr | ^l1ll ltll 1l 1rulers or swords, and rocking-tree above. There are grooves in the upper and -o ll 55 13 ^-'lBl under shell, into which the reed is fitted. E, the heddles, or harness, with a double "a^I ---- iii)[iij|- -! neck attached to each of the tower or card a:t=__- ~ 1U^ ~ 0~mInechanisms F F, of the Jacquard loom. The heddles are connected and work with the treddles B n, by means of cords, as shown in the figure. G G are wooden boxes for the cards. H, the yarn or warp-beam. In draw-looms of every kind, there is no sinking of any portion of the warp, as in plain cloth-weaving; but the plane of the warp is placed low, and the threads under which the shuttle is to pass are raised, while all the rest remains stationary. The harness part of this carpet-loom is moved by an assistant boy or girl, who thus allows the weft to be properly decussated, while the weaver attends to working the front mounting or heddles. Fig. 338, A repre338 sents the frame of a carpet draw-loom;',l.> _A'. B is a box or frame of pulleys, over ______ ====* Fwhich the cords of the harness pass, and are then made fast to a piece of wood, seen at E, which the weavers call a table. AFrom the tail of the harness the simples Ij ii~ c^- ----. ^ -~t' descend, and to the end of each is at. llll v /F//f|\\\\ l tached a small handle G, called a bob. l 11115110 /I/flAliK \ IA I These handles being disposed in pairs, l00I6l /////|/// |\\\\\K\ and their regularity preserved by means of a perforated board c, it is merely nelilIIlIllillill cessary to pull every handle in succesII i~:~i33]: yI ssion; the weaver, at the same time, -u x- - D -- | - ~ working his treddles with his feet, as in any other loom. The treddles are four in number, the fabric being that of plain or alternate cloth, and two treddles allotted for each web. The harness part of the carpet draw-loom is furnished with mails, or metallic eyes, to save friction; two thrsads heing drawn through each eye. The design br pattern of a carpet is drawn upolm cross-rule paper, exactly in the same way as every other kind of fancy-loom work, and is transferred from the paper to the mounting by the rules for damask weaving. Suppose that a double web is so mounted that every alternate thread of the one may be raised, so as to form a sufficient shed-way for the shuttle, without depressing the other in the least. Then suppose another web placed above the former, at such a distance that it will exactly touch the convexity of those threads of the former which are raised. Then, if the threads of the latter web are sunk while the others are raised, the two would be entirely incorporated. But if this be only partially done, that is, at particular places, only those parts immediately operated upon will be affected by the action of the apparatus. If the carpet is a two-colored pattern, as black and red, and if upon the upper sup I I, _ 380 CARPET. "ace, as extendel in the loom, red flowers are to be represented upon a black ground, then all those species of design paper which are colored may be supposed to represen the red, and those which are vacant the black. Then counting the spaces upon the paper, omit those which are vacant, and cord those which are colored, and the effect will be produced. But as the two webs are to be raised alternately, whatever is corded for the first handle must be plassed by for the second, and vice versa; so that the one wi. form the flower, and the otter the ground. The board by which the simples are regulated appears at r. D shows the weights. CARPET-NEW PATENT. MAr. Simcox, of Kidderminster, has patented an invention for an improved manufacture of carpets, in which, by dispensing with the Jacquard loom, as well as the iron wires and tags usually employed to produce terry fabrics, such as Brussels carpets and coach-lace, he can work his machinery at greater speed and more economically. His second improvement relates to the manufacture of fabrics with cut pile, such as Wilton or Axminster carpets. He makes a ribbed fabric, greatly resembling the Brussels carpet, by a combination of woollen and linen warp and weft, arranged in such a manner that the woollen warp, in the form of a ribbed surface, may constitute the face of the fabric, while the linen warp forms the ground or back of the fabric. The plan he prefers, as most resembling the Brussels, consists in weaving the fabric as-nearly as possible in the ordinary way, except that, instead of inserting a tag or wire to form the rib or terry, the patentee throws in a thick shoot or weft of woollen or cotton, over which the woollen warp is drawn, and forms a rib; the woollen warp being afterwards bound down with a linen shoot or weft in the ordinary way. The woollen warp employed being all of one colour, the fabric produced will be plain or unornamented, with a looped or terry pile; and upon this fabric any design may be printed from blocks. The looms differ from the former chiefly in the employment of two separate shuttles, one for the woollen and one for the linen weft. These shuttles are both thrown by the same pickers and the same picking-sticks, and consequently the shuttle boxes must be moved up and down as may be required, in order to allow the picker to throw the proper shuttle. It will also be necessary to work the healds in a suitable manner to form the proper shreds, in order that the woollen face may be properly bound to the linen ground. Figures illustrating the construction of his loom are given by the patentee. The second part of his invention relates to the production of fabrics with a cut pile, like the Axminstel or Wilton rugs or carpets. The ordinary mode of making some of these fabrics is to weave the pattern in by means of a Jacquard apparatus, and pass the woollen warp over a rod or tag, which is afterwards cut by passing a suitable knife along it, thereby producing the cut pile. Thq patentee produces the design and surface of the fabric from the weft in place of the warp as heretofore. For this purpose th'e weft is made to consist of thick woollen shoots, which must be painted or stained with suitable colours, precisely as the woollen warps have been heretofore done; and the woollen shoot, when thrown in, is, by means of suitably formed hooks, pulled up and turned into loops, which, when they are properly secured to the foundation or ground of the fabric, are afterwards cut by means of knives or cutting instruments, with which the hooks are furnished, for the pury' se of.releasing them from the loops, and producing the cut pile. The patentee observe-, that cotton and other cheap materials may be employed with great advantage in the production of some of these fabrics.-Newtol's Journal, xxxiv. 167; Another invention of improvements in manufacturing figured fabrics, principally designed for the production of carpeting, patented by Mr. James Templeton, of Glasgow, consists in producing the pattern either on one or both sides of the fabric, by means of printed weft; also in the use of printed parti-coloured fur or weft, in the manufacture of Axminster carpet, and other similar fabrics. This invention is also applicable to the production of figured chenille weft for the manufacture of chenille shawls.~Newton's Journal, xxxvii. 148. CARPETS, PRINTED. Mr. Wood has taken a patent for weaving and printing carpets, using an ordinary Brussels carpet loom. After putting in the wire, or otherwise forming the loop, he throws in the usual linen shoot, on the face, to bind it; and then, for the back shoot, he throws in a thick soft weft. Or, to make a better edge and more elastic back, he employs the ordinary two linen shoots,-one on the face and the other In the back,-and then (or before throwing in the second linen shoot) he draws down only one-half of the lower portion of the linen warp (being one-quarter of the whole), and throws in the thick shoot, which is driven up by the batten or lay, so as to cover the second linen shoot, which is then inside the fabric: from the thick shoot being bound onl) by each alternate yarn of the warp, it will be more elastic than if bound more closely by using every yarn; whilst the second linen shoot, having half the warp over't, holds down the face or first shoot; and any inequality in the taking up of the lin: CARTHAMUS. 381 warp, by one portion of it binding in a greater substance than the other, is remedied by drawing down the different portions in succession. In printing Brussels and other pile carpets, the patentee first provides a table, long enough to receive the entire length or piece of the carpet to be printed; at each end of the table there is a frame of the same height or level, sufficiently long to receive the cylinder printing machine when off the fabric; and on the surface of the table the printing blanket is laid between two rails or guides, which are fixed at exactly the same distance apart as the carpet is wide, so as to keep it in one position, ania to form the guides for the printing cylinders. The carpet is fastened to one end of the table, and is then laid on the top of the same, and drawn tight at the other end by a roller, which is furnished with a ratchet wheel and click. The printing cylinders are mounted in a movable frame, containing a corresponding number of colour cans and feeding rollers, to supply them with colour. This printing apparatus is passed over the table, and between the guide rails (tile patterns on the cylinder being coloured, and bearing upon the carpet), to the frame at the other end of the table, and then back again; and this process is repeated until the fabric is sufficiently coloured. In order to insure each part of the pattern or printing surface coming again and again on the same place, toothed wheels are affixed on the axis of the printing cylinders, which geer into racks fixed on the sides of the table; so that, however frequently the printing apparatus — asses over the fabric, every part of the pattern will fall on the same place. Instead of the printing apparatus being passed back again ever same table, it may, by the application of movable frames at the end of the tabl!, be moved sideways on to another table, and so successively.-Newton's Journal, yxxiv. 250. CARTHAMUS, or safflower (carthamus tincLorius), (Carthame, Fr.; F rber distel, Germ.), the flower of which alone is used in dyeing, is an annual plant cultivated in Spain, Egypt, and the Levant. There are two varieties of it —one which has large leaves, and the other smaller ones. It is the last which is cultivated in Egypt, where it fornms a considerable article of commerce. Carthamus contains two coloring matters, one yellow and the other red. The first alone is soluble in water; its solution is always turbid: with re-agents it exhibits the characters usually remarked in yellow coloring matters. The acids render it lighter, the alkalis deepen it, giving it more of an orange hue: both produce a small dun precipitate, in consequence of which it becomes clearer. Alum forms a precipitate of a deep yellow, in small quantity. The solution of tin and the other metallic solutions cause precipitaies which have nothing remarkable in them. The yellow matter of carthamlls is not employed; but in order to extract this portion, the carthamus is put into a bag, which is trodden under water, till no more color can be pressed out. The flowers, which were yellow, become reddish, and lose in this opera tion nearly one half of their weioht. In this state they are used. For extracting the red part of carthamus, and thereafter applying it to stuff, the property which alkalis possess of dissolving it is had recourse to, and it is afterwards precipitated by an acid. The process of dyeing consists, therefore, in extracting the coloring matter by means o0 an alkali, and precipitating it on the stuff by means of an acid. It is this fecula which serves for making the rouge employed by ladies. As to this rouge, the solution of carthamus is prepared with crystallized carbonate of soda, and it is precipitated by lemon juice. It has been remarked that lemons, beginning to spoil, were fitter for this operation than those which were less ripe, whose juice retained much mucilage. After squeezing out the lemon juice, it is left to settle for some days. The precipitate of carthamus is dried at a gentle heat upon plates of stone-ware; from which it is detached and very carefully ground with talc, which has been reduced,o a very subtile powder, by means of the leaves of shave-grass (presle), and successively passed through sieves of increasing fineness. It is the fineness of the talc, and the greater or less proportion which it bears to the carthamus precipitate, which constitute the difference between the high and low priced rouges. Carthamus is used for dyeing silk, poppy, vacarat (a bright orange-red), cherry, rose color, and flesh color. The process differs according to the intensity of the color, and the greater or less tendency to flame color that is wanted. But the carthamus bath whose application may be varied, is prepared as follows: The carthamus, from which the yellow matter has been extracted, and whose lumps have been broken down, is put into a trough. It is repeatedly sprinkled with cendres gravelees (crude pearlashes), or soda (barilla) well powdered and sifted at the rate of 6 pounds for 120 lbs. of carthamus; but soda is preferred, mixing carefully as the alkali is introduced. This operation is called amester. The amestred carthamus is put into a small trough with a grated bottom, first lining this trough with a closely woven clotm, When it is about half filled, it is placed over the large trough, and cold water is poured into the upper one, till the lower becomes full. The carthamus is then set over another 382 CASE-HARDENING..rough, till the water comes from it almost colorless. A little more alkAi is nnw mixed with it, and fresh water is passed through it. These operations are repeated till the car. thamus he exhausted, when it turns yellow. Alter distributing the silk in hanks upon the rods, lemon juice, brought in casks from Provence, is poured into the bath till it becomes of a fine cherry color; this is called turning the bath (virer le bain). It is well stirred, and the silk is immersed and turned round the skein-sticks in the bath, as long as it is perceived to take up the color. For punceeau (poppy color), it is withdrawn, the liquor is run out of it upon the pea, and it is turned through a new bath, where it is treated as in thie first. After this it is dried and passed through fresh baths, continuing to wash and dry it between each operation, till it has acquired the depth of color that is desired. When it has reached the proper point, a brightening is given it by turning it round the sticks seven or eight times in a bath or not water, to which about half a pint of lemon juice for each pailful of water has been added. When silk is to be dyed ponceau or flame color, it must be previously boiled as for white; it must then receive a slight foundation of annotto, as explained in treating of this substance. The silk should not be alumed. The nacarats, and the deep cherry colors, are given precisely like the ponceaux, only they receive no annotto ground;. and baths may be empl(hed w:,ch have served for the ponceat., so as to complete their exhaustion. Fresh baths are not made for the latter colors, unless there be no occasion for the poppy. With regard to the lighter cherry-reds, rose color of all shades and flesh colors, they are made with the second and la-t runnings of the carlhamus, which are weaker. The deepest shades are passed through first. The lightest of all these shades, which is an extremely delicate flesh color, requires a little soap to be put into the bath. This soap lighiens the color, and prevents it from taking too speedily, and becoming uneven. The silk is then washed, and a.litlle brightening is given it, in a bath which has served for the deeper colors. All these baths are employed the moment they are made, or as speedily as possible, because they lose much of their color upon keeping, by which they are even entirely destroyed at the end of a certain time. They are, moreover, used cold, to prevent the color from being injured. It must have been remarked in the experiments just described, that the caustic alkalis attack the extremely delicate color of carthamus, making it pass to yellow. This is the reason why crystals of soda are preferred to the other alkaline matters. In order to diminish the expense of the carthamus, it is the practice in preparing the deeper shades to mingle with the first and the second bath about one fifth of the bath of archil. Dobereiner regards the red coloring matter of carthamus as an acid, and the yellow as a base. His carthamic acid forms, with the alkalis, colorless salts, decomposed by the tartaric and acetic acids, which precipitate the acid of a bright rose-red. Heat has a remarkable influence upon carthamus, rendering its red color yellow and dull. Hence, the colder the water is by which it is extracted, the finer is the color. Light destroys the color very rapidly, and hitherto no means have been found of counteracting this effect. For this reason this brilliant color must be dried in the shade, its dye must be given in a shady place, and the silk stuffs dyed with it must be preserved as much as possible from the light. Age is nearly as injurious as light, especially upon the dye in a damp state. The color is very dear, because a thousand parts of carthamus contain only five of it. In preparing the finest rouge, the yellow coloring matter being separated by washing with water, the red is then dissolved by the aid of alkali, and is thrown down on linen or cotton rags by saturating the solution with vegetable acid. The color is rinsed out of these rags, dissolved anew in alkalis, and once more precipitated by lemon juice. The nest and freshest carthamus must be selected. It is put into linen bags, which are placed in a stream of water, and kneaded till the water runs off colorless. The bags are then put into water soured with a little vinegar, kneaded till the color is all expelled, and finally rinsed in running water. By this treatment the carthamus loses nearly half its weight. 6633 cwts. of safflower were imported into the United Kingdom in 1835, of which 2930 cwts. were retained for internal consumption. CASE-HARDENING is the name of the process by which iron tools, keys, &c., have their surfaces converted into steel. Steel when very hard is brittle, and iron alone is for many purposes, as for fine keys, far too soft. It is therefore an important desideratum to combine the hardness of a steely surface with the toughness of an iron body. These requisites are united by the process of case-hardening, which does not differ from the making of steel, except in the shorter duration of the process. Tools, utensils, or ornaments, intended to be polishled, are first manufactured in iron and nearly finished, after which they are put into an iron CASHMERE. 383 box, together with vegetable or animal charcoal in pow`er, and cemented for a certain time. This treatment converts the external part into a coating of steel, which is usually very thin, because the time allowed for the cementation is much shorter than when the whole substance is intended to be converted. Immersion of the heated pieces into water hardens the surface, which is afterwards polished by the usual methods. Moxon, in his Mechanic Exercises, p. 56, gives the following receipt for case-hardening:-" Cow's horn or hoof is to be baked or thoroughly dried and pulverized. To this add an equal quantity of bay salt; mix them with stale chamber-ley or white wine vinegar: cover the iron with this mixture, and bed it with the same in loam, or enclose it in an iron box; lay it on the hearth of the forge to dry and harden: then put it into the fire, and blow till the lump have a blood-red heat, and no higher, lest the mixture be burnt too much. Take the iron out, and immerse it in water to harden." I consider the vinegar to be quite superfluous. I shall now describe the recent application of prussiate (ferrocyanate) of potash to this purpose. The piece of iron, after being polished, is to be made brightly red-hot, and then rubbed or sprinkled over with the above salt in fine powder, upon the part intended to be hardened. The prussiate being decomposed, and apparently dissipated, the iron is to be quenched in cold water. If the process has been well managed, the surface of the metal will have become so hard as to resist the file. Others propose to smear over the surface of the iron with loam made into a thin paste with a strong solution of the prussiate, to dry it slowly, then expose the whole to a nearly white heat, and hinally plunge the iron into cold water, when the heat has fallen to dull redness. See ST EEI.. CASHMERE or CACHEMERE, a peculiar textile fabric first imported from the kingdom of Cashmere, and now well imitated in France and Great Britain. The material of the Cashmere shawls is the downy wool found about the rooets of the hair of the Thibet goat. The year 1819 is remarkable in the history of French husbandry for the acquisition of this breed of goats, imported from the East under the auspices of their government, by the indefatigable courage and zeal of M. Jaubert, who encountered every fatigue and danger to enrich his country with these va.aable animals, aided by the patriotism of M. Ternaux, who first planned this importation, and furnished funds for executing it at his own expense and responsibility. He placed a portion of the flock brought by M. Jaubert, at his villa of Saint Ouen, near Paris, where the climate seemed to be very favorable to them, since for several successive years after their introduction M. Ternaux was enabled to sell a great number of both male and female goats. The quantity of fine fleece or down afforded by each animal annually, is from a pound and a half to two pounds. The wool imported into Europe comes by the way of Casan, the capital of a govern. ment of the Russian empire upon the eastern bank of the Wolga; it has naturally a grayish color, but is easily bleached. Its price a few years back at Paris was 17 francs per kilogramme; that is, about 6 shillings the pound avoirdupois. The waste in picking, carding, and spinning, amounts to about one third of its weight. The mills for spinning Cachemere wool have multiplied very much of late years in France, as appears from the premiums distributed at the exposition of 1834, and the prices of the yarn have fallen from 25 to 30 per cent. notwithstanding their improved fineness and quality. There is a fabric made with a mixture of Cachemere down and spun silk, which is becoming very general. One of the manufacturers, M. Hindenlang, exhibited samples of Cachemere cloth woven with yarn so fine as No. 130 for warp, and No. 228 for weft. Messrs. Pollino, brothers, of Paris, produced an assortment of Cachemere pieces from 22 to 100 francs the yard, dyed of every fancy shade. Their establishment at Ferte-Bernard occupies 700 operatives, with an hydiaulic wheel of 60 horse power. The oriental Cashmere shawls are woven by processes extremely slow and consequently costly; whence their prices are very high. They are still sold in Paris at from 4,000 to 10,000 fiancs a piece; and from 100 to 400 pounds sterling in London. It became necessary, therefore, either to rest satisfied with work which should have merely a surface appearance, or contrive economical methods of weaving, to produce the real Cachemere style with much less labor. By the aid of the draw-loom, and still better of the Jacquard loonm M. Ternaux first succeeded in weaving Cachemere shawls perfectly similar to the oriental in external aspect, which became fashionable under the name of French Cachemere. But to construct shawls alocmether identical on both sides with the eastern, was a more difficult task, which was accomplished only at a later period by M. Bauson of Paris. In both modes of manufacture, the piece is mounted by reeding-in the warp for the different leaves of the heddles, as is commonly practised for warps in the Jacquard looms. The weaving of imitation shawvls is executed, as usual, by as many shuttles as there are:olors in the design, and which are thrown across the warp in the order established fby 384 CASK. the rteder. The greater number of these weft yarns being introduced only at intervals into the web, when the composition of the pattern requires it, they remain floating loose at the back of the piece, and are cut afterwards,.without affectingin n the least the quality of the texture; but there is a considerable waste of stuff in the weaving, which is worked up into carpets. The weaving of the imitation of real Cachemere shawls is different from the above. The yarns intended to form the weft are not only equal in number to that of the colors of the pattern to be imitated, but besides this, as many little shuttles or pirns (like those used by embroiderers) are filled with these yarns, as there are to be colors repeated in the breadth of the piece; which renders their number considerable when the pattern is somewhat complicated and loaded with colors. Each of these small bobbins or shuttles passes through only that portion of the flower in which the color of its yarn is to appear, and stops at the one side and the other of the cloth exactly at its limit; it then returns upon itself after having crossed the thread of the adjoining shuttle. From this reciprocal intertexture of all the yarns of the shuttles, it results, that although the weft is composed of a great many different threads, they no less constitute a continuous line in the whole breadth of the web, upon which the lay or batten acts in the ordinary way We see, therefore, that the whole art of manufacturing this Cachemere cloth consists in avoiding the confusion of the shuttles, and in not striking up the lay till all have fulfilled their function. The labor does not exceed the strength of a woman, even though she has to direct the loom and work the treddles. Seated on her bench at the end opposite to the middle of the beam, she has for aids in weaving shawls from 45 to 52 inches wide, two girl apprentices, whom she directs and instructs in their tasks. About four hundred days of work are required for a Cachemere shawl of that breadth. For the construction of the loom, see JACQUARD. In the oriental process, all the figures in relief are made simply with a slender pirn without the shuttle used in European weaving. By the Indians the flower and its ground are made with the pirn, by means of anintertwisting, which renders them in some measure independent of the warp. In the Lyons imitation of this style, the leaves of the heddles lift the yarns of the warp, the needles embroider as in lappet weaving, and the flower is united to the warp by the weft thrown across the piece. Thus a great deal of labor is saved, the eye is pleased with an illusion of the loom, and the shawls cost little more than those made by the common fly shuttle. Considered in reference to their materials, the French shawls present three distinct classes, which characterize the three fabrics of Paris, Lyons, and Nimes. Paris manufactures the French Cachemere, properly so called, of which both the warp and the weft are the yarn of pure Cachemere down. This web represents with fidelity the figures and the shades of color of the Indian shawl, which it copies; the decption would be complete if the reverse of the piece did not show the cut ends. The Hindoo shawl, also woven at Paris, has its warp in spun silk, which reduces its price without impairing its beauty much. Lyons, however, has made the greatest progress in the manufacture of shawls. It excels particularly in the texture of its Thibet shawls, the weft of which is yarn spun with a mixture of wool and spun silk. Nimes is remarkable for the low price of its shawls, in which spun silk, Thibet down, and cotton, are all worked up together. The value of shawls exported from France in the following years was1831. 1832. 1833. Francs. Francs. Francs. Woollen --- - 1,863,147 2,070,926 4,319,601 Cachemere down - - 433,410 655,200 609,900 Spun silk- - --- 401,856 351,152 408,824 [ It appears that M. J. Girard at Sevres, near Paris, has succeeded best in producing Cachemere shawls equal in stuff and style of work to the oriental, and at a lower price. They have this advantage over the Indian shawls, that they are woven without seams, in a single piece, and exhibit all the variety and the raised effect of the eastern colors. Women and children alone are employed in his factory. CASK (Tonneau, Fr.; Fass, Germ.), manufacture of by mechanical power. Mr. Samuel Brown obtained a patent in November, 1825, for certain improvements in machinery for making casks, which seems to be ingenious and worthy of record. His mechanism consists in the first place of a circular saw attached to a bench, with a sliding rest, upon which rest each piece of wood intended to form a stave of a cask is fixed; and the rest being then slidden forward in a curved direction, by the assistance of an adjustable guide, brings the piece of wood against the edge of the rotatory saw, and causes it to be cut into the curved shape required for the edge of the stave. The second feature is an apparatus with cutters attached to a standard, and traversing round with their CASSAVA. 385 carrier upon a centre, by means of which the upper arn lower edges of the cask are cut round and grooved, called chining, for the purpose of receiving the heads. Thirdly, an apparatus not very dissimilar to the last, by which the straight pieces of wood designed for the heads of the cask are held together, and cut to the circular figure required, and also the bevelled edges produced. And fourthly, a machine in which the cask is nmade to revolve upon an axis, and a cutting tool to traverse for the purpose of shaving the external part of the cask, and bringing it to a smooth surface. The pieces of wood intended to form the staves of the cask, having been cut to their required length and breadth, are placed upon the slide-rest of the first mentioned machine, anid confined by cramps; and the guide, which is a flexible bar, having been previously bent to the intended curve of the stave and fixed in that form, the rest is then slidden forward upon the bench by the hand of the workman, which as it advances (moving in a curved direction) brings the piece of wood against the edge of the revolving circular saw, by which it is cut to the curved shape desired. The guide is a long bar held by a seiies of movable blocks fitted to the bench by screws, and is bent to any desired curve by shifting the screws: the edge of the slide-rests which holds the piece of wood about to be cut, runs against the long guide bar, and of consequence is conducted in a corresponding curved course. The circular saw receives a rapid rotatory motion by means of a band or rigger from any first mover; and the piece of wood may be shifted laterally by means of racks and pinions on the side-rest, by the workman turning a handle, which is occasionally necessary in order to bring the piece of wood up to, or away from, the saw. The necessary number of staves being provided, they are then set round within a confining hoop at bottom, and brought into the form of a cask in the usual way, and braced by temporary hoops. The barrel part of the cask being thus prepared, in order to effect the chining, it is placed in a flame upon a platform, which is raised up by a treddle lever, that the end of the barrel may meet the cutters in a sort of lathe above: the cuteers are then made to traverse round within the head of the barrel, and, as they proceed, occasionally to expand, by which means the bevels and grooves are cut on the upper edge of the barrel, which is called chiting. The barrel being now reversed, the same apparatus is brought to act against the other end, which becomes chined in like manner. The pieces of wood intended to form the heads of the cask are now to be cut straight by a circular saw in a machine, similar to the first described; but in the present instance the slide-rest is to move forward in a straieht course. After their straight edges are thus produced, they are to be placed side by side, and confined, when a scribing cutter is made to traverse round, and cut the pieces collectively into the circular form desired for heading the cask. The cask having now been made up, and headed by hand as usual, it is;raced between centres, or upon an axle in a machine, and turned round by a rigger or band with a shaving cutter, sliding along a bar above it, which cutter, being made to advance and recede as it slides along, shaves the outer part of the cask to a smooth surface. CASSAVA. Cassava bread, conaque, ic., are different names given to the starch of the root of the Manioc (Jatropha Manihot, Linn.), prepare] in the following manner in the West Indies, the tropical regions of America, and upon the African coast. The tree belongs to the natural family of the euphorbiacece. The roots are washed, and reduced to a pulp by means of a rasp or grater. The pulp is put into coarse strong canvass bazs, and thus submitted to the action of a powerful press, by which it parts with most of its noxious juice (used by the Indians for poisoning the barbs of their arrows.) As the active principle of this juice is volatile, it is easily dissipated by baking the squeezed cakes of pulp upon a plate of hot iron. Fifty pounds of the fresh juice, when distilled, afford, at first, three ounces of a poisonous water, possessing an intolerably offensive smell; of which, 35 drops being administered to a slave convicted of the crime of poisoning, caused his death in the course of six minutes, amid horrible convulsions.* The pulp dried in the manner above described concretes into lumps, which become hard and friable as they cool. They are then broken into pieces, and laid out in the sun to dry. In this state they afford a wholesome nutriment, and are habitually used as such by the negroes, as also by many white people. These cakes constitute the only provisions laid in by the natives, in their voyages upon the Amazons. Boiled in water with a little beef or mutton they form a kind of soup similar to that of rice. The cassava cakes sent to Europe (which I have eaten with pleasure) are composed almost entirely of starch, along with a few fibres of the ligneous matter. It may be purified by diffusion through warm water, passing the milky) mixture through a linen cloth, evaporating the strained liquid over the fire, with constant agitation. The starch * Memoir of Dr. Fermin, communicated to the Academy of Berlin concerning experiments made at Cayct\ne pl)en ths jni' P of the Mlanic. 26 386 CASTING OF METALS. dissolved by the heat, thickens as the water evaporates, but on being stirred, it becomes granulated, and must be finally dried in a proper stove. Its specific gravity is 1-530that of the other species of starch. The product obtained by this treatment is known in commerce under the name of tapioca; and being starch very nearly pure, is often prescribed by physicians as an aliment of easy digestion. A tolerably good imitation of it is made by heating, stirring, and drying potato starch in a similar way. The expressed juice of the root of manioc contains in suspension avery fine fecula, which it deposites slowly upon the bottom of the vessels. When fieed by decantation from the supernatant liquor, washed several times and dried, it forms a beautiful starch, which creaks on pressure with the fingers. It is called cpipa, in French Guyana; it is employed for many delicate articles of cookery, especially pastry, as also for hair powder, starching linen, &c. Cassava flour, as imported, may be distinguished from arrow-root and other kinds of starch, by the appearance of its particles viewed in a microscope. They ar-1 spherical, all about 1-1000th of an inch in diameter, and associated in groups; those of potato starch are irregular ellipsoids, varying in size from 1-300th to 1-3000th of ar. inch; those of arrow-root have the same shape nearly, but vary in size from 1-500th to 1-800th of an inch; those of wheat are separate spheres 1-1000th of an inch. CASSIS, the black currant (ribes nigra, Linn.), which was formerli: celebrated for its medicinal properties with very little reason. The only technical use to which it is now applied is in preparing the agreeable liqueur called ratafia, by the following French recipe:-Stone, and crush three pounds of black currants, adding to the magma one drachm of cloves, two of cinnamon, four quarts of spirit of wine, at 98~ Baume (see AREOMETRE OF BAUME), and 2J pounds of sugar. Put the mixture into a bottle which is to be we-_ corked; let it digest for a fortnight, shaking the bottle once daily during the first eight days; then strain through a linen cloth, and finally pass through filtering paper. CASSIUS, purple powder of. A preparation used in the arts as a colour, chiefly for stained glass and porcelain. It is also employed in medicine by some French physicians, and has been prepared by the following prescription:-10 parts of acid chloride of gold are dissolved in 2000 parts of water. In another vessel, 10 parts of pure tin are dissolved in 10 parts of nitric acid mixed with 20 parts of hydrochloric, and this solution is diluted with 1000 parts of distilled water. The solution of tin is added by degrees to that of the acid chloride of gold, as long as any precipitate results which is allowed to subside; it is then washed, filtered, and then dried at a very gentle heat. The tin salt above used contains both the protoxide and binoxide in certain proportions. The double compound of chloride of tin with sal ammoniac, called the pink salt of tin, is the preferable form; as it is not altered by the atmosl)here, is of definite composition, and when boiled with metallic tin it takes up just so much as will form the protochloride; 100 parts of pink salt require for this purpose 10-7 parts of metallic tin. 1'34 gr. of gold are to be dissolved in aqua regia, without excess of the solvent, and this solution is to be diluted with 480 gr. of water. Then 10 gr. of the pink salt mixed with 1-07 gr. of tin filings, and 40 gr. of water, are to be exposed to a boiling heat till the metal is dissolved. 140 gr. of water are now to be poured upon that compound, and the resulting solution is to be gradually added to the gold liquor (slightly warmed) till no more precipitate forms. This when washed and dried is of a brown colour, and weighs 4'92 grs. The above method of preparing the solution of the sesquioxide of tin seems to be the best hitherto prescribed. CASTING OF METALS. (See FOUNDING.) Costs from elastic moulds.-Being much engaged in taking casts from anatomical preparations, Mr. Douglas Fox, Surgeon, Derby, found great difficulty, principally with hard bodies, which, when undercut, or having considerable overlaps, did not admit of the removal of moulds of the ordinary kind, except with injury. These difficulties suggested to him the use of elastic moulds, which, giving way as they were withdrawn from complicated parts, would return to their proper shape; and he ultimately succeeded in making such moulds of glue which not only relieved him from all his difficulties, but were attended with great advantages, in consequence of the small number of pieces into which it was necessary to divide the mould. The body to be moulded, previously oiled, must be secured one inch above the sur face of a board, and then surrounded by a wall of clay, about an inch distant from its sides. The clay must also extend rather higher than the contained body: into this, warm melted glue, as thick as possible so that it will run, is to be poured, so as to completely cover the body to be moulded; the glue is to remain till cold, when it will have set into an elastic mass, just such as is required. IHaving removed the clay, the glue is to be cut into as many pieces as may be necessary for its removal, either by a sharp-pointed knife, or by having placed threads in CASTOR OIL. 381 the requisite situations of the body to be moulded, which may be drawn away when the glue is set, so as to cut it out in any direction. The portions of the glue mould having been removed from the original, are to be placed together and bound round by tape. In some instances it is well to run small wooden pegs through the portions of glue, so as to keep them exactly in their proper positions. If the mould be of considerable size, it is better to let it be bound with moderate tightness upon a board to prevent it bending whilst in use; having done as above described, the plaster of Paris, as in coinmon casting, is to be poured into the mould, and left to set. In many instances wax may also be cast in glue, if it is not poured in whilst too hot; as the wax cools so rapidly when applied to the cold glue, that the sharpness of the impression is not injured. Glue has been described as succeding well where the elastic mould is alone applicable; but many modifications are admissible. When the moulds are not used soon after being made, treacle should be previously mixed with the glue (as employed by printers) to prevent it becoming hard. The description thus given is with reference to moulding those bodies which cannot be so done by any other than an elastic mould; but glue moulds will be found greatly to facilitate casting in many departments, as a mould may be frequently taken by this method in two or three pieces, which would, on any other principle, require many. CAST-IRON SCOURIN G. Cast-iron surfaces are said to be easily scoured by adding a little of any kind of organic matter, such as glycerine, stearine, naptlhaline, creosote to dilute sulphuric acid; zinc and brass yield to the same method, wi:'h great economy of labour, time and material, CASTOR. (Eng. and Fr.; Biber, Germ.) rhe castor is an amphibious quadruped, inhabiting North America; also found in small numbers in the islands of the Rhone. In the arts, the skin of this animal is employed either as a fur or as affording the silky hair called beaver, with which the best hats are covered. Beaver skins, which form a very considerable article of trade, are divided into 3 sorts: 1. The fiesh beaver skins from castors, killed in winter before shedding their hair; these are most in re. quest among the furriers, as being the most beautiful. 2. The dry or lean beavers are the skins of the animals killed during the moulting season; they are not much esteemed, as the skin is rather bare. 3. The fat castors: these are the skins of the first sort, which have been worn for some lime upon the persons of the savages, and have got imbued with their sweat. The last are principally used in the hat manufacture. In France, the marine otter has been for many years substituted in the place of the castor o0 beaver. CASTOR or CASTOREUM. This name is given to a secretion cf the castors, contained in pear-shap d cellular organic sacs, placed near the genital organs of both the male and female animals. It is a substance analogous to civet and musk, of a consistence similar to thick honey. It has a bitter acrid taste; a powerful, penetrating, fetid, and very volatile smell; but, when dried, it becomes incdorous. Several chemists, and in particular Bouillon Larrange, Laugier, and Hildebrandt, have examined castor, and FCund it to be composed of a resin, a fatty substance, a volatile oil, an extractive matter, benzoic acid, and some salts. The mode of preparing it is very simple. The sacs are cut off from the castors vhen they are killed, and are dried to prevent the skin being affected by the weather. In this state, the interior substance is solid, of a dark color, and a faint smell; it softens with heat, and becomes brittle by cold. Its fracture betrays fragments of membranes, indicating its organic structure. When chewed, it adheres to the teeth somewhat like wax; it has a bitter, slightly acrid, and nauseous taste. The castor bags, as imported, are often joined in pairs by a kind of ligature. Some times the substance which constitutes their value is sophisticated; a portion of the castoreum being extracted, and replaced by lead, clay, gums, or some other foreign matters. This fraud may be easily detected, even when it exists ina small degree, by the absence )f the membranous partitions in the interior of the bags, as well as by the altered smell and taste. The use of castoreum in medicine is considerable, especially in nel-rous and spasmodic diseases, and it is often advantageously combined with opium. CASTORINE. A chemical principle lately discovered to the amount of a few parts per cent. in Castoreum. CASTOR OIL. The expressed oil of the seeds of the Palma Christi, or Ricinus communis, a native tree of the West Indies and South America; but which has been cultivated in France, Italy, and Spain. Bussy and Lecanu discovered in it 3 species of fatty matters, obtained partly by saponification, and partly by dry distillation-the margaritlc, ricinic, and elaiodic acids. None of these has been separately applied to any ase in the arts. 388 CATECHU. The quartlty of castor oil imported in 1835 into the United Kingdom was 1,109,301 lbs.; retained for home consumption, 670,205 lbs. See OILS. CATECIHU, absurdly called Terra Japonica, is an extract made from the wood of the tree mimosa catechu, which grows in Bombay, Bengal, and other parts of India. B is prepared by boiling the chips of the interior of the trunk in water, evaporating thi solution to the consistence of sirup over the fire, and then exposing it in the sun te harden. It occurs in flat rough cakes, and under two forms. The first, or the Bombay, is of uniform texture, of a dark red color, and of specific gravity 1-39. The second is more friable and less solid. It has a chocolate color, and is marked inside with re" streaks. Its specific gravity is 1'28. According to Sir H. Davy, these two species are composed as follows:Bombay. Bengal. Tannin - - - - - 54-5 48-5 Extractive - - - - - 340 36-5 Mucilage - - - - - 65 8 Insoluble matters, sand and lime - - 5 7 100.0 100'0 Areka nuts are also found to yield catechu; for which purpose they are cut into pieces watered in an earthen pot with solution of nitre, and have a little of the bark of a species of min.osa added to them. The liquor is then boiled with the nuts, and affords an inspissated Decoction. Good catechu is a brittle, compact solid, of a dull fracture. It has no smell, but a very astringent taste. Water dissolves the whole of it, except the earthy matter, which is probably added during its preparation. Alcohol dissolves its tannin and extractive. The latter may be oxydized, and thus rendered insoluble in alcohol, by dissolving the catechu in water, exposing it for some time to a boiling heat, and evaporating to dryness. The tannin of catechu differs from that of galls, in being soluble in alcohol, and more soluble in water. It precipitates iron of an olive color, and gelatin in a mass which gradually becomes brown. It has been long employed in India for tanning skins, where it is said to effect this object in five days. I have seen a piece of sole leather completely tanned by it in this country in ten days, the ox-hide having been made into a bag, with the hair outside, and kept filled with the solution of catechu. In India it has also been used to rive a brown dye to cotton goods, and of late years it has been extensively introduced into the calico print works of Europe. The salts of copper with sal ammoniac cause it to give a bronze color, which is very fast; the proto-muriate of tin, a brownish yellow; the per-chloride of tin, with the addition of nitrate of copper, a deep bronze hue; acetate of alumina alone, a reddish brown, and, with nitrate of copper, a reddish olive gray; nitrate of iron, a dark brown gray. For dyeing a golden coffee brown, it has entirely superseded madder; one pound of it being equivalent to six pounds of this root. A solution of one part of catechu in ten parts of water, which is reddish brown, exhibits the following results: wilhAcids - - - A brightened shade. Alkalis - - - - A darkened shade. Proto-sulphate of iron - Olive brown precipitate. Per-sulphate of iron - Olive green do. Sulphate of copper - - Yellowish brown. Alum - - - - A brightening of the liquor. Per-nitrate of iron - - Olive green precipitate. Nitrate of copper - -Yellowish brown do. Nitrate of lead - - Salmon do. Proto-nitrate of mercury - Milk-coffee do. Muriate of alumina - Brown-yellow. Muriate of tin - - Do. do. Per-chloride of tin - - Do. darker. Corrosive sublimate - Light chocolate do. Acetate of alumina - - Brightening of the liquor. Acetate of copper - - Copious brown precipitate Acetate of lead - - Salmon colored do. Bichromate of potash - Copious brown do. Pure tannin may be obtained from catechu, by treating it with suphuric acid and car bonate of lead; but this process has no manufacturing application. CATGUT. 389 CATGUT (Corde a boyau,'r.; Darmsaite, Germ.), the name absurdly enough given to cords made of the twisted intestines of the sheep. The guts being taken while warm out of the body of the animal, are to be cleared of feculent matter, freed from any ad hering fat, and washed in a tub of water. The small ends of all the intestines are next to be tied together, and laid on the edge of the tub, while the body of them is left to steep in some water, frequently changed, during two days, in order to loosen the peritoneal and mucous membranes. The bundle of intestines is then laid upon a sloping table which overhangs the tub, and their surface is scraped with the back of a knife, to try if the external membrane will come away freely in breadths of about half the circumference. This substance is called by the French manufacturers filandre, and the process filer. If we attempt to remove it by beginning at the large end of the intestine, we shall not succeed. This filandre is employed as thread to sew intestines, and to make the cords of rackets and battledoors. The flayed guts are put again into fresh water, and, after steeping a night,-are taken out and scraped clean next day, on the wooden bench with the rounded back of a knife. This is called curing the gut. The large ends are now cut off; and sold to the pork-butchers. The intestines are again steeped for a night in fresh water, and the following day in an alkaline lixivium made by adding 4 ounces of potash, and as much pearl-ash, to a pail of water containing about 3 or 4 imperial gallons. This ley is poured in successive quantities upon the intestines, and poured off again, after 2 or 3 hours, till they be purified. They are now drawn several times through an open brass thimble, and pressed against it with the nail, in order to smooth and equalize their surface. They are lasv sorted, according to their sizes, to suit different purposes. Whip-cord is made from the above intestines, which are sewed together endwise by the filandre, each junction being cut aslant, so as to make it strong and smooth. The cord is put into the frame, and each end is twisted separately; for whip-cord is seldom made out of two guts twisted together. When twisted, it is to be sulphured (see SULPHURING) once or twice. It may also be dyed black with common ink, pink with red ink, which the sulphurous acid changes to pink, and green with a green dye which the color dealers sell for the purpose. The guts take the dyes readily. After being well smoothed, the cord is to be dried, and coiled up for sale. Hatters' cords for bowstrings.-The longest and largest intestines of sheep, after being properly treated with the potash, are to be twisted 4, 6, 8, 10, or 12 together, according to the intended size of the cord, which is usually made from 15 to 25 feet long. This cord must be free from seams and knots. When half dry, it must be exposed twice to the fumes of burning sulphur; and, after each operation, it is to be well stretched and smoothed: it should be finally dried in a state of tension. Clockmaker's cord.-This cord should be extremely thin, and be therefore made fiom very small intestines, or from intestines slit up in their length by a knife fitted for the purpose; being a kind of lancet surmounted with a ball of lead or wood. The wet gut is strained over the ball which guides the knife, and the two sections fall down into a vessel placed beneath. Each hand, pulls a section. Clockmakers also make use of stronger cords made of 2 or more guts twisted together. Fiddle and harp strings. -These require the greatest care and dexterity on the part of the workmen. The treble strings are peculiarly difficult to make, and are best made at Naples, probably because their sheep, from their small size and leanness, afford the best raw material. The first scraping of the guts intended for fiddle-strings must be very carefully performed; and the alkaline leys, being clarified with a little alum, are added, in a progressively stronger state fronf day to day, during 4 or 5 days, till the guts be well bleached and swollen. They must then be passed through the thimble, and again cleansed with the lixivium; after which they are washed, spun, or twisted and sulphured during two hours. They are finally polished by fiiction, and dried. Sometimes they are sulphured twice or thrice before being dried, and are polished between norse-hair cords. It has been long a subject of complaint, as well as a serious inconvenience to rusicians, that catgut strings cannot be made in England of the same goodness and strength as those imported from Italy. These are made of the peritoneal covering of the intestines of the sheep; and, in this country, they are manufactured at Whitechapel, and probably elsewhere in considerable quantity; the consumption of them for harps, as well as for the instruments of the violin family, being very great. Their chief fault is weakness; whence it is difficult to bring the smaller ones, required for the higher notes, to concert pitch; maintaining at the same time, in their form and construction, that tenuity or smallness of diameter, which is required to produce a brilliant and clear tone. The inconvenience arising from their breaking when in use, and the expense in the case of harps, where so many are required, are such as to render it highly desirable to improve a manufacture which, to many individuals may, however, appear sufficiently contemptible. 390 CEMENTS. It is well known to physiologists, that the membranes of lean animals are far norn tough than of those animals which a:e fat or in high condition; and there is no reason to doubt that the superiority of the Italian strings arises from the slate of the sheep in that country. In London, where no lean animals are slaughtered, and where, indeed, an extravagant and useless degree of fattening, at least for the purpose of food, is given to sheep in particular, it is easy to comprehend why their membranes can never afford a material of the requisite tenacity. It is less easy to suggest an adequate remedy; but & knowledge of the general principle, should this notice meet the eyes of those interested is the subject, may at least serve the purpose of diminishing the evil and improving the manufacture, by inducing them to choose in the market the offal of such carcasses as appear least overburdened with fat. It is probable that such a manufacture might be advantageously established in those parts of the country wheie the fashion has not, as in London, led to the use of meat so much overfed; and it is equally likely, that in the choice of sheep for this'purpose, advantage would arise from using the Welch, the Highland, or the Southdown breeds, in preference to those which, like the Lincoln, are prone to excessive accumulations of fat. It is equally probable, that sheep dying of some of the diseases accompanied by emaciation, would be peculiarly adapted to this pur, ose. That these suggestions are not merely speculative is proved by comparing the strength of the membranes in question, or that of the other membranous parts, in the unfattened Highland sheep, with that of those found in the London markets. CATHARTINE. The name proposed by MM. Feneulle and Lassaigne for a chemical principle, which they suppose to be the active constituent of senna. CAUSTIC. Any chemical substance corrosive of the skin and flesh; as potash, called common caustic, and nitrate of silver, called lunar caustic, by surgeons. CAVIAR. The salted roe of certain species of fish, especially the sturgeon. This p7;ouct forms a considerable article of trade, being exported annually from the town of Astrachan alone, upon the shores of the Caspian sea, to the amount of several hundred tons. The Italians first introduced it into Eastern Europe from Constantinople, under the name of caviale. Russia has now monopolized this branch of commerce. It is prepared in the following manner:- - The female sturgeon is gutted; the roe is separated from the other parts, and cleaned by passing it through a very fine scarce, by rubbing it into a pulp between the hands; this is afterwards thrown into tubs, with the addition of a considerable quantity of salt; the whole is then well stirred, and set aside in a warm apartment. There is another sort of caviar, the compressed, in which the roe, after having been cured in strong brine, is dried in the sun, then put into a task, and subjected to strong pressure. CAWK.- The English miner's name for sulphate of baryta, or heavy spar. CEDRA (Cedrat, Fr.) is the fruit of a species of orange, citron, or lemon, a tree which bears the same name. Its peel is very thick, and covered with an epidermis which encloses a very fragrant and highly prized essential oil. The preserves flavored-with it are very agreeable. The citrons are cut into quarters for the dry comfits, but are put whole into the liquid ones. The liquorist-perfumer makes with the peel of the cedra an excellent liqueur; for which purpose, he plucks them befi re they are quite ripe; grates down the peel into a little brandy, or cu'ts them into slices, and infuses these in the spirits. This infusion is distilled for making perfume; but the flavor is better wher. the infusion itself is used. See ESSENCES, LIQUORIST, PERFUMERY. CELESTINE. Native sulphate of strontia, found abundantly near Bristol, in the red marl formation. It is decomposed, by ignition with charcoal, into sulphuret of strontia, which is converted into nitrate by saturation with nitric acid, evaporation, and crystallization. This nitrate is employed for the production of the red light in theatrical fire-works. CEMENTATION. A chemical process, which consists in imbedding a solid body in a pulverulent matter, and exposing both to ignition in an earthen or metallic case. In this way, iron is cemented with charcoal to form steel, and bottle glass with gypsum powder, or sand, to form Reaumur's porcelain. CEMENTS. (Ciments, Fr.; Cmrrenfe, Ki/le, Germ.) S;,bstances capable of taking the liquid form, and of being in that state applied between the surfaces of two bodies,.o as to unite them by solidifying. They may be divided into two classes, those which are applied through the agency of a liquid menstruum, such as water, alcohol, or oil, and those which are applied by fusion with heat. The diamond cement for uniting broken pieces of china, glass, &c., which is sold as a secret at an absurdly dear price, is composed of isinglass soaked in water till it becomes soft, and then dissolved in proof spirit, to which a little gum resin, ammoniac, or galbanum, and resin mastic are added, each previously dissolved in a minimum of alcohol. When to he applied, it must be gently heated to liquefy it; and it should be kept fot use in a well-corked vial. A glass stopper would be apt to fix so as not to be remove l CEMENTS. 391 able. This is the cement employed by the Armenian jewellers in Turkey for glue. ing the ornamental stones to trinkets of various kinds. When well made it resists moistu re. Shellac dissolved in alcohol, or in a solution of borax, forms a pretty good cement. White of egg alone, or mixed with finely sifted quicklime, will answer for uniting objects which are not exposed to moisture. The latter combination is very strong, and is much employed for joining pieces of spar and marble ornaments. A similar composition is used by copper-smiths to secure the edges and rivets of boilers; only bullock's blood is the albuminous matter used instead of white of egg. Another cement in which an analogous substance, the curd or caseum of milk is employed, is made by boiling slices of skim-milk cheeses into a gluey consistence in a great quantity of water, and then incorporating it with quicklime on a slab with a muller, or in a marble mortar. When this compound is applied warm to broken edge: of stoneware, it unites them very firmly after it is cold. A cement which gradually indurates to a stony consistence may be made by mixing 20 parts of clean river sand, two of litharge, and one of quicklime, into a thin putty with linseed oil. The quicklime may be replaced with litharge. Wilen this cement is applied to mend broken pieces of stone, as steps of stairs, it acquires after some time a stony hardness. A similar composition has been applied to coat over brick walls, under the name of mastic. The iron-rust cement is made of from 50 to 100 parts of iron borings, Funded and sifted, mixed with one part of sal-ammoniac, and when it is to be applied moistened with as much water as will give it a pasty consistency. Formerly flowers of sulphur were useC. and much more sal-ammoniac in making this cement, but with decided disadvantage, as the union is effected by the oxydizement, consequent expansion and solidification of the iron powder, and any heterogeneous matter obstructs the effect. The best proportion of sal-ammoniac is, I believe, one per cent. of the iron borings. Another composition of the same kind is made by mixing 4 parts of fine borings or filings of iron, 2 parts of potter's clay, and 1 part of pounded potsherds, and making them into a paste with salt and water. When this cement is allowed to concrete slowly on iron joints, it becomes very nard. For making architectural ornaments in relief, a moulding composition is formed of chalk, glue, and paper paste. Even statues have been made with it, the paper aiding the cohesion of the mass. Mastics of a resinous or bituminous nature which must be softened or fused by heat ire the following:Mr. S. Varley's consists of sixteen parts of whiting sifted and thoroughly dried by a red heat, adding when cold a melted mixture of 16 parts of black rosin and 1 of bees'-.ax, and stirring well durinr the cooling. Mr. Snger's electrical and chemical apparatus cement consists of 5 lbs. of rosin, 1 of bees'-wax, 1 of red ochre, and two table-spoonsful of Paris plaster, all melted together. A cheaper one for cementing voltaic plates into wooden troughs is made with 6 pounds of rosin, 1 pound of red ochre, 2 of a pound of plaster of Paris, and I of a pound of linseed oil. The ochre and the plaster of Paris should be calcined beforehand, and added to the other ingredients in their melted state. The thinner the stratum of cement that is interposed, the stronger, generally speaking, is the junction. Boiled linseed oil and red lead mixed together into a putty are often used by coppersmiths and engineers, to secure joints. The washers of leather or cloth are smeared with this mixture in a pasty state. The resin mastic alone is sometimes used by jewellers to cement by heat cameos of white enamel or colored glass to a real stone, as a ground to produce the appearance of an onyx. Mastic is likewise used to cement false backs or doublets to stones, to alter their hue. Melted brimstone, either alone, or mixed with rosin and brick dust, forms a tolerably good and very cheap cement. Plumber's cement consists of black rosin one part, brick. dust two parts, well incorpo. rated by a melting heat. The cement of dihl for coating the fronts of buildings consists of linseed oil, rendered dry by boiling with litharge, and mixed with porcelain clay in fine powder, to give it the consistence of stiff mortar. Pipe-clay would answer equally well if well dried, and any color might be given with ground bricks, or pottery. A little oil of turpentine to thin this cement aids its cohesion upon stone, brick, or wood. It has been applied to sheets of wire cloth, and in this state laid upon terraces, in order to make them water tight; but it is little less expensive than lead. The bituminous or black cement for bottle-corks consists of pitch hardened by the addition of rosin and brick-dust. In certain localities where a limestone impregnated with bitumen occurs, it is dried, 392 CEMENTS. ground, sifted, and then mixed with about its own weight of melted pitch, either mineral, vegetable, or that of coal tar. When this mixture is getting semifluid, it may be moulded into large slabs or tiles in wooden frames lined with sheet iron, previously smeared over with common lime mortar, in order to prevent adhesion to the moulds, which, being, in moveable pieces, are easily dismounted so as to turn out the cake of artificial bituminous stone. This cement is manufactured upon a great scale in many places, and used for making Italian terraces, covering the floors of balconies, flat roofs, water reservoirs, water conduits, &c. When laid down, the joints must be well run together with hot irons. The floor of the terrace should be previously covered with a layer of Paris plaster or common mortar, nearly an inch thick, with a regular slope of one inch to the yard. Such bituminous cement weirhs 144 pounds the cubic foot; or a foot of square surface, one inch thick, weighs 12 pounds. Sometimes a second layer of these slabs or tiles is applied over the first, with the precaution of making the seams or joints of the upper correspond with the middle of the under ones. Occasionally a bottom bed, of coarse cloth or gray paper, is applied. The larger the slabs are made, as far as they can be conveniently transported and laid down, so much the better. For hydraulic cements, see MORTAR. An excellent cement for resisting moisture is mare by incorporating thoroughly eight parts of melted glue, of the consistence used by'arpenters, with four parts of linseed oil, boiled into varnish with litharge. This cement hardens in about forty-eight hours, and renders the joints of wooden cisterns and casks air and water tight. A compound of glue with one-fourth its weight of Venice turpentine, made as above, serves to cement glass, metal and wood, to one another. Fresb-ms ee cheese curd, and old skim-milk cheese, boiled in water to a slimy consistence, dissolved in a solution of bicarbonate of potash, are said to form a good cement for glass and porcelain. The giuten of wheat, well prepared, is also a good cement. White of eggs, with flour and water well-mixed, and smeared over linen cloth, forms a ready lute for steam joints in small apparatus. White lead ground upon a slab with linseed oil varnish, and kept out of contact of air, affords a cement capable of repairing fractured bodies of all kinds. It requires a few weeks to harden. When stone or iron are to be cemented together, a compound of equal parts of sulphur with pitch answers very well. Mr. Joseph Gibbs, a practical civil engineer of eminence, obtained a patent in May, 1850, for improvements in artificial stone, mortar and cements, and in the modes of manufacturing the same, of which the following abstract is worthy of attention. "The several descriptions of Roman cement are made from the septaria of either IIarwich or Sheppey, or from the septaria of the lias formation, or from beds of cement stone found in the upper division of the lias formation, or in the shale beds of the Kimmeridge clay. All these stones, when manufactured, produce a material of a dark brown colour, unfit for incrusting buildings so as to imitate stone, unless they are either coloured by washes, or by painting. zN ow, amongst the advantages to be obtained from the cements and mortars 1 have invented is tlis, that every description of freestone may be exactly imitated without any wash or painting whatsoever being applied. "Again, the cement called Portland cement is made by mixing clay and chalk, or river mud and chalk, in such proportions together that the combined materials may contain about the same proportions of lime, silica, and alumina, as are found in cements. These materials are ground together in water to a great degree of fineness. After subsidence, and also after obtaining the proper consistency, the pasty materials are dried in kilns, or otherwise, and afterwards burned like ordinary cements in calcining kilns. The materials are then ground in proper mills. To these materials, so prepared and so ground, are added from one-third to one-lalf of their weight in slag of copper smelting, or other furnaces, or the slag of over-burnt cement, which, combininlg withthe lime and silica, forms a cement which is much nearer the colour of stone than any of the Roman cements heretofore made. Now, as the combination of chalk and clay, or river mud, is expensive when manufactured, and causes these cements to be very dear; and further, as the materials are only corbined mechanically and not chemically, there is neither uniformity in their quality, nor can reliance be always placed on their stability; the object of my invention, therefore, is to lessen the expense of manufacturing artificial stone, mortars, and cements, and produce a superior quality of cement to those now in use. "My invention divides itself into three parts; the first of which relates to mortar and cements, the second to the manufacture of artificial stone, and the third to the modes of manufacturing the said mortar cements, and artificial stone. "I have found by research, analysis, and much experience, that there exists in nature fast beds of argillaceous marls and marly limestones, or nmarl stones, which contain tho due admixture of lime, silica, and alumina, from which hydraulic cements and artificial tone may be manufactured. The principal places for finding this marl and marly CEMENTS. 39S limestone (geologically speaking) are the chalk formation, the Wealden formation, the Purbeck beds, the lias formation, the mountain limestone, and the lowest strata of the coal measures. In the chalk formation, the marl will be found immediately at the junction of chalk with and just above the green sand; in that division of the sand usually called'gault,' or at such places where the fire-stone (or, as it is sometimes called, the'malen rock') exists, interposing between the gault'and the chalk marl. This chalk marl possesses a varying character, increasing in the amount of silica and alumina as it approaches'either the malen rock or the gault; in fact, sometimes when there is no malen rock (or fire-stone) the gault becomes a calcareous marl, charged with sufficient lime to make a cement, but the amount of silica and alumina, and lime composing the marl, can only be ascertained by experiment. The'upper beds of marl, and those nearest to the greystone rock of the chalk formation, will make hydraulic mortar quite equal, and often superior, to the best lias lime; and the lower beds will make cement equal to Roman cement, except that it does not contain a very noticeable quantity of either manganese or iron; consequently it is of light stone colour when manufactured, and is better adapted to cover buildings, and represent stone. The chalk marl may readily be found by the springs of water which issue from the back or escarpment face of the chalk formation, and above these springs (but in close proximity thereto) the hydraulic lime will be found, and below the springs the materials for making cement must be extracted. "The proper place for obtaining the ma:i - limestone in the Wealden formation is in what are termed by geologists the Ashburnham beds, above and below and in immediate contact with the Ashburnham limestone. These limestone marls are like perfect limestone when first extracted, but decompose by exposure to the air after a short time. The limestone itself, in particular localities, sometimes become a cement-stone or marl stone, which may be known by its not slackening in water after calcination. " The material for making cement out of the beds of Purbeck limestone is obtained from some of the partings which divide the ordinary Purbeck beds of limestone, and is exceedingly well calculated to make a cement of great purity and whiteness, but all the beds do not contain in their partings the quality desired, but the proper material may be readily found by noticing the decomposing character of the shale when ex posed to the air. "The materials which I extract from the lias formation, locally called'rummell' at the lime quarries at Barrow-on-Soar, in Leicestershire, is an especial bed of marly limestone, found above and separated from all the lias beds of limestone in that district. The same bed of' rummell' is found in other districts of the lias formation, and may be readily observed on the coast of Dorsetshire, near Lyme Regis. It is seen on the face of the limestone cliffs, imbedded in a marly shale, the whole of which decomposes on exposure to the air. This bed of'rummell' has no local name in the district of Lyme Regis, not having hitherto been applied to any useful purpose; but it may be easily found, as it exists in a deep bed of shale between the lias limestone beds and the beds of cement stone which heretofore have been worked, and are so now (but the cement from this last-named stone is of a deeper brown colour, and unfit for imitating stone, whilst the bed of'rummell' will make a cement of a light colour exactly like fieestone). "In some cases, as when I use the hardening materials (to be hereafter described) in combination with the calcareous marls from the lias formation, I use some of the partings of calcareous shale existing between the lias beds of workable limestone, provided such calcareous partings or shale beds contain sufficient lime, which shale, after calcination, I combine with the hardening material, in the manner hereafter to be directed, either by itself or in combination with the'rummell' of this formation along with the hardening materials. " The materials which I extract to make cements firom the mountain or carboniferous limestone are only found in the upper part of that great deposit, and must be sought for in or at the immediate junction of the limestone shale (which shale lies under the mill-stone grit, and above the mountain or carboniferous limestone, dividing the two formations). These materials consist of mountain limestone, limestone shale, and bastard limestone (that is, the limestone which will not slack after calcination, but still retains its shape after being dipped in water). These two materials are found above the beds of workable limestone, which beds are wrought for making ordinary limes (the shales and the bastard limestone, or limestone marl, being always found together). These shales produce a dark cement, but the bastard limestone produces a cement of a light stone colour, and therefore more fit for imitating stone. " In addition to these substances, I extract from this formation sparry iron stone, to make hardening materials with. "The materials which I extract from the coal measures for making cement, or for mixing with the other cementitious materials, are found only in the lowest beds of the toal measures, often connected with the last two seams of coal, and before that I.~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 394 CEMENTS. stratum the millstone grit. These cementitiqus materials consist, first, of the coal shalh (called metals by miners), and round septarla nodules (boilams by the local miners about Congleton in Cheshire). The'metals' will not in all cases make cement, but most of them in contact with the boilams (or septaria balls) will do so. These boilams are composed chemically of sulphur, lime, iron, and manganese, and are therefore easily distinguishable; they are, in fact, a species (as well as the'metals') of pyrites. The'metals' and the septaria balls make excellent cement, of great hardness, but of dark colour. I use, however, this cement, as well as other materials, in mixing with some of the cements I have before specified, to give them hardness-the process of doing which, and the nature of the materials, will be described hereafter-such materials will,be called hardening materials. " When any of the materials just enumerated are to be made into cements, the usual course of proceeding for making cements is to be followed; that is, by burning in kilns and grinding in mills, in the way cement is now manufactured; but I recommend that the marls and marl stones be first dried in kilns or ovens, at a heat fit for baking, until all moisture be driven off, and that then the calcination be prolonged as much as possible, but that the heat be kelpt so low as is only just sufficient to effect complete calcination,-this being indispensable, to avoid the commencement of vitrification, which would destroy the adhesive properties of the cement. These observations will be found equally applicable to kilns, such as are now in use, or to the kiln of the improved description, to be described hereafter, and which forms part of this invention. " Although t have described certain new materials for making cements and mortars therefrom, and such materials are capable of forming good cements without any admixture whatever, yet, in some cases, I make a composition of the various cements to obtain particular qualities; thus, for instance, I take a quantity of the pyrites septaria, called boilams, and mix it with an equal quantity of the chalk marl before described. In this case the chalk marl keeps the colour light, and the septaria or boilams of the coal measures before described give to the chalk marl a considerable degree of hardness. I also make a mixture of equal parts of the bastard limestone before described for a like purpose, and with the same result; but with the' rummells' of the lias formation before described, or the rich argillaceous shale of that formation, noi more than one-third or one-quarter part by weight of the septaria or boilams is need ful to give great hardness and strength to the cement made therefrom. The same ob servation applies to the cement stone of the Ashburnham beds already described, as well as the cement made from the interposing Purbeck shale partings. " But in many cases a cement is required of a hardness beyond what would be afforded from either of the cement stones I have described, or the mixture of two oi more of them together; and in these cases I use substances to be combined with any of these cement stones or their mixtures, which I have called'hardening materials.' These materials (in addition to the one I have described, namely, the pyritous septaria or boilams) consist - "First: Of the slag or cinder derivable from iron blast furnaces. " Secondly: Slag from puddle furnaces, or from reheating or mill furnaces. "Thirdly: Slag derivable from copper, lead, or tin furnaces, or the slag from cement kilns. "Fourthly: The sparry iron of the carboniferous strata. "Fifthly: The pyritous earth known by geologists as Folkestone pyrites, which pyritous earth is a thin lamina, or bead, or band of earth, in concretions just below the gault strata, and which it separates from the rock and sand bed just below the gault. The pyrites may be found in other places in similar positions; but the locality just indicated, namely, Folkestone in Kent, will be a sufficient guide to find a similar material elsewhere. This pyritous earth may be calcined in ordinary lime kilns, the same as the cement stones I have before enumerated. If this pyrites be mixed with chalk marl or any other of the white cement stones I have before mentioned, the imitation of stone will be very exact, and may be sculptured afterwards with the same facility as ordinary freestone. The same effect may be produced by mixing in the like propor tions this calcined pyritous earth with the artificial hydraulic cements now commonly made (and which cements are composed of chalk and clay, or mud, in due proportions, anId ground together before calcination), the pyritous earth or Folkestone pyrites displacing in this case the ground slag with which such cements are now usually combined. "The various slags and cinders require only to be ground under edgestones to a fine powder, and then to be mixed with any of the various cements I have enumerated, namely, the cement from the chalk, the cement fiom the lias, the cement from the Wealden and Purbeck beds, the cement from the mountain limestone, and the cement from the coal measures; these mixtures must be effected by sifting the materials together, or by some other mode which will effectually incorporate and combine them; and the CHAINWORK. 395 quantities may be genera ly from one quarter (by weight) to one of slag, mixed with one of calcareous caement. " In some cases 1 grind pyritous septaria of the coal measures, or other equivalent materials (having the same chemical properties), into a fine powder, and mix such powder with about its equal weight of some of the calcareous marls after they are made into cement, instead of mixing such marls with the slags, or with the calcined pyrites of Folkestone, as before directed. In other cases, I mix with the cement made from chalk or other marls an equal weight of any of the cements now in use, or of the calcined septaria of the London clay basin, called Roman cement stone, more especially that part of it which is called sandstone; but in the case of using any of the septaria of the London clay, the marl and the stone may be calcined, and ground together in equal proportions, or thereabouts. " Claims:-1st. The manufacture of mortar and cement from chalk marls, the calcareous marls of the Ashburnham beds, the calcareous shales of the Purbeck formation, the rummell beds of the lias formation, the calcareous and mountain limestome shales, bastard limestone and the'metals,' and pyritous septaria of the coal formation, all or any of them, when prepared for the purpose by grinding c- pounding, and by treating with water as described, and whether the same are combined or not combined with certain hardening materials (afterwards specified), or other cementitious substances. " 2. The use of the'hardening materials' described, when used in combination with any of the calcareous substances enumerated in the preceding claim, or in combination with any other natural calcareous marl or marlstones. " 3. The use of the calcined Folkestone pyritous earth, the sparry ironstone or white ironstone of the mountain limestone, and the calcined pyritous septaria of the coal measures, as' hardening materials' in combination with any artificially-formed cement composed of chalk, or lime and clay, ground and calcined in the manner now usually practised for manufacturing artificial cements. " 4. The mixture of any of the before described marls or marlstones, or pyritous septaria, from the coal measures, with each other, or with any of the water cements orlimes now in use, or the materials of which the same are composed. " 5. A particular process of grinding and pounding cement and materials mixed therewith, as described. " 6. The consolidation of cement and materials mixed with such cement by concussion, for forming blocks or other solid shapes in moulds. " 7. A process of making artificial stone by putting plastic materials between lattices or other convenient forms; and also certain methods of casting hollow parallelograms in cement, to be afterwards filled up with concrete, for walls of artificial stone. " 8. The use of a kiln, with fire-vaults under the whole area of such kiln, such vaults communicating with each other in various directions through spaces between the bricks composing such vaults. " 9. The use of a brick with projections for constructing fire-vaults, as described, for calcining marls, marlstones, cements, and other materials used for making metallic mortars. " 10. The use of a circular or continuous kiln, for the purpose of making mortars and cements." CERASIN. The name given by Dr. John to those gums which swell, but do not dissolve in water; such as gum tragacanth. It is synonymous with BASSORINo E which see. CERATE, from cera, wax. An unguent, of rather a stiff consistence, made of oil, or lard and wax, thickened occasionally with pulverulent matters. CERINE. A substance which forms from 70 to 80 per cent. ofbees'-wax. It may be obtained by digesting wax, for some time, in spirits of wine, at a boiling temperature. The myricine separates, while the cerine remains dissolved, and may be obtained from the decanted liquor by evaporation. Cerine is white, analogous to wax, fusible at 134~ F., hardly acted upon by hot nitric acid, but is readily carbonized by hot sulphuric acid. When treated with caustic alkaline lye, it is converted into margaric acid and ceraine. CERIUM. A peculiar metal discovered in the rare mineral, called. cerite, found only in the copper mines of Bastnaes, near Riddarhytta, in Sweden. Cerium extracted fiom its chloride by potassium, appears as a dark red or chocolate powder, which tissumes a metallic lustre by fiiction. It does not conduct electricity well, like other uetals; it is infusible; its specific gravity is unknown. It has been applied to no use in the arts. CERUSE. A name of white lead. See LEAD and WHITE LEAD. CETINE. The name given by Chevreul to spermaceti. CHAINWORK is a peculiar style of textile fabric, to which hosiery and tambour ing belong. See HOSIERY. 396 CHAMELEON MINERAL, CHALK. (Craie, Fr.; Kreide, Germ.) A friable carbonate of lime, white, opaque, soft, dull, oi without any appearance of polish in its fracture. Its specific gravity yaries from 2'4 to 2'c' It usually contains a little silica, alumina, and oxide of iron. It may be purified by trituration and elutriation. The siliceous and ferruginous matters subside first, and the finer chalky particles floating in the supernatant liquid nay be decanted with it, and obtained by subsidence. When thus purified, it is called whitening and Spanish white, in England; schlemmkreide, in Germany; blanc de Troyes, and blanc de Meudon, in France. Pure chalk should dissolve readily in dilute muritaic acid, and the solution should afford no precipitate with water of ammonia. CHALK-black. A mineral, called also drawinl-slate. CHALK-French. Steatite, or soap-stone; a soft magnesian mineral. CHALK-red. A clay coloured with the peroxide of iron, of which it contains about 17 per cent. CHALYBEATE is the name given in medicine to preparations of iron. The most agreeable, and one of the most powerful, forms of such medicines, is the improved chalybeate water, for which Mr. Henry Bewley, apothecary in Dublin, obtained a patent in June, 1842. The following is his valuable recipe:-Eight ounces of crystallized citric acid being dissolved in about four times their weight of water, heated to 170~ F., are saturated with pure peroxide of iron, in the washed state, after being precipitated by ammonia fiom the ferric sulphate. The solution is sweetened, flavoured, and charged highly with carbonic acid gas, so as to make a very palatable po.ion, agreeable also to the stomach. I find by analysis that 100 parts of Mr. Bewley's brilliant citrate of iron contain 28'9 of peroxide, 48'5 of citric acid, and 23 of water; and that a six-ounce phial of his chalybeate water contains of that citrate a quantity equivalent to nearly 8 grains of peroxide of iron. Similar compounds are also specified to be made with other organic salts, as the tartrate or lactate of iron.-Newton's Journal, xxii. 470. CHAMELEON MINERAL. As this comnpoupd-so long known in chemistry as a mere curiosity, on account of the surprising changes of color which it spontaneously assumes-has of late been largely employed for whitenir? tallow, palm oil, and decoloring other organic matters. it merits description in this dictionary. It exists in two states; one of which is called by chemists the manganate of potash, and the other the oxymanganate; denoting that the first is a compound of manganic acid with potash, and that the second is a compound of oxymanganic acid with the same base. They are both prepared in nearly the same way; the former by calcining together, at a red heat in a covered crucible, a mixture of one part of the black peroxide of manganese with three parts of the hydrate of potash (the fused potash of the apothecary). The mass is of a green color when cold. It is to be dissolved in cold water, and the solution allowed to settle, and become clear, but by no means filtered for fear of the decomposition to which it is very prone. When the decanted liquid is evaporated under the exhausted receiver of an air-pump, over a surface of sulphuric acid, it affords crystals of a beautiful green color, which should be laid on a clean porous brick to drain and dry. They may be preserved in dry air, but should be kept in a well-corked bottle. They are decomposed by water, but dissolve in weak water of potash. On diluting this much, decomposition of the salt ensues, with all the chameleon changes of tint; red, blue, and violet. Sometimes a green solution of this salt becomes red on being heated, and preserves this color even when cold, but resumes its green hue the moment it is shaken: it might, therefore, furnish the crafty votaries of St. Januarius with an admirable means of mystifying the worshippers at his shrine. The original calcined mass, in being dissolved, always deposites a considerable quantity of a brown powder, which is a compound of the acid and peroxide of man. ganese combined with water. Much of the potash remains unchanged, which may be recovered. The oxymanganate of potash is made by fusing, with a strong heat, a mixture of equal parts of peroxide of manganese and hydrate of potash, or one part of peroxide and two parts of nitre. The mass is to be dissolved in water, and, if the solution be green, it should be reddened by the cautious addition of a few drops of nitric acid. The clarified liquor is to be evaporated to the point of crystallization. Even the smallest crystals of this salt have such an intense red color, that they appear black with a green metallic reflection. In the air they gradually assume a steel gray hue, without undergoing any essential change of nature. A very little of the salt reddens a large body of water. The least portion of any organic matter added to the solution of this salt reduces the oxymanganic acid to the state of peroxide, which precipitates combined with water; and the liquor becomes green or colorless, according to circum. stances. A more permanent oxymanganic salt may be made as follows:-Melt chlorate of potash over a spirit lamp, and throw into it a few pieces of hydrate of potash, whict CHARCOAL, 397 immediately dissolve and form a limpid liquid. When peroxide of manganese in fine powder is gradually introduced into that melted mixture, it immediately dissolves, with the production of a rich green colour. After adding the manganese in excess, the whole is to be exposed to a gentle red heat, in order to decompose the residuary chlorate of potash. It is now a mixture of manganate of potash, chloride of potassium and peroxide of manganese. It forms with water a deep green-coloured solution; which when boiled assumes a fine red colour, in consequence of its becoming an oxymanganate, and it ought to be decanted off the sediment while hot. By cooling, and stil more after further evaporation, the oxymanganate of potash separates in crystals pos sessed of great lustre; but towards the end colourless crystals of chloride of potassium. Both the above salts are readily decomposed by organic bodies and other combustibles, whereby they have their acid converted into an oxide, with the disengagement of Qxygen, and the destruction of many vegetable and animal colours. In this respect they resemble the nitrates and chlorates. CHARCOAL. The fixed residuum of vegetableg exposed to ignition out of contact 3f air. In the article CARBON, I have described the general properties of charcoal and t.l simplest mode of making it. I shall here detail the best systems of manufacturing this nroduct upon the continent of Europe. To carbonize wood under a moveable covering, the plan of meiler, or heaps, is employed very much in Germany. The wood is arranged either in horizontal layers, or in nearly vertical ones, with a slight slope, so as to form conical rounded heaps of differ.nt sizes. The former are called lying meiler, fig. 339; the latter standing neiler, figs. 340. and 341. 340 344 341 Both are distributed in much the same way. In districts where the wood can be transported into one place by means of rivers, ot mountain-slides, a dry flat space must be pitched upon, screened fiom storms and floods, which may be walled round, having a slight declivity made in the ground, toward the centre. See fig. 342. Into this space the tarry acid will partially fall, and may be conducted outward, through a covered gutter beneath, into a covered tank. The mouth of the tank must be shut, during the coaking, with an iron or stone slab, luted with clay. A square iron plate is placed ever the inner orifice of the gutter, to prevent 342 d it being choked with coal ashes. tFig. 342 represents a walled meiler'~_.~-~.~...~..~~,L * -(n~] —-— P station; a, the station; b, the ~.'~'~'~~~~~~ gutter; c, the tank, which is covered with the slab d; e, a slab which serves to keep the gutter clear of coals. The cover of the heaps is formed of earth, sand, ashes, or such other matter as may be most readily found in the woods. They should be kindled in the centre. From 6 days to 4 weeks may be required for charring a heap, according to its size; hard wood requiring most time; and the slower the process, the better and greater is the product, generally speaking. 343 Charring of wood in mounds (Haufe or liegende werke), figs. 343 and 344, differs from that in the meiler, because the wood in the h hautfe is successively charred, and E l =~ 15 ffi;9 | the charcoal is raked out by little and little. The product is said to be greater in this way, and also D a a CI better. Uncleft billets, 6 or 8'-'^Ov' & S " - ~-~'-0 3 ~ --- *'feet long, being laid over each 0 fti fother, are covered with ashes, and CJ-k (^l~~l I llyf W g othen carbonized. The station is,~ — K sometimes horizontal, and some. times made to slope. The length o^ ^ OI ^^ ^^ y ^ may be 24 feet, the breadth 8 344 feet; and the wood is laid cross. 398 CHASCHISCH. wise. Piles are set perpendicularly to support the roof, made of boughs and -eaves, covered with ashes. Pipes are occasionally laid within the upper part of the mounds, which serve to catch and carry off some of the liquid products into proper tanks. Fig. 345 is a vertical section, 345 m1 h f and fig. 346, a half bird's-eye view, i h n.n j and half cross section, at the height of the pit-bottom, of Chaheausm f?=1 - PIsiere's kiln for making wood char-..~,..;^ coal. a is the oven; b, vertical air-pipes; c c, horizontal flues for small pits which communicate by short horizontal pipes e e, with the vertical ones; f, the sole of the kiln, a ci-cle oi brickwork, upon which the cover or heod h reposes; i CVi, a pipe which leads t: the cistern off the gaseous matter; mn m, holes in the iron cover or lid. ^^^^^^ ^346 ^The distribution of the w-nd is /c like that in the horizontal meiers, t.~^ la c// /or heaps;. it is kindled in the cn^"S-^lll^C t^^^^xral vertical canal withe burning fuel, and the lid is covered with ^'j^^/.5iCt ) 1 afew inches of earth. At the bec co ginning of the operation all the __ - Bydraught flues are left open, but they are progressively closed, as occasion requires. In eight kilns — ~.~ ~C__ Ckof this kind, 500 decasters of oak y7i wood are carbonized, from which 16,000 hectolitres of charcoal are obtained, equal to 64,000 pounds I'-^^^^^^^^^^t -r^ French, being about 25 per cent.; besides tar and 3000 velts of owood vinegar, of from 20 to 30 ^^^^ —' <3/ Baume. At Crouy upon the Ourcq, near Meaux, there is a well-constructed kiln for making turf-charcoal. It resembles most nearly a tar-kiln. Infig. 347, a is the cylindrical coaking play, whose surrounding walls are heated by the flame which passes through the intermediate space b. The place itself is divided by partitions of fire tiles 34'7 W e 1 g^ into threeestages, through the apertures in which the a1 e flames of the fire c c, rise, and heat the exterior of the m 1 coaking apartment. In order to confine the heat, there l i i n the enclosing walls of the outer kiln a cylindrical g inl a 2 t g hollow space d, where the air is kept stagnant. Through g I I4 |(^ the apertures left in the upper end at e, the turf is inw troduced; they are then shut with an iron plate f, l I- W which is covered with ashes or sand. The fire-place opens above this aperture, and its outlet is provided A t e K W, Crouywith a moveable iron cover g, in which there is a small - hole for the issue of the gases. The sole of the hkiln consists of a cast iron slab h, which may be raised by means ofa hook i upon it. This is drawn back after the carbonization is completed, whereby the charcoal falls from the coaking space into a subjacent vault. The volatile products are carried off by the pipe k, and led into the condensing cistern; the gases escaping to the ire-place where they are burned. The iron slab is protected from the corrosion of the acid vapors by a layer of coal ashes. CHASCHISCH. Hadschy is not the correct term for this narcotic drug, for Hadschy means a pilgrim; the true name is, according to pronunciation, Chaschisch, the Arab word for hemp (Cannabis sativa). By this name all intoxicating drugs, whose chief constituent is this herb, are well known over the whole of the East. The mode of preparing chaschisch is the following: CHIMNEY. 399 The tops and all the tender parts of the hemp plant are collected after tlEe period of inflorescence, dried and kept for use. It must be premised that the hemp plant is in the East distinguished by its narcotic properties, although botanists are unable to detect any difference between this and the European species. The dried hemp, or chaschisch, is used1 st. Boiled in fat, butter, or oil, with a little water; the filtered product is employed:n all kinds of pastry. 2nd. Powdered for smoking: 5 or 10 grs. of the powder are smoked from a common pipe (tsubuk) with ordinary tobacco (tiuitin), or from a water pipe (nargiele) with another kind of tobacco (tombeki). The tombeki is probably the leaf of a species of Lobelia; it is smoked in a nargiele, and is uncommonly narcoctic; so much so, that it is ordinarily steeped in water for a few hours before it is used to weaken it, and the pipe is charged with it whilst it is yet wet. 3rd. Formed with tragacanth mucilage into pastiles, which are placed upon a pipe and smoked in similar doses. These two last preparations are so termed esrar (esrar is the Arab word for "secret"); they are the most active of all the preparations of chaschisch, and the first pipe will cause cerebral congestion in beginners. 4th. Made into an electuary with dates or figs and honey. This preparation is of a dark brown, almost black, colour, and tastes of dates and hemp; it is less active than the esrar. 5th. Lastly, another electuary is prepared of the same ingredients with the addition of spices, clove, cinnamon, pepper, amber, and musk. This preparation is used as an aphrodisaic. Chaschisch is said not to produce stupor but the most pleasant species of intoxication. The person under its influence feels with perfect consciousness in the best of all humnours; all impressions fromn without produce the most grateful sensations; pleasant illusions pass before his eyes, and he feels comfortably happy; he thinks himself the happiest man on earth, and the world appears to him Paradise. From this in.-ginative state he passes into the every day state, with a perfect recollection of all sensations, and of every thing he has done and of every word he has spoken. The effects of a continued use of the narcotic are emaciation and nervous debility. CHEESE (coinposition of). Cheese of certain dairies and districts is apt to undergo a remarkable decomposition whereby valerianic acid is formed. Messrs. Jljenko and Laskowsi distilled along with water a turbid ammoniacal liquor, which being redistilled along with some sulphuric acid, and the product neutralized by barytes, the.resulting saline compound proved to be the valerianate of that base, mixed with compounds of butyric acid, caproic acid, caprylic acid, and capric acid. The cheese was from Limbourg. Valerianic acid was found by M. Balard in the cheese of Roquefort. CIIICA is a red colouring principle made use of in America by some Indian tribes to stain their skins. It is extracted from the bignonia chica by boiling its leaves in water, decanting the decoction, and allowing it to settle and cool, when a red matter falls down, which is formed into cakes and dried. This substance is not fusible, and when burned, diffuses the same odor as animal bodies do. t is insoluble in cold water, very soluble in alcohol and ether, but after the evaporation of these liquids, it is recovered unchanged. Fats and unctuous oils both dinsolve it. It is soluble in carbonated and caustic alkaline leys, from which it is precipitated by the acids without alteration. An excess of alkali, however, speedily decomposes it. Nitric acid transforms it into oxalic acid, and a bitter matter. Chlorine makes it white. The savages mix this pigment with the fat of the cayman or alligator, and rTb their skins with the mixture. It =ay probably be turned to account in the arts of civilized nations. CHIMNEY. (Chemin&c, Fr.; Schornstein, Germ.) Chimney is a modern invention for promoting the draught of fires and carrying off the smoke, introduced into England so late as the age of Elizabelh, though it seems to have been employed in Italy 100 years before. The Romans, with all their luxurious refinements, must have had their Epicurean cookery placed in perpetual jeopardy from their kitchen fires, which, having no vent by a vertical tunnel in the walls, discharged their smoke and frequently their flames at the windows, to the no small alarm of their neighbors, and annoyance of even the street passengers. Chimneys in dwelling houses serve also the valuable purpose of promoting salubrious circulation of air in the apartments, when not foolishly sealed with anti-ventilating stovechests. The first person who sought to investigate the general principles of chimney draughts, in subserviency to manufacturing establishments, was the celebrated Montgolfier. As the ascent of heated air in a conduit depends upon the diminution of its specific gravity, or, in other words, upon the increase of its volume by the heat, the ascensional force may e deduced from the difference between the density of the elastic fluid in the interior of AOO CHIMNEY..he chimney, and of the external air; that is, between the different heights of the internal and external columns of elastic fluid supposed to be reduced to the same density. In the latter case, the velocity of the gaseous products of combustion in the interior of the chimney is equal to that of a heavy body let fall from a height equal to the difference in height of the two aerial columns. To illustrate this position by an example, let us consider the simple case of a chimney of ventilation for carrying off foul air from a factory of any kind; and suppose that the tunnel of iron be incased throughout with steam at 212 decrees Fahr. Suppose this tunnel to be 100 yards high, then the weight of the column of air in it will be to that of a column of external air 100 yards high, assumed at 32~ F., inversely as its expansion by 180~; that is, as 1000 is to 1-375; or as 72-727 is to 100. The column of external air at 32~ being 100 yards, the internal column will be represented by 72-727; and the difference=27-27, will be the amount of unbalanced weight or pressure, which is the effective cause of the ventilation. Calculating the velocity of current due to this difference of weight by the well-known formula for the fall of heavy bodies, that is to say, multiplying the above difference, which is 27-27, by the constant factor 19.62, and extracting the square root of the product; thus V 19-62 X 27'27 = 23-13 will be the velocity in yards per second, which, multiplied by 3, gives 60-30 feet. The quantity of air which passes in a second is obtained of course by multiplying the area or cross section of the tunnel by this velocity. If that section is half a yard, that is = a quadrangle 24 feet by 2, we shall have 23-13 X 0-5 = 11-565 cubic yards, = 3124 cubic feet. The problem becomes a little more complicated in calculating the velocity of air which has served for combustion, because it has changed its nature, a variable proportion of its oxygen gas of specific gravity 1111, being converted into carbonic acid gas of specific gravity 1'524. The quantity of air passed through well constructed farnaces may, in general, be regarded as double of what is rigorously necessary for combustion, and the proportion of carbonic acid generated, therefore, not one half of what it would be were all the oxygen so combined. The increase of weight in such burned air of the temperature of 212~, over that of pure air equally heated, being taken into account in the preceding calculation, will give us about 19 yards or 57 feet per second for the velocity in a chim. ney 100 yards high incased in steam. Such are the deductions of theory; but they differ considerably from practical results, in consequence of the friction of the air upon the sides of the chimneys, which varies likewise with its form, length, and quality. The direction and force of the winds also exercise a variable.influence upon chimney furnaces differently situated. In chimneys made of wrought i''on, like those of steamboat%, the refrigeration is considerable, and causes a diminution of velocity far greater than what occurs in a factory stalk of well built brick work. In comparing the numbers resulting from the trials made on chimneys of different materials and of different fbrms, it has been concluded that the obstruction to the draught of the air, or the deduction to be made from the theoretical velocity of efflux, is directly proportional to the length of the chimneys and to the square of the velocity, and inversely to their diameter. With an ordinary wrought-iron pipe, of from 4 inches to o inches diameter, attached to an ordinary stove, burning good charcoal, the difference is prodigious between the velocity calculated by the above theoretical rule, and that ob. served by means of a stop-watch, and the ascent of a puff of smoke from a little tow, dipped in oil of turpentine thrust quickly into the fire. The chimney being 45 feet high, the temperature of the atmosphere 68~ Fahr., the velocity per second was, - Mean temperature Trials. By theory. By experiment. of chimney. 1 26.4 feet 5 feet 190~ Fahr. 2 29'4 5-76 214 3 34-5 6-3 270 To obtain congruity between calculation and experiment, several circumstances must be introduced into our formule. In the first place, the theoretical velocity must be multiplied by a factor, which is different according as the chimney is made of bricks, pottery, sheet iron, or cast iron. This factor must be multiplied by the square root of the diameter of the chimney (supposed to be round), divided by its length, increased by four times its diameter. Thus, for pottery, its expression is 2-06 / —L-; D being the diameter, and L the length of the chimney. A pottery chimney, 33 feet high, and 7 inches in diameter, when the excess of its mean temperature above that of the atmosphere was 205~ Fahr., had a pressure of hot air equal to 11-7 feet, and a velocity of 7-2 feet per second. By calculating from the last formula, the same number very nearly is obtained. In none of the experiments did the velocity exceed 12 feet per second, when the difference of temperature was more than 410~ Fahr. CHIMNEY. 401 Every different form of chimney would require a special set of experirents to be made for determining the proper factor to be used. This troublesome operation may be saved by the judicious application of a delicate differential barometer, such as that invented by Dr. Wollaston; though this instrument does not seem to have been applied by its very ingenious author in measuring the draughts or ventilating powers of furnaces. If into one leg of this differential syphon water be put, and fine spermaceti oil into the other, we shall have two liquids, which are to each other in density as the numbers 8 and 7. If proof spirit be employed instead of water, we shall then have the relation of very nearly 20 to 19. I have made experiments on furnace draughts with the instrument in each of these states, and find the water and oil syphon to be sufficiently sensible; for the weaker draughts of common fire-places the spirits and oil will be preferable barometric fluids. To the lateral projecting tube of the instrument, as described by Dr. Wollaston, I found it necessary to attach a stop-cock, in order to cut off the action of the chimney, while placing the syphon, to allow of its being fixed in a proper state of adjustment, with its junction line of the oil and water at the zero of the scale. Since a slight deviation of the legs of the syphon from the perpendicular changes very considerably the line of the level, this adjustment should be made secure by fixing the horizontal pipe tightly into a round hole, bored into the chimney stalk, or drilled through the furnace door. On gently turning the stop-cock, the difference of atmospherical pressure corresponding to the chimney draught, will be immediately indicated by the ascent of the junction line of the liquids in the syphon. This modification of apparatus permits the experiment to be readily rectified by again shutting off the draught, when the air will slowly re-enter the syphon; because the projecting tube of the barometer is thrust into the stop-cock, but not hermetically joined; whereby its junction line is allowed to return to the zero of the scale in the course of a few seconds. Out of many experiments made with this instrument, I shall content myself with describing a few, very carefully performed at the breweries of Messrs. Trueman, Hanbury, and Buxton, and of Sir H. Meux, Bart., and at the machine factory of Messrs. Braithwaite; in the latter of which I was assisted by Captain Ericsson. In the first trials at the breweries, the end of the stop-cock attached to the differential barometer was lapped round with hemp, and made fast into the circular peep-hole of the furnace ~doorof a wort copper, communicating with two upright parallel chimneys, each 18 inches square and 50 feet high. The fire was burning with fully its average intensity at the time. The adjustment of the level being perfect, the stop-cock orifice was opened, and the junction level of the oil and water rose steadily, and stood at 14 inches, corresponding to 12-'5 = 0-156 of 1 inch of water, or a column of air 10*7 feet high. This difference of pressure indicates a velocity of 26 feet per second. In a second set of experiments, the extremity of the stop-cock was inserted into a hole, bored through the chimney stalk of the boiler of a Boulton and Watt steam-engine of twenty-horse power. The area of this chimney was exactly 18 inches square at the level of the bored hole, and its sumlnit rose 50 feet above it. The fire-grate was about 10 feet below that level. On opening the ston-cock, the junction line rose 2~ inches. This experiment was verified by repetition upon different days, with fires burning at their average intensity, and consuming fully 12 lbs. of the best coals hourly for each horse's power, or nearly one ton and a third in twelve hours. If we divide the number 24 by 8, the quotient 0'28 will represent the fractional part of 1 inch of water, supported in the syphon by the unbalanced pressure of the atmosphere in the said chimney; which corresponds to 19' feet of air, and indicates a velocity in the chimney current of 35 feet per second. The consumption off fuel was much more considerable in the immense grate under the wort copper, than it was under the steam-engine boiler. In my experiments at Messrs. Braithwaite's factory, the maximum displacement of the junction line was 1 inch, when the differential oil and water barometer was placed in direct communication with a chimney 15 inches square, belonging to a steam boiler, and when the fire was made to burn so fiercely, that on opening the safety-valve of the boiler, the excess of steam beyond the consumption of the engine rushed out with such violence as to fill the whole premises. The pressure of one eighth of an inch of water denotes a velocity of draught of 23'4 feet per second. In building chimneys, we should be careful to make their area rather too large than too small; because we can readily reduce it to any desired size, by means of a sliding register plate near its bottom, or a damper plate applied to its top, adjustable by wiles or chains, passing over pulleys. Wide chimneys are not so liable as narrow ones to have their draught affected by strong winds. In a factory, many furnace flues are often conducted into one vertical chimney stalk, with great economy in the first cretion, and increased power of draught in the several fires. Vast improvements have been made in this country, of late years, in building stalks 27 CHIMNEY. for steam boilers and chemical firnaces. Instead of constructing an expansive, lofty scaffolding of timber round the chimney, for the bricklayers to stand upon, and to place their materials, pigeon-holes, or recesses, are left at regular intervals, a few feet apart, within the chimney, for receiving the ends of stout wooden bars, which are laid across, so as to form a species of temporary ladder in the interior of the tunnel. By means of these bars, with the aid of ropes and pulleys, everything may be progressively hoisted, for the building of the highest engine or other stalks. An expert bricklayer, with a handy laborer, can in this way raise, in a few weeks, a considerable chimney, 40 feet high, 5 feet 8 inches square outside, 2 feet 8 inches inside at the base, 28 inches outside, and 20 inches inside at the top. To facilitate the erection, and at the same time increase the solidity of an insulated stalk of this kind, it is built with three or more successive plinths, or recedures, as shown in fig. 348. It is necessary to make such chimneys thick and substantial near the base, in order that they may sustain the first violence of the fire, and prevent the sudden dissipation of the heat. When many flues are conducted into one chimney stalk, the area of the latter should be nearly equal to the sum of the areas of the former, or at least of as many of them as shall be going simultaneously. When the products of combustion from any furnace must be conducted downwards, in order to enter near the bottom of the main stalk, they will not flow off until the lowest part of the channel be heated by burning some wood shavings or straw in it, whereby the air syphon is set agoing. Immediately after kindling this transient fire at that spot, the orifice must be shut by which it was introduced; otherwise the draught of the furnace would be seriously impeded. But this precaution is seldom necessary in great factories, where a certain degree of heat is always maintained in the flues, or, at least, should be preserved, by shutting the damper plate of each separate flue, whenever its own furnace ceases to act. Such chimneys are finished at top with a coping of stone-slabs, to secure their brickwork against the infiltration of rains, and they should be furnished with metallic conducting rods, to protect them from explosions of lightning. When small domestic stoves are used, with very slow combustion, as has been recently proposed, upon the score of a misjudged economy, there is great danger of the inmates beint suffocated or asphyxied, by the regurgitation of the noxious burned air. The smoke doctors who recommend such a vicious plan, fiom their ignorance of chemical science, are not aware that the carbonic acid gas, of coke or coal, must be heated 2500 F. above the atmospheric air, to acquire the same low specific gravity with it. In other words, unless so rarefied by heat, that gaseous poison will descend through the orifice of the ash-pit, and be replaced by the lighter air of the apartment. Drs. Priestley and Dalton have long ago shown the co-existence of these two-fold crossing currents of air, even through the substance of stone-ware tubes. True economy of heat, and salubrity, alike require vivid combustion of the fuel, with a somewhat brisk draught inside of the chimney, and a corresponding abstraction of air from the apartment. Wholesome continuous ventilation, under the ordinary circumstances of dwelling houses, cannot be secured in any other way. Were these mephitic stoves, which have been of late so ridiculously puffed in the public prints, generally introduced, the faculty would need to be immediately quadrupled to supply the demand for medical advice; for headaches, sickness, nervous aliments, and apoplexy, would become the constant inmates of every inhabited mansion. The phenomena of the grotto of Pausilippo might then be daily realised at home, among those who ventured to recline upon sofas in such carbonated apartments; only instead of a puppy being suffocated pro tempore, human beings would be sacrificed, to save two penny worth of fuel per diem. The figures upon the following page represent one of the two chimneys, recently erected at the Camcren Town station, for the steam boilers of the two engines of 60 horse-power each, belonging to the London and Birmingham Railway company. These engines then drew their train of carriages up the inclined plane of Hampstead Hill The chimneys were designed by Robert Stephenson, Esq., engineer to the Company, executed by William Cubitt, Esq., of Gray's Inn road, - and do equal honour to both gentlemen, being probably among the most elegant and substantial specimens of tiis style of architecture in the world. In the section,fig. 348., A represents a bed of concrete, 6 feet thick, and 24 feet square. B, brick footings set in cement; the lower course 19 feet square. c, Bramley-fall stone base, with a chain of wrought iron let into it. D, a portion, 15 feet high, curved to a radius of 113 feet, built entirely of Ialm paviours, (a peculiarly good kind of bricks). E, shaft built of Malm paviours in mortar. F, ditto, built from the inside, without exterior scaffolding. G, the cap ornatnented, (as shown in the plan alongside,) with Portland stone, the Iressings being tied together with copper cramps and an iron bond. Fiq. 349. represents the mouldings of the top, upon an enlarged scale. CHINA INK. 403 APg. 850., a plan of the foundation, upon an enlarged scale. qig. 351., ditto, at the level of the entrance of the flue, as seen in Fig. 352., the elevation of the chimney. Fig. 353., plan at the ground level I, in fig. 348. and 352.'K,fig. 348., the lightning conducting rod 349 352 348 lEL[//// / / E \ E/v / D 3353 to f O Do 0v9 S 4O CHINA INK. (.Encre de Chine, Fr.; Chinesischer Tusch, Germ.) The finest kind of this useful pigment is seldom met with in our markets. According to a description in a Japanese book, it is made from the condensed smoke or soot of burned camphor; and hence, when of the best quality, it has this odour. Most of the China 404 CHLORATE OF POTASH. ink is made from oil-lampblack occasionally disguised as to smell, with musk, ol with a little camphor black. The binding substance is gelatine. commonly made trom parchment or ass' skin; but isinglass answers equally well. A good imitation may be made by dissolving isinglass in warm water, with the addition of a very little alkali (soda), to destroy its gelatinizing power; and incorporating with that solution, by levigation on a porphyry slab, as much of the finest lampblack as to produce a mass oi the proper consistence. The minute quantity of alkali serves also to saponify the oil,vhich usually adheres to lampblack; and thereby to make a pigment readily miscible with water. CHINTZ is a peculiar style of fast-printed calico, in which figures of at least five different colours are impressed upon a white or light coloured ground. CHLORATE OF POTASH, commonly called oxymuriate of potash. This interesting saline compound has become the object of a pretty extensive manufacture, in consequence of its application to make matches for procuring instantaneous light, and a detonating powder for fire-arms. It may be prepared both in the humid and dry way. Having made a strong solution of purified potash, or carbonate of potash, with from two to three parts of water, we pass through it in a Woulfe's apparatus a current of chlorine gas, till it ceases to absorb any more. Chloride of potash and chloride of potassium alone are formed as long as there is an excess of alkali in the solution; but afterwards, in the further reaction of the materials, the chloride passes into the state of a chlorate, and, as such, precipitates from the solution. During the first half of the operation, that is, till the potash be about one half saturated with chlorine, as indicated by litmus paper ceasing to be darkened and beginning to be blanched, only the chloride of potassium or muriate of potash falls. The process should be interrupted at this point in order to remove the salt, to wash it, to add the washings to the liquor, and then to transmit the gas freely through the solution. As the operation advances, less muriate of potash is formed, and at length nothing but the pure chlorate is separated in crystals. When finally the bubbles of gas pass through without being sensibly absorbed, the process is known to be completed; the liquid may then be allowed to settle, and be poured off from the crystals of chlorate of potash, which are purified from the muriate by dissolving them in three times their weight of boiling water, and filtering the solution while hot. On its cooling, the chlorate will separate in pearly-looking crystalline plates. It may be rendered quite pure by a second crystallization, in which state it does not affect solution of nitrate of silver. The above potash ley usually gets a reddish tint in the course of the process in consequence of a little manganesic acid coming over with the chlorine, but it gradually loses this color as the saturation becomes complete, when the solution turns yellow. The tubes for conveying the gas should be of large diameter, if they be plunged into the saline solution, because the crystallization which takes place in it is apt to choke them up. This inconvenience may however be obviated by atlaching to the end of the glass tube, a tube of caoutchouc terminated in a small glass funnel, or simply the neck of a caoutchouc bottle with a part of its body, whose width will not be readily closed with a saline crust. The residuary lixivium may be used against another operation, or it may be evaporated down to half its bulk and set aside to crystallize, whereby some more chlorate will be obtained, mixed indeed with muriate and carbonate, from which however it may be separated by a second crystallization. In general the pure chlorate obtained does not exceed one tenth the weight of the potash employed; because in thus treating potash with chlorine, five sixths of it are converted into muriate of potash and only one sixth into chlorate, and a part of the latter adheres to the muriate, or is lost in the mother waters of the crystallizations. The chlorate of potash may be more conveniently mannfactured, like that of lime, ir the dry way. St. Romer patented at Vienna the following method for that purpose in 1821:-Ten pounds of crystallized peroxyde of tnanganese are to be finely pulverized, amied with ten pounds of plumbago, and thirty pounds of common salt, ard put into the leaden retort represented in fig. 355, p. 410. From the middle of the helmet-shaped hd of this vessel, a lead tube, two feet long, and two inches wide, conducts to the receiver, which is a square earthen pan, hard glazed both within and without, of the same capacity with the retort. The end of the tube must be made fast to a frame at the height of six inches above the bottom of the receiver. Upon its inner sides, four inches apart, brackets are to be fixed for supporting a series of laths or shelves of white wood, on which a number of little paper or pasteboard boxes are to be laid. In these boxes ten pounds of the purest carbonate of potash, prepared from tartar, are to be spread. The receiver must now be covered with a lid made tight by a water lute. Twenty pounds of concentrated sulphuric acid previously diluted with sixteen pounds of water, and then cooled, are to be poured upon the mixed materials in the retort, the lid immediately secured, with the tube adjusted in the receiver. The whole must be allowed to operate spontaneously with. out heat for twelve hours. At the end of this time the retort is to be surrounded with a water bath and steadily heated during twelve hours, and then left to cool for six hours CHLORATE OF POTASH. 405 The apparatus must now be opened, the cakes of chlorate of potash removed: and freed from muriate by solution and crystallization. M. Liebig proposes the following process for obtaining chlorate of potash:Heat chloride of lime in water till it ceases to destroy vegetable colors. In this case a mixture of chloride of calcium and chlorate of potash is obtained. This is to be dissolved in hot water, and to the solution concentrated by evaporation, chloride of potassium is to be added, and then suffered to cool. After coolinz, a quantity of crystals of chlorate of potash is obtained, which are to be redissolved and crystallized again to purify them. M. Liebig considers that this will be a cheap process for obtaining chlorate of potash. From 12 ounces of chloride of lime, of so bad a quality that it left 65 per cent. of insoluble matter, he obtained an ounce of chlorate of potash. The only difficulty to overcome in this process is, from the chloride of lime not being so easily decomposed by heat as is generally supposed; a solution of it may be kept boiling for an hour without losing its bleaching power. The best method is to form a thin paste with chloride of lime and water, and then to evaporate it to dryness. If it be required to prepare it by passing chlorine into cream of lime, it is advantageous to keep it very hot. The chlorate of potash which separates from the solution by crystallization, has not the form of scales which it usually possesses, but is prismatic: whether thiv is occasioned by some admixture has not been ascertained; but on re-crystallizing, it is obtained in the usual form. The solution ought not merely to be left to cool, in order to procure crystals, for the crystallization is far from being terminated even after complete cooling; crystals continue to be deposited for 3 or 4 days. The following modification of the process for making chlorate of potash is that of M. Vee. A solution of chloride of lime, marking 18~ or 20~ Baume, is to he set upon the fire in a lead or cast iron pot, and when it begins to get hot, there is to be dissolved in it a quantity of chloride of potassium sufficient to raise the hydrometer 3 or 4 degrees. It must be then concentrated as quickly as possible till it marks 30~ or 31~, taking care that it does not boil over by the sudden extrication of oxygen. The concentrated liquor is set aside to crystallize in a cool place; where a deposile of chlorate of potash forms, mixed with chloride of potassium. The mother waters being evaporated to the density of 36%, afford another crop of crystals, after which they may be thrown away. The salts obtained at the first crystallization are to be re-dissolved, and the solution being brought to 15~ or 16~ is to be filtered, when it will afford upon cooling pure chlorate of potash. Chlorate or oxymuriate of potash has a cooling, somewhat unpleasant and nitrouc taste. It does not bleach. At 60~ F. 100 parts of water dissolve six parts of it, and at its'boiling point or 220~, sixty parts. When heated to dull ignition in a glass retort, it gives out 39'15 per cent. of its weight of oxygen, and becomes thereby chloride of potassium. When stronly triturated in a mortar it crackles, throws out sparks, and becomes luminous. It deflarates upon red-hot cinders like nitre: when triturated along with sulphur, or phosphorus, it detonates with great violence, not without danger to the hands of the operator, if they be not protected by a thick glove. Similar detonations may te produced with cinnibar or vermilion, sulphurct of potassium, sugar, volatile oils, &c., but they can be effected only by the smart blow of a heated hammer and anvil. A mixture of sugar or starch with chlorate of potash is readily inflamed by a drop of sulphuric acid, and this experiment is the basis of the preparation of the oxygenated matches, as they have been commonly called. The following formula forms a good paste for tipping the said matches, made of narrow slips of either wood or card. Thirty parts of the chlorate in fine powder are to be mixed gently with a spatula upon paper with ten parts of flowers of sulphur well levigated, eight of sugar, five of gum arabic, and enough of vermilion to give the whole a rose tint. We begin by mixing tenderly together the sugar, the gum, and the salt previously pulverised; we then add as much water as shall reduce the mixture to a thin paste, and lastly introduce the sulphur; after which all must be well incorporated. The points of the matches, either previously tipped with sulphur or not, are to be dipped in that paste, so as to get coated with a little of it, and are lastly laid in a warm place till they become thoroughly dry. To kindle one of them, it must be touched with strong sulphuric acid, which, for this purpose, is usually kept in a small well-stopped vial, and thickened with amianthus. Aspen is reckoned the best wood for matches. Of late years a detonating priming for fire-arms has been much used with the percussion locks. The simplest formula for making it is to take ten parts of gunpowder, to lixiviate it with water, and to mix the residuum, while moist, with five parts and a quarter of chlorate of potash, reduced to an extremely fine powder. The paste may be made pretty thin, for the salt is sparingly soluble in cold water, and it mixes best when tolerably fluid. This powder when dry is dangerous to handle, being very apt to 406 CHLORINE. explode. But this danger is guarded against by letting fall a drop of the paste into each copper percussion cap, and leaving it to dry there. In the detonation of this powder, besides muriate of potash, there are generated a little sulphate of potash and chlorine gas, Which rust the metal very fast. For which reason fulminate of mercury is now preferred by many sportsmen as a detonating powder. See FULMINATE. The following ingenious and easy way of making this valuable chlorate has been lately suggested by Professor Graham:-Mix equal atomic weights of carbonate of potash and hydrate of lime (70 of the former, if pure, and 37 of slaked lime in powder), diffuse them through cold water, and transmit chlorine gas through the mixture. The gas is absorbed with great avidity, and the production of a boiling heat. When the saturation is complete, carbonate of lime remains, and a mixture of muriate and chlorate of potash, which latter salts are to be separated, as usual, by the difference of their solubility in water. It has been remarked on the above process, that it effects no saving of potassa, and therefore is far inferior to the one long practised in several parts of Germany, especially at Giessen, and introduced into this country a good many years ago by Dr. Wagenmann, from Berlin. The chlorine is passed into a mixture of one equivalent of chloride of potassium (76), and 6 equivalents of hydrate of lime (222), previously stirred with water to the consistence of a thin paste. Thus the calcium of the lime unites with the chlorine to form chloride of calcium, while the chloride of potassium is converted into chlorate of potassa, which salt is easily separated in crystals by its sparing solubility. Chlorate of potash may also be made by saturating with chlorine a mixture of 74 parts of chloride of potassium (muriate of potash) and 168 parts of quicklime, brought to the consistence of a thin pap by the cautious addition of water. The mass being dissolved in warm water, and evaporated and cooled, yields crystals of chlorate of potash, while a mother water of chloride of calcium (muriate of lime) remains. The following process has likewise been prescribed:-Mix 10 parts of good chloride of lime with water into a pap, and evaporate to dryness, whereby it is converted into a mixture of chloride of calcium and chloride of lime devoid of bleaching power; dissolve it in water, filter, concentrate the solution by evaporation, then add to it 1 part of chloride of potassium, and cool for crystallization. The salt which may thereby be separated fiom the chloride of calcium will afford 0'83 of pure chlorate of potash. By this process of Professor Liebig five sixths of the potash are saved, but much oxygen is wasted in the evaporation to dryness of the chloride of lime, and consequently much chloric acid is lost towards the production of the salt. Vee mixes the chloride of lime pap, before heating it, with the chloride of potassium, boils the mixture smartly, whereby much oxygen is undoubtedly thrown off, and then sets the liquor aside to crystallize. L. Gmelin suggests that saturation of the liquor with chlorine before boiling might be advantageous. Gay Lussac has suggested to make this valuable salt by precipitating a solution of chloride of lime with carbonate (or sulphate) of potash, saturating the liquor after filtration with chlorine gas, evaporating, and crystallizing. Profossor Juch's process is to pass chlorine gas into a mixture of 1 pound caustic lime and 1 pound carbonate of potash, with 8 pounds of water. The resulting chloride of potash readily separates in the filtered liquid by crystallization from the very soluble chloride of calcium. By this method potash is not wasted in the useless production of chloride of potassium. CHLORATES, compounds of chloric acid with the salifiable bases. The only acid belonging to this class of any manufacturing importance is the following: CHLORIC ACID; the acid constituent of the preceding salt; it consists of one equivalent prime of chlorine = 35-476, + 5 of oxygen, = 40'065; of which the sum 75-535 is the prime equivalent of the acid. CHLORINE; the most energetic of the undecompounded bodies, or chemical elements as they are usually called, exists, under ordinary circumstances, as a greenish yellow gas, but, when exposed to a pressure of 4 atmospheres, it becomes a yellow transparent liquid. In the first state, its density compared to air, reckoned 1'000, is 2'47; in the second, its density compared to water, 1-000, is 1*33. No degree of cold hitherto tried, has liquefied the gas when dry. It is obtained by putting into a glass retort a mixture of 3 parts of common salt, with 2 parts of peroxyde of manganese, and pouring upon it 2 parts of sulphuric acid diluted w-ith its own weight of water; or, more conveniently, by pouring moderately strong muriatic acid upon peroxyde of manganese in a retort; and in either case applying the gentle heat of a spirit lamp or a water bath, while the beak of the retort is plunged under brine upon the shelf of the pneumatic trough. The gas issues, and may be received in the usual way into inverted glass jars, or vials; but the first which comes over, being mixed with the air of the retort, must be rejected. It has a peculiar smell, and irritates the nostrils most violently when inhaled, as also the windpipe and lungs. It is eminently noxious to animal life, and, if oreathed in its undiluted state, would prove instantly fatal. It supports the combustion of many bodies, CHLORIDE OF LIME. 407 and indeed spontaneously burns several without their being previously kindled. The resulting combinations are called chlorides, and act most important parts in lnany manufacturing processes. Water absorbs, at the ordinary temperature of the atmosphere, about double its volume of chlorine, and acquires the colour, smell, and taste of the gas, as well as its power of destroying or bleaching vegetable colours. When this aqueous chlorine is cooled to 3t~ Fahr. dark yellow crystalline plates appear in it of the hydrate of chlorine, which are composed in 100 parts of 27'7 chlorine, and 72'3 water. If these crystals be heated to about 45~ they liquefy, and the gas flies off. Chlorine has a powerful affinity for hydrogen, not only combining with it rapidly in the gaseous, but seizing it in many of its liquid and solid combinations, as in volatile oils, which it inflames, and in yellow wax, cotton and flax, which it whitens. The con pound of chlorine and hydrogen gases is muriatic acid gas. Manganese, when mixed with liquid muriatic acid, as in the above process, abstracts the hydrogen, and lets the chlorine gas go free. When chlorine is passed into water, it decomposes some of it, seizes its hydrogen to form a little muriatic acid, and enables its oxygen to unite either with the chlorine, into chlorous acid, or with the remaining water, and to constitute oxygenated water. Hence, aqueous chlorine, exposed to the sunbeam, continually evolves oxygen, and, ere long, becomes muriatic acid. This watery compound acts in a powerful way upon coloured vegetable fibres, extracting their hydrogen or colouring element by the twofold affinities of the chlorine and oxygen for it. Hence chlorine as a bleaching agent, requires to be tempered by the quiescent affinity of some alkaline base, potash or lime. Malaria, or morbific and putrescent miasmata, consists chiefly of hydrogenous matter as their basis, and are best counteracted by chlorine, where.it can be conveniently applied. Chlorides of Potash, Soda, and Lime.-These are the most important preparations through which chlorine exercises its peculiar powers upon the objects of manufactures. When a weak solution of caustic potash or soda is saturated with chlorine, it affords a bleaching liquor which is still used by some bleachers and calico-printers -for their most delicate processes; but the price of the alkalis has led to the disuse of these chlorides as a general means, and has occasioned an extensive employment of chloride of lime. Upon the manufacture of this interesting compound I made an elaborate series of experiments, several years ago, and published the results in the 13th volume of Brande's Journal for April, 1822. I have no reason to suppose, from any thing that has been published since, that the processes there described have been essentially improved, or that any errors, either theoretical or practical, of any moment, exist in that memoir. I shall therefore first present my readers with a brief abstract of it, and then make such observations as subsequent inquiries suggest. In the researches which I made, at many different times, upon the nature of the chloride of lime, I generally sought to combine the information flowing from both synthesis and analysis; that is, I first converted a known portion of hydrate of lime into bleaching-powder, and then subjected this chloride to analysis. Two hundred grains of the atomic proto-hydrate of pure lime were put into a glass globe, which was kept cold by immersion in a body of water at 50~. A stream of chlorine. after being washed in water of the same temperature in another glass globe, connected to the former by a long narrow glass tube, was passed over the calcareous hydrate. The globe with the lime was detached from the rest of the apparatus from time to time, that the process might be suspended as soon as the augmentation of weight ceased. This happened when the 200 grains of hydrate, containing 151-9 of lime, had absorbed 130 grains of chlorine. By one analytical experiment, it was found that dilute muriatic acid expelled from 50 grains of the chloride, 20 grains of chlorine, or 40 per cent.; and by another, from 40 grains, 16'25 of gas, which is 40'6 per cent.. From the residuum of the first 39-7 grail of carbonate of lime were obtained by carbonate of ammonia; from that of the second, 36-6 of ignited muriate of lime. The whole results are therefore as follows: Sylthesis. 1st Analysis. 2d Analysis. Mean Cl.lorine - - 3939 40'00 40-62 40-31 Lime- - - - 46-00 44-74 4607 45-40 Water - - - 14-60 15-26 13-31 14-28 100 00 1 O00'00 100;00 11000 U......~~~~~~~~~~ _.~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 408 CHLORIDE OF LIME. Though the heat generated by the action of the dilute acid had carried off in the analytical experiments a small portion of moisture with the chlorine, yet their accordance with the synthetic experiment is sufficiently good to confirm the general results. The above powder appears to have been a pure chloride, without any mixture of muriate. But it exhibits no atomic constitution in its proportions. To 200 grains of that hydrate of lime 30 grains of water being added, the powder was subjected to a stream of chlorine in the above way, till saturation took place. Its increase of weight was 150 grains. It ought to be remarked, that in this and the preceding experiment, there was no appreciable pneumatic pressure employed to aid the condensation of chlorine. In the last case, we see that the addition of 30 grains of water has enabled the time to absorb 20 grains more of chlorine, being altogether a quantity of gas nearly equal to that of the dry lime. Thus, an atom of lime seems associated with seven ninths of an atom of chlorine. Analysis by muriatic acid confirmed this composition. It gave Chlorine - 395 - 51'8 cubic inches. Lime - 39 9 Water - 20-6 100-0 A great variety of apparatus has been at different times contrived for favouring the combination of chlorine with the slaked lime for the purposes of commerce. One of the most ingenious forms is that of a cylinder, or barrel, furnished with narrow wooden shelves within, and suspended on a hollow axis, by which the chlorine was admitted, and round which the barrel was made to revolve. By this mode of agitation, the lime-dust, being exposed on the most extensive surface, was speedily impregnated with the gas, to the requisite degree. Such a mechanism I saw at MM. Oberkampf and Widmer's celebrated fabrique de toiles peintes, at Jouy, in 1816. But this is a costly refinement, inadmissible on the largest scale of British manufacture. The simplest, and, in my opinion, the best construction for subjecting lime-powder to chlorine, is a large chamber 8 or 9 feet high, built of silicious sandstone, having the joints of the masonry secured with a cement composed of pitch, resin, and dry gypsum in equal parts. A door is fitted into it at one end, which can be made air-tight by strips of cloth and clay-lute. A window on each side enables the operator to judge how the impregnation goes on by the color of the air, and also gives light for making the arrangements within at the commencement of the process. As water lutes are incomparably superior to all others, where the pneumatic pressure is small, I would recommend a large valve or door on this principle to be ma le in the roof, and two tunnels of considerable width at the bottom of each side wall. The three covers could be simultaneously lifted off by cords passing over a pulley, without the necessity of the workman approaching the deleterious gas, when the apartment is to be opened. A great number of wooden shelves, or rather trays, 8 or 10 feet long, 2 feet broad, and 1 inch deep, are provided to receive the riddled slaked lime, containing generally about 2 atoms of lime to 3 of water. These shelves are piled one over another in the chamber, to the height of 5 or 6 feet, cross bars below each keeping them about a' inch asunder, that the gas may have free room to circulate over the surface of the calcareous hydrate. The alembics for generating the chlorine, which are usually nearly spherical, are in some cases made entirely of lead, in others of two hemispheres, joined together in the middle, the upper hemisphere being lead, the under one cast-iron. The first kind of alembic is enclosed, for two thirds from its bottom, in a leaden or iron case, the interval of two inches between the two being destined to receive steam from an adjoining boiler. Those which consist below of cast-iron have their bottom directly exposed to a very gentle fire; round the outer edge of the iron hemisphere a groove is cast, into which the under edge of the leaden hemisphere fits, the joint being rendered air-tight by Roman or patent cement. In this leaden dome there are four apertures, each secured by a waterlute. The first opening is about 10 or 12 inches square, and is shut with a leaden valve, with incurvated edges, that fit into the water channel at the margin of the hole. It is destined for the admission of a workman to rectify any derangement in the apparatus of rotation, or to detach hard concretions of salt from the bottom. The second aperture is in the centre of the top. Here a tube of lead is fixed, which tlescends nearly to the bottom, and down through which the vertical axis passes. To its lower end the cross bars of iron, or of wood, sheathed with lead, are attached, by whose revolution the materials receive the proper agitation for mixing the dense manganese with the sulphuric acid and salt. The motion is communicated either by the hand of a workman applied from time to time to a winch at top, or it is given by connecting the axis with wheel work, impelled by a stream of water or a steam-engine. The third CHLORIDE OF LIME. 409 opening admits the syphon.formed funnel, through which the sulphuric acid is introduced; and the fourth is the orifice of the eduction-pipe. Manufacturers differ much from each other in the proportion of their materials for generating chlorine. In general, 10 cwt. of salt are mixed with from 10 to 14 cwt. of manganese, to which mixture, after its introduction into the alembic, from 12 to 14 cwt. of sulphuric acid are added in successive portions. That quantity of oil of vitriol must, however, be previously diluted with water, till its specific gravity becomes about 1-6 But, indeed, this dilution is seldom actually made, for the manufacturer of bleaching. powder almost always prepares his own sulphuric acid for the purpose, and therefore carries its concentration no higher in the leaden boilers than the density of 1'65, which from my table of sulphuric acid, indicates 4 of its weight of water, and therefore a more of such acid must be used. The fourth aperture, I have said, admits the eduction pipe. This pipe is afterwards conveyed into a leaden chest or cylinder, in which all the other eduction pipes also terminate. They are connected with it simply by water-lutes, having a hydrostatic pressure of 2 or 3 inches. In this general diversorium the chlorine is washed from adherin? muriatic acid, by parsing through a little water, in which each tube is immersed, and from this the gas is let off by a pretty large leaden tube, into the combina. tion room. It usually enters in the top of the ceiling, whence it diffuses its heavy gas equally round. Four days are required, at the ordinary rate of working, for making good marketable bleaching-powder. A more rapid formation would merely endanger an elevation of temperature, productive of muriate of lime, at the expense of the bleaching quality. But skilful manufacturers use here an alternating process. They pile up, first of all, the woolen trays only in alternate shelves in each column. At the end of two days the distillation is intermitted, and the chamber is laid open. After two hours the workman enters, to introduce the alternate trays covered with fresh hydrate of lime, and at the same time rakes up thoroughly the half-formed chloride in the others. The door is then se(ured, and the chamber, after being filled for two days more with chlorine, is again opeued, to allow the first set of trays to be removed, and to be replaced by others, con taming fresh hydrate, as before. Thus the process is conducted in regular alternation: thus, to my knowledge, very superior bleaching-powder is manufactured, and thus the chlorine may be suffered to enter in a pretty uniform stream. But for this judicious plan, as the hydrate advances in impregnation, its faculty of absorption becoming diminished, it would be requisite to diminish proportionately the evolution of chlorine, or to allow the excess to escape, to the great loss of the proprietor, and, what is of more consequence, to the great detriment of the health of the workmen. The manufacturer generally reckons on obtaining fiom one ton of rock-salt, employed as above, a ton and a half of good bleaching-powder. But the following analysis of the operation will show that he ought to obtain two tons. When a mixture of sulphuric acid, common salt, and black oxyde of manganese are the ingredients used, as by the manufacturer of bleaching-powder, the absolute proportions are, upon the oxygen scale of equivalents: — 1 atom muriate of soda - - 75 29-70 100'0 1 atom peroxyde of manganese - 5'5 21'78 73-3 2 atoms oil of vitriol 1-846 - - 12-25 48-52 163-3 25.25 100.00 And the products ought to be; - Chlorine disengaged - -1 atom. 4-5 17 82 Sulphate of soda - 1 - 9'0 35-64 Prolo-sulphate of manganese - 1 - 9.5 37-62 Water - - - 2 - 2-25 8-92 25-25 100-00 These proportions are, however, very different from those employed by many, nay, I believe by all manufacturers; and they ought tc be so, on account of the impurity of their oxyde of manganese. Yet making allowance for this, I am afraid that many of them commit great errors in the relative quantities of their materials. From the preceding computation, it is evident that 1 ton of salt with 1 ton of the above native oxyde of manganese properly treated, would yield 0-59 of a ton of'chlorine, which would impregnate 1-41 tons of slaked lime, producing 2 tons of bleaching-powder, stronger than the average of the commercial specimens; or allowing for a little loss, which is unavoidable, would afford 2 tons of ordinary powder, with a little more slaked lime. }Fi. 354 represents a retort of lead, well adapted to the evolution of chlorine from the ixture of salt, manganese, and sulphuric acid, or from manganese and muriatic acid. 410 CHLORIDE OF LIME. The interior vessel is cast in lead, and it has round its bottom T art a cast-iron steam case. The salt and manganese are introduced by the aperture c, and the sulphurie ex id 355 E I A, r —----- --- --- -- r........A1 IGh acid by the syphon funnel F. The contact of these three substances is continually renewed by the agitator or stirrer B, which consists of wrought or cast iron sheathed with lead. e is the gas discharge pipe. The residuums are drawn off by the bottom discharge pipe G. The heating case receives its steam by the pipe h. The chlorine gas, fig. 355. is conveyed from the retort B, into the chamber I, by the tube E E E. This chamber is divided into four compartments, to receive the gas disengaged from four retorts, like the above. The bottom of it is covered with a stratum three or four inches thick of quicklime, newly slaked and sifted, which is stirred about from time to time, by the rakes L L L L. When the saturation is sufficient, the chloride of lime is taken out by the doors K K K K. The size of this apparatus allows 2 cwt. of manganese, and its equivalent quantity of salt and sulphuric acid, or of muriatic acid, to be introduced at once into the retort. D is the handle of the agitator. The same form of retort will suit perfectly well to prepare chlorine for making liquid chloride of lime, which is preferred by many bleachers and calico-printers who have conveniences for preparing it themselves. The most concentrated solutions of the dry chloride of lime do not mark more than 6~ B. (sp. grav. 1-04), and discolour only 50 volumes of Gay Lussac's solution of indigo, whilst the chloride made in the humid way marks from 8~ to 9~ B. (about 1'060), and discolours 80 volumes of the same solution. In the chloride of lime apparatus, most generally used by the skilful calico-printers of Miilhausen, the mixture of muriatic acid and manganese is put into glass globes, with long necks, heated upon a sand-bath. The chlorine is conveyed by glass tubes into a cylindrical stone cistern, containing milk of lime. The furnace of the sandbaths is made of cast iron, and has brick partitions, to give each retort its own fire. The smoke of all these fires goes off by a flue into sheet iron pipes. The cistern is made of siliceous sandstone. Its cover is of wood, coated with a resinous cement; and it fits at its edges into grooves cut in the stone. A wheel serves to agitate the liquid continually; its paddles being kept at two inches distance from the sides of the cistern. The milk of lime is introduced by a funnel, and the chloride is drawn off by a discharge pipe. I think the lead retort and agitator used in this country greatly preferable to the experimental laboratory plan described above. In all such apparatus we should avoid giving any pressure to the tubes or vessels, and should not therefore dip the extremities of the gas pipes beneath the surface of the liquid, but rather facilitate the combination of the chlorine and the lime, by enlarging the surfaces of contact and by agitating. Intermediate vessels containing water, or the chemical cascade of M. Clement, are very useful for absorbing any muriatic acid which may be disengaged along with the chlorine, and thereby preventing the needless formation of muriate of lime in the chambers or cisterns of impregnation. When the solution of the chlorine of lime is mixed with hydrate of lime, it bears, without decomposing, a pretty high temperature, provided it be not too long continued; it may even, in certain cases, be raised too near the boiling point without suffering a marked loss of its discolouring power; but when the chloride is deprived of that excess of lime, it is decomposed in a short time, even at a heat of 110~ F. When chlorine is admitted to milk of lime, it infallibly produces some muriate of lime; but the quantity is kept at a minimum by constantly prescribing an excess of ChILORIDE OF LIME 411 lime to the gas with the agitator, and by keeping the temperature as low as possible. Hence the influx of gas should not be so rapid as to generate much heat. An automatic agitator, moved by steam or water power, is therefore much better than one driven by the hand of the operator, who is apt to intermit his labours. If the liquor becomes hot at the end of the process, it should be immediately drawn off into large stone bottles, and cooled. The rose-colour which sometimes supervenes is due to a minute quantity of manganese. The strongest liquid chloride of lime that can be prepared will not dis colour more than 80 times its volume of Gay Lussac's indigo test. On acting upon cotton cloth with a concentrated solution of chloride of lime, at from 110~ to 120~ F., pure carbonic acid gas is disengaged, and the texture of the cloth is injured. Here the hydrogen of the water and the cotton being seized by the chlorine, the liberated oxygen combines with the carbon to form carbonic acid. In the discharge troughs, where printed calicoes are passed through strong solutions of chloride of lime, stalactitic crusts of carbonate of lime come to be formed in this way. The chlorometre of Gay Lussac consists of a test solution of indigo and a graduated tube. One part of the best indigo, passed through a silk sieve, is to be dissolved in nine parts of concentrated sulphuric acid, by the aid of a water-bath heat applied for six hours. The sulphate of indigo is now to be diffused through such a body of water that one volume of chlorine gas shall discolour exactly ten times its volume of this dilute solution. The test liquor should be protected from the agency of light. Mr. Crum, of Thorniebank, near Glasgow, has lately modified Dr. Dalton's copperas test for chloride of lime, and made it convenient to a practical man. The doctor justly considered that the more chlorine any bleaching powder contains, the more of the green sulphate of iron will it convert into the red sulphate, so that we have only to add suc. cessive portions of the chloride to a given weight of the dissolved copperas, and note the point at which all the ircn gets peroxidized. See BLEACHING. Besides the method of analysis already quoted from my memoir on the manufacture of the chloride of lime, another occurred to me long ago, which I often practised as an easy and expeditious test. Chlorine decomposes ammonia. If therefore water of ammonia, faintly tinged with litmus, be added slowly to a solution of a given weight of chloride of lime, the colour will continue to disappear till the chlorine be all neutralized by the reaction of the hydrogen of the ammonia. The quantity of liquid ammonia of a certain strength requisite to neutralize, in this way, a certain volume, say, one cubic inch, or a thousand grain measures, of chlorine gas, may be assumed as the standard of such a chlorometer. As chlorine or chloride of lime, when mixed with water of ammonia, causes the disengagement of azote, the quantity of this gas evolved may also be made the foundation of an accurate and convenient chlorometer. The two substances should be mixed over mercury, in a graduated syphon tube. The shut end A and the open end B are both graduated to one scale; for example, to hundredths of a cubic inch, or to grain or 10 grain measures. The tube is to be filled with A mercury, and then 10 measures of it are to be displaced at the open end by inserting a wooden plug. This space being filled with the solution of chloride of lime, is to be turned up into the shut end by covering the open end with the finger, and inverting the tube; a few drops of water may be sent through to wash the mercury. The ammonia being now let up will cause a reaction, and evolve a quantity of azote, equivalent to the chlorine present. The action may be quickened by holding the sealed end of the tube obliquely over a lamp heat. The mercury is protected from the chlorine by the ammonia; and should any notion be entertained of such an action, the ammonia may be let up first. 1 have made innumerable researches over mercury with a detached apparatus of that kind, which combines precision with rapidity of result. It was by a similar mercurial syphon that I analysed the carbonates, as described in the first edition of my Dictionary of Chemistry, 32 years ago. M. Gay Lussac takes, as the basis of his indigo chlorometer, the fact, that one pound of pure crystallized peroxide of manganese is capable of affording, with muriatic acid, 0'7964 parts of a pound of chlorine; or one kilogramme yields 251j litres; that is, one pound yields 2511 pound measures. Hence 3-98 grammes of that manganese are capable of affording 1000 gramme measures, or 1 litre of chlorine; or, in round numbers, 4 grains will yield 1000 grain measures. This quantity of gas being received into that volume of milk of lime, constitutes therefore Gay Lussac's primary standard. The small retort in which the manganese and muriatic acid are put ought to be heated to ebullition, to discharge every particle of chlorine. To prevent the manganese, in this experiment, from sticking to the bottom in a cake, it has been proposed to mix it previously with a little plumbago. See CHLOROMETRY. For preparing the chlorides of potash and soda, the same apparatus may be employed as for the liquid chloride of lime. The alkaline solutions should be weak, containing not more than a pound to the gallon of water. Potash liquor, saturated 412 CHLOLIDE OF LIME. with chlorine, is much employed at Paris for whitening linen, under the name of the water of Javelle, the place where it was first made as a manufacture. One hundred parts of chlorine are said to saturate 133 parts of pure potash, and 195 of the carbonate: but the latter should not be used for preparing the bleaching fluid, as the carbonic acid resists the combination of the chlorine. A chloride of carbonate of soda has been lately recommended as a disinfecting substance against contagious miasmata 0o fornites. One hundred parts of chlorine will saturate 150 of the dry carbonate, and 405 of the crystallized. M. Payen prepares this medicinal chloride, by adding 138 parts of carbonate of soda to a liquid, consisting of water 1800, chloride of lime 100, at 98~ of strength, by Gay Lussac's standard. The chloride of lime is to be dissolved, and the sediment well washed; the carbonate of soda, dissolved by heat, is to be poured into the solution, the precipitate allowed to subside, the clear fluid decanted, and the solid matter washed upon a filter. The collected solutions ale neutral chloride of soda. Sixty-two parts of the carbonate of soda are then to be dissolved in the remainder of the water, and added to the preparation; the whole being thus filtered, a limpid liquid is obtained, indicating 5~ by the hydrometer of Baumr. The chloride of magnesia was long ago proposed by Sir H. Davy for bleaching linen, as being preferable to chloride of lime, because the resulting muriate of magnesia was not injurious to the fibre of cloth, as murin'te of lime may be, under certain circumstances. -I prepared a quantity of chloride of magnesia, by exposing a hydrate of that earth in the chlorine chamber of a large manufactory of chloride of lime at Glasgow, and obtained a compound possessed of considerable discolouring powers; but I found that the chlorine was so feebly saturated by the base, that it destroyed the colours of fast-dyed calicoes as readily as chlorine gas or chlorine water did, and was therefore dangerous for common bleaching, and destructive in clearing the grounds of printed goods, which is one of the most valuable applications of the calcareous and alkaline chlorides. The occasion of my making these experiments was the importation of a cbnsiderable quantity of magnesite, or native atomic carbonate of magnesia, from the district of Madras, by ad enterprising friend of mine. Encouraged by the encomiums bestowed on the chloride of magnesia by many chemical writers, he expected to have benefited both the country and himself, by bringing home the earthy base of that compound, at a moderate price; but was disappointed to his cost. 1)r. Thomson is of opinion that the bleaching compound of lime and chlorine is not a chloride of lime, but a combination of chlorous acid with lime and of chlorine with calcium: consisting in its most concentrated state of 3 atoms of chloride of calcium = 21 1 atom of chlorite of lime - - 11 32 So that about one-third of the weight is chlorite of lime, to which alone the bleaching powers of the substance are owing. He admits a fact, rather inconsistent with this opinion, that bleaching powder does not attract moisture from the atmosphere with nearly so much rapidity as might be expected from a mixture containing two-thirds of its weight of so deliquescent a salt as muriate of lime; unless this indeed be prevented by the chloride and chlorite being united into a double salt, which is a mere conjecture without either proof or analogy. And further, when dilute sulphuric or muriatic acid is poured upon bleaching powder, a profusion of chlorine is given out immediately, which he also admits to be inconsistent with the notion of its being a mixture of chloride of calcium and chlorite of lime, for no such evolution takes place when the above acids are mixed with solutions of chloride of calcium and chlorate of potash. Though I am of opinion that bleaching powder is simply a chloride of lime, in which the lime corresponds to the water in the aqueous chlorine, yet I cannot see the truth or appositeness of his last reason, because chlorine is certainly given out when chlorate of potash is acted upon by dilute muriatic acid, as any man may prove by adding to a mixture of these two substances a vegetable colour; for it will be speedily blanched. Dr. Thomson considers the chloride which is at present made in Mr. Tennant's great factory, as containing one atom of chlorine associated with one atom of lime, or, taking his num. bers, as consisting of Hydrate of lime 4-625 Chlorine - 4'5 or nearly equal weights of the chlorine and the base; indicating a surprising degree of excellence in the preparation. The average commercial samples of bleaching powder from different factories which I examined some years ago, did not possess nearly that strength; but varied in their quantity of chlorine from 20 to 28 per cent. In my synthetic experiments related above, the greatest quantity of chlorine that would com. bine with the atomic hydrate of lime was in the proportion of 130 to 200; but there ia CHLORINE AND ALKALI. 413 no doubt that, if the lime contains additional water, it will condense more gas. I have never seen a chloride of lime of the strength mentioned by Dr. Thomson, and I should think there must be some fallacy in his statements. I have recorded in the paper above quoted an experiment which proves that, with additional moisture, a chloride of lime may be obtained of the following composition:Chlorine 39'5 Lime - 39'9 Water - 20-6 100'0 In the article BLEACHING, of the Encyclopoedia Britannica, Dr. Thomson deduces, from a test trial of Mr. Crum, that the best bleaching powder is a compound of 1 atom chlorite of lime = 11, 3 atoms chloride of calcium = 21, and 3 atoms of water= 9. "But," adds he, "in general the whole lime is not accurately saturated with chlorine. Accordingly, when the bleaching powder is dissolved in water a small residue almost always remains undissolved. Unless the powder be fresh made, a portion of chlorite is always converted into chloride of calcium. It is probable, therefore, that the best bleaching powder, as it comes into the hands cf the bleachers, consists of 1 atom chlorite of lime - 11 3 atoms chloride of calcium 21 6 atoms water - - - 675 Impurity - - - 2-25 41-00 If we consider the bleaching powder as a compound of chlorine and lime, our mode of calculating will not be altered. Instead of 1 atom chlorite of lime, and 3 atoms chloride of calcium, we shall have 4 atoms chloride of lime, 6 atoms water, and 2'25 of impurity as before." In such ambiguity does this able chemist place this interesting compound, for theoretical reasons, of which I cannot see the value. Surely there is no difficulty in conceiving chlorine to exercise a direct attractive force towards the hydrate of lime, as it is known to do towards each of its elementary constituents, the oxygen and the calcium. Such refinements as the preceding tend merely to mystify a plain matter. Even the chlorous acid here brought into play to form the ideal cLlorite, is by his own admission a hypothetical being. "When chlorate of potash," says Dr. Thomson, "is mixed with sulphuric acid, and made into small balls the size of a pea, if we expose these balls to a heat somewhat lower than that of boiling water, a bright yellowish green gas separates, which may be received over mercury. Its smell is peculiar and aromatic. Water absorbs at least seven times its volume of it. It destroys vegetable blues. Its constituents are, 1 volume chlorine 2'5 or 4'5 2 volumes oxygen 2-222 or 4. Thus this compound consists in weight of chlorine 4-5, oxygen 4 = 85. It has been called quateroxide of chlorine, but it is more probably a teroxide. It has been supposed by some to possess acid properties, and has therefore been called chlorous acid. But this is only as yet a hypothesis. Surely this, by the doctor's own showing, is very slender authority for renouncing our long-received doctrines concerning the constitution of bleaching powder. I shall conclude by remarking that the ultra-atomists are now in a dilemma about this substance; M. Welter, and many French chemists, calling it a sub-chloride of 1 atom of chlorine to 2 atoms of lime, and Dr. Thomson showing that Mr. Tennant, the greatest and best manufacturer of it, has produced it in the state of a chloride, or 1 atom of each. The fact is, in chloride of lime, as in water of ammonia, alcohol, and muriatic acid, there is no sufficient reason for definite proportion in any term short of saturation, and therefore we shall find that chloride in every gradation of strength from 1 per cent. of chlorine up to 40 per cent.-the strongest which I succeeded in preparing, though I passed a constant stream of chlorine in great excess over a pure hydrate of lime for upwards of 24 hours, with frequent renewal of the surface; indeed, till it refused to absorb any more gas, as indicated by its remaining stationary in weight. CHLORINE AND ALKALI (Manufacture of). Mr. Tennant Dunlop of Glasgow obtained, in March, 1847, a patent for an improved method of producing chlorine. The process he usually adopts is to bring together common salt, nitrate of soda, or nitric acid and sulphuric acid, in suitable proportions; heat being then applied, chlorine or an oxide of azote and muriatic acid are evolved; these gases are caused to pass through a condenser charged with sulphuric acid of sufficient strength to absorb the oxide of azote; and then the chlorine and muriatic acid are separated by means of water. In applying the product resulting from the above process, he obtains nitric acid fiom 414 CHLOROME'TEY. the sulphuric acid charged with oxide of azote, which is true nitrous sulphuric acid. This is effected by the aid of atmospheric air, steam, and water. He introduces tha nitrous sulphuric acid into a suitable vessel, and by the addition of water and heat, he effects the disengagement of oxide of azote, which being caused to traverse a condenser with a sufficient quantity of air and steam or water, is by this means transformed into nitric acid. This acid may be again used in the manufacture of chlorine, and again recovered, and so on. Sometimes, instead of treating the nitrous sulphuric acid as just described, the patentee causes the oxide of azote to be evolved, and to pass into a chamber into which a current of sulphuretted hydrogen is streaming; by which means sulphate of ammonia is obtained and sulphur deposited. CHLOROMETRY; Chlorometrie, is the name given by the French to the process for testing the decoloring power of any combination of chlorine, but especially of the com mercial articles, the chlorides of lime, potash, and soda. M. Gay Lussac proposed many years ago the following graduatwed method of applying indigo to this purpose. As indigo varies much in its'dyeing quality, and of consequence in the proportion of chlorine required for its decoloration, he assumes as the unity of blanching power, one litre of chlorine gas, measured at the mean pressure of 29'6 inches, and at the temperature of melting ice. This volume of gas, when combined with a determinate quantity of water, is employed to test the standard solution of indigo. For this purpose a solution in sulphuric acid of any sample of indigo is taken, and diluted with water to such a degree that 10 measures of it, in a graduated tube, are decolored by that one measure of combined chlorine aas. Each measure of indigo solution so destroyed is called a degree, and this measure being divided into five parts, the real test of chlorine is given to fiftieths, which is sufficiently nice. For the standard of the assays, a chloride of lime as pure and fully saturated as possible is taken, and dissolved in such a quantity of water, that the solution shall contain, or be equivalent to, one volume of chlorine gas. Calculation proves that this condition is exactly fulfilled by dissolving 4938 grammes of the said chloride in half a litre of water; or in English measures, 5 gr. very nearly in 500 grain measures of water. This solution, which serves for a type, indicates 10~ in the assay, or proof; that is to say, each single volume destroys the color of 10 volumes of the dilute indigo solution. It may be remarked that a greater degree of precision is in general attainable with a weak solution of chlorine or a chloride, for example at 4~ or 5~, than with one much stronger; consequently if, after a preliminary trial, the standard considerably exceeds 10~, a given volume of water must be added to the solution, and then the above proof must be taken. If the volume of water added was double, the number of degrees afterward found must be tripled, to obtain the true title of the chloride. It is, however, to be observed that the degree of decoloration varies with the time taken in making the mixture; the more slowly the chlorine is added to the indico, the less of it escapes into the atmosphere, and the more effective it becomes in destroying the color. The best mode of obtaining comparable results, is to pour suddenly into the test quantity of chlorine the whole volume of tne indigo solution likely to be decolored; but it is requisite to find approximately beforehand, what quantity of indigo-blue will probably be destroyed. When it comes to the verge of destruction, it is green; but yellowish-brown when entirely decomposed. I have tried the indigo test in many ways, but never could confide in it. The sulphuric solution of indigo is very liable to change by keeping, and thus to lead to erroneous results. The method of testing the chlorides by green sulphate of iron, described under bleaching, is in my opinion preferable to the above. M. Gay Lussac has recently proposed another proof of chlorine, founded on the same principle as that by green vitriol, namely, the quantity of it requisite to raise a metallic substance from a lower to a higher stage of oxydizement. He now prescribes as the preferable plan of chlorometry, to pour very slowly from a graduated glass tube, a standard solution of the chloride, to be tested upon a determinate quantity of arsenious acid dissolved in mulatic acid, till the whole arsenious be converted into the arsenic acid. The value of the chloride is greater the less of it is required to produce this effect. It is easy to recognise, by a few drops of solution of indigo, the instant when all the arsenious acid has disappeared; for then the blue tint is immediately effaced, and cannot be restored by the addition of a fresh drop of indigo solution. In graduating the arsenical chlorometer, M. Gay Lussac takes for his unity the decolouring power of one volume of chlorine of 32~ Fahr., and divides it into 100 parts. Suppose that we prepare a solution of chlorine containing its own volume of the gas, and an arsenious solution, such that, under a like volume, the two solutions shall reciprocally destroy each other. Let us call the first, the normal solution of chlorine, and the second, tihe normal arsenious solution. We shall fix at 10 grammes the-weight of chloride of lime subjected to trial; and dissolve it in water, so that the total volume of the solution shall be a litre (1000 grammes measure,) including the sediment. If we take a constant volume of this solution, 10 centimetres cube (10 gramme measures,) for ex ample, divided into 100 equal parts, and pour into it gradually the arsenious solution CHOCOLATE. 415 (measured by like portions), till the chlorine be destroyed, the bleaching power will be proportional to the number of portions of the arsenious solution, which the chloride shall have required. If the chloride has destroyed 100 portions of the arsenious solution. its title will be 100; if it has destroyed 80 portions, its title will be 80, &c., and so torthl On pouring the acidulous arsenious solution into the chloride of lime, this will become very acid; the chlorine will be emitted abundantly, and the proof will be quite incorrect. If, on the contrary, we pour the solution of the chloride of dime into the arsenious solution, this evil will not occur, since the chlorine will always find plenty of arsenious acid to act upon, whatever be the dilution of the one or the other; but in this case, the standard of the chlorine is not given directly, as it is in the inverse ratio of the number of portions which are required to destroy the measures of the arsenious solution. If 50 portions of the chloride have been required, the proof will be 100X 0o-=200~; if 200 have been required, the proof will be 100X- 0 =50~, &c. This evil is not, however, very serious, since we have merely to consult a table, in which we can find the proof corresponding to each volume of the chloride employed for destroying the constant measure of the arsenious solution. The arsenious solution should be slightly tinged with sulphate of indigo, so as to show, by the disappearance of the color, the precise point or instant of its saturation with chlorine, that is, its conversion into arsenic acid. If the arsenious acid be pure, the normal solution may be made directly by dissolving 4439 grammes of it in muriatic acid (free from sulphurous acid), and diluting the solution till it occupies one litre, or 1000 grammes measure. Jnunales de Chimie et Physique, LX. 225. CHOCOLATE is an alimentary preparation of very ancient use in Mexico, from which country it was introduced into Europe by the Spaniards in the year 1520, and by them long kept a secret from the rest of the world. Linnaeus was so fond of it, that he gave the specific name, theobroma, food of the gods, to the cacao-tree which produced it. The cacao-beans lie in a fruit somewhat like a cucumber, about 5 inches long and 3{ thick, which contains from 20 to 30 beans, arranged in 5 regular rows with partitions between, and which are surrounded with a rose-colored spongy substance, like that of water-melons. There are fruits, however, so large as to contain from 40 to 50 beans. Those grown in the West India islands, Berbice and Demarara, are much smaller, and have only from 6 to 15; their development being less perfect than in South America. After the maturation of the fruit, when their green color has changed to a dark yellow, they are plucked, opened, their beans cleared of the marrowy substance, and spread out to dry in the air. Like almonds, they are covered with a thin skin or husk. In the West Indies they are immediately packed up for the market when they are dried; but in the Caraccas they are subjected to a species of slight fermentation, by putting them into tubs or chests, covering them with boards or stones, and turning them over every morning, to equalize the operation. They emit a good deal of moisture, lose the natural bitterness and acrimony of their taste by this process, as well as some of their weight. Instead of wooden tubs, pits or trenches dug in the ground are sometimes had recourse to for curing the beans; an operation called earthing (terrer). They are lastly exposed to the sun, and dried. The latter kind are reckoned the best; being larger, rougher, of a darke- brown color, and, when roasted, throw off their husk readily, and split into several irregular fragments; they have an agreeable mild bitterish taste, without acrimony. The Guiana and West India sorts are smaller, flatter, smoother-skinned, lighter-colored, more sharp and bitter to the taste. They answer best for the extraction of the butter of cacao, but afford a less aromatic and agreeable chocolate. According to Lampadius, the kernels of the West India cacao beans contain, in 100 parts, besides water, 53'1 of fat or oil, 16-7 of an albuminous brown matter, which contains all the aroma of the bean, 10'91 of starch, 7, of gum or mucilage, 0'9 of lignine, and 2-01 of a reddish dye stuff somewhat akin to the pigment of cochineal. The husks form 12 per cent. of the weight of the beans; they contain no fat, but, besides lignine, or woody fibre, which constitutes half their weight, they yield a light brown mucilaginous extract by boiling in water. The fatty matter is of the consistence of tallow, white, of a mild agreeable taste, called butter of cacao, and not apt to turn rancid by keeping. It melts only at 122~ Fahr., and should, therefore, make tolerable candles. It is soluble in boiling alcohol, but precipitates in the cold. It is obtained by exposing the beans to strong pressure in canvas bags, after they have been steamed or soaked in boiling water for some time. From 5 to 6 ounces of butter may be thus obtained from a pound of cacao. It has a reddish tinge when first expressed, but it becomes white by boiling with water. The beans, being freed from all spoiled and mouldy portions, are to be gently roasted over a fire in an iron cylinder, with holes in its ends for allowing the vapours to escape; the apparatus being similar to a coffee-roaster. When the aroma begins to be well developed, the roasting is known to be finished; and the beans must be turned out, cooled, and freed by fanning and sifting from their husks. The kernels are then 416 CHOCOLATE. to be converted into a paste, either by trituration in a mortar heated to 130~ F., or by the following ingenious and powerful machine. The chocolate paste has usually in France a little vanilla incorporated with it, and a considerable quantity of sugar. which varies from one-third of its weight to equal parts. For a pound and a hailf of cacao, one pod of vanilla is sufficient. Chocolate paste improves in its flavour by keeping, and should therefore be made in large quantities at a time. But the roasted beans soon lose their aroma, if exposed to the air. 357 l l A i l y 7 Fig,. 357 represents the chocolate mill. Upon the sole A, made of marble, six conical rollers B B, are made to run by the revolution of the upright axis or shaft q, driven bv the agency of the fly wheel E and bevel wheels i K. The sole A rests upon a strong iron plate, which is heated by a small stove, introduced at the door H. The wooden frame work F, forms a ledge, a few inches high, round the marble slab, to confine the cocoa in the act of trituration. c is the hopper of the mill through which the roasted beans are introduced to the action of the rollers, passing first into the flat vessel n, to be thence evenly distributed. After the cacao has received the first trituration, the paste is returned upon the slab, in order to be mixed with the proper quantity ofsugar, and vanilla, previously sliced and ground up with a little hard sugar. When the chocolate is sufficiently worked, and while it is thin with the heat and trituration, it must be put carefully into the proper moulds. If introduced too warm, it will be apt to become damp and dull on the surface; and, if too cold, it will not take the proper form. It must be previously well kneaded with the hands, to ensure the expulsion of every air bubble. In Barcelona, chocolate millon is this construction are very common, but they are turned by a horse-gin set to work in the under story, corresponding to H in the above figure. The shaft G is, in this case, extended down through the marble slab, and is surrounded at its centre with a hoop to prevent the paste coming into contact with it. Each of these horse-mills turns out about ten pounds of fine chocolate in the hour, firom a slab two feet seven inches in diameter. Chocolate is flavoured with cinnamon and cloves, in several countries, instead of the more expensive vanilla. In roasting the beans the heat should be at first very slow, to give tim e to the humidity to escape; a quick fire hardens the surface, and injures the process. In putting the paste into the tin plate, or other moulds, it must be well shaken down to insure its filling up all the cavities, and giving the sharp and polished impression so much admired br b connoisseurs. Chocolate is sometimes adulterated with starch; in which case it will form a pasty consistenced mass when treated with boiling Bater. The harder the slab upon which the beans are triturated, the better;' and thence porphyry is far preferable to marble. The grinding rollers of the mill should be made of iron, and kept very clean. About eight years ago, samples of chocolate were sent to me for analysis, by order of the Lords of the Admiralty. It was made at the victualling-yard, Deptford, for the e use of the Royal avy, by the government chocolate mills, where about CHOCOLATE. 417 400 tons are annually prepared, to be distributed to the sailors and convicts at the rate of an ounce daily, and to be used at their breakfast. After taking the said choco. late for some time, men in several ships complained of its occasioning sickness, vomiting, purging, and more serious maladies, terminating in a few eases fatally. I examined it with great care, but could find no injurious ingredient in it, and no chemical alterations from the beans of the Guyaquil coco from which it was manufactured. But I observed that it consisted of gritty grains, from very imperfect trituration or milling; that these grains were quite immiscible with water, like so much fine gravel; that they contained many sharp spicule of the coco-bean husks, and that hence, when swallowed, they were calculated to form mechanically irritating lodgments in the villous coats of the stomach and bowels, whereby they could produce the morbid effects certified by several naval surgeons. It was, moreover, obvious that, fiom the insoluble condition of the chocolate, it could be of little use as an article of food, or as a demulcent substitute for milk, and that, in fact, three-fourths of it were, on this account, an ineffective article of diet, or were wasted. Ilaving reported these results and opinions to the Lords of the Admiralty, they were pleased after a few weeks' consideration, to request me to go down to the victualling-yard at Deptford, and superintend the preparation of a quantity of chocolate in the best manner I could with the means there provided. I accordingly repaired thither on the 13th September, 1842, and experienced the utmost courtesy and cooperation from Sir John lill, the Captain Superintendent, and his subordinate officers. The coco-beans had been hitherto milled, after a slight roasting upon ti e sole of an oat-kiln, along with their husks. As I was satisfied, from analysis, that the husks were no better food than saw-dust, and that they might cause irritation by their minute spiculse left after grinding between rotating millstones, I set about a plan for shelling them, but could find no piece of apparatus destined for the purpose. There was, however, a pea-shelling mill, which had been,used only for one day some years before, and had stood ever since idle*, which, on being cleaned and having its millstones placed at a proper distance, was found to answer pretty well The beans for experiment, to the amount of 6 cwt., had been previously roasted, under my care, at a well-regulated heat, with much stirring, in the oat-kiln; and, on being cold, were run tl'rough the shelling mill, which was put in communication with the fanners of the flour mill. By this arrangement, the coco-beans were tolerably shelled, and the kernels separated from their scaly husks. The weighings were accurately made. 6 cwt. of the Guyaquil coco - - - 62 lbs. Lost in roasting - 43 shells - - 54 117 waste - - 20) Remained for milling - - 555 On the 14th September I made a report to the Lords of the Admiralty upon the experiments of the 13th, of which the following is an outline. After describing the pains taken to regulate the roasting temperature, and to equalize the effect upon the beans by moving them occasionally by a rake, I stated that the oat-kiln was not well adapted to the purpose of roasting the coco, because it was impossible to turn the beans regularly and continuously during the process, so that they could not be equally roasted, and because it was an unwholesome operation for the workmen, who must go into a chamber filled with noxious gases and iumes, to use the rakes. When the door of the kiln was shut, to allow the burned air from the fire below to draw up through it, mischief might be done to the stratum of coco on the sole, and when the door was again opened, to permit a person to go in and stir, time and heat were wasted in replenishing the chamber with fresh air. I understood that a revolving-cylinder-roasting machine had been made by Messrs. Rennie for the chocolate process at Deptford; but, for reasons unknown to me, it had never been employed. The diminution of weight by roasting and shelling may be estimated at about 17 per cent. A part of this loss is moisture, which should be completely expelled, to prevent its causing the chocolate to become mouldy at sea. But a part of the defalcation was also due to some of the coco remaining in the crevices of the pea-splitting mill and the fanners, which would not be observable if these were in constant employment. I think, therefore, that the roasted kernels may be estimated in general at 85 per cent. of the raw beans. Fig. 358 represents the chocolate mills at the victualling-yard, Deptford, as mounted * It was found that peas in their skin kept better at sea than the spilt peas, and they were also pre [erred by the sailors in their natural state. 28 418 CHOCOLATE. by the celebrated engineers, Messrs. Rennie. There are four double mill-stones A, B, C, D, each three feet in diameter, of which the nether rests upon a bed of cast iron, like a drum-head, kept at the temperature of about 220~ by the admission of steam to the case below. Over each mill there is a feeding-hopper 1, 2, 3, 4, in commu nication by the pipes 5, 6, 7, 8, with the general reservoir E, charged upon the floor above with cocoa through the funnel placed over it. The vertical shafts which turn these mills are marked F, G, H, L; they are moved by the train of bevel-wheels above, which are driven by an arm from the main shaft of the steam engine. Each mill can, of course, be thrown in and out of geer at pleasure. At i, I, i, i, the discharge-spout 358, zz- zzz —---- is shown, which pours out the semi-fluid hot chocolate into shallow cylindrical tin pans, capable of containing about nine pounds of chocolate each. These four mills are capable of converting upwards of a ton of coco into good chocolate in a day, on the system of double trituration which I adopted, and two tons on the former rough plan. I found that the two stones of each mill had been placed so far asunder as would allow entire beans to pass through, as spurious chocolate, at one operation; but the chocolate thus discharged was in a very gritty state, whereas good chocolate in the liquefied state should CHOCOLATE. 419 be smooth and plastic between the fingers, and spread upon the tongue without leaving any granular particles in the mouth. To obtain such a result, I divided the milling into two steps; for the first, two pairs of the stones, A and c, were set as close together as for a paint mill (which they closely resemble), and the other two pairs, B and D, were left at their ordinary distance. The paste obtained from the first set was transferred, while nearly liquid, into the hoppers of the second pairs, from which it issued at the spouts as thin and smooth as honey from the comb. In subserviency to these experiments, I made an analysis of the Guyaquil coco, which I found to be composed as follows:Concrete fat or butter of coco, dissolved out by ether - - 3 Brown extractive, extractible by hot water, after the operation of ether 10 Ligneous matter, with some albumine - 30 Shells - - - - 14 Water - - - -. Loss - - - - 3 100 The solid fat of the coco shouldbe most intimately combined by milling with the extractive albumine, and ligneous matter, in order to louder it capable of forming an emulsion with water; and, indeed, on account of the large proportion of concrete fat in the beans some additional substance should be introduced to facilitate this emulsive union of the fat and water. Sugar, gum, and starch or flour are well adapted for this purpose. Under this conviction, I employed in the first of these trials at Deptford, made with one-half of the above roasted kernels = 277- lbs., 5 per cent. of sugar, which was first mixed upon a board with shovels, and the mixture was then put progressively into the hoppers of the two mills B and i. The paste which ran out of their spouts was immediately poured into the hoppers of A and c, from which it flowed smooth and very thin into the concreting pans. The sugar supplied to me was exceedingly moist, whereas it ought to be dry, like the bag sugar of the Mauritius. The other half of the coco kernels was milled alone once by the ordinary mills B and D. I subjected next day samples of these two varieties of chocolate to the following examination, and compared them with the sample of chocolate as usually made at Deptford, as also with a sample of chocolate sold by a respectable grocer in London. A like quantity of these four samples was treated with eight times its weight of boiling water, the diffusion well stirred, and then left to settle in a conical wineglass. Of the ordinary Deptford coco, four-fifths rapidly subsided in coarse grains, incapable of forming any thing like an emulsion with water, and therefore of little or no avail in making a breakfast beverage. 1. The single-milled chocolate made under my direction formed a smoother emulsion than the last, on account of the absence of the coco husks; but its particles were gritty, and subsided very soon. 2. The sugar double-milled chocolate, on the contrary, formed a milky-looking emulsion, which remained nearly uniform for some time, and then let fall a soft mucilaginous deposit, free from grittiness. 3. The shop chocolate formed a very indifferent emulsion, though it was well milled, because it contained evidently a large admixture of a coarse branny flour,, as is too generally the case. I have given small samples of the above No. 2. chocolate to various persons, and they have considered it superior to what is usually sold by our grocers. The presence of dry sugar in chocolate would also give it a conservative quality at sea, and prevent it from getting musty. The Lords of the Admiralty, after seeing the above two samples of chocolate and my report thereupon, were, about six weeks afterwards, pleased to request me to make at their victualling-yard further experiments in the preparation of chocolate; and they indicated two modes, one of milling twice with the husks, and another of milling twice without the husks; permitting me, at the same time, to mill a portion of the kernels with 10 per cent. of sugar, and a second portion of the kernels with 5 per cent. of sugar and 5 per cent. of the excellent flour used in making the biscuits for the royal navy. On the 24th October, 1842, I accordingly performed these experiments upon 12 cwt of Guyaquil coco as carefully roasted as possible on the kiln. The loss in drying and slightly roasting the 1344 lbs. of beans was 5 per cent. 1st experiment, 212 lbs. of roasted coco, milled twice with the husks, produced of chocolate - - - - 209 lbs 2d experiment, 191 lbs. ditto, milled twice without husks - - 189 420 CHROMATES. 3d experiment, 191 lbs. kernels, milled once along with 19 lbs. of sugar =210 lbs. - - - - 212* 4th experiment, 573 lbs. of kernels, milled twice along with 68 lbs. of flour and 34 of sugar = 675 - - - - - 669 Sample cakes of these four varieties of chocolate were subsequently sent to me fox examination and report. I found that the chocolate milled twice with the flour and sugar formed a complete emulsion with hot water, bland and rich, like the best milk. but the other three were much inferior in this respect. Sugar alone, with propel milling, would serve to give the kernels of well roasted coco a perfect emulsive property. Instead of merely milling with rotary stones, I would prefer, for the second or finishing operation, a levigating mill, in which rollers would be rolled either backwards and forwards, or, when slightly conical, in a circular direction, over a plane metallic, marble, or porphyry, slab as is now, indeed, very generally practised by the trade. The coco-beans should be well selected, without musty taint, and possessed of a fine aroma, like the best of that imported from Trinidad. There is a great deal of very coarse coco and chocolate on sale in London and in the provincial towns of the United Kingdom. Fig. 359. is an end view of one of the chocolate mills with its mitre-gearing. I consider the gritty chocolate hitherto 359 made at Deptford as a very bad substitute for the chocolate which was made fiom coco by the sailors themselves with a - pestle and mortar. y-..^ * t In 1840 the coco cleared for consumption in the United Kingdom was:] — T:2:J British plantation - - 2,041,492 lbs. Foreign - - - 186 Coco-nut husks and shells - 753,580 Chocolate and coco paste - 2,066 Of the cocoa-nut shells, 612,122 lbs. were consumed in Ireland!'~:] l and less than 4000 lbs. of coco. Of coco, 726,116 lbs. were consumed in her Majesty's navy. { How scurvily are the people of Ireland treated by their own. _ k _ ggrocers! Upwards of 600,000 lbs. of worthless coco husks served out to them along with only 4000 lbs. of coco-beans! The quantity of coco imported in 1850 amounted to 4,478,252 cwts., and in 1851 to 6,773,960 cwts.; the entries for home consumption were 3,103, 926 and 3,024,338 cwts.; the re-exports were 1,443,363 and 1,543,455 cwts.; and the gross amount of duty 16,0591. and 15,7781. respectively. CHROMATES, saline compounds of chromic acid with the basis. See CaROMIUM. Messrs. Swindell and Co. obtained a patent in November, 1850, for obtaining copper, silver, and chrome, from their ores. 1st. To obtain copper and silver, or copper only, firom their ores, according to this invention, the ores are first roasted to drive off the sulphur, and convert the metals to the state of oxides, after which the prepared ores are placed in tanks, and a solution of ammonia or its salts, of a strength of about 0'980, pumped on in sufficient quantity to saturate them. This solution is removed at the expiration of twelve to twenty-four hours, and will be found saturated with the metallic oxides, which are to be dissolved in boiling water and precipitated-the silver by hydrochloric, and the copper by hydrosulphuric acids or otherwise. 2nd. The ore from which zinc is obtained is the native sulphuret, which is mixed with about its own weight of common salt (for which muriate of potash, or of any earth, may be substituted), and exposed in a calcining furnace to a slow protracted heat, until all the sulphur present is converted into sulphuric acid. The products of this operation will be sulphate of soda, muriate of zinc, and muriate of iron, which are to be dissolved out in boiling water, and the two latter precipitated by lime, or other means, after the sulphate of soda has been separated in the usual manner. The oxide of zinc, when thus precipitated, may be smelted in the usual way. In treating chromium (chromite of iron), the ore is pulverized and mixed with common salt, muriate of potash, or hydrate of lime, and exposed in a reverberatory furnace to a red or even a white heat, the mixture being stirred every ten or fifteen ainutes, and steam at a very elevated temperature introduced during the operation, until the desired effect is obtained, which may be ascertained by withdrawing a portion This small excess proceeded from a residue of the last experiment. CHROMIUM. 421 from the furnace and testing it, as customary. The products of this operation are finally treated in the manner usual for chromic and bichromic salts. The mixture of chromium and common salt produces chromate of soda, the greater portion, or perhaps all of the iron contained in the chromium being absorbed by the hydrochloric acid evolved from the salt, and carried off in the form of sesquichloride of iron. From the first mixture is manufactured pure bichromate of soda, which, by the addition of hydrochloric acid, may be converted to chlorochromate; and from the last, or lime mixture, is produced a chromate of that earth, from which, by the addition of soda or potash, there may be obtained a compound salt, which, with those previously mentioned, may be advantageously employed in the operation specified in the title. CHROMIC ACID. To a boiling saturated solution of bichromate of potash, add as much oil of vitrol as will convert the potash into a bisulphate. Let the whole cool, and be then washed with a little water, and stirred, when the liquid decanted from the granular mass will be nearly pure chromic acid. The solution of chromic acid in oil of vitriol is preferable as an oxidizing agent to every other at present known. See CHROMIUM. CHROMIUM. The only ore of this metal, which occurs in sufficient abundance for the purposes of art, is the octohedral chrome-ore, commonly called chromate of iron, though it is rather a compound of the oxydes of chromium and iron. The fracture of this mineral is uneven; its lustre imperfect metallic; its color between iron-black and brownish-black, and its streak brown. Its specific gravity, in the purest state, rises to 4'5; but the usual chrome-ore found in the market varies from 3 to 4. According to Klaproth, this ore consists of oxyde of chromium, 43; protoxyde of iron, 34-7; alumina, 20*3; and silica, 2; but Vauquelin's analysis of another specimen gave as above, respectively, 55-5, 33, 6, and 2. It is infusible before the blowpipe; but it acts upon the magnetic needle, after having been exposed to the reducing smoky flame. It is entirely soluble in borax, at a high blowpipe heat, and imparts to it a beautiful green color. Chrome-ore is found at the Bare Hills, near Baltimore, in Maryland; in the Shetland Isles, Unst and Fetlar; the department of Var, in France, in small quantity; and near Portsoy, in Banffshire; as also in Silesia and Bohemia. The chief application of this ore is to the production of chromate of potash, from which salt the various other preparations of this metal used in the arts are obtained. The ore, freed, as well as possible, from its gangue, is reduced to a fine powder, by being ground in a mill under ponderous edge-wheels, and sifted. It is then mixed with one third or one half its weight of coarsely bruised nitre, and exposed to a powerful heat, for several hours, on a reverberatory hearth, where it is stirred about occasionally. In the large manufactories of this country, the ignition of the above mixture in pots is laid aside, as too operose and expensive. The calcined matter is raked out, and lixiviated with water. The bright yellow solution is then evaporated briskly, and the chromate of potash falls down in the form of a granular salt, which is lifted out from time to time from the bottom with a large ladle, perforated with small holes, and thrown into a draining-box. This saline powder may be formed into regular crystals of neutral chromate of potash, by solution in water and slow evaporation; or it may be converted into a more beautiful crystalline body, the bichromate of potash, by treating its concentrated solution with nitric, muriatic, sulphuric, or acetic acid, or, indeed, any acid exercising a stronger affinity for the second atom of the potash than the chromic acid does. Bichromate of potash, by evaporation of the above solution, and slow cooling, may be obtained in the form of square tables, with bevelled edges, or flat four-sided prisms. They are permanent in the air, have a metallic and bitter taste, and dissolve in about one tenth of their weight of water, at 60~ F.; but in one half of their weight of boiling water. They consist of chromic acid 13, potash 6; or, in 100 parts, 68'4 - 31'6. This salt is tnuch employed in calico-printina and in dyeing; which see. Chromate of lead, the chrome-yellow of the painter, is a rich pigment of various shades, from deep orange to the palest canary yellow. It is made by adding a limpid solution of the neutral chromate (the above granular salt) to a solution, equally limpid, of acetate or nitrate of lead. A precipitate falls, which must be well washed, and carefully dried out of the reach of any sulphureted vapors. A lighter shade of yellow is obtained by mixing some solution of alum, or sulphuric acid, with the chromate, before pouring it into the solution of lead; and an orange tint is to be procured by the addition of subacetate of lead, in any desired proportion. For the production of chromate of potash from chrome ore, various other processes have been recommended. The following formule, which have been verified in practice, will prove useful to the manufacturers of this important article:I. Two parts of chrome ore, containinng about 50 per cent. of protoxyde of chromium' One part of saltpetre. l. 422 CHROMIUM. II. Four parts of ohrome ore, containing 5 I per cent. of protoxyde of chromium. Two parts of potashes. One part of saltpetre. [II. Four parts of chrome ore. - 34 Two of potashes. Four tenths of a part of peroxyde of manganese. IV. Three parts of chrome ore. Four parts of saltpetre. Two parts of argal. Some manufacturers have contrived to effect the conversion of the oxyde into an acid, and of course to form the chromate of potash, by the agency of potash alone, in a calcining furnace, or in earthen pots fired in a pottery kiln. After lixiviating the calcined mixtures with water, if the solution be a tolerably pure chromate of potash, its value may be inferred, from its specific gravity, by the following table:At specific gravity 1*28 it contains about 50 per cent. of the salt. 1-21 33 1-18 25 1-15 20 1-12 16 1-11 14 1'10 12 In making the red bichromate of potash from these solutions of the yr ilow salt, nitric acid was at first chiefly used; but in consequence of its relatively high -price, sulphuric, muriatic, or acetic acid has been frequently substituted upon the great scale. There is another application of chrome which merits some notice here; that of its green oxyde to dyeing and painting on porcelain. This oxyde may be prepared by decomposing, with heat, the chromate of mercury, a salt made by adding to nitrate of protoxyde of mercury, chromate of potash, in equivalent proportions. This chromate has a fine cinnabar red, when pure; and, at a dull red heat, parts with a portion of its oxygen and its mercurial oxyde. From M. Dulong's experiments it would appear, that the purest chromate of mercury is not the best adapted for preparing the oxyde of chrome to be used in porcelain painting. Ie thinks it ought to contain a little oxyde of manganese and chromate of potash, to afford a green color of a fine tint, especially for pieces that are to receive a powerful heat. Pure oxyde of chrome preserves its color well enough in a muffle furnace; but, under a stronger fire, it takes a dead-leaf color. The green oxyde of chrome has come so extensively into use as an enamel color for porcelain, that a fuller account of the best modes of manufacturing it must prove acceptable to many of my readers. That oxyde, in combination with water, called the hydrate, may be economically prepared by boiling chromate of potash, dissolved in water, with half its weight of flowers of sulphur, till the resulting green precipitate ceases to increase, which may be easily ascertained by filtering a little of the mixture. The addition, of some potash accelerates the operation. This consists in combining the sulphur with the oxygen of the chromic acid, so as to form sulphuric acid, which unites with the potash of the chromate into sulphate of potash, while the chrome oxyde becomes a hydrate. An extra quantity of potash facilitates the deoxydiiement of the chromic acid by the formation of hyposulphite and sulphuret of potash, both of which have a strong attraction for oxygen. For this purpose the clear lixivium of the chromate of potash is sufficiently pure, though it should hold some alumina and silica in solution, as it generally does. The hydrate may be freed from particles of sulphur by heating dilute sulphuric acid upon it, which dissolves it; after which it may be precipitated, in the state of a carbonate, by carbonate of potash, not added in excess. By calcinine a mixture of bichromate of potash and sulphur in a crucible, chromic acid is also decomposed, and a hydrated oxyde may be obtained; the sulphur being partly converted into sulphuret of potassium, and partly into sulphuric acid (at the expense of the chromic acid), which combines with the rest of the potash into & sulphate. By careful lixiviation, these two new compounds may be washed away, and the chrome green may be freed from the remaining sulphur, by a slight heat. Liebig and W6hler have lately contrived a process for producing a subchromate of lead of a beautiful vermilion hue. Into saltpetre, brought to fusion in a crucible at a gentle heat, pure chrome yellow is to be thrown by small portions at a time. A strong ebullition takes place at each addition, and the mass becomes black, and continues so while it is hot. The chrome yellow is to be added till little of the saltpetre remains undecomposed, care being taken not to overheat the crucible, lest the colot of the mixture should become brown. Having allowed it to settle for a few minutes,'luringr which the dense basic salt falls to the bottom, the fluid part, consisting of i'~~~~~~~~~~~~~ —----------— ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~''/~~~~~~~~~~~ CHROMIUM. 423 ehromate of potash and saltpetre, is to be poured off, and it can be employed again in preparing chrome yellow. The mass remaining in the crucible Is to be washed with waler. and the chrome red being separated from the other matters, is to be dried after proper edulcoration. It is essential for the beauty of the color, that the saline solution rhould not stand long over the red powder, because the color is thus apt to become of a dull orange hue. The fine crystalline powder subsides so quickly to the bottom after every ablution, that the above precaution may be easily observed. As Chromic.Acid will probably ere long become an object of interest to the calico printer, I shall describe here the best method of preparing it. To 100 parts of yellow ehromate of potash, add 136 of nitrate of barytes, each in solution. A precipitate of the yellow chromate of barytes falls, which being washed and dried would amount to 130 parts. But while still moist it is to be dissolved in water by the intervention of a little nitric acid, and then decomposed by the addition of the requisite quantity of sulphuric acid, whereby the barytes is separated, and the chromic acid remains associated with the nitric acid, from which it can be freed by evaporation to dryness. On re-dissolving the chromic acid residuum in water, filtering and evaporating to a proper degree, 50 parts of chromic acid may be obtained in crystals. This acid may also be obtained from chromate of lime, formed by mr.nng chromate of potash and muriate of lime; washing the insoluble chromate of lime wnich precipitates, and decomposing it by the equivalent quantity of oxalic acid, or for ordinary purposes even sulphuric acid may be employed. Chromic acid is obtained in quadrangular crystals, of a deep red color; it has a very acrid and styptic taste. It reddens powerfully litmus paper. It is deliquescent in the ai:. When heated to redness it emits oxygen, and passes into the deutoxyde. When a little of it is fused along with vitreous borax, the compound assumes an emerald green color. As chromic acid parts with its last dose of oxygen very easily, it is capable in certain styles of calico printing of becoming a valuable substitute for chlorine, where this more powerful substance would not from peculiar circumstances be admissible. For this ingenious application, the arts are indebted to that truly scientific manufacturer, M. Daniel Knchlin, of Mulhouse. He discovered that whenever chromate of potash has its acid set fiee by its being mixed with tartaric or oxalic acid, or a neutral vegetable substance, (starch or sugar for example,) and a mineral acid, a very lively action is produced, with disengagement of heat, and of several gases. The result of this decomposition is the active reagent, chromic acid, possessing valuable properties to the printer. Watery solutions of chromate of potash and tartaric acid being mixed, an effervescence is produced which has the power of destroying vegetable colors. But this power lasts no longer than the effervescence. The mineral acids react upon the chromate of potash only when vegetable coloring matter, gum, starch, or a vegetable acid are present, to determine the disengagement of gas. During this curious change carbonic acid is evolved; and when it takes place in a retort, there is condensed in the receiver a colorless liquid, slightly acid, exhaling somewhat of the smell of vinegar, and containing a little empyreumatic oil. This liquid heated with the nitrates of mercury or silver reduces these metals. On these principles M. Kcechlin discharged indigo blue by passing the cloth through a solution of chromate of potash, and printing nitric acid thickened with gum upon certain spots. It io probable that the employment of chromic acid would supersede the necessity of having recourse in many cases to the more corrosive chlorine. The following directions have been given for the preparation of a blue oxyde of chrome, The concentrated alkaline solution of chromate of potash is to be saturated with weak sulphuric acid, and then to every 8 lbs. is to -be added 1 lb. of common salt, and half a pound of concentrated sulphuric acid; the liquid will now acquire a green color. To be certain that the yellow color is totally destroyed, a small quantity of the liquor is to have potash added to it, and filtered; if the fluid is still yellow, a fresh portion of salt and of sulphuric acid is to be added; the fluid is then to be evaporated to dryness, redissolved, and filtered; the oxyde of chrome is finally to be precipitated by caustic potash. It will be of a greenish-blue color, and being washed, must be collected upon a filter. Chromate of Potash, adulteration of, to detect. The chromate of potash has the power of combining with other salts up to a certain extent without any very sensible change in its form and appearance; and hence it has been sent into the market falsified by very considerable quantities of sulphate and muriate of potash, the presence of wnich has often escaped observation, to the great loss of the dyers who use it so extensively. The following test process has been devised by M. Zuber, of Milhouse. Add a large excess of tartaric acid to the chromate in question, which will decompose it, ant produce in a few minutes a deep amethyst color. The supernatant liquor will, ifthe chromate be pure, afford now no precipitate with the nitrates of barytes or silver; whence the absence of the sulphat-s and muriates may be inferred. We must, however, use dilute solutions of the chromate and acid, lest bitartrate of potash be precipitated, which will take place if less than 60 parts of water be employed. Nor must 124 CITRIC ACID. we test the liquid till the decomposition be complete, and till the colour verge rathet towards the green than the yellow. Eight parts of tartaric acid should be added to on, of chromate to obtain a sure and rapid result. If nitrate of potash (saltpetre) is the adulterating ingredient, it may be detected by throwing it on burning coals, when deflagration will ensue. The green colour is a certain mark of the transformation of the chromic acid partially into the chrome oxide; which is effected equally by the sulphur. ous acid and sulphuretted hydrogen. Here this metallic acid is disoxygenated by the tartaric, as has been long known. The tests which I should prefer are the nitrates o silver and baryta, having previously added so much nitric acid to the solution of the suspected chromate, as to pievent the precipitation of the chromate of silver or baryta. The smallest adulteration by sulphates or muriates will thus be detected. CHROMIUM, OXIDE OF.-Mix intimately 45 parts of gunpowder with 240 parts of perfectly dry chromate of potash, and 35 parts of hydrochlorate of ammonia (sal ammoniac), reduce to powder, and pass throlgh a fine sieve; fill a conical glass or other mould with this powder, gently pressed, and invert so as to leave the powder on a porcelain slab of any kind. When set on fire at its apex with a lighted match, it will brn down to the bottom with brilliant coruscations. The black residuum, being elutriated with warm water, affords a fine bright green oxide of chromium. CinROlmIUm, green oxide of.-Ignite bichromate of potash with a quarter of its weight of flowers of sulphur, by projecting the mixture into a red hot crucible in small successive portions, stirring the pasty mass till the excess of sulphur is burnt off; pulverize the cooled mass, and wash with water till it affords no precipitate with chloride of barium or acetate of lead. The powder which remains on being gently dried is of a beautiful green color, and may be used as a pigment, or to prepare pure chromium. CINNABAR; the native red sulphuret of mercury. It occurs sometimes crystallized in rhomboids; has a specific gravity varying from 6-7 to 8-2; a flat conchoidal fracture; is fine grained; opaque; has an adamantine lustre, and a color passing from cochineal to ruby red. The fibrous and earthy cinnabar has a scarlet hue. It is met with disseminated in smaller or larger lumps in veins, which are surrounded by a black clay, and is associated with native quicksilver, amalfarn, with iron-ore, lead-glance, blende, copper-ore, gold, &c. Its principal localities are Almaden in Spain, Idria in the Schieferaebirge, Kremnitz and Schemnitz in Hungary; in Saxony, Bavaria, Bohemia, Nassau, China, Japan, Mexico, Columbia, Peru. It consists of two piimes of sulphur, = 32-240, combined with one of mercury, = 202,863; or in 100 parts of 12-7 sulphur - 87-3 mercury. It is the most prolific ore of this metal; and is easily smelted by exposing a mixture of it with iron or lime to a red heat in retorts. Factitious cinnabar is called in commerce VERMILION, which see, as also MERCURY. CINNAMON. (Cuinelle, Fr.; Zimmi, Germ.) Is the inner bark of the latrus cinnanmomum, a handsome-looking tree which grows naturally to the height of 18 or 20 feet, in Java, Sumatra, Ceylon, and other islands in the East Indian seas. It has been transplanted to the Antilles, particularly Guadaloupe and Martinique, as well as Cayenne, but there it produces a bark of very inferior value to the Oriental. Cinnamon is gathered twice a year, but not till after the tree has attained to a certain age and maturity. The young twins yield a bark of better quality than the larger branches. The first and chief harvest takes place from April to August; the second, from November to January. After having selected the proper trees, all the branches more than three years old are cut off; the epidermis is first removed with a two-edged pruning knife, then a longitudinal incision is made through the whole extent of the bark, and lastly, with the bluntest part of the knife, the true bark is carefully stripped off in one piece. All these pieces of hark are collected, the smaller ones are laid within the larger, and in this state they are exposed to the sun, whereby in the progress of drying, they become rolled into the shape of a quill. These convoluted pieces are formed into oblong bundles of 20 or 30 lbs. weight, which are placed in warehouses, sorted and covered with mats. Good cinnamon should be as thin as paper, have its peculiar aromatic taste, without burning the tongue, and leave a sweetish flavor in the mouth The broken bits of cinnamon are used in Ceylon for procuring the essential oil by distillation. 445,367 lbs. of cinnamon were imported into this kingdom in 1835, of which 16,604 only were retained for internal consumption. CITRIC ACID. (Scide citrique, Fr.; Citronensaure, Germ.) Scheele first procured this acid in its pure state from lemon juice, by the following process. The juice put into a large tub, is to be saturated with dry chalk in fine powder, noting carefully the quantity employed. The citrate of lime which precipitates, being freed from the supernatant foul liquor, is to be well washed with repeated atfusion and decantation of water. For every 10 pounds of chalk employed, nine and a half pounds of sulphuric acid, diluted with six times its weight of water, are to be poured while waim upon the citrate of lime, and well mixed with it. At the end of twelve hours, or even sooner, the citrate will be all CIVET. 42.5 decomposed, dilute citric acid will float above, and sulphate of lime will be found at the bottom. The acid being drawn off, the calcareous sulphate must be thrown on a canvass filter, drained, and then washed with water to abstract the whole acid. The citric acid thus obtained may be evaporated in leaden pans, over a naked fire till it acquires the specific gravity 1'13; after which it must be transferred into another vessel, evaporated by a steam or water bath till it assumes a syrupy aspect, when a pellicle appears first in patches, and then over the whole surface. This point must be watched with great circumspection, for if it be passed, the whole acid runs a risk of being spoiled by carbonization. The steam or hot water must be instantly withdrawn, and the con centrated acid put into a crystallizing vessel in a dry, but not very cold apartment. At the end of four days the crystallization will be complete. The crystals must be drained, re-dissolved in a small portion of water, the solution set aside to settle its impurities, then decanted, re-evaporated, and re-crystallized. A third or fourth crystallization may be necessary to obtain a colourless acid. If any citrate of lime be left nndecomposed by the sulphuric acid, it will dissolve in the citric acid, and obstruct its crystallization, and hence it will be safer to use the slightest excess of sulphuric acid, than to leave any citrate undecomposed. There should not, however, be any great excess of sulphuric acid. If there be, it is easily detected by nitrate of barytes, but not by the acetate of lead as prescribed by some chemical authors; because the citrate of lead is not very soluble in the nitric acid, and might thus be confounded with the sulphate, whereas citrate of barytes is perfectly soluble in that test acid. Sometimes a little nitric acid is added with advantage to the solution of the coloured crystals, with the effect of whitening them. Twenty gallons of good leuan juice will afford fully ten pounds of white crystals of citric acid. Attempts were made both in the West Indies and Sicily, to convert the lime and lemon juice into citrate of lime, but they seem to have failed through the difficulty of drying the citrate for shipment. The crystals of citric acid are oblique prisms with four faces, terminated by dihedral summits, inclined at acute angles. Their specific gravity is 1'617. They are unalterable in the air. When heated, they melt in their water of crystallization; and at a higher heat, they are decomposed. They contain 18 per cent. of water, of which onehalf may be separated in a dry atmosphere, at about 100~ F., when the crystals fall into a white powder. Citric acid in crystals is composed by my analysis of carbon, 35'8, oxygen 59'7, and nydrogen 45; results which differ very little from those of Dr. Prout, subsequently obtained. I found its atomic weight to be 8'375, compared to oxygen 1,000. I cannot account for Berzelius's statements relative to the composition of this acid. Citric acid in somewhat crude crystals is employed with much advantage in calicoprinting. If adulterated with tartaric acid, the fiaud may be detected by adding potash to the solution of the acid, which will cause a precipitate of cream of tartar. The manufacture of citric acid so closely resembles that of tartaric acid, that the makers of one commonly fabricate the other. The raw material in this case is pretty generally a black fluid, like thin treacle, which comes from Sicily, and is obtained by inspissating the expressed juice of the lemon,-the rind having previously been removed from the lemon for the sake of its essential oil. This black juice is impure citric acid, and requires to be treated with chalk, as practised with respect to the first operation on tartar; by which means, an insoluble citrate of lime is formed; and this, after being well washed with cold water, is decomposed by sulphuric acid; and the solution, after undergoing the action of animal charcoal and proper evaporation,yields brownish crystals on cooling. These are re-dissolved, discoloured, and crystallized three or four times ere they can be sent into the market, for citric acid is more tenacious of colouring matter than most of the other vegetable acids. At Nice, and in the South of France, a portion of chloride of lime is digested upon the citrate of lime, to bleach it prior to decomposition by sulphuric acid. For this purpose, the washed citrate is exposed in shallow vessels to the action of the sun's rays, covered by a weak solution of chloride of lime. In a few hours decolouration ensues; and it is moreover stated that the mucilage which hangs about the citrate of lime, and impedes the subsequent crystallization of the acid, is in this way destroyed, and the number of re-crystallizations requisite to give a saleable aspect to the citric acid thereby diminished. The use of chloride of lime for this purpose seems unknown; or, at least, is not practised in England. Of the samples of citric acid shown in the Great Exhibition, those from Howards and Kent, of Stratford, Pontifex and Wood, of Millwall, and J. Huskisson, of Gray's Inn Road, were extremely beautiful; and in respect to size and crystalline form surpassed anything exhibited in the French, Prussian, or Italian departments. CIVET. (Civette, Fr.; Zibeth, Germ.) This substance approaches in smell to musk and ambergris; it has a pale yellow colour, a somewhat acrid taste, a consistence 420 CLAY. like that of honey, and a very strong aromatic odour. It is the product of two smal quadrupeds of the genus viverra (v. zibetha and v. civetta), of which the one inhabits Africa, and the other Asia. They are reared with tenderness, especially in Abyssinia The civet is contained in a sac, situated between the anus and the parts of generation, in either sex. The animal fiees itself from an excess of this secretion by a contractile movement which it exercises upon the sac, when the civet issues in a vermicular form and is carefully collected. The negroes are accustomed to increase the secretion by irritating the animal; and likewise introduce a little butter, or other grease, by the natural slit in the bag, which mixes with the odoriferous substance, and increases its weight. It is employed only in perfumery. According to M. Boutron-Chalard, it contains a volatile oil, to which it owes its smell, some free ammonia, resin, fat, an extractiform matter, and mucus. It affords by calcination an ash, in which there are some carbonate and sulphate of potash, phosphate ot lime, and oxide of iron. CLAY (Argile, Fr.; Thon, Germ.) is a mixture of the two simple earths, alumina and silica, generally tinged with iron. Lime, magnesia, with some other colouring metallic oxides, are occasionally present in small quantities in certain natural clays. The different varieties of clay possess the following common characters:1. They are readily diffusible through water, and are capable of forming with it a plastic ductile mass, which may be kneaded by hand into any shape. This plasticity exists, however, in very different degrees in the different clays. 2. They concrete into a hard mass upon being dried, and assume, upon exposure to the heat of ignition, a degree of hardness sometimes so great as to give sparks by collision with hardened steel. In this state they are no longer plastic with water, even when pulverised. Tolerably pure clays, though infusible in the furnace, become readily so by the admixture of lime, iron, manganese, &c. 3. All clays, even when previously fieed from moisture, shrink in the fire in virtrte of the reciprocal affinity of their particles; they are very absorbent of water in their dry slate, and adhere strongly to the tongue. 4. Ochrey, impure clays emit a disagreeable earthy smell when breathed upon. Brongniart distributes the clay into:1. Fire-clays, (argiles apyres, Fr.; feuerfeste, Germ.) 2. Fusible, (schmelzbare, Germ.) 3. Effervescing (brausende, Germ.) from the presence of chalk. 4. Ochrey (ocreuses, Fr.; ockriqe, Germ.) Fire-clay is found in the greatest abundance and perfection for manufacturing pur poses in, 1. Slate-clay. (7Ton-schiefer, Germ.) Its colour is gray or grayish yellow. Massive, dull, or glimmering from admixture of particles of mica. Fracture slaty, approaching sometimes to earthy. Fragments tabular. Soft, sectile, and easily broken. Sp. gr.= 2'6. Adheres to the tongue, and breaks down in water. It occurs along with pit coal; which see. Slate-clay is ground, and reduced into a paste with water, for making fire-bricks; for wnich purpose it should be as fiee as possible from lime and iron. 2. Common clay or loam.-This is an impure coarse pottery clay, mixed with iron ochre, and occasionally with mica. It has many of the external characters of plastic clay. It is soft to the touch, and forms, with water, a somewhat tenacious paste; but is in general less compact, more friable, than the plastic clays, which are more readily diffusible in water. It does not possess the property of acquiring in water that commencement of translucency which the purer clays exhibit. Although soft to the touch, the common clay wants unctuosity, properly so called. Tile best ex amnple of'this argillaceous substance is afforded in the London clay formation, which consists chiefly of bluish or blackish clay, mostly very tough. Those of its strata which effervesce with acids partake of the nature of marl. This clay is fusible at a stlong heat in consequence of the iron and lime which it contains. It is employed in the manufacture of bricks, tiles, and coarse pottery ware. 3. Potter's clay, or Plastic clay.-This species is compact, soft, or even unctuous to the touch, and polishes with the pressure of the finger; it forms, with water, a tenacious, very ductile, and somewhat translucent paste. It is infusible in a porcelain kiln, but assumes in it a great degree of hardness. Werner calls it pipe-clay. Good plastic clay remains white, or if gray before, becomes white in the porcelain kiln. The geological position of the plastic clay is beneath the London clay, and above the sand which covers the chalk formation. The plastic clay of the Paris basin is described as consisting of two beds separated by a bed of sand. Thile lower bed is the proper plastic clay. The plastic clay of Abondant, near the forest of Dreux, analyzed by Vauquelin, gaveSilica, 43-5; alumina, 332; lime, 0-35; iron, 1; water, 18. CLAY. 427'Tllis clay is employed as a fire clay for making tie bungs or seggars, or coarse earthenware cases, in which china ware is fired. The plastic clay of Dorsetshire and Devonshire supplies thd great Staffordshire potteries. It is gray-coloured, less unctuous than that of Dreux, and consequently more friable. It becomes white in the pottery kiln, and is infusible at that heat. It causes no effervescence with nitric acid, but falls down quickly in it, and becomes higher coloured. Its refractoriness allows of a harder glaze being applied to the ware formed fr'om it without risk of the heat requisite for making the glaze flow affecting the biscuit either in shape or colour. "Most of the plastic clays of France," says M. Brongniart, "employed for the same ware, have the disadvantage of reddening a little in a somewhat strong heat; and hence it becomes necessary to coat them with a soft glaze, fusible by means of excess of lead at a low heat, in order to preserve the white appearance of the biscuit. Such a glaze has a dull aspect, and cracks readily into innumerable fissures by alternations of hot and cold water." Ience one reason of the vast inferiority of the French stone-ware to the English. 4. Porcelain clay or Kaolin earth.-The Kaolins possess very characteristic properties. They are friable in the hand, meagre to the touch, and difficultly form a paste with water. When fieed from the coarse and evidently foreign particles interspersed through them, they are absolutely infusible in the porcelain kiln, and retain their white colour unaltered. They harden with heat like other clays, and perhaps in a greater degree; but they do not acquire an equal condensation or solidity, at least when they are perfectly pure. The Kaolins in general appear to consist of alumina and silica in nearly equal proportions. Most of the Kaolin clays contain some spangles of mica which betray their origin fromn disintegrated granite. This origin may be regarded as one of their most distinctive features. Almost all the porcelain clays are evidently derived from the decomposition of the felspars, granites, and principally those rocks of felspar and quartz, called graphic granite. Hence they are to be found only in primitive mountain districts, among banks or blocks of granite, forming thin seams or partings between them. In the same partings, quartz and mica occur, being relics of the granite; while some seams of Kaolin retain the external form of felspar. The most valuable Kaolins have been found:In China and Japan. The specimens imported from these countries appear pretty white; but are more unctuous to the touch, and more micaceous than the porcelain clays of France. In Saxony. The Kaolin employed in the porcelain manufactories of that country has a slight yellow or flesh colour, which disappears in the kiln, proving, as Wallerius observed, that this tint is not owing to any metallic matter. In France, at Saint-Yriex-la-Perche, about 10 leagues from Limoges. The Kaolin occurs there in a bed, or perhaps a vein of beds of granite, or rather of that felspar rock called Pe-tun-tse, which exists here in every stage of decomposition. This Kaolin is generally white, but sometimes a little yellowish, with hardly any mica. It is meagre to the touch, and some beds include large grains of quartz, called pebbly by the China manufacturers. This variety, when ground, affords, without the addition of any fusible ingredient, a very transparent porcelain. Near Bayonne. A Kaolin possessing the lamellated structure of felspar, in many places. The rock containing it is a graphic granite in every stage of decomposition. In England in the county of Cornwall. This Kaolin or China clay is very white, and more unctuous to the touch than those upon the continent of Europe mentioned above. Like them it results from the decomposition of the felspars and granites, occurring in the middle of these rocks. Mr. Wedgewood found it to contain 60 of alumina or pure clay, and 40 of silica, in 100 parts. Pure clay, the alumina of the chemist, is absolutely infusible; but when subjected to the fire of a porcelain kiln, it contracts into about one-half of its total bulk. It must, however, be heated very cautiously, otherwise it will decrepitate and fly in pieces, owing to the sudden expansion into steam of the water combined with its particles, which is retained with a considerable attractive force. It possesses little plasticity, and consequently affords a very short paste, which is apt to crack when kneaded into a cake. It is not only infusible by itself, but it will not dissolve in the fusible glasses; making them merely opaque. If either lime or silica be added separately to pure clay, in any proportion, the mixture will not melt in the most violent furnace; but if alumina, lime, and silica be mixed together, the whole melts, and the more readily, the nearer the mixture approaches to the following proportions:-1 of alumina, 1 of lime, and 3 of sand. If the sand be increased to five parts, the compound becomes infusible. These interesting facts show the reciprocal action of those earths which are mixed most commonly in nature with alumina. 1628 CLAY. Iron in small quantity, but in a state not precisely determined, though -probably ol protoxide, does not colour the clays till they are subjected to a powerful heat, There are very white clays, such as those of Montereau, which do not become red till calcined in the porcelain kiln; the oxide of iron contained in them, which colours them in that case, was previously imperceptible. It appears from this circumstance, that the clays fit for making fine white stone ware, as also the Kaolins adapted to the manufacture of porcelain, are very rare. Iron in larger proportion, usually colours the clays green or slate-blue, before they have been heated. Such clays, exposed to the action of fire, become yellow or red according to the quantity of iron which they contain. When the iron is very abundant, it renders the clays fusible; but a little lime and silica must also be present for this effect. The earthenware made with these ferruginous clays can bear but a moderate baking heat; it is thick, porous, and possesses the advantage merely of cheapness, and of bearing considerable alternations of temperature without breaking. Alumina and the very aluminous natural clays which possess most plasticity are apt to crack in drying, or to lose their shape. This very serious defect for the purposes of pottery is rectified, in some measure, by adding to that earth a certain quantity of sand or silica. Thus, a compound is formed which possesses less attraction for water and dries more equably fiom the openness of its body. The principal causes of the distortion of earthenware vessels, are the unequal thickness of their parts, and quicker desiccation upon one side than another. Hard burnt stone-ware ground to powder, and incorporated with clay, answers still better than sand for counteracting the great and irregular contraction which natural pottery paste is apt to experience. Such ground biscuit is called cement; and its grains interspersed through the ware, may be regarded as so many solutions of continuity, which arrest the fissures. The preceding observations point out the principles of those arts which employ clay for moulding by the wheel, and baking in a kiln. See PORCELAIN and POTTERY. The chemical composition of the clays shown at the Great Exhibition was unfortunately not given, as it ought to have been. The injurious effect of this ignorance will, by-and-by, come under consideration, when speaking of the art of the potter; but, for the present, we shall content ourselves with a hasty glance at the various specimens of clay exhibited in Class I.,-r-adding, as usual, a few practical hints for the analysis of these substances, together with some analytical investigations recently made upon average market samples of clay, for the express purpose of elucidating this obscure subject. In a manufacturing point of view, clays may be conveniently divided into three classes; for although a fourth (that is to say, common marl clay) exists, yet, as its employment is limited to the making of bricks and other coarse articles in which improvement is nearly hopeless, so far as regards material, we shall confine our observations to the three finer qualities, named, respectively, china clay or kaolin, fire-clay, and potter's clay. In china clay, Jenkins & Courtney, of Truro; Whitley of Truro; C. Thriscutt, of St. Austell; the West of England China Stone and Clay Company; Truscott, Martyn, B3rown, Michell, and Wheeler, Philip & Co., all of St. Austell; and W. Phillips, of the Morley Works, near Plympton, together with Sir G. Hodson, Bart., of Wicklow in Ireland, exhibit some samples of great beauty and apparent purity. In fire-clay, the articles shown by King & Co., Squires & Son, and F. T. Rafford, of Stourbridge, with those from Cowan & Co., Ramsey & Co., and Potter, of Newcastle, are excellent; and a sample from Pease of Darlington, also deserves notice. In potter's clay, Whiteway, Watts, & Co., of Dorset; Fayle & Co., of Thames Street, London; W. & J. Peike, of the Isle of Purbeck; N. Burnet, of Gateshead; and the North Devon Pottery Company, are the most remarkable, though there are many very respectable looking samples from other quarters. In the manufacture of earthenware goods, it is indispensably necessary to mix the clay, in the first instance, with some infusible material, which does not contract or diminish under the influence of heat; for all kinds of clay shrink very much by the action of a high and prolonged temperature, and are therefore liable, during such exposure, to warp and twist out of shape, or become cracked in tie furnace. Hence a remedy is sought as above indicated, and for this purpose, silica, in a minute state of division, is generally preferred; though felspar, and a kind of decomposing granite, called Cornish stone, are also used. But whatever may be the material, its introduction into the body of the earthenware is conducted on purely empirical principles, for, as the composition of the clay is unknown, no attempt can be or is made to effect a combination in unison with the laws of chemical affinity. The substances employed are recognised only as clay, and perhaps ground flint; nor is any other test used to ascertain the proper proportion of each towards the other, than the uncertain judgment of a workman, or the equally fallacious practice of an established rule. As, however, all clays, in a state of natural purity, consist of silica and alumina, united together in definite atomic proportions, there can be no doubt that perfection in earthenware depends upon this simple law; and CLAY. 429 that the only true mode of fabricating a uniform and really valuable kind of potteryvare, would be to follow out the indications of nature, and constantly preserve an atomic ratio in the admixture of the flint and clay of which that pottery-ware is composed. Of course, under existing circumstances, this is impossible; for, as we have previously remarked, the precise composition of the different clays used in the arts is totally unknown; and, independent of any chemical difficulties that may be presumed to exist in determining this important fact for themselves, our manufacturers may justly plead that no simple and satisfactory mode of analyzing clay has yet been published. Hence the present empirical system is universal; and the accidental admixtures it produces testify to the truth of our remarks, by cracking and flying to pieces under very trivial alterations of temperature, no less to the annoyance than loss of the public at large. Nor can this be wondered at, when it is remembered that, in almost every tea-cup, saucer, or plate upon our tables, the laws of natural combination have been violated by the prevalence of an artificial and incompatible form of arrangement, the work of sheer ignorance and chance. So far as our investigations have yet gone, it appears that kaolin, or china 2lav, has arisen from the decomposition of felspar under two different conditions; for the resulting compound is not alike in both cases; though to what cause this difference can be ascribed we are unable with certainty to say. Felspar, in it original state, has exactly the same composition as anhydrous alum, with this exception, that in the one case the bases are united to sulphuric, and in the other to silicic acid. Felspar, therefore, consiste of one atom of potash and one of silica, united to two atoms of alumina and three c4 silica; or, in other words, it is formed of the silicate of potash and the silicate of alumina, combined in the ratio of one atom of the former to two of the latter. Now, it is found that, when felspar is long exposed to the action of the weather, it becomes disintegrated and falls into a state of powder, which, ultimately, by absorbing water, assumes a pasty consistence, and thus forms the article called china clay. The nature of this decomposition is not, however, uniform or invariable, for analysis proves that the residuary produce has not always the same composition. When felspar decomposes in an absolutely wet or rainy atmosphere, the silicate of potash would appear to be simply washed away by the excess of water; and, in this case, the resulting clay has a composition of three atoms of silica and two of alumina; but, when merely a moist atmosphere has existed, then the silicate of potash itself seems to become decomposed, probably by carbonic acid, thus leaving the whole of the silica united to the alumina; the potash then escaping as a carbonate. Under such circumstances, we have found china clay to consist of four atoms of silica and two of alumina; or, what is the same thing, of two of acid and one of base. Of course an alternating atmosphere would produce a mixture of these; and such layers may actually be traced in many specimens of clay, as though the summer and winter portions of the year had each furnished a distinctly separate amount of decomposed felspar. But felspar is not the only source from whence our silicate of alumina has been formed; as there are many other minerals which, by the action of the atmosphere, furnish clays of different compositions: thus, the substances known to mineralogists under the names leucite, albite, analcime, nepheline, mesotype, and sodalite, all yield silicate of alumina, which contains, indeed, various proportions of the two ingredients, but is nevertheless, in a commercial sense, clay. In point of fact even granite has contributed its quota to the clay formation, for though slowly and imperfectly, yet in time it crumbles down into supersilicate of alumina: as may be noticed by carefully examining the once smooth surface of the granite on Waterloo and London Bridges, which is gradually assuming a cavernous character. With such evidence before us of the infinite variety existing in clay, it is surely high time that the attention of manufacturers was directed to the necessity of analyzing this substance, and adding to it neither more nor less silica than is sufficient to produce a useful atomic compound. The proper proportion might soon be arrived at by a few carefully conducted experiments, after which the whole of the uncertainty now connected with differences in the material would vanish for ever, and with it no small amount of the loss occasionally caused by earthenware spoilt or broken in the kiln. To determine the quantity of alumina in clay, a given weight of this substance, say 100 grs., well dried and in fine powder, should be mixed with double its weight of fluor spar, also in fine powder, then the mixture placed in a platinum or leaden vessel, and about 400 grs. of strong sulphuric acid poured over it. Next expose the whole to a heat of from 212~ to 250~ Fahr. for half an hour; then add three or four ounces of water, and throw the mixture on a filter, adding a little water at the end of the filtration, so as to obtain the whole of the soluble matter. To the filtered fluid add now an excess of a solution of ammonia, by which the alumina will be precipitated and this, after being well washed on a filter, and dried at a red heat, must have its amount determined by the balance. If, however, the precipitate thrown down by ammonia has a deep yellow or red 2olour, the presence of iron is indicated; and this must be removed before drying the alumina. For this purpose, a quantity of tartaric acid should be added, so as to redissolve 430 CLAY. the mixed precipitate, and the solution slightly supersaturated with carbonate of solda when, on adding hydrosulphate of ammonia, the iron will separate as a black sulphuret leaving the alumina still in solution; from whence it may be obtained by evaporating the whole to dryness, heating red hot, and then washing away the alkaline salts by hot water; the alumina is then left pure, and, after being dried, may be weighed. As the presence of iron in clay is a serious drawback, the quantity of black sulphuret formed becomes a good indication of the impurity of the sample under examination, and is therefore worthy of notice. Although the proportion of alumina in clay is the chief commercial feature required by the makers of earthenware, yet it may sometimes be requisite to determine also the amount of silica present; which may be done by fusing together in an iron crucible or pan, at a full red heat, one part of the clay in question with three parts of pure potash,roth being in fine powder, and carefully mixed before fusion. The fused mass must, when cold, be boiled for some time in water, until it is thoroughly disintegrated; when it should be poured into a porcelain vessel, and supersaturated with muriatic acid; after which, by evaporating to dryness, a residue will be obtained, that, fter careful washing with boiling water, consists merely of the silica contained in the slay in question. After being heated red hot, it may be weighed as usual. If lime be suspected to exist with the alumina in clay, this may be separated, when in solution, by means of tartaric acid and carbonate of soda, as above indicated; for in such cases, the lime will fall at once as a carbonate, leaving the alumina behind in the fluid. Independent, however, of the defects in British earthenware due to the non-atomic admixture of its ingredients, there are others arising out of the nature of the ingredients themselves; so that, taken as a whole, we cannot avoid coming to the unpleasant conclusion, that, in the great arena of competition at the Crystal Palace, England is decidedly beaten in the manufacture of fine earthenware, even by countries greatly its inferiors in capital, intelligence, and natural resources. France, Germany, Sweden, Denmark, Spain, Russia, Turkey, and China, all exhibited porcelain of a quality unmatched by anything in the British department, and no more lamentable contrast could possibly be drawn than between the chemical apparatus from Saxony and the clumsy abortions, which, under that name, disfigured some of the compartments claimed by one or two of our Staffordshire manufacturers. In the one case we find a really handsome, light, and elegant article, the glaze of which has evidently penetrated throughout the entire substance of the body, and has converted the whole into a uniform vitrification; in the other, a thick, coarse, opaque, and spongy mass, is merely glazed over on its extreme surface by a fusible compound, having no properties in common with the body of the article, and endowed with very different powers of expansibility by heat; so that, after being used a few times, the glaze becomes cracked and shivered in a thousand directions, as may be seen by examining the earthenware in common use throughout Great Britain. Nior is the unsightly appearance caused by this cracking of the glaze the whole evil; for earthen vessels thus flawed acquire the property of absorbing fluids into their pores, and can never afterwards be thoroughly cleaned. In spite, therefore, of "warranted not to absorb," and other groundless legends of similar import, imprinted upon many British goods, a piece of really non-absorbent earthenware, for common use, is an actual curiosity in this country, and invariably suggests the idea of a foreign origin. lqow this defect can be remedied only in two ways; and, as our manufacturers have vainly endeavoured to carry out, practically, one of these ways, we are not without hopes of persuading them to try the other. If a glazing material could be discovered, the expansions and contractions of which, by heat, exactly corresponded with those of the biscuit ware, or silicate of alumina, under the same influence, then the present system of covering a spongy body by a coating of vitrifiable glaze would answer the desired intention well enough; for to the cheapness and durability of earthenware would thus be superadded the cleanliness of glass. But this desideratum has been sought for, over and over again, during the last half century, and nothing but disappointment has resulted. In proof of which we have only to ask-where is that glazed earthen vessel, which, though made expressly for the use of the apothecary, will retain oil, after being two or three times heated and cooled? The answer to this question must be our argument in favour of abandoning such a system of glazing, and adopting the only other mode by which a non-absorbent pottery ware can be fabricated. The body of the ware itself must undergo a semivitrification, as happens with the finest kind of china; so that, even if by long use the glaze come to be fairly worn off, still the non-absorbent principle would remain as perfect as at first. We know that this is impracticable under existing circum stances; and that, so long as the:present empirical mode of compounding the materiafls of which the body of the wvare is made continues, no chance of improvement remains. A mixture of silica and alumina, in the proportion of four atoms of the former to one of the latter, would bear or require a certain quantity of fusible material to induce semi vitrification throughout the mass; but a compound of three atoms of silica and one o/ CLAY. 481 alumina would probably be melted down into a worthless slag by exactly the same addition. Here then lies the root of that difficulty which has hitherto so injuriously restricted the employment of felspar and other vitrifiable bodies in the fabrication of British earthenware. Those who have attempted to use such substances have occasionally succeeded to admiration; and nothing but the uncertainty of the result, and repeated failures, have induced them to abandon the employment of a class of articles which, if capable of being controlled, every intelligent manufacturer admits would confer perfection on his art. But it is a great mistake to suppose that these inequalities of action arise out of some peculiarity in the vitrifiable materials themselves, or are in any way the work of chance. The materials are, or ought to be, uniform, and certainly can be made so, whilst, for the rest, there is no such thing as chance in nature,-the laws of chemistry are not accidental or variable, they are immutable. We have shown, however, that clays not only differ from each other, but, as it were, from themselves; since, from the same pit, and within a few inches of the same spot, clays of very contrary characters may be procured. Plasticity is no more an indication of the presence or purity of clay, than sweetness is a test of sugar. In a rough way both these qualities have a value; but the arts are now fast approaching an epoch, when all such fallacious aids must give place to the guidance of philosophy; and the sooner our manufacturers become convinced of this grand truth the better for themselves and their country. The propriety of knowing the exact composition of the raw materials employed in any art or manufacture does not, indeed, admit of dispute-it is imperative; and hence we are the more astonished at the scantiness of information respecting the analysis of so important a production as clay. In face of such apathetic ignorance, would any one believe that, independently of an immense home consumption, our exports of earthenware last year amounted to a million sterling? Had the clays of this country been of a tolerably uniform composition, like some of those in China and on the continent, of course mere practice would long ago have enabled our potters to produce articles of the highest quality. But surely this is a sorry compliment to men surrounded by all the resources of science and capital. Where there is no difficulty there can be but little merit, and still less profit. It is the great glory of British enterprise and industry to despise so low and facile a position. Our manufacturers must meet and overcome the trivial impediments connected with variations in the clay they purchase, and, by properly adjusting the other materials (so as to bring on exactly the due amount of vitrification needed in the body of the ware), produce, from any kind of clay, articles identical with those which other nations fabricate from the very finest clays only. With the prodigious commercial and other advantages possessed by Great Britain, the world at large ought to expect this at our hands, and not the sub-mediocre workmanship displayed in the Great Exhibition. Before quitting this subject, a few remarks upon the substances used in the formation of glazes may not be inappropriate. The million is still supplied with earthenware, the glaze of which contains lead, and is, consequently, dangerous to health, though, when Well burned on, this danger is greatly diminished, from the increased insolubility of the silicate of lead in weak acids. It is, however, an objectionable mode of glazing earthenware, and requires to be watched with caution, more especially where borax is used at the same time, for the borate of lead is more easily acted on than the silicate. It has been lately suggested that oxide of zinc would form a sufficiently fusible compound with silica, and is cheap enough to supplant oxide of lead in the glazing of common earthenware. The latter assertion is undoubtedly true, and, although we entertain some suspicions as to the easy fusibility of silicate of zinc, yet this is precisely one of those problems which, from their important sanitary bearing, deserve immediate investigation. On the continent a very pure kind of felspar, mixed probably with a little carbonate of baryta and oxide of tin, forms the only glaze used upon porcelain and the china vessels intended for chemical purposes. This glaze is practically perfect. It is so hard as to withstand the attack of a file, and it resists the action of the strongest acids and alkalis at all temperatures below 300~ Fahr.-the hlydrofluoric acid and its salts alone exepted. In the French, Saxon, and Prussian departments of the Crystal Palace, there were several good specimens which illustrated the value of this kind of glaze Amongst the English goods-and chiefly those from Staffordshire-were a variety of articles made in what is termed Parian, a compound, the unfitness of which for statuary purposes we now briefly animadvert upon, with reference however only to its employment in the higher branches of Decorative Art. The employment of this material,:- indeed any other form of alumina where sharpness and symmetry are wanted, cannot be sufficiently condemned, since it is totally contrary to the natural properties of alumina, and betrays infinite ignorance regarding first principles. The philosophical mind of Wedgewood would have revolted at so palpable an absurdity; for not alone was he well acquainted with the continuous contractility of aluminous compounds, but, taking advantage of that knowledge, he was able to construct an instrument for measuring high degrees of heat, which, although not rigidly perfect, is at this day still 432 COAL. found the only available guide for furnace operations on a large scale. And the value of this instrument or pyrometer, as it is termed, depends upon the fact, that the longer and higher the temperature to which clay is exposed, the smaller it becomes. Now bearing in mind that earthenware is an extremely bad conductor of heat, let us imagine the Greek Slave, for example, correctly modelled in clay or Parian, and subjected to the heat of a porcelain furnace. The smaller portions of the figure, as the nose, eyelids, fingers, &c., would receive much more of the impress of the fire than the larger ones,-as the head, shoulders, &c.; consequently, however symmetrical the origina. model might have been, the extra contraction in the smaller parts must destroy every thing like anatomical harmony and beauty. The fingers would become short and dumpy, and the nose flat and snubbed. But this is a small part of the mischief, for since clay, when burnt, is a bad conductor of heat, and the action of the fire is from without to within, the exterior of the figure must contract vastly more than the interior; consequently, the outside becoming too small for the inside, a series of cracks or fissures make their appearance to compensate for the inequality. These, of course, are filled up by a subsequent operation; but, it is needless to add, at the expense of every thing which would have rendered the result valuable as a work of art. The general appearance of the- Parian figures shown in the Exhibition bears us out in this censure; for the features are universally flat, soulless, and devoid of expression; nor can we imagine a more hopeless task than attempting to remedy this defect. CLOTI, MANUFACTURE OF. See COTTON, FLAX, WEAVING, WOOL. CLOTH-BINDING. Nothing places in so striking a point of view the superior taste, judgment, and resources of London tradesmen over those of the rest of the world, than the extensive substitution which they have recently,made of embossed silks and calicoes for leather in the binding of books. In old libraries, cloth-covered boards indeed may occasionally be seen, but they have the meanest aspect, and are no more to be compared with our modern cloth-binding, than the jupon of a trull with the ballet dress of Taglioni. The silk or calico may be dyed of any shade which use or fancy may require, impressed with gold or silver foil in every form, and variegated by ornaments in relief, copied from the most beautiful productions in nature. This new style of binding is distinguished not more for its durability, elegance, and variety, than for the economy and dispatch with which it ushers the offspring of intellect into the world. For example, should a house eminent in this line, such as that of Westleys, Friarstreet, Doctor's-commons, receive 5000 volumes from Messrs. Longman & Co. upon Monday morning, they can have them all ready for publication within the Incredibly short period of two days; being far sooner than they could have rudely boarded them upon the former plan. The reduction of price is not the least advantage incident to the new method, amounting to fully 50 per cent. upon that with leather. The dyed cloth being cut by a pattern to the size suited to the volume, is passed rapidly through a roller press, between engraved cylinders of hard steel, whereby it receives at once the impress characteristic of the back, and the sides, along with embossed designs over the surface in sharp relief. The cover thus rapidly fashioned, is as rapidly applied by paste to the stitched and pressed volume; no time being lost in mutual adjustments; since the steel rollers turn off the former of a shape precisely adapted to the latter. Iard glazed and varnished calico is moreover much less an object of depredation to moths and other insects, than ordinary leather has been found to be. CLOTH-DRESSING, by Heycock of Leeds, without stretching the warp-threads or creasing the cloths from list to list. Ile lays several pieces of cloth in an extended state above one another upon a wooden platform, until a pile of a suitable thickness is formed, a perforated plate is then brought down on the cloth by screws, and steam is admitted into a hollow chambel beneath, from which it penetrates all the folds of the cloth, but is confined at the sides. It seems to be a purpose-like invention. COAL. Under PITCOAL, the composition of several excellent coals is stated, with their peculiar qualities, as analyzed by me; such as the Llangenneck, Powell's Duffryn steam coal, the Blackley Hurst coal, Lancashire, the Varley Rock vein coal, near Pontypool, &c. The quantity of coals and culm exported in 1850 was 3,351,880 tons, and in 1851, 3,4i7,060 tons; declared value respectively, 1,284,2241. and 1,302,0251. COAL GAS. From what is generally admitted concerning the impurities which exist in crude coal-gas, it must be evident to those conversant with the principles of chemistry that these impurities can never be thoroughly removed by any single reagent, for some of them possess affinities diametrically opposite to the others. Thus, any means employed to absorb carbonic acid and sulphuretted hydrogen gases would leave the ammonia free; whilst an agent capable of combining with the latter, would not at all affect the former impurities. Hence the process of coal gas purification, as now carried on at the best gas works, is divided into two distinct parts. By one of these the whole f the ammonia and a portion of the carbonic acid and sulphuretted hydrogen are taken away, by the other, the remainder of the carbonic acid and sulphuretted hydrogen are totally re COAL. 433 moved; so that the gas ultimately passes forth to the consumer free from all contamination either by ammonia, carbonic acid, or sulphuretted hydrogen gas. And the absence of these impurities may at any time be demonstrated by applying the following simple tests: —litmus paper, slightly reddened by an acid, will undergo no change' when held for a few minutes in a current of the gas; this proves the absence of ammonia, for otherwise the paper would become blue. Paper, dipped into a solution of the acetate of lead, and held in a current of the gas, will remain white, which shows that the gas is destitute of sulphuretted hydrogen, as, under contrary circumstances, it would assume a deep brown or black hue. Lastly, if the gas be allowed to blow for a few minutes through a clear solution of lime in water, the solution will not become milky and turbid, as it would do if carbonic acid were present in the gas. N'o coal gas which does not vindicate its purity by resisting the analytical powers of the above tests can be regarded as sufficiently good for the purposes of illumination and heating. To separate the ammonia from coal gas, a variety of modes is at present in use; thus, Mr. Lowe employs cold water minutely divided in an apparatus which he terms a "scrubber," and which is perfectly analogous to the cascade c/hitnique of Clement J)esormes. With a similar view Mr. Palmer mixes the gas with steam, and then subjects the mixture to a condensing temperature, so as to obtain water, minutely divided in drops, like rain or dew, aid therefore presenting a considerable surface for chemical action. Mr. Johnson prepares a compound, consisting of sulphate and biphosphate of lime, by acting on burnt bones with sulphuric acid; and this he disposes in trayls, so as to absorb the ammnonia and produce a mixture of sulphate of ammonia and phosphate of lime, which, as might be expected, ie finds an extremely efficient fertilizing agent. Mr. Laming employs a solution of chloride of calcium or muriate of lime, absorbed into sawdust, which he disposes in the same manner as that followed by Mr. Johnson, and by which the muriate of lime is gradually decomposed with the formation of carbonate of lime and muriate of amrmonia,-the resulting compound being either valuable as a manure, or as a source for the manufacture of sal arnmmoniac. Sulphate of lime, and various other earthy metallic salts, have also been proposed and employed,-such as the sulphates of magnesia, alumina, zinc, iron, and manlganese, and the chlorides of the same metals. With the exception of the sulphate of lime, they do not; however, seem to possess any advantage over the modes we have mentioned as now in use for the absorption of ammonlia; and hence it may be as well to examine more minutely the actions of those methods, and their effects upon the gas undergoing purification. The process of Lowe is extremely simple ill theory, andl, where the! saving of the ammonia is not an object of importance, has much to recommend it. Here the ammonia is, so to say, washed out by means of water; and the application of the scrubber may either be made before or after the other impurities are taken away, with, however, this difference in the result:-if the gas, after quitting the condenser, is passed at once into the lime purifier, and the scrubber applied afterwards, nothing but ammonia will be removed by the water; but if the scrubber be employed in the first instance, then, with every atom of armmonia taken away, one of carbonic acid and sulphuretted hydrogen will follow, and hence a great economy of linle in this way arises; for the ammonia, though itself an impurity, thus becomes a purifying agent, and the liquid fiomr the scrubber consists, not of aqueous ammonia merely, but of a solution of carbonate and hydrosulphate of ammonia.. It is, however, very difficult to separate the whole of the ammonia, either free or combined with carbonic acid, by Lowe's scrubber, without the application of a very large body of water; and it has been suggested, that excessive ablution diminishes considerably the illuminating power of coal gas. This circumnstance, if true-and it is far from improbable-dermonstrates the necessity of limiting the action of water upon gas, and must, inl some degree, interfere with the employment of an otherwise invaluable instrument of purification. The plan of Palmer is precisely similar in its effect to the scrubber of Lowe, but more costly, and, except when conducted with great care, less efficacious, as the entire success depends upon the perfection of the condensation; for, unless the condensed water be cooled down to the mlean temperature of the atmosphere, little or no ammoniaa will combine with it; and there is, mloreover, a still greater danger of injuring the light-giving power of the gas by condensed steam, than by an equal weight of cold water. This method cannot, therefore, be considered as equal to the former, more especially when coal gas, of low specific gravity, is to be purified. The mere recital of Johnson's process allmost details its mode of action; and it would scarcely be necessary to say more concerning it, but for the contrast it presents to that of Laming, and the substances before alluded to. If the phosphate of lime or bone earth, mentioned as part of Johnson's mixture, be regarded as a sponge for holding the sulphuric acid which he employs, then the anmmonia is taken up firom the gas by simple elective affinity with the production of sulphate of ammonia; and this is, beyond doubt, a true explanation of the modes operandi in Johnson's case. Here, however, It will lie noticed that nothing but anmmonia is removed, for the carbonic acid and sul29 434 COAL.'phuretted hydrogen remain unaffected; consequently this system might be employed either before or after lime purification. Now, Laming's plan differs altogether fromn this, and, as will readily be seen, admits of application only before lime purification. The foul coal gas from the condenser contains carbonate of ammonia in a gaseous condition; and it has just been shown, that the process of Laming depends upon the use of muriate of lime. But at the ordinary temperature of this country these two substances are incompatible with each other; and, consequently, as fast as the carbonate of ammonia is brought by the current of gas into contact with the muriate of lime, mutual decomposition ensues, and both the ammonia and carbonic acid are solidified; the former becoming converted into muriate of ammonia, and the latter into carbonate of lime, by an interchange of elements with the muriate of lime used in the process; therefore the result differs thus far from that of Johnson,-that carbonic acid as well as ammonia is taken from the gas, and consequently a saving of lime, or other purifying material, effected: of course sulphate of lime would act in the same way, though less powerfully; whereas metallic salts, in general, having more affinity, after decomposition, for sulphuretted hydrogen than for carbonic acid, will produce an economy of lime by removing the former and not the latter impurity. Such, then, is a descriptive outline of the methods actually followed at the present day for the purification of coal gas fiom the ammonia it con tains; and although seemingly abundant enough to have exhausted the subject, yet there is still an extensive field open to improvement even here. Amongst the large class of ammoniacal compounds known to chemists, it seems strange that no one has yet taken advantage of that interesting series which suffers decomposition by the mere application of a moderate temperature, evolving at the same time pure ammoniacal gas, and yielding, as a residue, the substance originally employed for purification. We shall enumerate but one or two substances of this kind for the purpose of illustrating our argument, leaving the whole question as open as ever to practical investigation. When phosphate of magnesia is exposed to the action of ammoniacal gas, its acid becomes divided in such a way as to produce the triple salt called ammoniaco-phosphate of magnesia; and as this is a much more insoluble substance than the simple phosphate, we have only to pass impure coal gas through a solution or aqueous mixture of the latter, to insure the precipitation of all the ammonia contained in the gas; whilst, at the same time, the compound which it has formed with the phosphate of magnesia is very easily decomposed, so as to admit of a continuous usage of the same material; foi: at a temperature considerably below a red heat, the triple phosphate of magnesia parts with all its ammonia, and becomes simple phosphate again, with the renewal of its primitive power as an absorber of ammlln iacal vapours. But the ammonia which is expelled by heat might very easily be condensed in water, and thus originate a valuable commodity for the market. By this means there can be no doubt phosphate of magnesia might be employed over and over again in the purification of coal gas, whilst the ammonia procured from it would contain neither sulphur nor any other impurity. An iron vessel might be used for the distillation; and if too high a heat was not given to the phosphate of magnesia, its purifying action would remain unaltered; thus presenting altogether a fair opening for the investment of talent and industry. Similarly, boracic acid deserves attention, fiom the facility with which, even at the temperature of boiling water, it parts with the greater portion of any ammonia previously united to it, at the ordinary heat of the climate in this country. It offers, consequently, a commodious vehicle for collecting and conveying the ammonia of gas works into public use, without the risk of nuisance or loss. Many other substances possessing this double property of absorbing and giving off ammonia by a trifling change of temperature might be pointed out; but this lies beyond our province; it is the principle only which we attempt to elucidate, with a view to its practical application in some specific instance. Presuming that the impure gas has had all its ammonia separated by proper treatment, we have now to consider in what way the carbonic acid and sulphuretted hydrogen may be most easily got rid of. Lime is the agent commonly selected, and all things duly admitted, there is a great mass of evidence in its favour,-so much so, indeed, that, until lately, it has had no competitor. At present, however, the oxide of iron is becoming a formidable rival; and therefore we propose to examine into their respective merits, which, after all, are less alike than might be supposed in two substances selected to perform one and the same operation. When properly prepared and moistened, lime removes from imnpure coal gas both carbonic acid and sulphuretted hydrogen with extreme energy, and consequently effects thorough purification after the ammonia has been got rid of. Oxide of iron combines only with the sulphuretted hydrogen contained in the gas, and not with tile carbonic acid; so that coal gas purified in this way requires subsequent application of lime, or some other material capable of combining tith carbonic acid. Thus far, therefore, the advantage is much in favour of lime. But when lime has absorbed all the impurity it can attract from coal gas, or, in technical COA.. 435 phrase becomes "foul," it is not only altogether useless, but, much worse than this. it is a serious nuisance, in consequence of the evolution of sulphuretted hydrogen the moment it comes in contact with atmospheric air, which arises from the action of the atmo spheric carbonic acid upon the hydrosulphate of lime contained in the foul mass. Gas-lime refuse is therefore a grave inconvenience to many gas companies. Now with oxide of iron no such inconvenience is felt; for this substance in uniting with sulphuretted hydrogen produces a compound which yields no noxious or unhealthy emanations by the contact of air, but is, under such influence, simply oxidized, and in a great measure restored to its primitive power, so that it may be used over and over again, ten, twenty. or even thirty times in succession. These peculiarities give the oxide of iron a decided superiority in many situations, though up to the present moment its practical application has been extremely limited. When limie contained in a purifier has ceased to purify gas, the general impression is that in has been wholly resolved into carbonate and hydrosulphate of lime; but this is very far indeed fiom being the case, for even the foulest lime seldom contains less than one-fifth of all its lime free or uncombined; and gas-lime refuse is occasionally to be had so imperfectly saturated that fully one-half of the lime paid for by the gas company may be said to be thrown away. In the first place, it is not customary to examine the lime itself, so as to determine its chemical value or combining proportion, and still worse, it is not usual, secondarily, to analyze the lime refuse with a view to ascertain how much lime is passing away unacted onr As both of these desiderata may be secured without the application of any great chemical skill, we shall proceed to give a brief description of the means needed to solve the trifling problems, beginning with the lime itself. Having selected froom the bulk a fair sample of lime, let this be ground to a fine powder in a clean and dry mortar; then weigh out 100 grs. of the powder, and place it in a tumbler or other suitable vessel, where it is to be repeatedly washed with a warm but not hot solution of sal ammoniac in water,-the temperature being about 80~ or 90~ Fahr. Great care must be taken that, in washing the lime, no solid particles are allowed to escape with the ammoniacal solution; and, as soon as it is observed that the fluid containing the sal ammoniac ceases to restore the colour of reddened litmus paper, after it has been poured upon the lime, then common water may be used to wash the remaining lime; after which it must be dried at a red heat, and then weighed;-the loss will indicate the amount of pure lime present iii the 100 grs. taken. This mode of analysis depends upon the fact that lime, at the temperature indicated, decomposes muriate of ammonia and becomes soluble, but any carbonate of lime, silicate of lime, alumina, or other inactive impurity, remains undissolved, and may therefore have its quantity determined by the balance. Foul gas-lime, or refuse, is somewlhat more complex, but nevertheless far from difficult in its analysis. Having, as before, selected a fair sample, let 200 grs. be weighed out, and placed in a scoppered bottle, with an equal weight of sal ammoniac, and four ounces of water, heated, as before, to about 80~ or 90~; shake the whole well together, and keep the mixture warm for twenty minutes; then filter rapidly into a stoppered retort, and wash the filter with two ounces of hot water, which are to be added to the filtered solution. Next distil over one-half of the fluid into a receiver containing 100 grs. of sulphate of copper, dissolved in water, and set the fluid remaining in the retort aside to cool. Collect the black precipitate now contained in the receiver upon a filter, and wash it well with hot water, then dry and weigh it: it is the sulphuret of copper, and contains one-third of its weight of pure sulphur. The fluid in the retort must now be mixed with an excess of carbonate of soda, and the white precil)itate which ensues well washed, dried, and then weighed. One hundred grains of this precipitate, which is carbonate of lime, indicate 56 grs. of pure lime; and if from this we deduct the quantity combined with sulphuretted hydrogen, as given by the sulphuret of copper, the remainder will be the total quantity of pure lime in the 200 grs. of gas-lime refuse, which had not been utilized in the purifier. Thus, suppose that 200 grs. of any sample in question have given 24 grs. of sulphuret of copper, and 80 of carbonate of lime, then the total amount of lime will be 44 8 grs., from which 14 grs. must be deducted for that united to sulphuretted hydrogen, since the atom of sulphur is to that of lime as 16 to 28, and 24 grs. of sulphuret of copper contain 8 grs., or one-third of its weight of copper, which is consequently equal to 14 grs. of pure lime. This supposed sample has therefore given 30'8 grs., or 15'4 per cent. of free lime. Thus, in place of the mere rule of thumb system, too commonly pursued in gas works, a good gas engineer will control the entire produce of his manufactory by determining, first, the total amount of sulphur given off in a gaseous form by the coal he uses; next the chemical power of his lime; and lastly, whether or not the action and arrangement of the purifying apparatus is such as to insure the proper saturation of the limewith the impure constituents of the coal gas. Without the occasional employment of analytical processes, similar to those previously given, it is altogether impossible to conduct gas-works with that certainty an con fidence essential to perfect economy. 436 COAL. It might be supposed that with the purification of coal gas the chief difficulties of a gas engineer ended, but this is very wide of the truth; for upon no point is there greater diversity of opinion, and more discrepancy in result, than exists regarding the proper mode of burning gas for the purposes of illumination and heating. As regards the former question, it seems hitherto to-have been impossible of solution, from the fact that quantity and intensity of light have been confounded together; and persons have been surprised to find that a bright white light, of great intensity to the eye, has, nevertheless, illuminated a given space worse than a large quantity of dull, yellow, smoky-looking light. Thus, if when an argand oil lamp is burning with great brilliancy the central aperture for the admission of air be closed, the flame will immediately become yellow and smoky, yet, on examining tllh walls of the apartment, it will be found that they are better illuminated than with the more brilliant light. In the former case, many of the particles of carbon are consumed before they take on the solid condition, whereas in the latter, they are all separated from the hydrogen of the oil, and become red-hot solid bodies ere they inter into combustion. But as the quantity of light is proportioned to the number of solid particles heated, and its intensity to the elevation of the temperature to which they are heated, it follows, that part of the carbon is employed in producing heat, to give intensity of light to tile remainder, in the one case, whilst in the other, the whole of the carbon becoming solid reflects a great quantity of light of less intensity. For the ordinary wants of society, the latter is the best light. A knowledge of these matters enables us easily enough to explain the vast difference in illuminating power which one and the same gas displays when consumed in different burners. Thus, a thin gas, of low specific gravity, which affords an excellent light in an argand burner, will scarcely yield any light at all with a fish-tail or bat's-wing; and a rich cannel coal gas, well adapted to either of the latter burners, requires infinite care to prevent it from smoking in an argand. In determining the relative illuminating powers of different gases, it is therefore necessary to select for each gas that form of burner best suited to display its light-giving properties, and not continue the present Procrustean system of cutting down the power of the gas to an arbitrary standard of burner; the only result of which has been a series of assertions and contradictions too disgraceful for further notice. In photometrical experiments, a spermaceti candle, of a determined size, is commonly employed, and, in a rough way, answers remarkably well. But sperm, like wax and tallow, gives quantity of light, but not of an intensity equal to gas, as may be seen in a moment by contrasting the comparatively yellow flame of the one with the brilliant white light of the other. They are therefore like musical instruments tuned to a different pitch, and can never harmonize with each other. The better plan would be to select olefiant gas as a photometrical standard, since this compound is uniform in composition, and can be easily prepared at a few minutes' notice. It possesses, moreover, the advantage of being consumed in similar burners to that employed for the gas to be tested, and is under the influence of the same barometric and thermometric variations. The Bunsen photometer, as modified by Mr. A. King, of Liverpool, is, perhaps, the best instrument to employ in experiments on comparative illumination. Regarding the ultimate analysis of coal gas little need be said, as the results have no specific value or meaning. The only correct mode of analysis is by passing a known volume of the gas over oxide of copper in a tube heated red-hot, and collecting first the moisture by chloride of calcium; secondly, the carbonic acid by hydrate of lime or solution of potash, as followed in ordinary organic analyses; and, lastly, receiving the incombustible residue over water in the pneumatic receiver: from which three products, the quantity of hydrogen, carbon, and nitrogen may be deduced. The ultimate analyses of coal gas, as also the estimation of its value fiom the condensation of what is termed its olefiant gas, whether by chlorine, sulphuric or nitric acid, are processes of no practical value to the public, and serve only to mislead the ignorant. From the vast reduction which is now taking place in the prices of coal gas, its calorific power has become one of the most interesting questions of the day; and when the waste of fuel consequent upon lighting a common fire, with the quantity consumed after the fire is no longer wanted, are carefully inquired into, it seems very clear, that for at least 4 or 5 months of the year it is cheaper to cook by gas in London than by coal, at the existing prices of these articles. An apposite illustration of the correctness of this assertion is afforded by the warm bath of Mr. Defries, in which 45 gallons of water are heated from the temperatures of 500 to 100~ Fahr. by 30 cubic feet of gas, and at a cost of only three pence. Now, to effect this at all by coal would entail an expense of at least fourpence; but to do so in tile same period of time (5 minutes), would certainly entail an outlay of not less than a shilling. Of course, where the operation is to be repeated, or go on continuously, a different result would ensue; but for extemporaneous use, coal gas will always be cheaper than coal. But even this surprising economy has been exceeded by a very elegant arranrlgent, invented by Mr. F. I. Evans, of Westminster, in which a coil of iron tubing is so disposed, as to present an immense surface to the heating influence of the burnt gas, and thus absorb the whole of the heat. In this way, a current of cold COAL. 437 water entering at one end of the tube flows out of the other continuously, and at any required temperature, according to the velocity of the current, and the quantity of gas consumed in a given time. For the requirements of the Humane Society, for the public hospitals and charities, a simple apparatus of this kind must find a ready application, and deserves to be better known. According to direct experimehts, made with great care, Mr. Evans has found that common Newcastle coal gas, of sp. gr. -416, has an evaporative value equal to about 22 times its weight, or, in other words, that 1 Ib. of such gas will convert, theoretically, 22 lbs. of water into steam; and this accords very well with the results given by Defries with his bath, in which 30 cubic feet of gas are stated to heat 45 gallons, or 450 lbs. of water at 50~. This is equal to 15 lbs. similarly heated for each cubic foot of gas, weighing, say 206 grains, or 750 lbs. of water heated one degree by the same means. This, estimating the latent heat of steam at 960, gives 25 parts of water boiled off for every one part of gas consumed, which is very nearly three times as great as the heating power of good Newcastle coal. But practical experiments were wanting to show he real amount of water which can be boiled off by gas, as burnt in ordinary burners beneath a boiler. This deficiency has been supplied by Mr. Evans, to whom we are indebted for the following tabular statement:-One cubic foot of gas, weighing about 205 grs., and of sp. gr.'413, boiled off four tenths of a pound of water, or 13'6 times its weight. One cubic foot, weighing about 290 grs., and of sp. gr. -564, boiled off five tenths of a pound, or 12 times its weight. One cubic foot, weighing about 360 grs., and of sp. gr.'700, boiled off seventenths of a pound, or 13'6 times its weight. Thus showing that in the case of gas, onethird at least of all the heat evolved passes off unabsorbed by the boiler. In our comments on coal we had occasion to remark that something like one-half of all the fuel consumed under steam boilers is wasted; and it now appears that fully onethird of all the gas employed in our culinary operations must be thrown away, and lvill continue to be so until the hand of improvement is applied in the proper quarter. There is, unquestionably, much scope for ingenuity in devising the best forms of apparatus for burning gas, and utilizing its waste heat. A very elegant little machine, which promises to elucidate some obscure points as regards the purity of gas, has lately been added to the ordinary testing chemicals of a gas engineer. This consists of a bent tube,'forming, as it were, the horizontal flue of a furnace, in which the products of combustion arising from gas may be condensed, and afterwards examined with reference to their nature. Mr. A. Wright, of Westminster, is the inventor and maker of the apparatus in question, and by its means two curious facts may at almost any time be demonstrated. One of these is, that sulplsuric acid is an invariable product of the combustion of coal gas;'the other, that very frequently, and more especially with cannel coal gas, a substance possessing all the properties of aldelhyde makes its appearance. The latter seems to be a product of imperfect combustion, and gives rise to that peculiarly offensive odour produced wherever large quantities of coal gas are burnt in a close compartment. It is commonly believed by chemists, that coal gas contains ammonia, which in burning is converted into ritrous or nitric acid; but the apparatus of Mr. Wright demonstrates at once the fallacy of this opinion, by proving that whenever gas contaminated with ammonia is consumed, the ammonia either passes off unchanged, or is simply decomposed into its elements; for carbonate of ammonia, and not nitrate, makes its appearance in the condensed products. Before quitting the subject of coal gas, it is necessary to say a few words upon the composition and use of what is called ammoniacal liquor. This fluid condenses in the hydraulic main, and flows out with the tar, from which it afterwards separates by gravitation. Its specific gravity varies, as also does its composition; but the following may be regarded as a fair average: in one gallon, of specific gravity of 1'017, there were found of sesquicarbonate of ammonia 5984 grains, hydrosulphate of ammonia 420 grains, muriate of ammonia 985 grains, with a trace of ferrocyanate and sulphocyanate of ammonia; consequently, if the small quantity of sulphuretted hydrogen existing in ammoniacal liquor be removed, hs it may be by the application of the requisite proportion of carbonate of lead, an ammoniacal solution will be produced, extremely well adapted for many useful purposes in the arts, such as scouring woollens, flax, and other goods, as well as for washing in general. In all these cases, ammonia is greatly to be preferred to soda, even at the same price; but as the ammoniacal liquor of many gas works is actually thrown away, and under no circumstance sells for more than a farthing a gallon, it is discreditable to our industrial economy that this very obvious application of ammoniacal liquor should continue to be neglected; more especially as the fluid, even after being used as above indicated, is still an excellent fertilizing agent. In the Great Exhibition, there were but few illustrations of the manufactures peculiar to gas; a circumstance attributable to the risk of permitting the necessary experiments to take place, by which alone the actual value of any improvement in gas apparatus can be correctly determined. lencc, in the Crystal Palace, merely articles of established reputation were shown. whichl. lnving been long before tihe 438 COAL. public eye, by no means represented the existing condition of this branch of nanufac, ture. On this account, although the decision of the executive committee to exclude experimental gas apparatus seems somewhat unfortunate, yet, when the great value of the goods shown in tile Exhibition is duly considered, there can be but two opinions concerning the propriety of the step. The various samples exhibited were neverthe less extremely good of their kind, both in the British and Foreign departments. In clay retorts, the best specimen was in Class 27., by Cowan & Co., of Blaydonburn, Newcastle-on-Tyne; and the next in quality stood in the Belgian portion of the Exhi bition. M1. Pauvels, of Paris, exhibited a very good retort also; and there were several satisfactory-looking samples from other quarters. COAL GAS, COMPOSITION OF. From the most recent investigations into the composition of coal gas, it appears extremely doubtful whether any gaseous compound exists in it to which the name olefiant gas can, wi h prop)riety, be accorded, and it certainly seems to have been assumed on very hasty and unfounded data, that to the presence of olefiant gas the illuminating force of common coal gas is chiefly due. Without pretending to deny altogether the presence of the olefiant in the gas of our streets, it is nevertheless susceptible of proof that the quantity which, on the most liberal computation, can be allowed, is infinitely small and insignificant, and, in a practical sense, warrants the now prevailing opinion that there is really none. In support of this, it can be shown that if common coal gas be made to traverse very slowly a great length of tube exposed to the refrigerating effect of a bath of ice and salt, the gas will issue from the other end of the tube almost entirely deprived of its illuminating power; and a similar result may be obtained at oldinary temperatures by passing the gas through alcohol and other reagents. In the case of alcohol, the effect is, however, very instructive, for the alcohol gains exactly that which the gas loses in illuminating power, and, after the experiment, it is found to burn with a bright white flame, and to become milky with water.'Now, on the supposition that the photogenic power of coal gas was due to olefiant, none of these results should follow, for no such cold would liquefy olefiant gas, nor would alcohol absorb it in any great degree. Moreover, all attempts to obtain, through the agency of fuming sulphuric acid, any compound like sulpho-vinic acid have utterly failed, even when tried upon a rather large scale. Hence, in regarding coal gas, it is theoretically molre correct to consider its luminosity, as arising fi'oml the presence of various volatile hydrocarbons or naphthas, rather than from any permanently elastic fluid whatever. This view of the case has latterly become very prevalent, and is now leading to the most important improvements in the manufacture of illuminating gas. It has long been known that ordiinary bituminous coals will yield a much larger volume of gas than may, with propriety, as regards the photogenic poxer of that gas, be taken away fiom the coal. Thllis arises from the circumstance, that the first portions of gas are nuch richer in hydrocarbons than the remainder of the charge, and a period arrives at which the gas, though still great in quantity and eminently combustible, ceases to possess any value whatever as an illuminating agent. Moreover, it is known that the mixed gas obtained by decomposing water through the agency of carbon at a red heat is also colmbustible, but devoid of photogenic power; and it is owing to a correct appreciating of the circumstances upon which the value of coimmon coal gas depends, that both these and other forms of combustible gas have lately been rendered as permanently lunminous and well-adapted for the production of light as the best kinds of common coal gas. Hlaving once clearly comprehended the cause of luminosity in ordinary gas, but few steps are required to perceive that the latter portion of a chiarge of coal, when distilling in a retort, needs but a/part of the surplus hydrocarbons of the first portion to renlder it equally valuable, and we are insensibly drawn to the means of effecting the desired end. Thus, if the latter portions of the charge be stored away separately, and passed in regular quantities over coal which is undergoing the primary action of destructive distillation, it is clear that such gas will become charged with the hydrocarbons of that primary distillation, and thus, in all respects, resemble the first part of the charge, or, in other words, be made equal to the best gas; at the same time the amount of labour and expense incurred in condensing out these surplus hydrocarbons nust be much diminished by the presence of an amount of gas capable of retaining them permanently in solution at ordinary temperatures. Not only, therefore, is it possible to procure in this way a much larger quantity of gas of an average illuminating power from a given weight of coal, but the expense of this production is decreased by the diminished condeination needed for the whole, as compared with that required for a part of the gas under the old system. But there is a still greater advantage than these, and one scarcely to have been expected. These poor gases consist chiefly of hydrogen gas, and it has been discovered that this gas possesses the remarkable property of preventing the decomposition of every forml of hlydlocarbon at a red heat. Thle consequence, therefore, of passing such gas over coals, in its primary state of distillation, is to prevent the decomposition of the various naphthas by the heat employed, and which, without the presence of hydrogen, L,,uld be resolved into solid carboni anld li ht carburetted lydrogen, the former of which COAL. 439 remaining in the retort impairs the utility of that vessel, whilst the illuminating power of the gas produced is greatly diminished by the loss of solid matter. Now it has been stated that to these naphthas the luminosity of gas is to be attributed, and therefore their preservation in the way described, by the action of hydrogen, would of itself be an immense step in advance of our former practice; but when to this is added the fact that, with a vastly increased preservation of hydrocarbon, there is also a vastly increased production of combustible gas to render that hydrocarbon available for public use, the real merit of the new discoveries in gas-making must strike even the most thoughtless observer. Of course, the same argument which applies to the use of the residuary gas from a charge of coal, is equally fitted to illustrate the beneficial operation of the gases evolved by decomposing water with red hot carbon. In this latter instance, however, an important fact presents itself, for unless the whole of the surplus watery vapour has been removed or condensed from this water gas, the hydrocarbons arising from the incipient distillation of the coal are destroyed, und, therefore, the object sought to be gained is lost. This accounts perfectly for the innumerable failures which have taken place in attempting to employ steam and water gas for the purpose of illumination; nor, until ftis subject was investigate' by Mr. T. G. Barlow, does any one appear to have formed a correct opinion of the cause of such invariable want of success. Mr. Barlow, however, not only discovered the peculiar preservative F-ower of hydrogen, but also the no less remarkably destructive action of steam, and hence, by nierely condensing this latter, he has been enabled to employ water gas with a suce asA which bids fair to prove a very profitable manufacturing speculation, and for the details of which he has secured her Majesty's letters patent in conjunction with Mr. Gore. For the application of the residuary gas from common coal to the preservation of the hydrocarbons arising from fixed oils and fats during distillation, and for the production from coals, lignite, tar, &c., of a larger amount of illuminating gas than can be obtained by the ordinary process, the public is indebted to Messrs. G. Lowe and F. I. Evans, both well known as engineers in the service of the Chartered Gas Company. That these improvements will, in some measure, revolutionise the manufacture of gas seems pretty obvious. To determine with any degree of precision the value of a gas as an illuminating agent is really a very difficult, though seemingly a very simple affair. The most general method is by the instrument called the Bunsen photometer. The indications of this instrument (at best but imperfect) have been so largely improved by the ingenious modifications made in its use by Mr. Alfred King, of Liverpool, that it has come to occupy a position in the public confidence, to which in its original condition it had not the slightest title. The great difficulty to overcome was the securing of one uniform standard of illumination, without which, as a matter of course, the indications of the photometer were utterly valueless. This indispensable condition has been in a great meusure arrived at by Mr. King, who employs a spermaceti candle, and ascertains the amount of spermaceti actually consumed during the experiment, and then reduces this to one uniform rate of 120 grains of spermaceti burnt per hour as contrasted with an hour's consumption of the gas to be tried at the rate of five feet per hour, or in a series of ratios, from 2 to 5 feet per hour; there are, however, many disturbing causes in the burning both of the candle and of the gas, anda very serious one results fiom the fact that the shape 80 of the flame of the gas materially affects its photogenic meter, thus the flat side of a bat's-wing burner will give almost one-third more light 70 than the edge of the same burner, though the rate of consumption be unaltered. 60 It is necessary, therefore, to adopt some other means of determining the value of a gas than by photometry, and it would appear that 50 this may be effected by the agency of bromine. This substance possesses in a singular degree the power of removing from coal gas the whole of the vapours upon which its luminosity depends, and if these vapours were uniform in composition, all that need be done would be to determine their volume per cent. But this is quite useless, for the vapours 30 differ in themselves to an incredible extent, and therefore it is not only the volume, but the specific gravity of these vapours also, which must be 20 obtained, or in other words, their total weight, for this weight represents the value of the gas. Nlow if we take a tube bent, closed at one end, 10 and graduated, as shown in the following figure, we possess at once an [ instrument for determining the value of a gas by volume. This tube must be filled in the first place with water, and so much of the gas passed up into it as will occupy the graduated po;tion, when the residuary water will act as a valve. Having placed the whole for a few minutes in a cylindrical vessel containing water, so as to secure a uniform 140 COAL. temperature, the tube must be raised to the water level, and the exact quantity ol Ias recorded. When this has been done, a few drops of bromine, in all about the size of a pea, are to be dropped through the water in the tube, and a stopper or cork applied; the whole must then be well agitated, until the gas becomes tinged with the red hue of the bromine, after which the stopper must be removed under water, and a few drops of a strong solution of potash being added the stopper is to be replaced, and the whole again agitated until the bromine tint of the gas has disappeared, when the stopper must be again withdrawn under water, and the tube placed as at first in a vessel of water to regain its original temperature, when the water-level must be once more made, and the amount of absorption read off and recorded. This operation does not last more than 10 or 15 minutes, the barometer need not therefore be consulted. Precisely similar to this, but on a larger scale, is the first part of the opc(-ation for determining the weight of the condensed portion. In this case a vessel shaped as below is necessary. as beo This, as is evident, differs very slightly from the tube, the bottom being provided with the same water-joint contrivance for the introduction of the bromine, whilst the stopper is pierced by a hole, in which a stop-cock is very carefully fixed, so that after the action of thL bromine and caustic potash, the gas may be removed by an exhausted flask so i''t its specific gravity can be readily determined. Before doing this, it is however advisable to wash the gas two or three times with cold water, whichllis easily done if we introduce the bottle into a vessel of warm water so as to expand the gas, and thus expel the fluid through the water-joint tube, which being effected, we have only to close this opening and immerse the bottle in cold water, when, by withdrawing the stopper joint, cold water will rush in, and this may be repeated at pleasure, the object being to wash the residuary or incondensable gas thoroughly; this operation requires but a short time, and if we have taken beforehand the specific gravity of the original gas, the amount of its condensation, and now know the specific gravity of the incondensable portion, it is clear that we possess the means of knowing the exact weight of that which has been condensed. Thus, a cannel coal gas at Westminster was analyzed in this way, its illuminating power by the photometer being 20 candles per 5 feet. This gas had a specific gravity of *48500, and a condensation of 9 per cent., whilst the specific gravity of the uncondensed portion was'336. But if 100 weigh'33600, then 91, the amount of uncondensed, must weigh 30576, and this deducted from'48500, leaves'19924 for the condensed gas, which, as we have seen, is equal to 9'5 per cent., and bringing this to the uniform standard of 100 measures, we have 2'09 for the specific gravity of this condensed vapour; and if this specific gravity be multiplied by the amount of condensation, we shall have the true value of the gas in numbers, which, by a singular coincidence, run very close with the indications of the photometer as chosen by Mr. King, that is to say, the number of spermaceti candles burning 120 grains per hour, which the gas is equal to when consumed at the rate of 5 feet per hour. In this instance that number, it will be remembered, was 20, and 2'09, the specific gravity of the condensed gas, multiplied by 9'5, its per centage absorption by bromine, gives 20'855, a very close approximation. A vast number of experiments have been made, all of which are equally conclusive as to the value of these indicators. COALS (heating powers of). An accurate, systematic, and intelligible report upon the calorific properties of coal has long been needed by the manufacturing and mercantile interests of this country. In addition to the vast importance of such an inquiry, it would be perhaps impossible to point out a subject on which less difference of opinion exists as to the extent and nature of the information wanted than the one before us. Science, properly speaking, has little or nothing to do with the question; the object in view is purely and exclusively practical, and is meant for the guidance of practical men and for practical purposes. Theory, above all things, should be carefully avoided in such investigations; and supremely indifferent about the assistance of any eminent chemist on such an occasion, we should, nevertheless, insist strongly upon the necessity of providing a good stoker. Mr. Hume. M. P., however thought otherwise; and to him the country is indebted for the first report upon the coals destined for the steam navy. Of this report we will venture to say at once that a more garbled, more inaccurate, and less impartial job was never exhibited-nay, not even in the House of Commons. To begin at the beginning of this disgraceful affair, we will merely remark that Mr. Hume (whose honesty and integrity are beyond suspicion) directed the attention of the Lords ef the Admiralty to a subject which, if these Lords attended to anything but their salaries, must have occupied their attention years ago. Mr. Hume, after referring theii COAL. 441 lordships to an American report, with experiments, on the evaporative value of coals, says:" They have decided by direct and practical tests the comparative usefulness of American and English coals, as well as the relative value of the former in their numerous varieties; and I submit to your lordships that a similar inquiry should be instituted into the comparative usefulness of English, Scotch, and Irish coals, with the view of ascertaining the best for the naval steamers of this country. I may be allowed to point out to your lordships that there is a public establishment in Craig's-court perfectly qualified to apply the requisite direct and positive tests to the coals without delay; and to that establishment may be added one chemist of eminence to assist in what is an object of great national importance." Upon this the Admiralty applied to Sir H. de la Beche, who, after the usual preliminary remarks, observes:" As the funds of the Museum of Economic Geology are, unaided, inadequate to an investigation of this order, I would suggest that the Admiralty be requested to furnish aid to the amount of 6001. for the remainder of the year ending the 31st of March, 1846. With this aid I have little doubt that we should be enabled to accomplish much this year which may be of value, and have organized a system of inquiry alike effective, and, viewing its national importance, which can be carried out at comparatively small cost to the public." We must content ourselves by guessing at the meaning of the last paragraph, and, as far as this can be done with safety, we may conclude that, in the opinion of Sir H. de la Beche, the funds of the Economic, plus 6001., would answer the object in view, to wit, the obtaining a practical report upon the evaporative power of English, Scotch, and Irish coals. If anything else is meant, why is 60(). named? The question is very fairly put by Lord Lincoln, who, in reference to the establishment in Craig's-court, asks, in plain English, "What is the course you would recommend for making it effective for the purposes to which such an inquiry would be obviously directed " Sir H. de la Beche in answer mentions 6001. in addition to the funds of the Museum of Economic Geology; yet something more appears to have been given by the following "memorandum":"The Admiralty having acceded to the recommendation made in the foregoing letter, and subsequently also supplied additional funds for the investigation, the latter was commenced as soon as the-needful apparatus was erected and proper assistance procured, which could not be accomplished until March, 1846." Now, what is the meaning of the additional funds supplied for the investigation? Were the funds of the Economic, plus 6001., spent on apparatus alone? And was it to the mere erection of this apparatus that Sir Ii. de la Beche alluded when, in 1845, he wrote, " With this aid I have little doubt that we should be enabled to accomplish much this year," &c.? There is a mystery about the very commencement of that business. Seldom do we find Government officials ready to comply with the prayer of a petition which has merely public utility to recommend it; but Mr. Hume has nothing to complain of on that score in the present instance, for in addition to the Craig's-court establishment he solicited but one chemist, when lo! the investigation falls into the hands of Dr. Lyon Playfair, Mr. Wilson, Mr. J. Arthur Phillips, Mr. Kingsbury, Mr. Wrightson, Mr. Galloway, Mr. Hoy,. and William Hutchinson, all and each endowed with qualifications of a peculiar and important character bearing upon the investigation in hand, and tending of course to render the report superlatively correct, useful, impartial, &c., &c. There is an old axiom regarding broth made by a multiplicity of cooks, but perhaps it does not apply to parliamentary reports and chemists. The mystery does not, however, end here. Mr. Hume had requested that the inquiry should be made upon English, Scotch, and Irish coals. Now, the following is the list af coals operated on:NAMES OF COALS EMPLOYED IN THE EXPERIMENTS. MWELSHGraigola, Three Quarter Rock Vein, Anthracite, Jones and Co. Cwm Frood Rock Vein, Old Castle Fiery Vein, Cwm Nanty Gros, Ward's Fiery Vein, Resolven, Binea, Pontypool, Llangenneck, Bedwas, Pontrepoth, Ebbw Vale, Pontrefellin, Porth Mawr, Duffryn, Coleshill. Mynydd Newydd, 442 COAL. ScoTI — )alkeith Jewel Seam, Fordel Splint, D)alkeith Coronation Seam Grangemouth. Wallsend Elgin. ENGLISIBroomhill, Lydney (Forest of Dean). InRIHSlievar lagh Irish Anthracite. From which it appears that the inquiry has been made almost exclusively upon Welr1 coals, for, out of twenty-seven samples of coal examined, 19 were Welsh, 5,, Scotch, 2,, English, 1 was Irish. One of two things is very plainly exhibited by this table; either Wales is, above all other places in the world, blessed with coals " suited to the steam navy," or a most unjust and uncalled-for selection has been made for private purposes. It is vain to talk of a next report; it will require years to complete another report, even if such another disgraceful exhibition of partiality was attempted; and meanwhile our steam navy must be supplied with the euphonious productions of Wales, to the exclusion of the vast coalfields of Newcastle. Of the two samples of English coal examined I am practically acquainted with but one, for of the Lydney coal I know nothing; as regards the Broomrhill coal, however, I can safely assert that its only recommendation consists in its belonging to Earl Grey, for at Newcastle it is regarded as an unimportant secondrate coal, the very name of which has not yet found its way into the London market. It is far inferior for steam purposes to the whole of the undermentioned coals, many of which are, in fact, the best steam coals for sea-going vessels in the kingdom Carr's Hartley, West Hartley, Hasting's Hartley, Bate's West Hartley, Hedley's Iartley; Buddle's West Hartley, Newcastle Iartley, Davidson's West Hartley, Percy North Hartley, Nelson's West Hartley. Richardson's Hartley, Why these and many others have been passed over so unceremoniously to make room for the wholesale introduction of the Welsh coal remains to be explained; we will now, however, examine the report itself. The first circumstance which attracts attention in this report is the appearance of certain very simple equations, which, although well enough adapted for a boy just commencing algebra, are singularly out of place here, since those who understand such things generally prefer to make their own equations; and those who do not are but little likely to benefit by such a display of learning. A curious attempt is made at page 13. to prove that the evaporative value of a bituminous coal is expressed by the evaporative value of its coke:-' It is easy," says the report, " from analysis to examine whether the duty performed by the coal is to be attributed to its fixed ingredients or coke, by estimating the work which the latter is capable of performing. This may be done by subtracting the ashes in the coal from its amount of coke, and estimating the remainder as carbon; this carbon multiplied by its heating power, 13268, and divided by 965-7, orthe latent heat of steam, indicates the number of pounds of water which the coke by itself could evaporate without the aid of the combustible ingredients of the coal. These results are placed in column 3. of Table 6. (see next page), in juxtaposition with the actual work done by the coal, and it will be seen that, notwithstanding several striking exceptions, which might have been expected, they on the whole show that the work capable of being performed by the coke alone is actually greater than that obtained by experiments with the original coal." Now, if this table proves anything, it proves the very reverse of the position attempted to be established, unless theory is presumed to be equal to practice, which it certainly is not, or why the necessity of spending upwards of 6001. in practical experiments? But theory may be justly compared with theory, and then the table, so far from proving " that the evaporative value of a bituminous coal is expressed by the evaporative value of its coke," clearly proves that the evaporative power of a bituminous coal is an immense deal greater than that of its coke; indeed almost double; and that the volatile ingredients of coal evolve in burning relatively a much greater proportion of heat thar COAL. 443 the fixed constituents; this is, indeed, precisely what might have been expected from the well-known caloric power of hydrogen, which is three times greater than that EXTRACT FROM TABLE 6., SHOWING THE ACTUAL DUTY AND THAT WHICH IS THEORETICALLY POSSIBLE OF THE COALS EXAMINED. Actual IN umber of Number of lbs. Total Number Amount of Ibs. of Waler o Water of lbs. of XWaer Amount of bulphate of ol.verted coL,v l tt:a i ito convertible A mmonia Ammonlia.ame or Locality of CoaL ito o Stoam n tealn by the into Steam Correspolldillg correspol ling by II),. of Ooke Ieft by by lib. of to the iito.ren to the Nitrogen coal. the Coal. the C oal. contaidined in coitaihed i. the Coal. the Coal. Practical. Theoretical. Theoretical. Graigola - 935 11-301 130563 0497 1.932 Anthracite, Jones and Co. 9-46 12-554 14-593 0225 09990 ()ld Castle Fiery Vein - 8-94 106U1 14936 1590 6175 Ward's Fiery Vein - -14614 238 4 808 nines --. 994 11'560 156 6741 Laslgenneck - - -8 O 10 599 14-260 1 299 5-044 Pontrep"th - - 872 1(0873 14 838 0'218 0-848 Poist.efellin 6 36 10 841 13 767 a trace - Powell's Diffryn - 10'149 11134 15092 16 835 Mynydd Newydl - 952 9831 14 904 1'808 7'340 Three Quarter Rock Vein 8 84 7(181 13106 1293 5-044 Cwm Frood Rock Vein 80 8628 14'788 1347 50232 Coin 1 Nasty Gros - - 42 8243 13'932 19'19 7'448 Resolven - 953 10-234 13971 1 675 6505 Polltypool - - 747 8144 14'295 1 639 6'361 Bedwas - 99 8-897 14-841 1-748 6-788 Etobw Vale - 10-21 10441 15635 2622 10 182 Porth Mawr Rock Vein 7.53 6047 12811 1554 6)033 SCodleshil - - - - 8~60 6468 12'799 1.785 6 930 Dalkeith Jewel Seam -708 6-239 12313 1-214 0 471 Dalkeith Coronation - 7 71 6'924 1272 atrace Wallsend Elgin - - - 846 6560 13422 112 6-647 Fordel Splint - - 756 6.560 13 817 1 372 5327 Grangemouth - 7'40 7-292 13-692 1-639 6-364 Broomhilll - - - 30 7-711 14 863 2-234 S8674 Park End Lydney - 8 52 6f567 13 257 147 9617 Slievardagh - - 9-85 10-895 12482 0279 1084 of carbon. There is, however, clearly a design throughout this report to extol the anthracite coals at the expense of the bituminous; and, if Messrs. de la Beche and Co. could succeed in establishing the fact that the heating power of coal is due solely or even principally to its relative amount of carbon, it follows that Welsh coal must rise in the market, for the greater part of the coal from that district is of the anthracite kind, none of which is worked in the north of England. To prove the absurdity, how ever, of the above attempt, I will quote two or three cases from Table No. 6.:Theoretical Name of the Coal. Weight of Water Excess Evaporated due to Volatile by by Ingredients. Coke. Coal. _____ WELSH- 2 Graigola - - - - 11301 13-563 2 262 Old Castle Fiery Vein - 10-601 14-936.073 The thin Mynydd Newydd - - 9-831 14904 5h speaks SCOTCH -for itself. Dalkeith Jewel Seam - 6-239 12-313 6-074 ENGLISH - Broomhill - - -'711 14-863 7-152J After theoretically demonstrating that " the evaporative value of a bituminous coal is expressed by the evaporative value of its coke, the heat of combustion of its volatile products proving in practice little more than that necessary to volatilize them," we are suddenly greeted with the following paragraph:"The whole system of manufacturing coke is at present very imperfect. Besides losing the volatile combustible substances, which, under new adjustments, might be made of much value, an immense quantity of ammonia is lost by being thrown into the atmosphere. Ammonia and its salts are daily becoming more valuable to agriculture, and it is their comparative high price alone which prevents their universal use to all kinds of cereal cultivations. By a construction of the most simple kind the cokeovens now in use might be made to economize much of the nitrogen, which invariably escapes in the form of ammonia. As an inducement to this economy,. we have ap-. 444 COAL. >ended to Table 6. two columns showing the quantity of ammonia and its corres pouding quantity of commercial sulphate which each 100 lbs. of the respective coals may be made to produce. When it is remembered that the price of sulphate of ammonia is about 131. per ton, or that 100 tons (of coal, we suppose) in coking is (are?) capable of producing on an average about six tons of this salt, its neglect is highly relrehensible." Nothing has tended half so much to retard the cultivation of chemistry by our practical manufacturers as the kind of statements of which the above is a sample. Written by individuals wholly ignorant of the subject of which they treat, these assertions serve only to amuse practical men, and to demonstrate the stupendous folly and assurance of their authors. Imperfection is an attribute of humanity, but that the present system of making coke is very imperfect remains to be proved. The volatile combustible matter of the coal is. not lost; on the contrary, it is employed as a means of converting the cinder of the coal into coke, and that, too, by the heat which it evolves in burning; and if that heat was so inconsiderable as the report would lead us to suppose, mere cinder alone vwml) remain in the coke-oven, even after the heat had been kept up for ninety-six hours. Perhaps the framers of the report may want to know the distinction between cinders and coke. Coke, if good, sinks in water; bad coke or cinder swims. The reason of this is very simple. The longer and higher the heat to which carbon fiom wood or coal is exposed the more it contracts, and consequently the denser it becomes. The volatile combustible matter of the coal is employed, then, in producing the requisite temperature for coking, and the oven is so contrived as to retain the heat a sufficient time to produce the necessary aggregation of the particles of carbon, or, in plain words, the condensation of the coke: to assert that this volatile combustible matter is lost is perfectly ridiculous. We are next informed that "an immense quantity of ammonia is lost by being thrown into the atmosphere," and that by "a construction of the most simple kind this loss might be avoided." Lord Dundonald, about fifty years ago, had the same idea, and tried it on a large scale; it is unnecessary to say that it proved to be a complete failure, although sulphate of ammonia was then worth four or five times its present price. But the most absurd part of this scientific soap-bubble is contained in the last sentence:-" 100 tons in coking is capable of producing on an average about six tons of this salt" (sulphate of ammonia). Now, let us for a few minutes imagine my Lord Grey desirous as (we have no doubt he is) of making the most of his Broomhill coal. Passing his eye down column 1. of Table 6., he sees at a glance that 100 tons of coal will produce 8-674 tons of sullphate of ammonia, worth 131. per ton. Making a little allowance for loss, he says to himself, "Well, call it 8~ tons; and now how much sulphuric acid is required?" We will suppose him practically acquainted with Dr. Wollaston's scale, and that, valuing common "chamber acid" at three farthings per cent., he has arrived at the following conclusion:1. s. d. 100 tons of coal, at 3s. 4d. per ton = 16 13 4 6A tons of sulphuric acid, as above = 45 10 0 62 3 4 will produce 1. s. d. 8j tons of sulphate of ammonia, worth 110 10 0 and 70 tons of coke, at 8s. 6d. per ton 29 15 0 140 5 0 A promising speculation truly, if his lordship could only economize "the nitrogen which invariably escapes in the form of ammonia." But, most unfortunately, the nitrogen does not " invariably escape in the form of ammonia," for in practice nine-tenthe of it invariably escape in the form of nitrogen, as any experienced gas manufacturer can testify, and as the experiments quoted in the report abundantly prove, for according to Mr. F. C. Wrightson (a pupil of iebig), who (vide Report, page 6.) had fitted "himself by special study for an undertaking requiring so much delicacy of manipulation,"-according, then, to Mr. Wrightson (page 58.), the Binea coal and the Llangenneck coal gave by actual experiment in 100 parts 0'08 of ammonia, or'310 of sulphate of ammonia. N ow, if we compare this with Table 6. we shall findBinea coal might, could, would, or 6-741 really did 0-310 Llangenneck should produce 5-044 produce 0310 or about Ith of the quantity theoretically obtained by Sir H1. De la Beche and Dr. Lyon COAL. 445 Playfair; yet these are the individuals who find fault with our manufacturers, and pretend to improve our processes. With quite as much practical utility might these gentlemen have detailed to us the quantity of pure diamond which the, coals in question would produce, if we knew how; as the amount of ammonia which they might give off if they would. Of the analytical part of the report we will say little more than that it is in perfect keeping with the rest. In the first place, chloride of calcium is employed to remove water and ammonia from the gas, although a very little practical knowledge of gas purification would have taught the operator that, when water and ammonia are absorbed by chloride of calcium, carbonic acid is also taken up, so as to produce carbonate of lime and muriate of ammonia; and as this carbonic acid must have been regarded either as ammonia or water, it follows that the experimental results are valueless. The substance which ought to have been employed to absorb water and ammonia under the circumstances is tile fused or glicial phosphoric acid; but what real value can we attach to experiments made upon less than half a grain of coal, in which the errors, and errors there are, have been multiplied at least 300,000 times? For example, at page 58., we find " Anthracite, from T. Aubrey and Co." The quantity of this coal taken for analysis was 0'2763 of a grain, or rather more than J of a grain. Now, supposing it had even equalled I of a grain, then to bring this to a pound it must be multiplied 21,000 times, and to raise this last to the weight of water which 1 lb. of such coal could theoretically evaporate, as represented at column 4. of Table 6., this 21,000 must he multiplied by 14-593; therefore, if any error occurred in the analysis of this anthracite coal, it has been multiplied upwards of 306,453 times; in regard to the quantity of water which 1 lb. of such coal can evaporate, as exhibited in column 4. of Table 6. The idea, however, of weighing the lo'oth of a grain is perfectly new to us, who have always regarded even the oo0th as something too nearly approaching the imponderable. These remarks apply equally to the experiments with litharge; no allowance is made, or notice taken of the error arising from the presence of iron pyrites in the coal, although this substance would reduce more than 9 times its weight of litharge, and the error thus produced has been multiplied upwards of 90,000 times in column 6. of Table 4.; and in tle case of the anthracite coal above mentioned this error has been increased 104,507 times. Nor is the quantity of iron pyrites inconsiderable in many of these coals, for, according to Table 3., the following contain a portion of sulphur equ-ivalent to bisulphuret of iron, as under:Slievardagh - - - 1267 per cwt. of iron pyrites for which Resolven - - - - 9'50,, no allowance has been Bedwas - - - - 6-56,, made in the litharge exCwm Nanty Gros - - - 564,, periments. To pretend to attach any value to such experiments, or to the conclusions drawn rom them, is a mere fallacy, and, as the whole of the theoretical part is based upon these analyses, with them it must fall to the ground as erroneous and illusory. Under these.circumstances it becomes necessary to inquire most carefully into the large ann practical essays made for the purpose of determining the quantity of water evaporated during many successive hours by considerable quantities of each particular coal. With a few exceptions, each coal was burnt for eight hours, and the experiment repeated three times, the quantity of coal consumed and of water evaporated being noted ir each instance, and an average drawn from the three results obtained by each coal. If carefully conducted, this method ought to have furnished some valuable information, but the discrepancies in respect to the three results obtained from some of the coals are so enormous and unaccountable as to render the whole table suspicious, doubtful, and therefore valueless; indeed, the differences observable between many of the dif ferent samples of coal are much less than the.experimental differences given by one and the same coal, and which occasionally amount to little short of twenty per cent., as the following table will show [see p. 446.]. The idea of forming a table fiom experiments producing such discordant results is altogether preposterous, yet, turn in what direction we may, the same evidence of blundering and incapacity presents itself. In the first place, the selection of the coals was bad and unfair in the extreme, and no way calculated to answer the practical end in view; secondly, the proximate analyses are worthless, from the employment of chloride of calcium for a purpose for which it was not adapted; thirdly, the ultimate analyses are made in quantities too small to entitle them to any confidence when their results are raised to practical purposes; fourthly, the litharge experiments are erroneous; and fifthly, the practical essays by means of the Admiralty boiler are so completely at valiance amongst themselves as to defy all arrangement or computation. The entire report is, in fact, a disgrace to the age and country we live in, and carries with it all the internal evidence of a job. As it is possible, however, that the Admiralty may really be serious in;t desire to ascertain the true value of steam-coal, we will venture to throw out a few hints, in order 446 COBALT I.j~~~~ ~Extreme Difference in Three Name of Coal. Trials as to the Amount of Water evaporated.w_____v__________ ___by each respective Coal Duffryn i- 23 per cent, Old Castle 11' i Ward's - - - 5'3 Binea - - - - - 147 Llangenneck - - - - 16 Mynydd - - - - 49 Three Quarter - - 14, Graigola - - - 2'1 Lydnley - - - - 118 Pontrepoth - - - 9-1 Cwm Frood - - 1'3 Anthracite - - - - Cwm Nanty Gros - - 48 Grangenouth - - 6 7 lBroonmhill -. 5'2 Resolven 18'9 Pontypool - - - - 177,, Bedwas - - - - 13'4'orth Mawr - -'5 Ebbw Vale - - 5- - 15-7 Fordel Splint - - - - 14-5 Coleshill- - 11 5 Wallsend Elgin - -3 -3 that that august body of well-paid functionaries may look before they leap into a subject so intimately connected with our national interests. In working a seam of coal, experience has shown that the quality of the coal is nct uniform, and that a coal mlay be improving or deteriorating as the workings are carried on, in one or another direction. From this it follows tlat any particular coal examined, say in 1846, is by no means to be regarded as possessing the samle value in 1848, since this may have changed considerably, if the working of the coal has been carried on to any great extent; and it is the determination of this very fact which constitutes the real source of utility to be derived fiom a Government investigation. The proximate value of a coal is soon determined by actual experiment, from the amount of work done, and a market value is given in accordance with these rough results; but, when once that value has become fixed, there it remains for many years, whether the coal continues uniform or not, and it is only slowly and by degrees that the change becomes apparent. An establishment for determiining matters of this kind is, therefore, much needed, but, to be useful, it must obviously be permanent. Again, as the transmission of heat fiom one body to another is proportional to the difference of temperature between the bodies themselves, it is clear that the water operated on should have one uniform temperature in all the experiments, and there are many reasons why this should be the boiling point The quantity of water evaporated should not be inferred from the quantity which has escaped fiom a boiler during an experiment; independent of the possibility of leakage, much water is occasionally carried off mechanically by the steam; hence the origin of "priming" The most unobjectionable method would be to distil the water and afterwards measure it, the still-head being provided with a return-pipe, as is usual, for the fluid,mechanically projected. The ordinary modes of favouring the transmission of heat from the furnace to the boiler, and of preventing its escape in any other direction than into the refrigeratory, should be had recourse to. A chemist is of no use for such iivestigations; if any chemnical question should arise out of tlhe experiments, it would be better to consult some one of established reputation. The stoker should be intelligent, and practically acquainted with the different nodes of fire necessary for anthracitic, open-burning, and bitumninous, or caking coal; for whilst thle first of these will take, nay requires, eighteen or twenty inches of fuel on the bars, the last will not bear more than four or six, without an enormous loss of heating-power. To this cause must be ascribed much of the discrepancy apparent in the experimental results obtained by the Admiralty boiler.-Mr. Lewis 17honmpson, in "The Cheenical limes" for December, 1848. COBALT. This metal being difficult to reduce from its ores, is therefore very little known, and has not hitherto been employed in its simple state in any of the arts; but its oxide has been extensively used on account of the rich blue colour which it imparts to glass, and the glazes of porcelain and stone-ware. The principal ores of cobalt are COBALT 447 those designated by mineralogists under the names of arsenical cobalt and gray cobalt. The first contains, in addition to cobalt, some arsenic, iron, nickel, and occasionally silt ver, &c. The other is a compound of cobalt with iron, aisenic, sulphur, and nickel. Among the gray cobalts, the ore most esteemed for its purity is that of 1.iaberr in Sweden. It is often in regular crystals, which possess the lustre and color of polished steel. The specific gravity of cobalt pyrites is 6 36 to 4-66. The Tunaberg variety afforded to Klaproth, cobalt, 44; arsenic, 55-5; sulphur, 0:5; so that it is an arsenluret. Others, however, contain much sulphur as well as iron. It imparts at the blowpipe a blue color to borax and other fluxes, and gives out arsenical fumes. The ore being picked, to separate its concomitant stony matter, is pounded fine and passed through a sieve; and is also occasionally washed. The powder is then spread on the sole of a reverberatory furnace, the flue of which leads into a lone horizontal chimney. Here it is exposed to calcination for several hours, to expel the sulphur and arsenic that may be present; the former burning away in sulphurous acid gas, the latter being condensed into the white oxyde or arsenious acid, whence chiefly the maiket is supplied with this article. This calcining process can never disengage the whole of these volatile ingredients, and there is therefore a point beyond which it is useless to push it; but the small quantities that remain are not injurious to the subsequent operations. The roasted ore is sifted anew; reduced to a very fine powder, and then mixed with 2 or 3 parts of very pure silicious sand, to be converted into what is called zuifre. With this product glasses are generally colored blue, as well as enameis and pottery glaze. In the works where cobalt ores are treated, a blue glass is prepared with the zaffie, which is well known under the name of smalt or azure blue. This azure is made by adding to the zaffre 2 or 3 parts of potash, according to its ricnness in cobalt, and melting the mixture in earthen crucibles. The fused mass is thrown out while hot into water; and is afterwards triturated and levigated in mills mounted for the purpose. There remains at the bottom of the earthen pot a metaillc lump, which contains a little cobalt, much nickel, arsenic, iron, &c. This is called speiss. As it is the oxyde of cobalt which has the coloring quality, the calcination serves the purpose of oxydizement, as well as of expelling the foreign matters. A finer cobalt oxyde is procured for painting upon hard porcelain, by boiling the cobalt ore in nitric acid, which converts the arsenic into an acid, and combines it with the different metals present in the mineral. These arseniates, being unequally soluble in nitric acid, may be separated in succession by a cautious addition of carbonate of soda or potash; and the arseniate of cobalt as the most soluble remains unaffected. It has a rose color, and is easil, distinguishable, whence the precipitation may be stopped at the proper point. The above solution should be much diluted, and the alkali should be cautiously added, with frequent agitation. The cobalt ores, rich in nickel, are exposed to slow oxydizement in the air, whereby the iron, cobalt, arsenic, and sulphur get oxygenated by the atmospheric moisture, but the nickel continues in the metallic state. This action of the weather must not be extenled beyond a year, otherwise the nickel becomes affected, and injures the cobalt blue. The ore hereby increases in weight, from 8 to 10 per cent. Fig. 362 is a longitudinal section of the furnace: fig. 363, a horizontal section upon a level with the sole of the hearth. It is constructed for wood fuel, and the hearth is composed of fire-bricks or tiles. The vapors and gases disengaged in the roasting pass off throulgh the flues a a, into the channels b b, and thence by c into the common vent, or poison chamber. See the representation of the ooison +ower of Altenberg, under the article ARSENIC. The flues are cleared out by means of openings left at suitable situations in the brick-work of the chimneys..'. /..%/.; r -............. The azure manufacture is carried _____ ^ ^/;, V on chiefly in winter, in order that 862. /,,./.\, the external cold may favour the more complete condensation of the [ — //''/XX^~ f/-j~/ ~''~ 1 acids of arsenic. From 3 to 5 cwt. o f Sehlich (pasty ore) are roasted at - - one operation, and its bed is laid H ^ | a I IUj3 ~ from 5 to 6 inches thick. After two II Jours, it must be turned over; and fis ^ X,2^ the stilring must be repeated every @1/%w1F// ///a///_ __/ /?/9~ -half hour, till no more arsenic is observed to exhale. The process being ____?_'^^' ^ tthen finished, the ore must be raked 1_ ^^^^^; out of the furnace, and another charge //; ///'/.;.introduced. 448 COBALT. The duiation of the roasting ia regulated partly by the proportion of sulphur and arsenic present, and ^.j^,,.,, /-J' T /partly by the amount of nickel; which must not be suffered to beI363 - i i / /come oxydized, lest it should spoil the color of the smalt. The latter - - — 1 Y X 1 __....I. ores should be but slightly roasted, so as to convert the nickel into speiss....., T i -The roasted ore must be sifted in a ~z^^ln7// ///^/7//^.z//// ^/' /l, // ~ safety apparatus. The loss ofweioht in the roasting amounts, upon the 364 average, to 36 per cent. The roasted ore has a brownish gray hue, and is!:.1S~.....~- [called safflor in German, and is distrihuted into different sorts. F F S is the finest saJ)'e; F S, fine; O S, J f f) ordinary; and M S, middling. These 99 _ l 9 varieties proceed from various mixhX _Iu | 6 tll i tures of the calcined ores. The /el 1]HI |(7l] I e t roasted ore is around up along with called zaffre. It is then mixed with a sufficient quantity of potash foi converting the mixture into a glass. e I~ ~/~ Figs. 364 an-d 365, represent a 7 7......-.. ^^^^round smalt furnace, in two vertical sections, at right angles to each other. The fire-place is vaulted or arched; the flame orifice a, is in the 365 middle of the furnace; b is the feed hole; c, a tunnel which serves as an ash-pit, and to supply air; d, openinns through which the air arrives at the fiuel, the wood being placed upon the vault; e, knee holes for takina out the scorike from the pot bottoms; f, working orifices, with cast-iron plates g, in front of them. - ^ ^^^^^ ^fa —.y/ /^ - Under thrse are the additional out[t @ 6....~ I l lets h. The smoke and flame pass / _o) off through the orifices i, which ter-.: ~ y/ / d/~~? cdL/ d l minate in expanded flues, where the ( d) cd~ d~ ~ sand may be calcined or the wood may he baked. Eight hours are sufficient for one vitrifying operation, during which the glass is stirred about several times in the earthen melting pots. The preparation of the different shades of blue glass is considered a secret in the.melting works; and marked with the following letters:-F F F C, the finest; F Ct fine; M C, middling; O C, ordinary. A melting furnace, containing 8 pots of glass, produces in 24 hours, from 24 cwts. of the mixture, 19 cwts. of blue glass; and from ~ to a cwt. of scorise or speiss (speise). The composition speise, according to Berthier, is,-nickel, 49'0; arsenic, 37'8; sulphur, 7'8; copper, 1'6; cobalt, 3-2 in 100. Nickel, arsenic, and sulphur, are its essential constituents; the rest are accidental, and often absent. The freer the cobalt ore is from foreign metals, the finer is the colour, and the deeper is the shade; paler tints are easily obtained by dilution with more glass The presence of nickel gives a violet tone. The production of smalt in the Prussian states amounted, in 1830, to 7452 cwts., and in Saxony to 9697 cwts.; in 1825, to 12,310 cwts. One process for making fine smalt has been given under the title AZURE; I shall introduce another somewhat different here. The ore of cobalt is to be reduced to very fine powder, and then roasted with much care. One part, by weight, is next to be introduced, in successive small portions, into an iron vessel, in which three parts of acid sulphate of potassa has been previously fused, at a moderate temperature. The mixture, at first fluid, soon becomes thick and firm, when the fire is to be increased, until the mass is in perfect fusion, and all white vaporrs have ceased. It is then to be taken out of the crucible with an iron COCHINEAL. 449 ladle, the crucible is to be recharged with acid sulphate of potash, and the operation continued as before, until the vessel is useless. The fused mass contains sulphate of cobalt, neutral sulphate of potassa, ard arseniate of iron, with a little cobalt. It is to be pulverized, and bWiled in an iron vessel, with water, as long as the powder continues rotuh to the touch. The white, or yellowish white residue, may be allowed to separate from the solution, either by deposition or filtration. Carbonate,f potassa, free from silica, is then to be added to the solution, and the carbonate of cobalt thrown down is to be separated and well washed, if possible, with warm water; the same water may be used to wash other portions of the fused mass. The filtered liquid which first passes is a saturated solution of sulphate of potassa: being evaporated to dryness in an iron vessel, it may be reconverted into acid sulphate by fusing it with one half its weight of sulphuric acid: this salt is then as useful as at first. The oxyde of cobalt thus obtained contains no nickel; so little xyde of iron is present, that infusion of Salls does not show its presence; it may contain a little copper, if that metal exists in the ore, but it is easily separated by the known methods. Sometimes sulphureted hydrogen will produce a yellow brown precipitate in the solution of the fused mass; this, however, contains no arsenic, but is either sulphuret of antimony or bismuth, or a mixture of both. It has been found advantageous to add to the fused mass sulphate of iron, calcined to redness, and one tenth of nitre when the residue is arseniate of iron, and contains no arseniate of cobalt. There is then no occasion to act upon the residue a second time for the cobalt in it. This process is founded on the circumstances that the sulphate of cobalt is not decomposed by a red heat, and that the arseniates of iron and cobalt are insoluble in all neutral liquids. It is quite evident, that, to obtain a perfect result, the excess of acid in the bisulphate of potassa must be completely driven off by the red heat a pplied. 110,646 Ibs. of smalts were imported into the United Kingdom in 1835, and 96,949 were retained for horne consumption. In 1834, only 16,223 Ibs. were retained. In 1835, 322,562 lbs. of zaffres were imported, and 336,824 are stated to have been retained, which is obviously an error. 284,000 lbs. were retained in 1834. COCCULUS INDICUS, or Indian berry, is the fruit of the Menivpermtm Cocculus, a large tree, which arows upon the coasts of Malabar, Ceylon, &c. The fruit is blackish, and of the size of a large pea. It owes its narcotic and poisonous qualities to the ve.eto-alkaline chemical principle called picrotoxia, of which it contains about one fiitieth part of its weight. It is sometimes thrown into waters to intoxicate or kill fishes; and it is said to have been employed to increase the inebriating qualities of ale or beer. ts use for this purpose is prohibited by act of parliament, under a penalty of 2001. upon,he brewer, and 5001. upon the seller of the drug. COCHINEAL was taken in Europe at first for a seed, but was proved by the obserrations of Lewenhoeck to be an insect, being the female of that species of shield-louse, or coccus, discovered in Mexico, so long ago as 1518. It is brought to us from MIexico, where the animal lives upon the cactus opuntia or nopal. Two sorts of cochineal are gathered-the wild, from the woods, called by the Spanish name gruna silvestra; anl the cultivatedor the granafina, termed also mesteqne, fiom the name of a Mexican province. The first is smaller, and covered with a cottony down, which increases its buik with a matter useless in dyeing; it yields, therefore, in equal weight, much less coior, and is of inferior price to that of the fine -cochineal. But these disadvantages are compensated in some measure to the growers by its being reared more easily, and less expensively; partly by the effect of its down, which enables it better to resist rains and storms. The wild cochineal, when it is bred upon the field nopal, loses in part the tenacity and quantity of its cotton, and acquires a size double of what it has on the wild opuntias. It may therefore be hoped, that it will be improved by persevering care in the rearing of it, when it will approach more and more to fine cochineal. The fine cochineal, when well dried and well preserved, should have a gray colour, bordering on purple. The gray is owing to the powder, which naturally covers it, and of which a little adheres; so also to a waxy fat. The purple shade arises from the colour extracted by the water in which they were killed. It is wrinkled with parallel furrows across its back, which are intersected in the middle by a longitudinal one; hence, when viewed by a magnifier, or even a sharp naked eye, especially after being swollen by soaking for a little in water, it is easily distinguished from the factitious, smooth, glistening, black grains, of no value, called East India cochineal, with which it is often shamefully adulterated by certain London merchants. The gen uine cochineal has the shape of an egg, bisected through its long axis, or of a tortoise, being rounded like a shield upon the back, flat upon the belly, and without wings. These female insects are gathered off the leaves of the niopal plant, after it has ripened 30 450 COCHINEAL. its fruit, a few only being left for brood, and are killed, either by a momentary immersion in boiling water, by drying upon heated plates, or in ovens: the last become of an ash-gray color, constituting the silver cochineal, or jaspeada; the second are blackish. called negra, and are most esteemed, being probably driest; the first are reddish brown, and reckoned inferior to the other two. The dry cochineal being sifted, the dust, with the imperfect insects and fragments which pass through, are sold under the name of granillo. Cochineal keeps for a long time in a dry place. Hellot says that he has tried some 130 years old, which produced the same effect as new cochineal. We are indebted to MM. Pelletier and Caventou for a chemical investigation of cochineal, in which its coloring matter was skilfully eliminated. Purified sulphuric ether acquired by digestion with it a golden yellow color, amounting by Dr. John to one tenth of the weight of the insect. This infusion left, on evaporation, a fatty wax of the same color. Cochineal, exhausted by ether, was treated with alcohol at 40~ B. After 30 infusions in the digester of M. Chevreul, the cochineal continued to retain color, althou'h the alcohol had ceased to have any effect on it. The first alcoholic liquors were of a red verging on yellow. On cooling, they let fall a granular matter. By spontaneous evaporation, this matter, of a fine red color, separated, assuminz more of the crystalline ap. pearance. These species of crystals dissolved entirely in water, which they tinged of a yellowish-red. This matter has a very brilliant purple-red color; it adheres strongly to the sides of the vessels; it has a granular and somewhat crystalline aspect, very different, however, fiom those compound crystals alluded to above; it is not altered by the air, nor does it sensibly attract moisture. Exposed to the action of heat, it melts at about the fiftieth degree centigrade (122~ Fahr.). At a higher temperature it swells up, and is decomposed with the production of carbureted hydrogen, much oil, and a small quantity of water, very slightly acidulous. No trace of ammonia was found in these products. The coloring principle of cochineal is very soluble in water. By evaporation, the liquid assumes the appearance of sirup, but never yields crystals. It requires of this matter a portion almost imponderable to give a perceptible tinge of bright purplish red to a large body of water. Alcohol dissolves this coloring substance, but, as we nave already stated, the more highly it is rectified the less of it does it dissolve. Sulphuric ether does not dissolve the coloring principle of cochineal; but weak acids do, possibly owing to their water of dilution. No acid precipitates it in its pure state. This coloring principle, however, appears to be precipitable by all the acids, when it is accompanied by the animal matter of the cochineal. The affinity of alumina for the coloring matter is very remarkable. When that earth, newly precipitated, is put into a watery solution of the coloring principle, this is immediately seized by the alumina. The water becomes colorless, and a fine red lake is obtained, if we operate at the temperature of the atmosphere; but if the liquor has been hot, the color passes to crimson, and the shade becomes more and more violet, accord ing to the elevation of the temperature, and the continuance of the ebullition. The salts of tin exercise upon the coloring matter of cochineal a remarkable action. The muriatic protoxyde of tin forms a very abundant violet precipitate in the liquid. This precipitate verges on crimson, if the salt contains an excess of acid. The muriatic deutoxyde of tin produces no precipitate, but changes the color to scarlet-red. If gelatinous alumina be now added, we obtain a fine red precipitate, which does not pass to crimson by boiling. To this colouring principle the name carminium has been given, because it forms the basis of the pigment called carmine. The process followed in Germany for making carmine, which consists in pouring a certain quantity of solution of alum into a decoction of cochineal, is the most simple of all, and affords an explanation of the formation of carmine, which is merely the car minium and the animal matter precipitated by the excess of acid in the salt, which has taken down with it a small quantity of alumina; though it appears that alumina ought not to be regarded as essential to the formation of carmine. In fact, by another process called by the name of Madame Cenette of Amsterdam, the carmine is thrown down, by pouring into the decoction of cochineal a certain quantity of the binoxalate of potash. When carbonate of soda is added, then carminated lake also falls down. That carmine is a triple compound of animal matter, carminium, and an acid, appears from the circumstance, that liquors which have afforded their carmine, when a somewhat strong acid is poured into them, yield a new formation of carmine by the precipitation of the iast portions of the animal matter. But whenever the whole animal matter is thrown down, the decoctions, although still much charged with the colouring principle, can afford no more carmine. Such decoctions may be usefully employed to make car minated lakes, saturating the acid with a slight excess of alkali, and adding gelatinous alumina. The precipitates obtained, on adding acid to the alkaline decoctions of COCHINEAL. 451 earmines, since they do not contain alumina; but the small quantity of alumina which is thrown down by alum in the manuilfacture of carmine, augreirnts its hulk and wseiiht It gives, besides, a greater lustre to the color, even though diluting and wealtkein'ir it a little. The carmines found in the shops of Paris were analyzed, and yielded the same products. They are decomposed by the action of heat, with the diffusion at first of a very strong smell of burning animal matter, and then of sulphur. A white powder remained, amounting to about one tenth of the matter ermployed, and which was found to be alumina. Other quantities of carmine were treated with a solution of caustic potash, which completely dissolved them, with the exception of a beautifull red powder, not acted on by potash and concentrated acids, and which was recognised to be red sulphuret of mercury or vermilion. This matter, evidently foreign to the carmine, appears to have been ad. ded in order to increase its weight. The preceding observations and experiments seem calculated to throw some light on the art of d-eing scarlet and crimson. The former is effected by employing a cochineal bath, to which there have been added, in determinate proportions, acidulous tartrate of potash, and nitro-muriatic deutoxyde of tin. The effect of these two salts is now well known. The former, in consequence of its excess of acid, tends to redden the color, and to precipitate it along with the animal matter; the latter acts in the same manner, at first by its excess of acid, then by the oxyde of tin which falls down also with the carmine and animal matter, and is fixed on the wool, with which it has of itself a strong tendency to combine. MM. Pelletier and Caventour remark, that " to abtain a beautiful shale, the muriate of tin ought to be entirely at the maximum of oxydizement; and it is in reality in this state that it must exist in the solution of tin prepared according to the proportions prescribed in M. Berthollet's treatise on dyeing." We hence see why, in dyeing scarlet, the employment of alum is carefully avoided, as this salt tends to convert the shade to a crimson. The presence of an alkali would seem less to be feared. The alkali would occasion, no doubt, a crirrson-cololed bath; but it would be easy in this case to restore the color, by using a large quantity of tartar. We should, therefore, procure the advantage of having a bath better charged with coloring matter and animal substance. It is for experience on the large scale to determine this point. As to the earthy salts, they must be carefully avoided; and if the waters be selenitish, it would be a reason foi adding a.ittle alkali. To obtain crimson, it is sufficient, as we know, to add alum to the cochineal bath, Fr to boil the scarlet cloth in alum water. It is also proper to diminish the dose of the salt of tin, since it is found to counteract the a tin of the alum. The alkalis ought to be rejected as a means of chanaing scarlet to crimson. In fact, crimsons by this process cannot be permanent colors, as they pass into reds by the action of acids. According to M. Von Grottliuss, carmine may be deprived of its golden shade by ammonia, and subsequent treatment with acetic acid and alcohol. Since this fact was made known, M. Herschel, color maker at Halle, has prepared a most beautiful carmine. The officers of Her Majesty's Customs have lately detected a system of adulterating cochineal, which has been practised for many years upon a prodigious scale by a mercan. tile house in London. I have analyzed about 100 samples of such cochineal, from which it appears that the genuine article is moistened with gum-water, agitated in a box ol eather bag, first, with sulphate of baryta in fine powder, afterward with bone of ivory black, to give it the apipearalce of negra cochineal, and then dried. By this means about 12 per cent. of worthlless heavy slar is sold at the prlice of cocllineal, to thle eriichmient of the sophisticators, and the disgrace and injury of British trade and m;riiifactures. The specific gravity of genuinee cochineal is 1'25; that of the cochirne;l loaded with the barytic sullphate, 1'35. This was taken in oil of turpentine and reduced to water as unity, because the waxy fat of the insects prevents the intilmate contact of the latter liquid witl them, and the ready expulsion of air from their wrinkled surfa;ce. They are not at all acted upon by the oil, but are rapidly altered by water, especially when they have been gummied and barytified. Ianded. Delivered. Stock, Ist of anuary. December, 1851 - 1,203 bags 692 bags - bags 1850 -- 1.605 - 595 - 12 Months, 1851 - - 16,561 - 16,180 - 9,01 - 1850 -- 17,765 - 13,096 - 8.620 - 1849 - 12.604 - 13,594 -,951 - 1848 - 18,521 - 1 l.506 - 4.93 - Humboldt states that so long ago as the year 1736, there was imported into Europe from South America cochineal to the value of 15 millions of francs. Its high price had for a long time induced dyers to look out for cheaper substitutes in dyeing red, and since science has introduced so many improvements in tinctorial processes, both madder and lao have been made to supersede cochineal to a very great extent. its price has, ila 452 COFFEE. consequence of this substitution, as well as from more successful modes of cultivation, fallen very greatly of late years. In January, 1852, the prices of Honduras cochineal ranged from 2.. 9d. to 5s. per lb., and Mexican from 2s. 7d. to 3s. 4d. per lb. COCOA, STEARINE, and ELAINE. Mr. Soames obtained a patent in September, 1829, for making these useful articles, by the following process:He takes the substance called cocoa-nut oil, in the state of lard, in which it is imported into this country, and submits it to a strong hydraulic pressure, having made it up in small packages, 3 or 4 inches wide, 2 feet long, and 1 or 1 inches thick. These packages art formed by first wrapping up the said substance in a strong linen cloth, of close texture, and then in an outward wrapper of strong sail cloth. The packages are to be placed sidl by side, in single rows, between the plates of the press, allowing a small space between the packages for the escape of the elaine. The temperature at which the pressure is begun, should be from about 50 to 55 decrees, or in summer as nearly at this pitch as can be obtained, and the packages of the said substance intended for pressure, should be exposed for several hours previously to about the same temperature. When the packages will no longer yield their oil or elaine freely at this temperature, it is to be gradually raised; but it must at no time exceed 65 degrees, and the lower the temperature at which the separation can be effected, the better will be the quality of the oil expressed. When the packages are sufficiently pressed, that is, when they will give out no more oil, or yield it only in drops at long intervals, the residuum in them is to be taken out and cleansed and purified, which is done by melting it in a well-tinned copper vessel, which is fixed in an outer vessel, having a vacant space between, closed at the top, into which steam is admitted, and the heat is kept up moderately for a sufficient time to allow the impurities to subside; but if a still higher decree of purity is required, it is necessary to pass it through filters of thick flannel lined with blotting paper. Having been thus cleansed or purified, it is fit for the manufacture of candles, which are made by the ordinary process used in making mould tallow candles. Having thus disposed of the stearine, or what is called the first product, he proceeds with the elaine or oil expressed from it, and which he calls the second product, as follows: that is to say, he purifies it by an admixture, according to the degree of its apparent foulness, of from 1 to 2 per cent. by weight of the sulphuric acid of commerce, of about 1-80 specific gravity, diluted with six times its weight of water. The whole is then to be violently agitated by mechanical means, and he prefers for this purpose the use of a vessel constructed on the principle of a common barrel churn. When sufficiently agitated, it will have a dirty whitish appearance, and is then to be d awn off into another vessei, in which it is to be allowed to settle, and any scum that rises is to be carefully taken,fd. In a day or two the impurities will be deposited at the bottom of the oil, which will then become clear, or nearly so, and it is to be'filtered through a thick woollen cloth, after which it will be fit for burning in ordinary lamps and for other uses. The process of separating the elaine from the stearine, by pressure, in manner afore. said, had never before beer applied to the substance called cocoa-nut oil, and consequently no product had heretofore seen obtained thereby fiom that substance, fit for being manufactured into candles in the ordinary way, or for being refined by any of the nsuUa moaes, o3 as to burn in ordinary lamps, both which objects are obtained by this method of preparing or manufacturing the said substance. Candles well made from the above material are a very superior article. The light produced is more brilliant than from the same sized candle made of tallow; the flame is perfectly colorless, and the wick remains free from cinder, or any degree of foulness dux-in combustion. COFFEE. The coffee is the seed of a tree of the family rubiaceea, and belongs to the Pentandria monogynia of Linnaeus. There are several species of the genus, but the only one cultivated is the Coffaea Lrabica, a native of Upper Ethiopia and Arabia Felix. It rises to the height of 15 or 20 feet; its trunk sends forth opposite branches in pairs above and at right angles to each other; the leaves resemble those of the common laurel, although not so dry and thick. From the angle of the leaf-stalks small groups of white flowers issue, which are like those of the Spanish jasmine. These flowers fade very soon, and are replaced by a kind of fruit not unlike a cherry, which contains a yellow glairy fluid, enveloping two small seeds or berries convex upon one side, flat and furrowed upon the other in the direction of the long axis. These seeds are of a horny or cartilaginous nature; they are glued together, each being surrounded with a peculiar coriaceous membrane. They constitute the coffee of commerce. It was not till towards the end of the 15th century that the coffee-tree began to be cul tivated in Arabia. Historians usually ascribe the discovery of the use of coffee as a be. verage to the superior of a monastry there, who, desirous of preventing the'monks from sleeping at their nocturnal services, made them drink he infusion of coffee upon the report of shepherds, who pretended that their flocks were more lively after browsing on the fruit of that )lant. The use of coffee was soon rapidly spread, but it encountered much COFFEE. 453 3pposition on the. part of the Turkish government, and became the occasion of publie assemblies. Under the reign of Amnurath TlT. the mufti procured a law to shut all the coffee-houses, and this act of suppression was renewed under the minority of Mahomet IV. It was not till 1554, under Solyman the Great, that the drinking of coffee was accredited In Constantinople; and a century elapsed before it was known in London and Paris. Solyman Aza introduced its use into the latter city in 1669, and in 1672 an Armenian established the first cafe at the fair of Saint Germain. When coffee became somewhat of a necessary of life, from the influence of habit among the people, all the European powers who had colonies between the tropics, projected to form plantations of coffee-trees in them. The Dutch were the first who transported the coffee plant from Mok. to Batavia, and from Batavia to Amsterdam. In 1714 the magistrates of that city sent a root to Louis XIV., which he caused to be planted in the Jardin du Roi. This became the pareni itock of all the French coffee plan. tations in Martinique. The most extensive culture of coffee is still in Arabia Felix, and principally in the kingdom of Yemen, towards the cantons of Aden and Moka. Although these countries are very hot in the plains, they possess mountains where the air is mild. The coffee is generally grown half way up on their slopes. When cultivated on the lower grounds it is always surrounded by large trees which shelter it fiom the torrid sun, and prevent its fruit from withering before their maturity. The harvest is gathered at three periods; the most considerable occurs in May, when the reapers begin by spreading cloths under the trees, then shaking the branches strongly, so as to make the fruit drop, which they collect, and expose upon mats to dry. They then pass over the dried berries a very heavy roller, to break the envelops, which are afterwards winnowed away with a fan. The interior bean is again dried before being laid up in store. In Demarara, Berbice, and some of our West India islands, where much good coffee is now raised, a different mode of treating the pulpy fruit and curing the beans is adopted. When the cherry-looking berry has assumed a deep-red color it is gathered, and immediately subjected to the operations of a mill composed of two woodenrollers, furnished with iron plates, which revolvt near a third fixed roller called the chops. The berries are fed into a hopper above the rollers, and falling down between them and the chops, they are stripped of their outer skin and pulp, while the twin beans are separated from each other. These beans then fall upon a sieve, which allows the skin and the pulp to pass through, while the hard beans accumulate and are progressively slid over the edge into baskets. They are next steeped for a night in water, thoroughly washed in the morning, and afterwards dried in the sun. They are now ready for the peeling mill, a wooden edge wheel turned vertically by a horse voked to the extremity of its horizontal axis. In travelling over the coffee, it bursts and detaches the coriaceous or parchment-like skin which surrounds each hemispherical bean. It is then freed from the membranes by a winnowing machine, in whicl four pieces of tin made fast to an axle are caused to revolve with great velocity. Corn fanners would answer better than this rude instrument of negro invention. The coffee is finally spread upon mats or tables, picked clean, and packed up for shipment. The most highly esteemed coffee is that of Moka. It s a smaller and a roundex bean; a more agreeable taste and smell than any other. Its -.or is yellow. Next to it in European reputation are the Martinique and Bourbon coffees; the former is larger than the Arabian, and more oblong; it is rounded at the ends; its color is greenirh, and it preserves almaot always a silver gray pellicle, which comes off in the roasting. The Bourbon coffee approaches nearest to the Moka, from which it originally sprung. The Saint Domingo coffee has its two extremities pointed, and is much less esteemed than the preceding. The coffee-tree flourishes in hilly districts, where its root can be kept dry, while its leaves are refreshed with fiequent showers. Rocky ground, with rich decomposed mould in the fissures, agrees best with it. Though it would grow, as we have said, to the height of 15 or 20 feet, yet it is usually kept down by pruning to that of five feet, for increasing the production of the fruit, as well as for the convenience of cropping. It begins to yield fruit the third year, but is not in full bearing till the fifth, does not thrive beyond the twenty-fifth, and is useless in general at the thirtieth. In the coffee husbandry, the plants should be placed eight feet apart, as the trees throw out extensive horizontal branches, and in holes ten or twelve feet deep, to secure a constant supply of moisture. Coffee has been analyzed by a great many chemists, with considerable diversity of results. The best analysis perhaps is that of Schrader. He found that the raw beans distilled with water in a retort communicated to it their flavor and rendered it turbid, whence they seem to contain some volatile oil. On reboiling the beans, filtering, and evaporating the liquor to a sirup, adding a little alcohol till no more matter was precipitated, and then evaporating to dryness, he obtained 17'58 ner cent. of a yellowish 454 COFFEE. brown transparent extract, which constitutes the characteristic part of coffee, though it is not in th:,lt state thie pure eproximate principle, called cqffeine. Its most remarkable reaction is its producing, with both the protoxyde and the peroxyde salts of iron, a fine grass green color, while a dark green precipitate falls, which re-dissolves when an acid is poured into the liquor. It produces on the solution of the salts of copper scarcel) any effect, till an alkali be added, when a very beautifil areen color is produced, which may be employed in painting. Coflee beans contain also a resin, and a fatty substance somewhat like suet. According to Robiquet, ether extracts from coffee beans nearly 10 per cent. of resin and fat, but he probably exagPerates the amount. The peculiar substance cafeine contained in the above extract is crystallizable. It is remarkable in regard to composition, that after urea and the uric acid, it is amona organic products the richest in azote. It was discovered and described in 1820 by Runge. It does not possess alkaline properties. Pfaff obtained only 90 grains of cafeine from six pounds of coffee beans. There is also an acid in raw coffee, to which the name of cafeic acid has been given. When distilled to dryness and decomposed, it has the smell of roasted coffee. Coffee undergoes important changes in the process of roasting. When it is roasted to a yellowish brown it loses, according to Cadet, 12- per cent. of its weight, and is in this state difficult to grind. When roasted to a chestnut brown it loses 18 per cent., and when it becomes entirely black, though not at all carbonized, it has lost 23 per cent. Schrader has analyzed roasted coffee comparatively with raw coffee, and he found in the first 121 per cent. of an extract of coffee, soluble in water and alcohol, which possesses nearly the properties of the extract of the raw coffee, although it has a deeper brown color, and softens more readily in the air. He found also 10*4 of a blackish brown gum; 5'7 of an oxygenated extract, or rather apo'heme, soluble in alcohol, insoluble in water; 2 of a fatty substance and resin; 69 of burnt vegetable fibre, insoluble. On distilling roasted coffee with water, Schrader obtained a product which contained the aromatic principle of coffee; it reddened litmus paper, and exhaled a strong and agreeable odor of roasted coffee. If we roast coffee in a retort, the first portions of the aromatic principle of coffee condense into a yellow liquid in the receiver; and these may be addleld to the coffee roasted in the common way, from which this matter has been expelled and dissipated in the air. Chenevix affirmed that by the roasting of coffee a certain quantity of tannin possessing the property of precipkating gelatin is generated. Cadet made the same observation, and found, moreover, that the tannin was most abundant in the lightly roasted coffee, and that there was nearly none of it in coffee highly roasted. Payssi and Schrader, on the contrary, state that solution of gelatin does not precipitate either the decoction of roasted coffee or the alcoholic extract of this coffee. Runge likewise asserts that he could obtain no precipitate with gelatin; but he says that albumen precipitates from the decoction of roasted coffee the same kind of tannin as is precipitated from raw coffee by the acetate of lead, and set free from the lead by st-Lphureted hydrogen. With these resulti my own experiments azree. Gelatin certainly,cves not disturb clear infusion of roasted coffee, but the salts of iron blacken it. Schrader endeavored to roast separately the different principles of coffee, but none of them exhaled the aromatic odor of roasted coffee except the horny fibrous matter. He therefore concludes that this substance contributes mainly to the characteristic taste of roasted coffee, which cannot be imitated by any other vegetable matter, and which, as we have seen, should be ascribed chiefly to the altered cafeic acid. Accordin. to Garot, we may extract the cafeine without alteration fiom roasted coffee by precipitating its decoction by subacetate of lead; treating the washed precipitate with sulphureted hydrogen, and evaporating the liquid product to dryness. Of late years, much ingenuity has been expended in contriving various forms of apparatus for making infusions of coffee for the table. I have tried most of them, and find, after all, none so good as a cafetiere a la Belloy, the coffee biggin, with the perforated tinplate strainer, especially when the filtered liquor is kept siLmnering in a close vessel, set over a lamp or steam pan. The useful and agreeable matter in coffee is very soluble: it comes off with the first waters of infusion, and needs no boiling. To roast coffee rightly we should keep in view the proper objects of this process, which are to develop its aroma, and destroy its toughness, so that it may be readily ground to powder. Too much heat destroys those principles which we should wish to preserve, and substitutes new ones which have nothing in common with the first, but add a disagreea ble empyreuraatic taste and smell. If, on the other hand, the rawness or greenness is not removed by an adequate heat, it masks the flavor of the bean, and injures the bev erage made with it. When well roasted in the sheet-iron cylinders set to revolve over a fire, it should have a uniform chocolate color, a point readily hit by experienced roasters, who now manage the business very well for the principal coffee-dealers both of London and Paris, so far as my judgmient can determine. The development of the proper aroma COFFEE. 455 is a criterion by which coffee roasters frequently regulate their operati ns. When it loses more than 20 per cent. of its weight, coffee is sure to be injured. It should never be ground till immediately before infusion. Lielig's views of the process of nutrition have given fiesh interest to every analysis of articles of food. A watery infusion of coffee is used in almost every country as a beverage, and yet it is uncertain whether it is an article of nutrition or merely a condiment. A miinute examination of the raw seed, or coffee bean as it is called, must precede the determination of that disputed point. Caffeine is the principle best known, being most easily separated from the other substances, resisting most powerfully chemi cal reagents, and by assuming a crystalline state is discoverable in very small quantities. The constituents of coffee are:.1. Vegetablefibrine, which is the largest constitent, being an elastic horny substance, in which the other substances are incorporated. If we dry the beans at the heat of boiling water for several weeks we can easily reduce them to a fine powder, and by washing with ether, and then boiling in alcohol and water, we extract the soluble matter fromr the fibrine, which may then be boiled with weak solution of potash, and afterwards weak mruriatic acid, as long as any matter is taken up. The purification being completed by boiling in water the fibrine remains; and when rubbed in a mortar resermbles starch; when roasted it gives out the odor nearly of wood. 2. Fatty matter: the beans digested in ether give out a yellow-colored matter, which on evaporation becomes buttery with an odor of raw coffee, and amounts to 100 of the beans. 3. Caffeine: the ethereal solution contains caffeine, which may be remold by shaking with a solution of water. 4. Legumine: in addition to an acid which agrees in its properties with the acid found in oak and cinchona, we find in the coffee beans legumine similar to that of beans. The leguminie contains sullphur, whicl is the cause of their blackening a silver vessel in which the beans may be boiled with an alkali. Legumine and caffeine are the only nitrogenous constituenlts of coffee be;ns, consequently the only substances which could be nutritious, but they are not soluble in hot water as they exist in roasted coffee, and therefore it may be reckoned merely an exhilarating beverage. Roasted coffee affords a riuch richer infusion to hot water containing a minute quantity of carbonate of soda, and improves the quality of coffee on the stomach, by netu tralizing the caffeic acids. Coffee is sold in the shops in its roasted and ground state often adulterated with a variety of substances, but chiefly with chicory. This is the dried, roasted, and ground root of a plant called Cichorilum Irtybus, better known under the name of wild succory. Tile chicory imported firoi Belgium and Prussia is better than the British, which is usually colored with Venetian red, and is sold at a cheaper rate; chicory itself is frequently very impure, containing roasted peas and coffee flights, which are the membranous coat of the bean separated in tire act of roasting. If a little genuine ground coffee be thrown in a wineglassfull of water, it mostly floats, and slowly moistens, comniunicating scarcely any color to the liquid. Powdered chicory treated in the same way very speedily absorbs moisture, communicates a deep reddish brown tint to the water, and in a few minutes falls to the bottom. Hambro' powder contains roasted starch, and acquires a deep purplish color when moistened with a solution of iodine. The microscope shows in the chicory powder fragments of dotted ducts which do not exist in coffee. There is another substance which is mixed with coffee, called refining powder; it is merely caramel, or burnt sugar. It is used for enabling drained coffee to afford a dark colored infusion. If tannin exists in roasted ecffee, as maintained long ago by Chenevix, and generally admitted since, it 1must be very Jifferent from the tannin present in tea, catechu, kino, oak-bark, willow-bark, and other astringent vegetables; for I find that it is not, like them, precipitated by either gelatine, albumen, or sulphate of quinine. With regard to the action upon the animal economy of coffee, tea, and cocoa, which contain one conimon chemical principle called caffeine or theine, Liebig has lately advanced some ingeinious views, and has, in particular, endeavored to show that, to persons of sedentary hatlits in the present refined state of society, they afford eminently useful beverages, which contribute to the formation of the characteristic principle of bile. This important secreted fluid, deemed by Liebig to be subservient to the function of respiration, requires for its formation much azotised matter, and that in a state of combination analogous to what exists in caffeine. Tile quantity of this principle in tea and coffee being only from 2 to 5 per cent. might lead one to suppose that it could have little effect upon tile system even of regular drinkers of their infusions; but if the bile contains only one-tenth of solid matter, called choleic acid, which contains less than 4 per cent. of azote, then it may be shown thit 3 grains of caffeine would impart to 500 grains of 456 COFFEE. bile the azote which occurs in that crystalline precipitate of bile called taurinc, which is thrown down from it by by mineral acids. One atom of caffeine, 9 atoms of oxygen, and 9 of water, being placed together, produce the composition of 2 atoms of taurine. Now this is a very simple colnbina. tion for the living organism to effect; one already paralleled in the generation of hippuric acid in urine, by tile introduction of benzoic acid into the stomach; a physiological discovery made by my son, which is likely to lead to a more successful treatment of some of the most formidable diseases of man, particularly gout and gravel. If the preceding views be established, they will justify the instinctive love of mankind for tea. coffee, and cocoa, in spite of the denunciations and veto of neutropai..ic. honmec. pathic, and hydropathic doctors; sorry patlologists-hoc genus omnze. See TEA. In the years ending 5th January, 1851 and 1852, the imports of coffee were as follows:Entries for Home Gross Amount of importations. Consumrption. Duty. 1851. 1852. 1851. 1852. 1851. 1852. Entered before 15th April 1851- lbs. lbs.' bs. lbs. tbs. lbs. Of British Possessions 36,814,036 1,818,514 28,891,294 6,510.346 505,515 113,931 Foreign 13,989,116 5,018,806 2,335,546 443,418 61,305 11,637 Entered from 15th April, 1851: from British Possessions oift of Europe - - 34.077.563 - - 21,486,170 - - 268,599 From other Parts - 12,035,269 - 4,124,230 - - 51,572 50,803,152 52,950,152 81,226,840 32.564,164 566,820 445,739 The duty is 3d. per lb. Thie exports in the above years were respectfully 12,169,752 lbs. and 22,712,859 lbs. of wlicli 3,399,333 1bs. and 12,606,333 Ibs. wvere the produce of British Possessions, and 8,770,419 llbs. and 10,106,526 lbs. were Foreign. COFFEE ROASTING AND GRINDING. The gratefulness of tlie beveraige afforded by this seed depends upon many circumustances, which are seldotn all combined. Tile nature of the soil, tile climiate, seed, mode of culture, and cure, influence greatly the quality of ~~~~~~~~366 /X S|tlie fruit. But wlien all these particularts concur, and the berry is of tle firest sort, and most highly appreciated by the importer, it may be ruitted in the roasting; for if sotme berries be tinder and some over done, the whiole when ground will 1 H X Aj0','~,8 yyield an unpalatable infusion. The due J.l g }; —'/lil ptoint to which the torrefaction should be er ct tried, may be determined partly by...-i. ~ * i~ = j tlie color, and partly by the loss of weioglt, whlich poitnts, however-, are difll- -' l~il ll fetentt for each sort ofcffee. But perfect T —i —t - - V-_~ l ilj equality of ustulation is difficult of attain-ment with the ordinary cylindrical ma1l -1 11_WI 1- l cllines. Messrs. Law, of London and EdI 11 11 jI iinburgll, coffee smoerchants to the Queen, 7 _1 I_ _- - 1 j _ _- I: haid long been dissatisfied with the partial 1 —1 —1 -1 —:___ tiot manner in which the cylinder performed 1-11,I I IIT —i- )i|1 its duty, as it generally left some part of ---- --- F-Fi- 1 11 1gil its contents black, some dark brown, and otlhers paler; results which greatly injure 1,_ - "-_ —----— ~~-5- tile flavor of the beverage made with the' ~-===h —'-5=-~- C- coffee. Mr. William Law has conquered all these difficulties by his happy invention of tlhe globular roaster, actuated by a compound motion lilke that of ourl earth. Tiss rotster, with its double, rotary motion, is heated not over anr open file but in an atmosphere of hot air, throgllh a cast metal casing. The globe is so mounted as to revolve horizonitally, and also firom time to time vertically, whereby the included beans were tossed about and intelrmingled in all directions. In. equality of torrefaction becomes impossible. Tie consequence is the production of an article which on being ground evolves tlie most fragrant aroma, and when infused tie most grateful and exhilarating beverage. The position of the globe in fi. 366 shows COLLODION, 457 it as turned up by a powerful leverage out of the cast-iron heater, preparatory to ite bei ig emnptied and re-chtarged. The coffee, thus equally roasted, is finely ground in a mill between horizontal stones, like that of a corn-mill, and is thereby capable of giving out all its virtues to either boiling or cold water. COKE is carbonized pitcoal. See CIIARcoAL; and PITCOAL at the end. In manufacturing coke on the large scale, Mr. Wilkinson of Jarrow, near Gateshead, has contrived a system of machinery for saving manural labor in discharging the coke from the ovens, while he has so arranged the ovens themselves, as to equalize thie distribution of air among the coals, and to improve tile produce and increase its quantity. The preferable size of oven, in his opinion, is 14 feel long, $ feet wide, with the floor raised one foot above the level of the ground, and having an inclination to the front of 6 inches in the length of the bottom'-he perlpendicular height of the walls, up to the springer, being 3 feet, while the radius of tile arch is 4 feet. He connects crystallizing and evaporating pains for chemrical purposes with a range of 12 coke ovens. Tihe patentee claims as inventions his forming in the walls of coke ovens, flues with lateral openings for supplying air to the interior of tile oven, as also his peculiar mechanical apparatus for discharging the coke, and his plan of economizing heat by evaporation. COLCOTHAR OF VITRIOL (Rolge d'Angleterre, Fr.; Rothes Eisenoxgd, Germ.) is the brown-red peroxide of iron, produced by calcining sulphate of iron with a strong heat, levigating the resultilg mass, andr elutriating it into an impalpable powder. A better way of making it so as to compllete the separation of the acid, is to mix 100 parts of tile green sulphate of iron with 42 of comrnnon salt, to calcine the mixture, wash away the resulting sulphate of soda, anrd levigate the residuum. The sulphuric acidl in this case expels the chlorine of the salt in the form of muriatic acid gas, and saturates its alkaline base produced by tie chemlical reaction; whence an oxide will be obtained free from acid, much superior to whalt is comnmonly found in the shops. The best sort of polishing powder, called jeweller's red rouge, or plate powder, is the precipitated oxide of iron prepared bty adding solution of soda to solution of copperas, washing, drying, and calcining tile powder in shallow vessels with a gentle heat, till it. assumes a deep brown-red color. See IRON. COLLODION. M. Malgaignle has recently communicated to the French Medical Journals, some remarks on the preparation of gull-coctton for surgical purposes. Several Freuich chemists, at tile suggestion of M. Malgaigne, attempted to make an ethereal solution of this compound, bty pursuing the process recommended by Mr. Maynard in the American Journal of Medical Sciences, but they failed in procuring tile cotton in a state in which it could be dissolved in ether. It appears that these experimentalists had employed a mixture of nitric and sulplhuric acids; but M. Miallie ascertainied, after many trials, that the collodion, in a state fitted for solution, was much more easily procured by using a mixture of nitrate of potash and sulphuric acid. For the information of our readers who may be disposed to try this new adhesive material, we here give a descripltion of M. Miallie's process for its preparation. It appears from the results obtained from this chemist, tlhat cotton, in its most explosive form, is not the best fitted for making the ethereal solutionParts by weight. Finely powdered nitrate of potash - -40 Concentrated sulphuric acid - - - - - - 60 Carded cotton - - - - - - - 2 Mix the nitrate wlth the sulphuric acid in a porcelain vessel, then add the cotton, and agitate the mass for three minutes by the aid of two glass rods. Wash the cotton, without first pressing it, in a large quantity of water, and when all acidity is removed (indicated by litmus paper) press it firmly in a cloth. Pull it out into a loose mass, and dry it in a stove at a moderate heat. The compound thus obtained is not pure fulminating cotton; it always retains a small quanitity of sulphuric acid, is less inflammable than gun-cotton, and it leaves a carbonaceous residue after explosion. It has, however, in a remarlkable degree, the property of solubility in ether, especially when mixed with a little alcohol, and it forms there. with a very adhesive solution, to which the name of collodion has been applied. Preparation of Collodion. Parts by weight. Prepared cotton - -- 8 Rectified sulphuric ether - - - - - - 125 Rectified alcohol - - - 8 Put the cotton with the ether into a well-stopped bottle, and shake the mixture lot some minutes. Then add the alcohol by degrees, and continue to shake until the whole I _ COLORS USED IN PAINTING, WITH NOTICES OF THEIR CHEM1CAL' AND ARTISTICAL PROPERTIES.-By/ William Linton. W.x Colrs. Chemical Designation. Preparation. Chemical Characteristics. Artistical Properties. Additional Colors, with Remarks. Blaokened by Sulphuretted Hydrogen, Hdro-Sulphiuret of Ammonia, and There are other Whites of Lead, varying in body other foul gases, common to most do- The best White extant for Oil or Resin and brilliancy, and equally obnoxious to the acmestic atmospheres; for wiich reason vehicles when pure, which is generally ti of mephitic vapors; as Krems, Roman, Carbonae of Lead, Plates f lead exposed to a rapidly dring and protecie vehile is ascertained y itsexceeding whienessand and enetian Whites, and Slphate of Lead. The essential to eal it up against such evil opacity. Its usual adulteratlions are Sul- Whites of Bismuth, Pearl, and Antimony, are FLAKE WTVHITE with the acti,,n of vinegar-steam influences. [t has no injurious action phate of Barytes, Chalk, Pipe-clay, &c., injured by light as well as by mephitic vapors. ~ = an excess of Oxide. in beds of fermenting tan. upon Vegetalle and other colors, as all of which are partially transparent, Those of Zinc, Tin, Barytes, and Strontian, itsome have conjectured. It is perfecy and consequently l appear darker in uc- although they are comparatively secure against *^I~~~~~~~~ {>~ ~ ~~~~~~~~~~~~~~~itsoluble in diluted Nitric or Acetic Acid t ous or resinous vehicles. the foul gases, are too feeble in body to be satistwthen free from Pipe-clay or Sulphate of factory in unctuous or resinous vehicles.:Barytes. | I ] _ | _ _ l 1 l | A beautiful Orange tinted Yellow, of Resists the action of the fiul gases, i ht an excellent body; and an admirable sub. A combinaitthuitttiontoftCatdmiumi light, utitute for Naples Yellow, the Chromes, T here are other Mineral Yellows, but they arei I CADMIUI YELLOW Sulpliuret of Cadmium |&. It is a most durable and br iliant a other Mitneratl Yellows, whiich a re ll tst objetial. T Ct, ut; ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~~~~~~n ~lh r color. liable to injury from noxious vapors, of Lead, like all preparations of that metal, are'~ *^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~light, &c. blackened by the foul gases. The Chronmate of of i ^______________ ________ Bar/ytes is strongly acted upon by light. The ~f I united oxides of g —---------------- ------- * —---— nt oie fLeadc and uAntimony, furnish h P | STRONTIAN YELLOW Chromate of Strontlian added to one of Cbromate light, an d is perfectly durable. s t Y| (;e;llo w i a b h n s of^ Potash.> above. Mineral, or Subsulphate of Mercury, is rapidly "It _ ___ _____________ __________ ___________________________________________ ___________________________blackened by light, and by the foul airsackened b y l ight, and by the foul airs. Orpi ment or King~i Yellow (Ahsenic and Sulphur) is CO 2 W YELLOW OCHRE equally destructible; also Patent Yellow (Lead 44 i3l ROXFORID OCHRE Native Earths. consisting The Oxides of Iron are among the most and Salt heated violently). ROMAN OCHRE of staple colors of the palette. When The Vegetable Yellows are not to be depended D-1 ~ STONE OCHRE Silica and Alumina properly washed and prepared for oil upon. They soon disappear when applied in deliBir BOWN OCHRE coluoed by painting, they are incapable of injuring cate tints or thin glazings, epecially if subjected k TEH'RRA DI SIENNA Oxide of Iron. other colors, and may be said to con. to the action of the solar rays (a summary mode UMBER stitute the soiundest materials with of ascertaining the probable results of lengthened CO Oxides All Permanent Colors, whether Native which the chemistry of Nature has fur- periods in subdued lights). Gaitboge dissolved of or Calciued. nishcd the painter for the imitation of by Aither, or Alcohol, is equally fugitive. JAUNE DE MARS Iron A Chemical Preparation her wrks. 1. LIGHT RED Yellow Ochre, Calcined.. There are other Mineral Redst which are durable w _____________~~~~~~_________________________ ~Native Cinnabar is inferior in every respect to &-1>~~~~~~~~~~~~~~ C2 _ ^~~~~~~~~~~~~~~~~~~~~~~~Vermillion. Venetian Red is an inferior repre-.~! INDIAN RED A Native Earth. sentative of Indian Red, and Colcothar a still __________________ _ -___ _________ _ coarser one. Red Lead blackens in oil; and ~i $.;.. - lodzde of Mercury las no claim to durability. A perfectlyp iermanit ioulo not aiutid Among Vegetable Reds, the Madders have the MeR-ryt ndSulphrury. auh ii ait cuitic a lkai e s. oi A bahutiful color, and of an excellent best reputation for standing. All vegetable | VERBMILLIOf Buulphure of MUereury. rto m eth e r ac i ored h eateif. Vpo ret body colors, however, should be looked upon with sts~[pVERMILLONBioitlphi.ttti Mitcity. isbliedtogtr by a red heal if pir.pi Consists of SilitA, Alumina, Acitt, whith will not affect other Lime, Soda, and Pwtash, Maral Blues, will destroy the color KAtV Oxide o( Iron, Magnesia, ~ in Ul~ratnarine. This is one of its A moat invaluable pigment: too well ULTRAAINE SulhuicAid, atlhu Prepared frmat mnrl bs hria tests. taeofthe knog A taldtappreiatedtoteuieany ULTRAMARINE i cpha Aaid, lp alled Lapis Lazuli. batre a reio tat. Nat tat h ther Mineral Blues. bht they a to Gmelint, Varetrapp, meats do it any injury. Iti peretl behtter atvoided whent he Uttramtarisareavi and others), in its native durable. pbe h by ts tet p ta y Oxide of l baltd and Auina rm -; > —) ~~~~~ ~ ~~~~~state.. Cobalt Blue; and the Oxide of Cobalt and Glass, )-< ^j --- — "- ------------------------------ -------------------------- -------------------------- form aSmalt hetey rare bbohh bblackened byy oul ^4 It is regarded as a comn-airs. Prussian and Antwerp Blues are in much paapound of Silicate of Alh- use from the want of a permanent deep blue a they *<\ ~~~~~~~~~~~~~mina, Silicate of Soda, with Prepared by several diffi- A cheap and really valuable substitute are injured by light and alkalies. India o Lis ARTIFICIAL Sulphuret of Soium; the gult processes,, at ohiah Responds t tohe same tests as the na- for the native prodact. The best is trior in color and very fugitive. ULTRAMARINE coaor is owing to the reaction are kept secret by the ma tive mineral. that which is the least purple in its8 of the latter on the two kers. tint. former constituents. YeaI4 When Chromate of NAercury el ~~~~~~~~~~~~~~~~(tba Orantge paecipitateao CYIROME GREEN BChomidm. aninChrgNmate of Potais (Ti e Ap loting aatterll of lmerbs.). A opaqute light Grn, ofat fall body. ataaongly ignitad, O Txidetg tatata ctoalf) ^ ^ ^-(;~~~~~~~~~~~~~h omium remains in a powdaar. 0 pae Therearea other Mianeral Greena. Thase of Cop~~~~~~~~ ~~~~~~~~~~~~~. aa~~~~~~~~~~~~~~~~~~~~~~~~e, tha Emertald Gta tand Mianeal Grenar, -1` ^ TERRA VERTE Oxide of Copper. very insecure in oil vehicles. 0 0> _______________________ _ ______________________ Both qtuite p ermancnt-nativeaor ratn Bt dtiaB q Gte. do-a-ly o ------------------- -----------------— Native Minerals. cinad. Like the Ultramarines, acids Beutfl d icae Greens; deservedly0 CaMrabate f Copper,detroy their colors. favoritepigots wibh ot painters. MALACHITE united with Silicate. VANDYKE BROWN Decoampesed Decayed Wood, Peat, ora COLOGN EARTH Vegetable Matter. Bog Earth. _ —* r______ —- -- - -- --- - - -___ -________ _-__-_ —-----------.- _ These Browns are reputed permanent E-. Zint hemsl-, tha opacity with elaith TadbEaa bnbaityataaaa Vegatahlt and Animal Whif. Pilth and Mytrh, time gnerlltty ivtI.t tha in pitture sy The dark Browns, though chiefly of vegetable Bi,,,1 I- MUMMY Matte aoAinad. aith Anital Mlntt itg ai t ph rrii sem to be the only deyp transparent <3 M ^ Matter combined~~~~~~~~with Animal Matter, ~~~~~ being attributable probably t,, a loss of tasretBon -...kfrs.hich have.he reputation of being perma<1t-^ 0 _________________ ____________ _________________ ___________________ tranute in (he vehiclttratha~paatttehihhathaaapalatiatathihgpaaaa-er than Dr pa Broww. alattata ia tb. piget-atta dab atnet. The alp Rets, Yallows, Gtrat-a, atti A Ritural Pihab, ort Ratin, clrmaig lb. dtefect mote eidenttBlt, 11aaatI.t tgtia t ASPHALTUM Bitttmetn. fond floating on tat tad S.-a; atso after. the it ila tion of natural naphtha. IVORY BLACK Animal Matter. Calcined Ivory. A perfectly durable pigment. Of a hit Fwnsh-black tint. -all ~~~~~~~~~~~~~~~~~Caltainaad Vite Statks. Qbitt durableaht ena thet blae tintts raEathhaht 0 2.~ BLUE BLACK Vegetable Matter. Cotta-Nut Shealls, &..natul Of a Bluh-black tint. ___~____________________'________'_______________________________ _____________K_ In recording the defects and liabilities of colors, it should not be forgotten that the painter's vehicle or diluent must have considerable effect in preventing chemical action among such as are inimical to each other, by isolating and sustaininga their component particles from mutual contact. And if the vehicle be of a souad and firitly drying quality, even the external attacks from dainp and foul airs, to which many of the objectionable colors are liable. may often be successfully resisted. But should the vehicle be of a flimsy and impure character, instead 4^ of being a protector, it may become in itself an originator of mischief among tite colors. _ _i 460 COMB. of the liquid acquires a syrupy consistency. It may be then passed through a cloth, the residue strongly pressed, and the liquid kept in a well-secured bottle. Collodion thus prepared possesses remarkably adhesive properties. A piece of linen or cotton cloth covered with it and made to adhere by evaporation to the palm of the hand, will support a weight of twenty or thirty pounds. Its adhesive power is so great that the cloth will commonly be torn before it gives way. The collodion cannot be regarded as a perfect solution of the cotton. It contains suspended and floating in it a quantity of vegetable fibre, which has escaped the solvent action of the ether. The liquid portion may be separated from these fibres by a filter, but it is doubtful whether this is an advantage. In the evaporation of the liquid, these undissolved fibres by felt. ing with each other appear to give a greater degree of tenacity and resistance to the dried mass.;n the preparation of collodion it is indispensable to avoid the presence of water, as this renders it less adhesive; hence the ether as well as the alcohol should be purely rectified. The parts to which the collodion is applied should be first thoroughly dried, and no water allowed to come in contact with them until all the ether is evaporated to dryness by a steam heat, which must be continued for some time so as entirely to expel the alcohol or ether. The residuary matter should have the transparency and general characters of common resin. COLOPHANY, black rosin, the solid residuum of the distillation of turpentine, when all the oil has been worked off. COLORING MATTER. (Aatfire colorante, Fr.; Farbstoff, Germ.) See DYEING. the several dye-stuffs and pigments. COLUMBIUM, a peculiar metal extracted from a rare mineral brought from Haddam, in Connecticut. It is also called Tantalium, from the mineral tantalite and yttro-tantalite, found in Sweden. It has hitherto no application to the arts. It combines with two successive dose~ of oxygen; by the second it becomes an acid. COLZA Is a variety of cabbage, the brassica oleracea, whose seeds afford, by pressure, an oil much employed in France and Belgium for burning in lamps, and for many other purposes. This plant requires a rich but light soil; it does not succeed upon either sandy ir clayey lands. The ground for it must be deeply ploughed and well dunged. It should be sown in July, and be afterward replanted in a richly-manured field. In October it is to he planted out in beds, 15 or 18 inches apart. Colza may also be sowed in furrows 3 or 10 inches asunder. Land which has been just cropped for wheat is that usually destined to colza; it may be fresh dunned with advantage. The harvest takes place in July, with the sickle, a little before the seeds are completely ripe, lest they should drop off. As the seed is uroductive of oil, however, only in proportion to its ripeness, the cut plants are allowed to complete their maturation, by laying them in heaps under airy sheds, or placing them in a stack, and thatching it with straw. The cabbage-stalks are thrashed with flails, the seeds are winnowed, sifted, spread out in the air to dry; then packed away in sacks, in order to be subjected to the oil-mill at the berinning of winter. The oil-cake is a very agreeable food to cattle, and serves to fatten them. It is reckoned to defray the cost of the mill. Colza impoverishes the soil very much, as do, indeed, all the plants cultivated for the sake of their oleaginous seeds. It must not, therefore, be come back upon again for sil years, if fine crops be desired. The double ploughing which it requires effectually cleans the ground. See OILS, UNCTUOUS. COMB, the name of an instrument made of a thin plate either plane or curved of wood, horn, tortoise-shell, ivory, bone, or metal, cut out upon one or both of its sides or edges, into a series of somewhat long teeth, not far apart.~ which is employed for disentangling, iaymin parallel and smooth the hairs of man, horses, or other animals. A thin steel saw bow, mounted in an iron or wooden handle, is the implement used by the comb-maker to cut the bone, ivory, and wood into slices of from a twelfith to a quarter of an inch thick, and of a size suitable to that of the comb. The pieces of tortoise-shell as found in commerce are never flat, or, indeed, of any regular curvature, such as the comb must have. They are therefore steeped in boiling water sufficiently long to soften them, and set to cool in a press between iron or brass moulds, which impart to them the desired form which they preserve after cooling. After receiving their outline shape and curvature, by proper flat files or fine rasps, the place of the teeth is marked with a triangular file, and then the teeth themselves are cut out with a double saw, composed of two thin slips of tempered steel, such as the main-spring of a watA., notched with very fine sharp teeth. These slips are mounted in a wooden or iron stock or handle, in which they may be placed at different distances, to suit the width of the comb-teeth. A comb-maker, however, well provided in tools, has an assortment of double saws set at every ordinary with. The two slips of this saw have their teeth in different planes, so that when it begins to cut, the most prominent slip alone acts, and COMBUSTIBLE SUGAR. 461 when the teeth of this one have fairly entered into the comb, the other parallel bla'e begins to saw. The workman, meanwhile, has fixed the plate of tortoise-shell or ivory between the flat jaws of two pieces of wood, like a vice made fast to a bench so thai the comb intended to be cut is placed at an angle of 45~ with the horizon. He now saws perpendicularly, forming two teeth at a time, proceeding truly in the direction of the first tracing. A much better mode of making combs is to fix upon a shaft or arbor in a lathe a series of circular saws, with intervening brass washers or discs to keep them at suitable dis. tances; to set in a frame lilke a vice, in front of these saws, the piece of ivory or horn to be cut; and to press it forward upon the saws at an anele of 45 degrees, by means of a ir:ulated screw motion. When the teeth are thus cut, they are smoothed and polished with files, and by rubbing with pumice-stone and tripoli. Mr. Bundy, of Camden Town, obtained a patent so long ago as 1796, for an apparatus of that kind, which had an additional arbor fitted with a series of circular saws, or rather files, for sharpening the points of the comb-teeth. More recently, Mr. Lyne has invented a machine in which, by means of pressure, twc combs are cut out at once with chisels from any touch material, such as horn or tortoiseshell, somewhat softened at the moment by the application of a heated iron to it. The piece of horn is made fast to a carriage, which is moved forward by means of a screw until it comes under the action of a ratchet-wheel, toothed upon a part of its circumference. The teeth of this wheel brine a lever into action, furnished with a chisel or knife, which cuts out a double comb from the flat piece, the teeth of which combs are opposite to each other. By this means, no part of the substance is.ost, as in sawing out combs. The same carriage may be used, also, to hear a piece of ivory in the hard state toward a circular saw, on the principles above explained, with such precision, that from 80 to 100 teeth can be formed in the space of one inch by a proper disposition of the tool. Bullocks' horns, after the tips are sawed off, are roasted in the flame of a wood fire. till they are sufficiently softened; when they are slit up, pressed in" a machine between two iron plates, and then plunged into a trough of cold water, whereby they are hardened. A paste of quicklime, litharge, and water is used to stain Ihe horn to resemble tortoise-shell. See HORN. COMBINATION (Combinaison, Fr.; Verbindung, Germ.); a chemical term which denotes the intimate union of dissimilar particles of matter, into a homogeneous-looking compound, possessed of properties generally different from those of the separate cons itu ents. COMBUSTIBLE (Eng. and Fr.; Brennstoff, Germ.); any substance which, exposed in the air to a certain temperature, consumes spontaneously with the emission of lhcal and lihit. All such combustibles as are cheap enough for common use go under the name of Fuel; which see. Every combustible requires a peculiar pitch of temperature to be kindled, called its accendible point. Thus phosphorus, sulphur, hydrogen, carbureted hydrogen, carbon, each takes fire at successively higher heats. COMBUSTIBLE SUGAR. When sugar is acted on by a mixture of nitric and sulphuric acids, a peculiar substance is produced, having a close resemblance to common resin, not only in its appearance and physical characters, but also in regard to its solubility in alcohol, ether, volatile oils, &e., and insolubility in water. This substance is, however, extremely inflammable and explosive, and possesses many of the properties ascribed to the celebrated Greek fire. Its affinity for alcohol and ether is so great that water will not remove these fluids from it. "Not having yet succeeded in producing with it any definite basic compound which would enable me to control my results, I have not attempted its analysis. The only purposes to which I have applied it are to the formation of fusees for shells, and to the preservation of gunpowder and pyrotech. nical articles from damp and moisture. As a fusee, it is easily lighted, burns with great regularity, and appears absolutely incapable of being extinguished, circumstances whieh would render it of great use in ricochet practice. As a means of preventing the mischievous effect of damp and moisture on gunpowder it is of great value. The best mode of application is to plunge the gunpowder for a few seconds into an alcoholic or ethereal solution of the sugar compound, then withdraw it and allow it to dry at a gentle heat, say 120~ Fahr., though there is no danger of an explosion at 212~. In this way the gunpowder is covered by a coat of varnish easy of ignition and insoluble in water, which cannot therefore penetrate to the gunpowder, the explosive nature of which is rather augmented than diminished by this treatment. An ethereal solution of gun-cotton does not answer so well for this purpose, nor is it so manageable. I have not ascertained how far this new substance is useful in retaining the edges of wounds in approximation, but its alcoholic solution merits a trial. The following is the method which I have found most successful in the manufacture of this compound:"Mix together sixteen parts of concentrated sulphuric acid and eight parts cf nitric 4:62 CONCRETE. acid, spec. gray. 1-50; place the mnixture in cold water, and when the temperature has fallen to 60~ or less, stir in one part of finely-powdered sugar, which will become pasty in a few seconds, and is then. to be removed and plunged in cold water, when more sugar may then be added to the acid mixture, and removed as before. The compound is to be washed in water and dissolved in alcohol, to which a solution of carbonate of potash must be added in excess, so as to precipitate the substance, and neutralize its uncombined acid. After careful washing with water, it is again to be dissolved in alcohol or ether, and cautiously evaporated to dryness by a steam heat, which must be continued for some time, so as entirely to expel the alcohol or ether. The residuary matter should have the transparency and general character of common rosin."-Mir. L. Thompson. COMBUSTION (Eng. and Fr.: Verbrennung, Germ.) results in common cases from the mutual chemical reaction of the combustible, and the oxygen of the atmosphere, whereby a new Compound is formed; the heat and light evolved being most probably produced by the rapid motions of the particles during the progress of this combination. COMPOUND COLORS. If the effects of the coloring particles did not vary according to the combinations which they form, and the actions exercised upon them by the different substances present in a dyeing bath, we might determine with precision the shade which ought to result from the mixture of any two colors, or of the ingredients affording these colors separately. Though the chemical action of the mordants and of the liquor in the dye-bath often changes the result, yet theory may always predict them within a certain degree. It is not the color appropriate to the dye-stuffs which is to be considered as the constituent part of compound colors, but that which they must assume with a certain mordant and dye-bath. Our attention ought therefore to be directed principally to the operation of the chemical agents employed. 1. The mixture of blue and yellow dyes produces green. D'Ambourney, indeed, says that he has extracted a fast green froimi the fermented juice of the berries of the buckthorn (rhamnius fragula), but no dyer would trust to such a color. 2. The mixture of red and blue produces violet, purple, columbive (dove-color), pansy, amaranth, lilac, mallow, and a great many other shades, determined by the nature and tone ofTthe red and blue dye-stuffs, as well as their relative proportions in the bath. 3. The mixture of red and yellow produces orange, Tposdore, cinnamon. coquelicot, brick, capuchin; with the addition of blue, olives of various shades; and with dune instead of yellows, chestnut, snuff, musk, and other tints. 4. Blacks of the lighter kinds constitute grays; and, mixed with other colors, produce marrone (marroons), coffees, damnascenes. For further details upon this subject, see CALICO PRINTING, DYEING, as also the individual colors in their alphlabetical places. CONCRETE. The name given by architects to a compact mass of pebbles, sand, tnd lime cemented together, in order to form the foundations of buildings. Semple tays that the best proportions are 80 parts of pebbles, each about 7 or 8 ounces in weight, 40 parts sharp river sand, and 10 of good lime; the last is to be mixed with water to a thinnish consistence, and grouted in. It has been found that Thames ballast, as taken from the bed of the river, consists nearly of 2 pai ts of pebbles to 1 of sand, and therefore answers exceedingly well for making concrete; with from one seventh to one eighth part of lime. The best mode of making concrete, according to Mr. Godwin, is to mix the lime, previously ground, with the ballast in a dry state; sufficient water is now thrown over it to effect a perfect mixture, afier which it should be turned over at least twice with shovels, or oftener; then put into barrows, and wheeled away for use instantly. It is generally found advisable to employ two sets of men to perform itis operation, with three in each set; one man to fetch the water, &c., while the other two turn over the mixture to the second set, and they, repeating the process, turn over the concrete to the hariow-men. After being put into the barrows, it should at once be wheeled up planks, so raised as to give it a fall of some yards, and thrown iinto th foundation, by which means the particles are driven closer together, and greater solidity is given to the whole mass. Soon after being thrown in, the mixture is observed usually to be in commotion, and much heat is evolved with a copious emission of vapor, The barrow-load of'oncrete in the fall. spreading over the ground, will form generally n stratum of from 7.o 9 inches thick, which should be allowed to set before throwing in a second. Another method of making concrete, is first to cover the foundation with a certain quantity of water, and then to throw in the dry mixture of ballast and lime. It is next turned and levelled with shovels; after which more water is pumped in, and the operation is repeated. The former method is undoubtedly preferable. In some cases it has been found necessary to mix the ingredients in a pug-mill, as in mixing clay, &c. for bricks. For the preparation of a concrete foundation, as the hardening should be rapid. no more water should be used than is absolutely necessary to effect COOLING OF FLUIDS. 4G3 a perfect mixture of the ingredients. Hot water accelerates the induration. There is about.one fifth of contraction in volume in the concrete, in reference to the bulk of its ingredients. To form a cubical yard of concrete, about 30 feet cube of ballast and 83 feet cube of ground lime must be employed, with a sufficient quantity of water. CONGELATION (Eng. and Fr.; Gefriertng, Germ.); the act of freezing liquids. Many means are supplied by chemistry for effecting or promoting this process, but they do not, constitute any peculiar art or manufacture. See IcE-HousE. COOLING OF FLUIDS. In Mr. Derosnes's method, the cooling agents employed are a current of atmospheric air, and warm water of the same or nearly the same temrn perature as that of the vapors which are to be operated upon. Fig. 367 represents merely a diagram of the general features of an apparatus constructed upon the principles proposed to be employed, which will serve to explain the nature of this improvement. 867 Let A be the source ot K I the vapors, or the vessel boiler, alembic, or closed, IT pan that contains the liquid or sirup to be evaporated or concentrated. j 5y ^ j^\ <^^^U,,The pipe B, through which 11^^~~~ ~ ~~11 \ <^^^rthe vapor passes as it -I.al,,> s rises in the boiler, is sur~\. ~ ~ ^^^^> ml~rounded by another tube e\T~~~ R^~~ ^iw ~ c.oflarger diameter, closed at both ends. A pump D, I\ ^^ > draws from thereservoir E, i~\ K 11 I || warm water, which water has been heated by its pre[{ S 1lll^^ lo> ^^?^^^ vious and continual pasDQ',-, sage through the apparatus in contact with the ----------— _-I E ALL\_ LI 1.1 — surface ofthe vapor pipes. This pump forces the water by the pipe F, into the annular space or chamber between the pipes B and c, in which chamber, by its immediate contact with the pipe B, it acquires the temperature of the vapors intended to be refrigerated. The pipe G conveys th, water from the pipe c, into the annular colander or sieve i, which has a mnltitude of nmall holes pierced through its under part, and whence the warm water descends in the form of a continued shower of rain. To the end of the pipe B, a distiller's worm i i, is connected, which is placed beneath the colander H. The entire length of the worm-pipe should be bound round with linen or cotton cloth, as a conductor of the heat, which cloth will be continually moistened by the rain in its descent from the colander. As this water has been heated in passing alonmg the tube c, the shower of rain descending from the colander will be at a higher temperature than that of the atmosphere, and, consequently, by heatine the surrounding air as it descends, a considerable upward draft will be produced through the coils of the worm-pipe. If the colander and the worm-lpipe are enclosed within a chimney or upright tube, as K I, ropen at top and bottom, a current of ascending air will be produced within it by the descending shower of hot water, similar in effect to that which would be produced in a chimney communicating with a furnace, or to that of the burner of an argana lamp. Consequently, it will be perceived that in opposition to the descending rain, a strong upward current of air will blow through that part of the cylinder K K, which is beneath the colander. When the air first enters the lower aperture of the chimney oG tube K, it is of the same temperature and moisture as the external atmosphere; but in its passage up the tube it meets with a warmer and damper atmosphere, caused by the heat given out from the hot fluid continually passing through the pipes, and by the hot shower of rain, and also by the steam evolved from the surfaces of the coils of the worm, which are continually wetted by the descending rain, the evaporation being considerably augmented b3 the cloth bound round the worm-pipe, retaining the water as it descends in drops from coil t. coil. The atmosphere within the tube being of a higher temperature than without, a current of air constantly ascends and escapes at the upper aperture K, and its place is supplied by fresh air from the surroundin- atmosphere, entering the tube below. The fresh air thus admitted at the bottom of the tube, being cold and dry, will be suited to take up tle heat and moisture within, because the waterwithin the tube, beine in a state of dispersion as rain, presents to the air many points, or a very extended surface, an.4 also because it is of a higher temperature than the air; and, besides, cold dry air is cono inually renewed, and a source of warmth is furnished by the latent caloric to the 464 COOLING OF FLUIDS. steam, as fast as it is evolved. Thus a portion of the descending rain, or water, is evaporated, and the effect of this evaporation is to abstract caloric not only from the water held in contact with the coils of the worm-pipe by the cloth enveloping it, but also from the hot vapors which pass through the worm. This process of evaporation has, therefore, a cooling power, which is but slight in tile lower part of the chimney or tube K, because the temperature of the water, or rain, and of the worm, at this part, are of a lower temperature; but its refrigerating lower increases as it rises towards the colander, and there it acquires its maximum of intensity, so that at any point between the lower aperture of the cylinder and the ola(nder lthe current of air is always a little cooler than the atmosphere of thle region through which it passes (that is, as its maximum); and in passing this region of higher tenlper:,ture, it is not only put in equilionum of temperature, but also made to take up an additional quantity of aqueous vapors, which equalizes the new temperature it acquires with its capacity of saturation. The cooling caused by the evaporation acts in an incessant and progressive manner from the lower aperture of the cylinder to the under side of the colander; and this cooling not only acts as an agent of the evaporation which the current of air cools, but it refrigerates also, because it becomes warmned in abstracting caloric from the vapors or liquids passing through the worm; and this refrigeration acts also incessantly and progressively from the lower part of the tube or chimney to the colander. The patentee states, in conclusion, that " the velocity or force of the current of air that passes through the chimney or tube K, can be accelerated by artificial means, either by conducting the air and vapor passing from the upper aperture of the cylinder into the chimney or flues of a furnace, or by means of a revolving, forcing, or exhausting fan, or ventilator, or any other contrivance which will produce an increased current of air, but which is not necessary to be pariicularly described, as I only wish to explain the principles of a simple apparatus, constructed in any convenient form; and I would remark, tlat the area of the lower aperture through which the air is introduced into the chimney or tube K, and also the area of the upper aperture, or that through which it passes to the atmosphere,-should be in accordance with the effect intended to be obtained. "It is further to be remarkedl, that in order to obtain from this apparatus the best effect, the velocity of the current of air must be itself a maximum; and as the speed or velocity of the current of air is owing to and determined by the excess of the temperature of the descending waier, or rain, and of the coils of the worm to that of the exterior atmosphere, it ensues that the temperature of the water, or rain, must be a maximum. But this excess of temperature is a maximum only when the source of the rain is at the same temperature as the vapors to be condensed: if less warm, it would attract less air; or, if warmer, it would augment the temperature of the vapors intended to be condensed. Consequently, the shower of water employed in the tube K, as the agent for cooling, bestows its maximum of effect when it is as warm as the vapors to be condensed; therefore, I may express this proposition, viz.,'That in refrigerating with water, less of it may be expended when it is warm than when it is cold, and that the least quantity of water will be evaporated when it is as warm as the aqueous or spirituous vapors upon which it is to operate.' "This proposition may appear strange, nevertheless it is conformable to the laws of nature; and appears only strange, because until now warm water has not been employed with currents of air for refiirerating. " Hence it is necessary to raise the temperature of the water in the colander to the temperature of the vapors to be condensed: therefore, I cause the lukewarm water, pumped from the reservoir E, to circulate in the chamber c. In this circulation it also begins to act as a refrigerating medium, taking up a portion of heat from the vapors that pass through the pipe B, and afterwards it acts as a further condenser in the cylinder, in the way described. Finally, the portion of this water that is still in the fluid state, after having fallen down from coil to coil, arrives lukewarm to the inclined surface L, which conducts it into the reservoir E, from whence, it is pumped up into the chamber c, as before described. "The tube or chimney K may have more or less altitude; the higher it is the greater is the current produced. The force or velocity of the current of air can be governed by the areas of the introduction and exit apertures. If the cylinder rises only to the height Df the sieve, the effect is much less than when it is prolonged beyond this height. I would further remark, that if the cylinder was removed, a slight effect might be pro. duced, provided that a current of air be preserved in the cylindrical space limited by the toils of the worm, and also if the current was produced between the coils; or a central passa.ge might be formed in an apparatus of another shape than that above described. "I have only shown the application of the worm, because intending only to expiain the principles of this method of condensing and refrigerating. "The small quantity of water wasted in this manner of condensation, (that is, that portion passed off to the atmosphere in the form of vapors, at the upper aperture of the COPAL. 46Y cylinder x), may be replaced by a small stream of cold water, which may be brought to the apparatus, and perhaps most conveniently introduced;into thle reservoir E, or into tlhe chambller between thle pipes B and c. When operating upon aqueous vapors, the waste of waters is always less in weight than that of the vapors liquefied. When this apparatus is applied to tle purposes of distillation, the end of the worm should terminate in a vessel M, which is to receive the iproduce of the condensation. It will be seen that this improved proc(ess is applicable to various purposes, where condensation or refrigeration is required; for instance, in the boiling or concentration of sugar; to condeisiing and refrigerating distilled vapors, or steam, or saline liquids, either in vacuum or not; to cooling brewers' worts; and to the refrigeration of other liquors, or any other processes, when it may be required." I have inserted the specification of this patent verbatim. M. Derosne has busied himself during a long life with a prodigious number of ingenious little contrivances for clarifying and boiling syrups, distillation, &c., but he has:l this invention taken a b)older flight, having secured the exclusive privilege of condensinlg vapors, and coolingr liquors, with hot water, in preference to cold. iNo man at all versant in the scientific doctrines, or the practical applications of caloric, will ever seek to meddle with his monolpoly of such a scheme. lIe imay find, perhaps, some needy coplpersmith ready to esplouse that or any other equally foolish project, pr vided a productive job can be mlade of it, against credulous customers. For some rational methods of cooling liquors and condensing vapors, see REFRIGERATION, STILL, and SUGAR. COPAL, a resin which exudes spontaneously from two trees, the Rhus copallinum, andll the Elceocarpus copalifer, thle first of which grows in America, and the second in the East Indies. A third species of copal-tree grows on the coasts of Guinea, especially on tlhe banks of somrie rivers, amiiong whose sands the resin is found. It occurs in lumps of various sizes and of various shades of color, from the palest greenish yellow to darkish brown. I found its specific gravity to vary in different specimens from 1'()59 to 1'071, being intermediate in density belween its two kindred resins, anime aind amber. Some rate its specific gravity so high as 1'139, which I should think one of the errors with which chemical complilations teem. Copal is too hard to be scratched b}y the nail, i. hence the excellence of its varnish. It has a conchoidal fracture, and is without smell or taste. When exposed to lieat in a glass retort over a spirit lanmp, it readily melts into a liquid, which being further heated uboils with explosive jets. A viscid, oily-looking nmatter then distils over. After continuing the process for some time, no succinic acid is'found in the receiver, but the copal blackens in the retort. Anhydrous alcohol boiled upon it causes it to swell, and transforms it by degrees into an elastic, viacid sulbstance. It is not soluble in alcohol of 0-825 at the boiling point, as I have ascertailied. Copal dissolves in ether, and this ethereous solution may be mixed withl alcolil without decomposition. Caoutchloucinte acts very slightly uplon it by my experiments, even at the boiling temperature of this very volatile fluid; but a mixture of it wvith alcohol of 0'825, in equal parts, dissolves it very rapidly in the cold into a perfectly liquid varnish. Alcohol holding camphor in solution also dissolves it, but not nearly so well as the last solvent. According to Unverdorben, copal may be completely dissolved by digesting one part of it for 24 hours with one part and a half of alcohol (probably ainhydrous), because that portion of copal which is insoluble in alcohol dissolves in a very cancentrated solution of the soluble portion. Oil of petroleum and turpentine dissolve only 1 or 2 per cent. of raw copal. By particular managemeunt, indeed, oil of turpentine nay he combined with copal, as we shall describe under the article VARNISH. Fused copal possesses different properties fromi the substance in its solid state; for it then may be made to combine both with alcolhol and oil of turpentine. Unverdorben has extracted from the copal of Africa five different kinds of resin, none of which has, however, been applied to any use in the arts. The ultimate constituents of copal by my analysis are, carbon 79'87, hydrogen 9'00, oxygen 11'l; being of hydrogen 7 6 in excess above the quantity necessary to form water with the oxygen. Much information has been received from various sources concerning this somewhat ill-understood product of late years. It is now known that llhere are tlhree different kinds of copal in commerce, )but nothing is known of their distinuguishing characteristics. We have East Indian and West Indian copal, and, under the latter name, two very diffirent sumbstances. The East Indian, called also African, is more colorless, soft, and transparent, than the others; it forms a fine surfalce, and when heated emnits an agreeable odor. It furnishes the finest varnish. Fresh essence of turpentine dissolves it com. iletely, but not old. Essence digested upon sulphur will dissolve doiuble its own weight, without letting any fall. Fresh rectified oil of rosemary will dissolve it in any propor tion, but if the oil is thickened by age it serves only to swell this copal. 31 466 COPPER. When cautiously melted, it may be then dissolved in good essence of turpentine in any proportion, producing a fine varnish, of little color. A good varnish may be made by dissolving 1 part of copal, 1 of essence of rosemary, with from 2 to 3 of pure alcohol. This varnish should be applied hot, and when cold becomes very hard and durable. The West'India species, or American, comes to us, not in lumps of a globular form, but in small flat fragments, which are hard, rough, and without taste or smell. It is usually yellow, and never colorless like the other. Insects are very rarely found in it. It comes from the Antilles, Mexico, and North America. It will not dissolve in essence of rosemary. The third kind of copal, known also as West Indian, was formerly sold as a product of the East Indies. It is found in fragments of a concavo-convex form, the outer covering of which appears to have been removed. It contains many insects. When rubbed it emits an aromatic odor. It gives out much ethereous and empyreumatic oil when melted. It forms a soft varnish, which dries slowly. Fusel oil, or amyle spirit, has been lately used as a solvent of the hard copal; but it does not dry into a very solid varnish. Annexed is an account of the import of anim6 and copal, in the undermentioned years:1841. 1842. 1843. 1844. Quantities imported cwts. - 3336 3359 6493 Quantities exported cwts. - 1403 1508 2467 Retained for consumption cwts. - 2091 2085 2770 Nett revenue ~ 535 295 117 157 COPPER is one of the metals most anciently known. It was named from the island of Cyprus, where it was extensively mined and smelted by the Greeks. It has a reddish brown color inclining to yellow: a faint but nauseous and rather disagreeable taste; and when rubbed between the fingers it imparts a smell somewhat analogous to its taste. Its specific gravity is from 8-8 to 8'9. It is much more malleable than it is ductile; so that far finer leaves may be obtained from it than wire. It melts at the 27th degree of Wedgewood's pyrometer, and at a higher temperature it evaporates in fumes which tinge the flame of a bluish green. By exposure to heat with access of air, it is rapidly converted into black scales of peroxide. In tenacity it yields to iron; but surpasses gold, silver, and platinum, considerably in this respect. In mineralogy, the genus copper includes about 13 different species, and each of these contains a great many varieties. These ores do not possess any one general exterior character by which they can be recognised; but they are readily distinguished by chemical re-agents. Water of ammonia digested upon any of the cupreous ore in a pulverized state, after they have been calcined either alone or with nitre, assumes an intense blue color, indicative of copper. The richest of the ordinary ores appear under two aspects: the first class has a metallic lustre, a copper red, brass yellow, iron gray, or blackish gray color, sometimes inclining to blue; the second is without metallic appearance, has a red color, verging upon purple, blue, or green, the last tint being the most usual.' Few copper ores are to be met with, indeed, which do not betray the presence of this metal by more or less of a greenish film. Dr Scherer, of Freyberg, has arranged the ores of copper as follows:Symbol. Copper in 100. 1. Copperglanz (Kupferglaserz) Cu.2S 79 7 2. Kupferkies, Copper pyrites, Cu2S, FeS3 34-8 3. Buntkupfererz 3 Cu2S, Fe.23. 55'7 4. Fahlerz 4 (Cu.2S, FeS, ZnS, AgS (Sb S3 As S3) 14-41 5. Rothkupfererz Cu2O 88-5 6. Malachit 2 CuO, CO-2+-HO 57-4 7. Kupferlasur (2 (CuO, C02) + CuO. HO 55-3 Both Fahlerz and Buntkupfererz vary greatly in their proportion of copper. Fablers is very difficult to convert into pure copper by smelting, on account of the presence of antimony and arsenic in it. Kupferglanz is a disulphuret of copper. Buntkupfererz is purple or variegated copper ore. Rothkupfererz is the orange or red oxide of copper. Kuferlasur is blue carbonate of copper. Pure copper may be obtained in the solid state either by the reduction of the powaer of the pure oxide by a stream of hydrogen gas passed over it in an ignited tube, of by the galvanoplastic process. See ELECTRO-NIETALLURGY, or ELECTROTYPIE. 1. Native Copper occurs in crystals, branches, and filaments, its most common lo. cality being in primitive rocks. It is found abundantly in Siberia, at the mines of Tourinski, in those of Hungary, of Fundo-Moldavi in Gallicia, of Fahlun in Sweden COPPER. 4M7 of Cornwall, &c. The gangues of native copper are granite, gneiss, mica-slate, clay slate, quartz, carbonate or fluate of lime, sulphate of barytes, &c. The most remarka. ble masses of native copper hitherto observed were-first, one in Brazil, 14 leagues from Basa, which weiohed 2616 pounds; and secondly, another which Dr. Francis-le-Baron discovered in America to the south of Lake Superior. It was nearly 15 feet in circumference. 2. Sulphuret of Copper, the vitreous ore of Brochant. The texture of this ore is cornr sct; its fracture, conchoidal, surface sometimes dull; color, iron black or lead arav, often bluish, iridiscent, or reddish from a mixture of protoxyde. It is easily melted even by the heat of a candle; but more difficult of reduction than protoxyde. This ore yields to the knife, assuming a metallic lustre when cut. Its density varies from 4-8 to 5-34. Its composition, according to Klaproth, is 78-5 copper, 18'5 sulphur, with a little iron and silica. Its equivalent constitution by theory is 80 copper - 20 sulphur= 100; whence 78'5 of metal should be associated with 19'6 of sulphur. This ore is therefore one of the richest ores, and forms very powerful veins, which likewise contain some orange protoxyde. It is to be found in all considerable copper districts; in Siberia, Saxony, Sweden, and especially Cornwall, where the finest crystals occur. 3. Copper Pyrites resembles in its metallic yellow hue, su'phuret of iron; but the latter is less pale, harder, and strikes fire more easily with steel. It presents the most lively rainbow colors. Its specific gravity is 4'3. It contaits generally a good deal of iron, as the following analysis will show: copper 20, sulphur 37, iron 33, in 100 parts. According to Hisinger, the Swedish pyrites contains 63 of copper, 12 of iron, and 25 of sulphur. These ores occur in primitive and transition districts in vast masses and powerful veins; and are commonly accompanied with gray copper, sulphuret of iron, sparry iron sulphurets of lead, and zinc. 4. Gray Copper has a steel gray color, more or less deep, either shining- or dull; frac rure uneven; a distinct nmetallic lustre; difficult of fusion at the blowpipe; it communicates to glass of borax a yellowish-red color. Its density in crystals is 4-86. Its composition is very variable; consisting essentially of copper, iron, antimony, and sulphur. The exploration of this ore is profitable, in consequence of the silver which it frequently contains. It occurs in primitive mountains; and is often accompanied with red silver ore, copper pyrites, and crystallized quartz. 5. Protoxyde of Copper, or red oxyde of Copper: its color is a deep red, sometimes very lively, especially when bruised. It is friable, difficult of fusion at the blowpipe, reducible on burning charcal, soluble with effervescence in nitric acid, forming a green hquid. Its constitution, when pure, is 88-9 co.per+ 11 oxygen = 100. 6. Black oxyde of Copper is of a velvet black, inclining sometimes to brown or blue; and it acquires the metallic lustre on being rubbed. It is infusible at the blowpipe. Its composition is, copper 80-+ oxygen 20; being a true peroxyde. 7. Hydrosilicate of Copper consists essentially of oxyde of copper, silica, and water. Its color is green; and its fracture is conchoidal with a resinous lustre, like most minerals which contain water. Its specific gravity is 2'73. It is infusible at the blowpipe alone, but it melts easily with borax. 8. Dioptase Copper, or Emerald Malachite; a beaut iful but rare cupreous mineral, consisting of oxyde of copper, carhbnate of lime, silica, and water in varying proportions. 9. Carbonate of Copper, Malachite, is of a blue or green color. It occurs often in beautiful crystals. 10. Sulphale of Copper, Blue Vitriol, similar to the artificial salt of the laboratory The blue water which flows from certain copper mines is a solution of this salt. The copper is easily procured in the metallic state by plunging pieces of iron into it. 11. Phosphate of Copper is of an emerald green, or verdicris color, with some spots of black. It presents fibrous or tuberculous masses with a silky lustre in the fracture. It dissolves in nitric acid without effervescence, forming a blue liquid; melts at the blowpipe, and is reducible upon charcoal, with the aid of a little grease, into a metallic globule. Its powder does not color flame green, like the pow(er of riuriate of copper. 12. Muriate of Copper is green of various shadec.; its powder imparts to flame a remarkable blue and green color. It dissolves in nitric acid without effervescence; and is easily reduced before the blowpipe. Its density is 3-5. By Klaproth's analysis, it consists of oxyde of copper 73, muriatic acid 10, water 17. 13. drseniate of Copper. It occurs in beautiful blue crystals. Before the blowpipe it melt:s, exhaling fumes of a garlic odor, and it affords metallic globules when in contact witt, charcoal. See mere upon the ores at the end of this article. In the article METALLURGY. I have described the mode of working certain coppel mines; and snail content myself here with giving a brief account of two cupreous forma. tions, interesting in a geological point of view; that of the copper slate of Mansfeldt, and of the copper veins of Cornwall. The curious strata of bituminous schist in the first of these localities, are among the 468 COPPER. most ancient of any which contain the exuvie of organized bodies not testaceous. From among their tabular slabs the vast multitudes of fossil fish were extracted, which have rendered the cantons of Mansfeldt, Eisleben, Ilmenau, and other places in Thuringia and Voigtland so celebrated. Many of the fish are transformed into copper pyrites. Here also, have been found the fossil remains of the lizard family, called Moni/ors. Such is the influence of a wise administration upon the prosperity of mines, that the thin layer of slate in this formation, of which 100 pounds commonly contain but one pound and a half of copper, occasionally argentiferous, has been for several centuries the object of smelting works of the greatest importance to the territory of Mansfeldt and the adjoining country. The frequent derangements which this metallic deposite experiences, led skilful directors of the under-ground operations at an early period to study the order of superposition ot the accompanying rocks. From their observations, there resulted a system of facts which have served to guide miners, not only in the country of Man."oldt, but over a great pol tion of Germany, and in several other countries where the samn series of rocks, forming the immediate envelope of the cupreous schists, were found to occur in the same ordeX of superposition. Of the English copper works.-The deposites of copper in Cornwall occur always sX veins in granite, or in the schistose roiks which surround and cover it; and hence, the Cornish miners work mostly in the granite or greenish clay slate; the former of which they call growan, the latter killas. But tin is sometimes disseminated in small veins in porphyry or elvan, which itself forms great veins in the above rocks. No stratification has been observed in Cornwall. The copper veins are.Abundant in the killas and rare in the granite; but moust numerous near the line of junction of the two rocks. The different kinds of mineral veins in Cornwall may be classed as follows:1. Veins of elvan; elvan courses, or elvan channels. 2. Tin veins, or tin lodes; the latter word being used by the Cornish miners to signify a vein rich in ore, and the word course, to signify a barren vein. 3. Copper veins running east and west; east and west copper lodes. 4. Second system of copper veins, or contra copper lodes. 5. Crossing veins; cross courses. 6. Modern copper veins; more recent copper lodes. 7. Clay veins; of which there are two sets, the more ancient, called Cross-Fluckans; and the more modern, called Slides. There are therefore three systems of copper veins in Cornwall; of which the first is considered to be the most ancient, because it is always traversed by the two others, and because, on the contrary, it never cuts them off. The width of these veins does not exceed 6 feet, though occasional enlargements to the extent of 12 feet sometimes take place. Their length is unknown, but the one explored in the United Mines has been traced over an extent of seven miles. The gangue of these veins is generally quartz, either pure, or mixed with green particles analogous to chlorite. They contain iron pyrites, blende, sulphuret, and several other compounds of copper, such as the carbonate, phosphate, arseniate, muriate, &c. The most part of the copper veins are accompanied with small argillaceous veins, called by the miners fluckan of the lode. These are often found upon both sides of the vein, so as to form cheeks or salebandes. When two veins intersect each other, the direction of the one thrown out becomes an object of interest to the miner and geologist. In Saxony it is regarded as a general fact that the rejected portion is always to the side of the obtuse angle; this also holds generally in Cornwall, and the more obtuse the angle of incidence, the more considerable the out-throw. The great copper vein of Carharack, in the parish of Gwenap, is a most instructive example of intersection. The power of this vein is 8 feet; it runs nearly from east tc w st, and dips toward the north at an inclination of 2 feet in a fathom. Its upper part is in the killas, its lower part'in the granite. The vein has suffered two intersections; the first results from encountering the vein called Steven's fluckan, which runs from northeast tc south-west, throwing it out several fathoms. The second has been caused by another vein, almost at riaht angles to the first, and which has driven;t 20 fathoms out to the right side. The fall of the vein occurs, therefore, in one case to the right, and in the other to the left; but in both instances, it is to the side of the obtuse angle. This disposition is very singular; for one portion of the vein appears to have ascended, while another has sunk. The mining works in the copper veins are carried on by reverse steps; see MINES The grand shafts for drainage and extraction are vertical, and open upon the roof side of the vein, traversing it to a certain depth. These pits are sunk to the lowest point of the exploration; and, in proportion as the workings descend, by means of excavations ih the vein, the pits are deepened and put into communication toward their bottom with COPPER. 469 each new gallery of elongation, by means of transverse galleries. At present, the main shafts are fully 160 fathoms deep. Their horizontal section is oblong, and is divided into two compartments; the one destined for extraction, the other for the pumps. Their tim bering has nothing remarkable, but is executed with every attention to economy, the whole wood employed in these mines being brought from Norway. The descent of the workmen is effected by inclined shafts scooped out of the vein; the ladders are sliohtly inclined; they are interrupted every 10 fathoms by floors; the steps are made of iron, and, to pr event them from turning under the foot, the form of a miner's punch or jumper has been given them, the one end being round, and the other being wedge-shaped. The ore is raised either by means of horse-gins, or by steam-engine power, most fre quently of high pressure. I shall take the Consolidated Mines as an example. The draining, which is one of the most considerable sources of expense, both from the quantity of water, and from the depth of the mine, is executed by means of sucking and forcing pumps, the whole piston-rods of which, 120 feet long, are attached to a main-rod suspended at the extremity of the working beam of a steam-engine. On this mine three steam-engines are erected of very great power, for the purpose of drainage; the one called the Maria engine is of the first-rate force, and most improved construction. The cylinder is 90 inches in internal diameter, and the length of the stroke is 9 feet 11 inches. It works single stroke, and is incased in a coating of bricks to prevent dissipation of the heat.' The vapor is admitted at the upper end of the cylinder during the commencement of the fall of the piston, at a pressure capable of forming an equilibrium with a column of 60 inches of mercury. The introduction of the steam ceases whenever the piston has descended through a certain space, which ma) be increased or diminished at pleasure. During the remainder of the descent the piston is prcssed merely by this vapor in its progressive expansion, while the under side of the piston communicates with the condenser. It ascends by the counterweight at the pump end of the working beam. Hence, it is only during the descent of the piston that the effective stroke is exerted. Frequently the steam is admitted only during the sixth part of the course of the piston, or 18 inches. In this way the power of the engine is proportioned to the work to be done; that is, to the body of water to be raised. The maximum force of the above engine is about 310 horses; though it is often made to act with only one third of this power. The copper mines of the Isle of Anilesey, those of North Wales, of Westmoreland, the adjacent parts of Lancashire and Cumberland, of the south west of Scotland, of the Isle of Man, and of the south east of Ireland, occur also in primitive or transition rocks. The ores lie sometimes in masses, but more frequently in veins. The mine of Ecton in Staffordshire, and that of Cross-!ill burn, near Alston-moor in Cumberland, occur in transition or metalliferous limestone. The copper ores extracted both from the aranitic and schistose localities, as well as from the calcareous, are uniformly copper pyrites more or less mixed with iron pyrites; the red oxyde, carbonate, arseni.te, phosphate, and muriate of copper, are very rare in these districts. The working of copper in the Isle of Anglesey may be traced to a very remote era. It appears that the Romans were acquainted with the Hamlet mine near Holyhead; but it was worked with little activity till about 70 years ago. This metalliferous deposite lies in a greenish clay slate, passing into talc slate; a rock associated with serpentine and euphotide (gabbro of Von Buch). The veins of copper are from one to two yards thick, and they converge towards a point where their union forms a considerable mass of ore. On this mass the mine was first pierced by an open excavation, which is now upwards of 300 feet deep, and appears from above like a vast funnel. Galleries are formed at different levels upon the flank of the excavation to follow the several small veins, which run in all directions, and diverge from a common centre like so many radii. The ore receives in these galleries a kind of sorting, and is raised by means of hand windlasses to the summit of a hill, where it is cleaned by breaking and riddling. The water is so scanty in this mine that it is pumped up by a six-horse steam-engine. A great proportion of it is charged with sulphate of copper. It is conveyed into reservoirs containing pieces of old iron; the sulphate is thus decomposed into copper of cementation. The Anglesea ore is poor, yielding only from 2 to 3 per cent. of copper: a portion of its sulphur is collected in roasting the ore. Mechanical preparation of the copper ores in Cornwall.-The ore receives a first sorting, either within the mine itself, or at its mouth, the object of which is to separate all the pieces larger than a walnut. These are then reduced by the hammer to a smaller size; after which the whole are sorted into four lots, aecording to their relative richness. The fragments -f poor ore are pounded in the stamps so that the metallic portion may be separated by washing. The rich ore is broken into small bits, of the size of a nut, with a flat beater, formed 1.. 7T0 CGPPER. ol' a piece of ion 6 inches square and 1 inch thick, adapted to a wooder. handle. The tre to be bioken is placed upon plates of cast-iron; each about 16 inches square and 1j inch thick. These iron plates are set towards the edge of a small mound about a yard high, constructed with dry stones rammed with earth. The upper surface of this mound is a little inclined from behind forwards. The work is performed by women, each furnished with a beater; the ore is placed in front of them beyond the plates; they break it, and strew it at their feet, whence it is lifted and disposed of to the smeltinghouses. Inferior ores, containing a notable proportion of stony matters, are also broken with the beater, and the rich parts are separated by riddling and washing from the useless matters. The smaller ore is washed on a sieve by shaking it in a stream of water, which carries away the lighter stony pieces, and leaves the denser metalliferous. They are then sorted by hand. Thus by beating, stamping, and riddling in water, the stony substances are in a great measure separated. The finer ground matter is washed on a plane table, over which a current of water is made to flow. Finally, the ore nearly fine is put into a large tub with water, and briskly stirred about with a shovel, after which it settles in the-order of richness, the pure metallic ore being. nearest the bottom. The stamps used for copper ore in Cornwall are the same as those used for tin ores, of which we shall speak in treating of the latter metal, as well as of the boxes for washing the qine powder or slime. These, in fact, do not differ essentially from the stamping mills and washing apparatus described in the article METALLURGY. Crushing rolls are of late years much employed. See LEAD and TIN. Cornwall being destitute of coal, the whole copper ore which this county produces is sent for smelting to South Wales. Here are 15 copper works upon the Swansea and Neath, which pursue a nearly uniform and much improved process, consisting in a series of calcinations, fusions, and roastings, executed upon the ores and the' matters resulting from them. The furnaces are of the reverberatory construction; they vary in their dimensions and in the number of their openings, according to the operations for which they were intended. There are 5 of them:-1. The calcining furnace cr calciner; 2. The melting furnace; 3. The roasting furnace or roaster; 4. The refining furnace; 5. The heating or igniting furnace. 1. The calcining furnace rests upon a vault, c, into which the ore is raked down after being calcined; it is built of bricks, and bound with iron bars, as shown in the elevation, Jig. 268. The hearth, aBs,figs. 368 and 370, is placed upon a level with the lower horizontal binding bar, and has nearly the form of an ellipse, truncated at the two extremities of its great axis. It is horizontal, bedded with fire-bricks set on edge, so that it may be re. moved and repaired without disturbing the arch upon which it reposes. Holes, not visible J ew9 868 370'374 41flif~fwllf/ 0'77 7 g11IF11.p'D- r e.1' 311 < -f _'' - r..........,.b.... in the figure, are left in the shelves before each door, c c, through which the roasted ore is let fall into the subjacent vault. The dimensions of the hearth B B are immense, being from 17 to 19 feet in length, and from 14 to 16 in breadth. The fire-place, A,.fig. 370, is from 4} to 5 feet long, and 3 feet wide. The bridge or low wall, b, fi. 374, which separates the fire-place from the hearth, is 2 feet thick; and in Mr. Vivian's smelting-works is hollow, as shown in the figure, and communicates at its two ends with the atmosphere, in order to conduct a supply of fresh air to the hearth of the furnace. This judicious contrivance will be described in explaining the roasting operation. The arched roof of the furnace slopes down from the bridge to the beginning of the chimney, f, figs. 369, 370, its height above the hearth being at the first point about 26 inches, and from 8 to 12 at the second. Such great calcining furnaces have 4 or 5 doors, c c c c,fig. 370, one for the fire-place, as shown at the right hand in fig. 369, and 3 or 4 others for working the ore upon the COPPER. 47.1 reverberatory hearth. It thete be 3, 2 of them are placed bet ween the vertfcal binding oars upon one side, and a third upon the opposite side of the furnace; if there be 4, 2 are placed upon each side, facing one another. These openings are 12 inches square, and are bound with iron frames. The chimney is about 22 feet high, and is placed at one angle of the hearth, as atf, fig. 370, being joined by an inclined flue to the furnace. For charging it with ore there are usually placed above the upper part of the vault 2 hoppers, E E, in a line with the doors; they are formed of 4 plates of iron, supported in an iron frame. Beneath each of them there is an orifice for letting the ore down into th( hearth. These furnaces serve for calcining the ore, and the matts or crude coppers: for the latter purpose, indeed; furnaces of two stories are sometimes employed, as represented in fig. 373. The dimensions of each floor in this case are a little less than the preceding. Two doors, c c, correspond to each hearth, and the workmen, while employed at the upper story, stand upon a raised moveable platform. 2. Meltingfvrrtxa.r,figs. 371 and 372. The form of the hearth is also eiiptical, but the dimensions are smaller than 1 371, 72 in the calcining furnace. The length does not exceed 11 or i.. ^ if^^ feet, and the breadth varies from 7 to 8. The fire-place is however larger in proportion, its length being from 3} feet X:I'~ g~.*::. PI to 4, and its breadth from 3 to 31; this size being requisite to produce the higher temperature of this furnace. It has fewer openings, there being commonly three; one to the ^^;a{i ___W~:// fire-place at D, a second one, o, in the side, kept generally shut, and used only when incrustations need to be scraped r^'qk^G:^<%:, off the hearth, or when the furnace is to be entered for k*A B > repairs; and the third or working-door, G, placed on the c..E_ front of the furnace beneath the chimney. Through it the o.... scorira are raked out, and the melted matters are stirred and puddled, &c. The hearth is bedded with infusible sand,. and slopes slightly towards the side door, to facilitate the discharge of the metal. Above this door there is a hole in the wall of the chimney (fig. 372) for letting the metal escape. An iron gutter, o, leads it into a pit, K, bottomed with an iron receiving-pot, which may be lifted out by a crane. The pit IM is filled with water, and the metal becomes granulated as it falls into the receiver. The melting furnaces are surmounted by a hopper, L, as shown in fig. 371. Melting furnaces are sometimes used also for calcination. 373 1-H1 W m z There are some such near Swansea, which serve this double._Im/ ~ purpose; they are composed of 3 floors (fig. 373.) The floor 1 S/-B-/ i p u rpoA is destined for melting the calcined ore; the other two, c Fi,7,-7'f rest, c c the forms; d the sole or:i! l~ik X ~[ [! i. hearth-stone, which has a slope illl:! __... |l{ l of 3 inches towards the front'W''':I\ $ly~i^6 /j [ wall; e e, &c. casing walls of fire ".... _ ~ 6 l~ || ~ bricks; fJ, &c. filling up walls -- | —i | /t — l| i:~ i~'~ } ~built of rubbish stones; g g a E1 |........ m A.[......._ IC, mass through which the heat is [}|1|||: ^y1 i t|! slowly conducted; h h the two I-im * 1> -1 E holes through one or other of i~!~ Z ~ \ i.which alteinately the product of the smelting process is run off. I " into the fore-hearth. Beneath' f I { ] k 1I I _ the hearth-sole there is a solid 387 386 / -.body of loam; and the forerx'xxx,,',,,,~, 1',, " H' l~ hearth is formed with a mixture Bl^ —--- -— ^ ~ AH/ /i~/1~ of coal-dust and clay; k is the ['Y\[I~V'IE Bc _, r-'q 1the second travelling apron, upon which the 4X ll /, *f ~ squirrel cage cylinder presses, and applies the cotton in the form of a lap. Above the cylindric cage h, which turns in the diJ 31r^~ G^^o 1rection of its arrow, there is a pipe k, the continuation of the case i. This pipe, Br ^jfo' E E i though broken off in the figure, communicates by a branch pipe with an air~( ~e - ~ As sucking fan ventilator, not seen in this v ll0/ 1 ~ figure, but explained under FOUNDRY. The cage h, by its rotation, presses down, as we have said, the half-cleaned cotton upon the cloth a', which carries it forward to the second scutcher f', by the second set of -.v^^gl~i ~feed rollers e'. The second scutcher throws down the heavy dust upon the second grid n', through which it falls upon the bottom of the case. The first scutcher Ic'<^~ ~ makes about 1280 strokes of each of its two arms in a minute; the second 1300. The feed rollers for each are fluted. The feed cloth is either sustained by a board, or is made of parallel spars of wood, to secure it against bagging, which would render the ba,~ln~,~~~~~ bOS UCOTTON MANUFACTURE. delivery of the cotton irregular. The feed rollers make 8 turns in the minute; and as their diameter is 1- inches, they will introduce 8 times their circumference, or 37'7 inches of the cotton spread upon the apron in that time. Upon every 12th part of an inch of the cotton, therefore, nearly 3 blows of the scutcher arm will be applied. The second feed rollers move relatively wilh more slowness, so that for every 2*4 blows of the scutcher, only one twelfth of an inch of cotton wool is presented. The fan is enclosed in a cylindrical case. The wings or vanes revolve from 120 to 150 times in the minute; and while they throw the air out with nearly this velocity at their Eccentric outlet in the circumference, they cause it to enter, with equal velocity, at the centre. With this centre the squirrel cage is connected by a pipe, as above stated. The sound filaments of 392/ the cotton are arrested by the n sieve surface of the cylindric caze,..."......'..'. and nothing but the broken fragments and the light dust can pass through. The cotton wool in the blowing machine is wafted by the second scutcher into the space x, w, w, provided with a fine grid bottom; or it is sometimes wound up there /IZ j1 ~ / by rollers into a lap. In fig. 391 an additional ventilator is introduced beneath at m, 1: i I o, o, to aid the action of the 1f 1j J~ scutchers in blowing the cotton lf' 8I~ aonwards into the oblona trough a. The outlet of that fan is at /f ~ I / I^ t; and it draws in the air at its axis q. u and v are two doors P1/ 1H/~ ~ or lids for removing the cleaned cotton wool. This last fan is suppressed in many blowing ma/1 jk9 p\ ~ chines, as the scutchlin arms |i ||IpI \ ~ supply a sufficient stream of air. ~/^J ~\ ~ The dotted lines show how the ef^ itv'' G;h,>_ n umrollers and their subordinate pats a -ae omitted. After the slivers have been sufficiently extended and attenuated between the rollers, t3 I" Cthey proceed forwards, towards the 31 >*;* - II"l \ l I^ ^~1 spindles i i i, where they receive r,;|:==^3 Jthe twist, and are wound upon the'"" v, Vn i ^ - ~ bobbins h. The machine deline regard to the g f s of ts ma ted contains thirty spindles, but f..^,=,,,, \\ A —ll many bobbin and fly frames contain double or even four times thai L, Lo%, ~ * 5 number. Only a few of the spin dies are shown in fig. 405, for fbac of confusing the drawing. With regard to the drawing functions of this machine, I have already given abundant..~ 5bI COTTON MANUFACTURE. explanation, so far as the properties and operation of the rollers are concerned. The frame-work of this part of the machine, called the roller-beam, is a cast-iron bench upon which nine bearers, c, are mounted for carrying the rollers. The fluted rollers a a a, fig. 407, are constructed in four pieces for the whole length, which are parted from each other by thinner smooth cylindric portions, 2, called necks. Seven such partings for four rollers, and one parting for two rollers, constitute together the 30 fluted rollers of which the whole series consists. The coupling of these roller subdivisions into one cylinder, is secured by the square holes x, and square pins y,fig. 407, which fit into the 407 holes of the adjoining subdivision. The 3 -, * -w- w — 2 v top or pressure rollers b, are two-fold over z- - O:'^ -- — ^ the whole set; and the weighted saddle Z aa Z - Fa z. z presses upon the neck w, which connects every pair, as was already explained undei fig. 402. These weights g g, fig. 406, are applied in this as in the drau'ingfrarme; d are the bars faced with fannel for cleaning the top rollers. A similar bar is applied beneath the rollers, to keep the flutings clean. The structure and operation of the spindles - may be best understood by examining 408 the section fig. 408. They are made of iron, are cylindrical from i",^,. the top down to a2, but from this part down to the steel tipped rounded.~.; points they are conical. Upon this conical portion there is a pulley l., k, furnished with two grooves in its circumference, in which the cord runs that causes the spindle to revolve. The wooden bobbin h is slid upon the cylindrical part, which must move fieely upon it, as will be presently explained. To the bobbin another two-grooved |:fi j' n pulley or whorl g is made fast by means of a pin r, which passes l through it; by removing this pin, the bobbin can be instantly taken | off the spindle. The upper end of the spindle bears a fork s t, which may be taken off at pleasure by means of its left-handed -- screw; this fork, or flier, has a funnel-formed hole at v. One arm of the fork is a tube, s, u, open at top and bottom; the leg, t, is added merely as a counterpoise to the other. In fig. 406, for the sake of clearness, the forks or fliers of the two spindles here represented are left out; and in fig. 405, only one is portrayed for the r f same reason. It is likewise manifest from a comparison of these two finures that the spindles are alternately placed in two rows, sc that each spindle of the back range stands opposite the interval 2 between two in the front range. The object of this distribution is economy of space, as the machine would need to be greatly longer if the spindles stood all in one line. If we suppose the spindles and lk X the bobbins (both of which have independent motions) to revolve simultaneously and in the same direction, their operation will be as follows: The sliver, properly drawn by the fluted rollers, enters X the opening of the funnel r, proceeds thence downwards through the hole in the arm of the fork, runs along its tube u, s, and then winds round the bobbin. This path is marked, in fig. 408, by a dotted line. The revolution of the spindles in the above circumstances effects the twisting of the sliver into a soft cord; and the flier., t, or particularly its tubular arm s, lays this cord upon the bobbin: Were the speed of the bobbins equal to that of the spindles, that is, did the bobbin and spindle make the same number of turns in the same time, the process would be limited to mere twisting. But the bobbin anticipates the fliers a little, that is, it makes in a given time a somewhat greater number of revolutions than the spindle, and thereby effects the continuous winding of the cord upon itself. Suppose the bobbin to make 40 revolutions, while the spindle completes only 30; 30 of these revolutions of the bobbin will be inoperative towards the winding-on, because the fliers follow at that rate, so that the cord or twisted sliver will only be coiled 10 times round the bobbin, and the result as to the winding-on will be the same as if the spindle had stood still, and the bobbin had made 40 - 30 = 10 turns. The 30 turns of the spindles serve. therefore, merely the purpose of communicating twist. The mounting and operation of the spindles are obvious.y ihe same as they are upon the household flax wheel. In the boblin and fly frame there are some circumstances rvhich render the construction and the winding-on somewhat difficult, and the mechanism not a little complicated. It may be remarked, in the first place, that as the cord is wound on, the diameter of the bobbin increases very rapidly, and therefore every turn made round it causes a greater length of roving to be taken up in succession. Were the motions of the bobbins to continue unchanged in this predicament, the increased velocity of the winding-on would require an increased degree of extension, or it would COTTON MANUFACTURE. 519 occasion the rupture of Vte cord, because the front fluted rollers move with uniform speed, and therefore deliver always the same length of sliver in the same time. It is therefore necessary to diminish the velocity of the bobbins, or the number of their turns, in the same proportion as their diameter increases, in order that the primary velocity may remain unchanged. Moreover, it is requisite for the proper distribution of the cord upon the bobbin, and the regular increase of its diameter, that two of its successive convolutions should not be applied over each other, but that they shoul l be laid close side by side. This object is attained by the up and down sliding motion of the bobbin upon the spindle, to the same extent as the length of the bobbin barrel. This up and down motion must become progressively slower, since it increases the diameter of the bobbin at each rance, by a quantity equal to the diameter of the sliver. What has now been stated generally, will become more intelligible by an example. Let it be assumed that the drawing rollers deliver, in 10 seconds, 45 inches of roving, and that this length receives 30 twists. The spindles must, in consequence, make 30 revolutions in 10 seconds, and the bobbins must turn with such speed, that they wind up the 45 inches in 10 seconds. The diameter of the bobbin barrels being 1l inches, their circumference of course 4- inches, they must make 10 revolutions more in the same time than the spindles. The effective speed of the bobbins will be thus 30+10=40 turns in 10 seconds. Should the bobbins increase to 3 inches diameter, by the win(ling-on of the sliver, they will take up 9 inches at.tch turn, and consequently 45 inches in 5 turns. Their speed should therefore be reduced to 30+5=35 turns in 10 seconds. In general, the excess in number of revolutions, which the bobbins must make over the spindles, is inversely as the diameter of the bobbins. The speed of the bobbins must rermain uniform during the period of one ascent or descent upon the spindle, and must diminish at the instant of changing the direction of their up and down motion; because a fiesh range of convolutions then begins with a greater diameter. When, for example, 30 coils of the sliver or roove are laid in one length of the bobbin barrel, the bobbin must complete its vertical movement up or down, within 30 seconds in the first case above mentioned, and within 60 seconds in the second case. The motions of the drawing rollers, the spindles, and bobbins, are produced in the following manner:-A shaft c', figs. 405 and 406, extending the whole lenth of the machine, and mounted with a fly wheel d', is set in motion by a band from the running pulley upon the shaft of the mill, which actuates the pulley a'. b' is the loose pulley upon which the band is shifted when the machine is set at rest. Within the pulley a', but on the outside of the frame, the shaft c' carries a toothed wheel b2 with 50 teeth, which by means of the intermediate wheel c2 turns the wheel d2 upon the prolongoed shaft of the backmost fluted roller (m2, fig. 406.) This wheel d2 has usually 54 teeth; but it may be changed when the roove is to receive more or less twist; for as the spindles revolve with uniform velocity, they communicate the more torsion the less length of sliveris delivered by the rollers in a given time. Upon the same shaft with d2, a pinion e2 of 32 teeth is fixed, which works in a wheel f2 of 72 teeth. Within the frame a change pinion g2 is made fast to the shaft of f2. This pinion, which has usually from 24 to 28 teeth, regulates the drawing, and thereby the fineness or nzumber of the roving. It works in a 48-toothed wheel h2 upon the end of the backmost fluted roller a,,fig. 406. The other extremity of the same roller, or, properly speaking, line of rollers, carries a pinion 12, furnished with 26 teeth, which, by means of the broad intermediate wheel k2, sets in motion the pinion?,'2 of 22 teeth upon the middle roller. When the diameter of all the drawing rollers is the same, suppose 1 inch, their proportional velocities will be, with the above number of teeth in the wheel work, if g2 have 24 teeth, as 1::118:4-5; and the drawn sliver will have 4' times its original length. The front or delivery roller of the drawing frame is of late years usually made 1 or 1 inches in diameter. If 625 feet of the sliver fiom the drawing frame weighed one pound, 2790 feet of the roving will now go to this weight, and the number will be 1.12; that is, 1 hank and 12 hundredths to the pound. The front pair of fluted rollers makes about 90 revolutions, and deliver; 282'6 inches of roving in the minute, when of one inch diameter. The spindles i (figs. 405 and 406), rest, with their lower ends, in steps 1, which are fixed in an immoveable beam or bar 7n. To protect it fiom dust and cotton filaments, this beam is furnished with a wooden cover a, in which there are small holes for the passage of the spindles right over the steps. In fig. 405, two of the eight covers n, which compose the whole range 71, are removed to let the steps be seen. The cylindrical part of each spindle passes through a brass ring o; and all these 30 rings, whose centres must be vertically over the steps 1, are made fast to the copping beam p. This beam is so called, because it is destined not merely to keep the spindles upright by the rings attached to it, but, at the same time, to raise and lower along the spindles the bobbins 520 COTTON MANUFACTURE. which lest on these rings; for which purpose the two racks, or toothed bars mn rnm made fast to it, are designed, as will be presently explained. To effect the revolution of the spindles, there are attached to the main shaft c' two whorls or pulleys e'f, each bearing four grooves of equal diameter. Each of these pulleys puts one half of the spindles in motion, by means of a cord, which, after going round the whorls k, turns four times about the pulleys of the shaft c'. Two guide pulleys h', each four-grooved, and two others i',with a single groove, which turn independently of the others, upon the above shaft, serve to give the whorl cords the proper direction, as well as to keep them tight. The spindles revolve 200 times or thereby in the minute; and therefore impart two turns or twists to every three inches of the roving. The revolution of the bobbins is independent of that of the spindles, although it likewise proceeds from the shaft c', and differs from it in being a continually retarded motion. The simplest method of effecting this motion, is by means of the wooden or tin plate cone k", which revolves equally with the shaft c', and at the same time slides along it. The manner in which this operates is shown in section in fig. 409. Here we perceive the rod q2, which extends from the base toward the narrow end of the truncated cone, and p2 a forked bearer or carrier made fast to the shaft c' by a screw, which compels the cone, by means of that rod, to obey the movements of c'. In the large end 410 o ^s ot the cone there is an aperture, through which the bearer can be got at. The smaller end carries outside a projection o2, provided with a groove, which is embraced by the forked end of a rod q',fig. 410, that serves to shove the cone along upon the shaft c'. Directly under the cone, there is an upright round pillar p', upon which the holder o' of the two guide pulleys 1' is adjustable. A bar r2 placed along-side of the holder, prevents its turning round, but allows it to slide along p' by friction. The weight of the holder and the pulley is sufficient to distend the endless band n', which runs from the cone k', through under the pilley 1', and round the small drum m' on the shaft s2. A pulley or whorl t2. with four grooves, is made fast by means of a tube to this shaft, and slides along it backwards and forwards, without ever ceasing to follow its revolutions. The shaft possesses for this purpose a long fork, and the interior of the tube a correspcmncng tongue or catch. There is besides upon the tube beneath the pulley, at uI, a groove that goes round it, in which the staple or forked end of an arm like v2, fig. 410, made fast to the copping beam p, catches. By the up and down movement of that beam, the pulley 2 takes along with it the arm that embraces the tube, which thereiore rises and falis equally with the bobbins h', and their pulleys or whorls q. This is requisite, since the bobbins are made to revolve by the pulleys t 2, by means of two endless eords or bands. The most intricate part of the mechanism is the adjustment, by which the revolution of the bobbins is continually retarded, and their up and down, or copping motion, along the spindles, is also retarded in like proportion. The vertical pulley f' (towards the left end of the shaft c) has at its right side a somewhat larger disc or sheave g', with a perfectly uniform, but not a very smooth surface. Upon this sheave, a smaller horizontal pulley x' rubs, whose upper face is covered with leather to increase the friction The under end of the shaft y2 of the pulley x' turns in a step, which is so connected with the arm v' of the large bent lever t' v', that it always stands horizontally, whatever direction the arms of that lever may assume. The shaft y2 is steadied at top by an COTTON MANUFACTURE. 521 annular holder or bush, which embraces the fast arm x2 with its forked end. Upon its opposite side, this arm carries a pulley y2, upon which a cord goes, that is made fast to the holder of the shaft y2, and loaded with the weight z'. The weight presses tlhe pulley x' against the surface of g', in such wise as to effect the degree of friction necessary:n order that the revolution of g' may produce an uninterrupted revolution in x'. A pinion w', whose length must be equal at least to the semi-diameter of the sheave g', is placed upon the under end of the shaft y2. It has 22 teeth, and takes into a 62-toothed horizontal wheel e2. Upon the upper end of this wheel the conical pinion a3 is made fast, which may be changed for changing the speed, but usually has from 28 to 30 teeth. By this pinion the conical wheel b3 is turned, which has 30 teeth, and whose shaft is c3. This shaft carries upon its opposite end a six-leaved pinion, d3, which takes into the calender wheel f3, formed with cogs like a trundle, upon the long shaft e3. In fig. 411 the wheel f3 is exhibited with its pinion d3. Here we may remark, that in the circurmference of the wheel there is a vacant place,;3, void of teeth. When, by the motion of the wheel, the pinion comes opposite to this opening, it turns round about the last tooth of the wheel, falls into the inside of the toothed circle marked by the dotted lines, and thus gives now an inverse movement to the wheel f3, while itself revolves always in the same direction. This reversed motion continues till the opening g3 comes once more 411 412 pposite to the pinion, when this turns round about the ast tooth of that side, and beins apposite to workthe pinion, hen this turns round about the unflast torm mot of that side, and begins aaain to work in the exterior teeth. Thus, by the uniform motion of ds and its dependant parts, the wheel f3, with its shaft e3, revolves alternately to the right hand and the left. That this result may ensue, the shaft c3 of the pinion must be able to slide endwise, without losing its hold of a3 and b3. This adjustment is effected by placing the end of the said shaft, nearest b3, in a box or holder i3, in which it can turn, and which forms a vertical tube to this box, as a downward prolongation which is fixed to the tail of the conical pinion a3. Fig. 412 shows this construction in section upon an enlarged scale. The second bearer of the shaft nearest d3, neast possess likewise the means of lateral motion. When therefore the pinion d3 shifts through the opening of the wheel f3 outwards or inwards, its shaft c3, makes a corresponding small angular motion upon the pivot of a3, by means of the tube i3; a3 and b3 remain thereby completely in gear with one another. The above-described alternate revolutions of the wheel fa serve to produce the up and down motions of the bobbins. The shaft e3 has for this purpose two pinions n2 n% which work in the rack teeth ma2 m2 of the copping rail p, and thus alternately raise and sink it with the bobbins which rest upon it. The. weight of the copping beam and all its dependant parts, is poised by two counterweights m 4, whose cords run over the pulleys o0 o0 o4, fig. 405, and have their ends made fast to the frame, so as to make the upward motion as easy as the downward. The two upper pulleys out of the three of each weight are fixed to the frame; the under one, round which the cord first runs, is attached to the comping beam, rising and falling along with it. As long as the friction disc x' remains at the same height, the pulley g' derives its motion from the same circle of the said disc, and the up and down motion of the copping beam is also uniform. But when that disc ascends so as to describe with its edge a small circle upon the face of g', its motion must become proportionally more slow. This is the method, or principle of retarding thb copping motionsof the bobbins. It has been shown, however, that the rotation of the boooins should be also retarded in a progressive manner. This object is effected by means of the cone k', which, as the band n progressively approaches towards its smaller diameter, drives the pulleys or whorls q of the bobbins with decreasing speed, though itself moves uniformly quick with the shaft c. To effect this variation, the cone is shifted lengthwise along its shaft, while the band running upon it remains continually in the same vertical plane, and is kept distended by the weight of the pulley o'. The following mechanism serves to shift the cone, which may be best understood by the aid of the figures 413, 414, and 410. A long cast iron bar me, 522 COTTON MANUFACTURE. which bear' two horizontal projecting puppets, 0303, is made fast to the front uprich face of the co(pping beam A. Through the above puppets a cylindrical rod n3 passes freely 413................ v;"'(k=~-'3'"' 30 414 -I 3...... X.. -:. 73, ra," u' * -- q~I —- -_ —y __ ___ _ which is left out in fig. 410, that the parts lying behind it may be better seen. Upon this rod there is a kind of fork, p3 p3, to which the alternating rack bars q3 are made fast. The teeth of these racks ate at unequal distances from each other, and are sc at ranged, that each tooth of the under side corresponds to the space between two teeth in the upper side. Their number depends upon the number of coils of roving that may be required to fill a bobbin; and consists in the usual machines of from 20 to 22. The rod'n3 may be shifted in the puppet 03, like the fork p3 of the rack-rod, upon the rod n3, and along the suiface of ml3, where two wings /s3 a3 are placed, to keep the fork in a straight direction. Upon the bar m3, there are the pivots or fulcra of two stop catches c;,3 x3, of which the uppermost presses merely by its own weight, but the undermost by means of a counterweight y3, against the rack, and causes them thus to fall in between the teeth. In fig. 414, r3 shows the pivot of the catch or detent w3 by itself, the detent itself being omitted, to render the construction plainer. A pushing rod t3, upon which there is a pin above at s3, that passes behind the rack rod, between this and the bar m3, has for its object to remove at pleasure the one or the other of the two catches; the upper, when the upper end of the rod pushes against it; the under, by means of the above mentionedl pin S3. Both the catches are never raised at once, but either the under or the upper holds the rack bar fast, by pressing against one of the teeth. The vertical motion up or down, which the rod /l must take to effect the lifting of the catches, is given to it from the copping beam p; since upon it a horizontal arm v32, fi. 414, is fixed, that lays hold of that rod. Upon the pushing rod are two rings, h3 and k3, each made fast by a screw. When the copping beam is in the act of going up, the arm v3 at the end of this movement, pushes against the ring h3, raises up the rodl 13, and thus removes the catch w3, fig. 410, from the teetlh of the rod q3, before which it lies flat. At the descent of the copping rail, v2 meets the ring k3, when the motion in this direction is nearly completed, draws down the rod 13 a little, by means of the same, and thereby effects the removal of the catch x3, fig. 414, from the rod q3. Every time that one of the catches is lifted, the rack recovers its freedom to advance a little bit in the direction of the arrow; so far, namely, till the other catch lays hold upon the tooth that next meets it. The reason is thus manifest why the teeth of the upper and under sides of the bar q3 are not right opposite to each other, but in an alternate position. From the rack-bar, the sliding of the cone k', and the raising of the shaft y2, each by minute steps at a time, is produced as follows:A large rectangular lever ti, vi, wlose centre of motion is at pi, has at the upper end of its long arm tt, a long slot throagh which a stud r3 upon the rack q3 goes, (figs. 413, 414, 41(,) so that the lever must follow the motions of the rack bar. The end of the short arm of the lever bears, as already r'entioned, the step of the shaft yb; hence the friction disc xl will be raised in proportion as the rack bar advances, anti will come nearer to the middle point of g; consequently, its revolution and the shifting of the bobbins will become slower. Upon the cylindrical rod n3, the piece st sl furnished with a long slot is made fast, by means of a tube z, ( fig. 410,) and a screw. A fork t iu,w which by means of the screw nut a4 is made fast in the slot, embraces the arm it of:he bet.t lever; and a tube ri riveted to the surface of si, is destined to take up the draw rod q1 of the cone k, fig. 410. A weight f4, whose cord b4 is made fast to the cylindrical rod s3, endeavors to draw this rod continually in the direction of the arrow. In consequence of this arrangement, every time that the pushing bar 13 lifts up one of the eatches, the cone k1, the lever ti v1, and by it the rack bar qs, are set in motion. It is COTTON MANUFACTURE. 523 obvious, that the motion of the cone may be made greater or less, according as the fork u u is fixed further up or down in the slot of s1. The number of the teeth upon the bar q3 is so ordered, that the bobbins are quite full when the last tooth has reached the catch and is released by it. The rack bar, being restrained by nothing, immediately slides onwards, in consequence of the traction of the weight f4, and brings the machine to repose by this very movement, for which purpose the tollowina construction is employed. A rectangular lever which has its centre of motion in gr is attached to the side face of the beam A, and has at the end of its horizontal arm a pulley d4, over which the cord b4 of the counterweight f4 is passed. The end of the perpendicular arm is forked and embraces the long and thin rod kt, to whose opposite end the fork 14 is made fast. Through this fork the band which puts the machine in motion passes down to the pulley a]. With the bent lever another rod c4 is connected at h4, which lies upon the puppet e3 with a slot at e4, and hereby keeps the lever g4 in its upright position notwithstanding the weight f4. In the moment when, as above slated, the rack bar q3 becomes free, the arm p3 of its fork pushes in its rapid advance against the under oblique side of et, raises this rod, and thereby sets the lever g4 free, whose upright arm bends down by the traction of the weight, drives the rod k4 before it into the ring i4 fastened to it, and thus, by means of the fork 14, shifts the band upon the loose pulley bl. But the machine may be brought to repose or put out of gear at any time merely by shifting the rod k4 with the hand. The operation of the bobbin and fly frame may be fully understood fiom the preceding.escription. A few observations remain to be made upon the cone kl, the rack-bar q3, and the speed of the work. When we know the diameter of the empty bobbins, and how many turns they should make in a given time in order to wind-on the sliver delivered by the fluted rollers and the spindles; when we consider the diameters of the spindle pulleys q, and I2, as also the drum mrn,ig. 405, we may easily find the diameter which the cone must have for producing that number of turns. This is the diameter for the greatest periphery of the base. The diameter of the smaller is obtained in the same way, when the diameter of the bobbins before the last winding-on, as well as the number of turns necessary in a given time, are known. A bobbin and fly frame of the construction just described delivers from each spindle in a day of twelve hours, from 6 to 8 Ibs. of roving of the fineness of 1i English counts. One person can superintend two frames, piece the broken slivers, and replace the full bobbins by empty ones. The loss of cotton wool in this machine consists in the portions carried off from the torn slivers, and must be returned to the lapping machine. The fine bobbin and fly frame does not differ essentially from the preceding machine. The rovings from the coarse bobbin and fly frame are placed in their bobbins in a frame called the creel, behind and above the roller beam, two bobbins being allowed for one fluted portion of the rollers. These rovings are "united into one, so as to increase the uniformity of the slivers. The invention of the beautiful machine above described is due to Messrs. Cocker and Higgins, of Manchester, and as lately improved by Henry Houldsworth, jun., Esq., it may be considered the most ingeniously combined apparatus in the whole range of productive industry. In the fine roving fiame the sliver is twisted in the contrary direction to that of the coarse roving frame. For this reason the position of the cone is reversed, so as to present in succession to the band, or strap, diameters continually greater, in order that the rotation of the bobbins may be accelerated in proportion as their size is increased, because here the flier and the bobbin turn in the same direction, and the winding-on is effected by the precession of the bobbin; but if the winding-on took place by its falling behind, as in the coarse bobbin and fly frame, that is, if the flier turned less quickly than the bobbins the rotatory speed of the bobbin would be uniformly retarded; in which case the cone would be disposed as in the coarse frame. When, by any means whatever, a uniform length of thread is delivered by the rollers in a given time, the bobbin must wind it up as it is given out, and must therefore turn with a speed decreasing with the increase of its diameter by successive layers of thread. Hence proceeds the proposition, that the velocit- of the bobbin must be in the inverse ratio of its diameter, as already explained. With respect to the bobbin and fly frame, the twist is given to the sliver by means of a spindle, or flier, which turns in the same direction with the bobbin, but quicker or slower than it, which establishes two predicaments. The first case is wliere the flier turns faster than the bobbin. Here the winding-on goes in advance, as in.he coarse roving frame, or as in throstle spinning, where the yarn is wound on merely in consequence of the friction of the lower disc or washer of the bobbin upon the copping rail, and of the drag of the yarn. The second case is where the flier revolves jore slowly than the bobbin. Here the winding goes on in arrear, and as the bobbin t24 COTTON MANUFACTURE. turns faster, it must receive a peculiar motion, which is uniformly retarded in the ratli of its increase of diameter. This is the case with the fine bobbin and fly frame. When the cone is placed as in fig. 405, the winding-on, in either the coarse or fine frame, re. sults from the difference, whether greater or less, between the rotatory speed of the flier and bobbin. The motion of the bobbin and spindle is simultaneous, and takes place in the same direction, with a difference varying more or less with the varying diameters of the bobbins. To render the matter still clearer, suppose for a moment the spindle to be motionless, ihen the bobbin must revolve with such a speed as to lap-on the roving as fast as the rollers deliver it. The sliver comes forward uniformly; but the bobbin, by its increase of diameter, must revolve with a speed progressively slower. Now, suppose the spindle set a-whirlino, it is obvious that the bobbin must add to the movement requisite for winding-on the sliver, that of the spindle in the case of winding-on in arrear, or when it follows the fliers, and subtract its own motion from the twisting motion of the spindles, in the case of winding-on in advance, that is, when the bobbin precedes or turns faster than the fliers; for the diameter of the bobbin being 1l inches, 10 turns will take up 45 inches. Deducting these 10 turns from the 30 made by the spindle in the same time, there will remain for the effective movement of the bobbin only 20 turns; or when the diameter of the bobbin becomes 3 inches, 5 turns will take up the 45 inches, if tie spindle be at rest; but if it makes 30 turns in the time, the effective velocity of the bobbin will be 25 turns, = 30 -- 5. Hence in the fine bobbin and fly frame, the number of turns of the spindle, minus the number of turns made by the bobbin in equal times, is in the inverse ratio of the diameter of the bobbin. We thus perceive, that in the coarse frame the bobbin should move faster than the spindle, and that its speed should always diminish; whilst in the fine frame the bobbin should move slower than the spindle, but its speed should always increase. It is easy to conceive, therefore, why the cones are placed in reverse directions in the two machines. Not that this inversion is indispensably necessary; the cone of the fine roving frame might, in fact, be placed like that of the coarse roving frame; but as the torsion of the roving becomes now considerable, and as on that account the bobbin would need to move still faster, which would consume a greater quantity of the moving power, it has been deemed more economical to give its movement an opposite direction. We mentioned that the twist of the sliver in the fine roving frame was the reverse of that in the coarse; this is a habit of the spinners, for which no good reason has been given. The divisions of the rack-bar, and the successive diameters of the cone, must be nicely adjusted to each other. The first thing to determine is, how much the rack should advance for every layer or range of roving applied to the bobbin, in order that the cone may occupy such a place that the strap which regulates the pulley barrel may be at the proper diameter, and thuS fulfil every condition. The extent of this progressive movement of the rack depends upon the greater or less taper of the cone, and the increase which the diameter of the bobbin receives with every traverse, that is, every layer of roving laid on. But care should be taken not to taper the cone too rapidly, especially in the fine roving fiame, because in its progress towards the smaller end the strap would not slide with certainty and ease. We have already shown that the number of effective turns of the bobbin is inversely, as the diameter of the bobbin; or directly, as the successive diameters of the different points of the cone. H. Houldsworth, jun. Esq. has introduced a capital improvement into the bobbin and fly frame, by his differential or equation-box mechanism, and by his spring fingers, which, by pressing the soft sliver upon the bobbin, cause at least a double quantity to be wound upon its barrel. With the description of his patent equation-box, I shall conclude the description of the bobbin and fly frame. Fig. 415 represents a portion of a fly frame with Mr. Houldsworth's invention. a a a are the fiont drawing rollers, turning upon bearings in the top of the machine, and worked by a train of toothed wheels, in the way that drawing rollers are usually actuated. From the drawing rollers, the filaments of cotton or other material, b b, are brought down to, and passed through tne arms of the fliers c c, mounted on the tops of the spindles d d, which spindles also carry the loose bobbins e e. In the ordinary mode of constructing such machines, the spindles are turned by cords or bands passing from a rotatory tdrum ronnd their respective pulleys or whirls f, and the loose bobbins e, turn with them by the friction of their slight contact tU the spindle, as before said; in the improved machine, however, the movements of the spindles and the bobbins are inde. pendent and distinct from each other, being actuated fiom different sources.'The main shaft of the engine g, turned by a band and rigger A as usual, communicates motion by a train of wheels h, through the shaft i, to the drawing rollers at the reverse end of the machine, and causes them to deliver the filaments to be twisted. COTTON MANUFACTURE. 52c Upon the main shaft g, is mounted a cylindrical hollow box or drum-oulley. whence rne cord passes to drive the whirls and spindles f and d. and another to drive the bobbins e. 415 ff This cylindrical box pulley is made in two parts, k and 1, and slipped upon the axle with a toothed wheel m, intervening between them. The box and wheel are shown detached in fig. 416, and partly in section at fig. 417. That portion of the box with its pulley marked 1, is fixed to the shaft g; but the other part of the box and its pulley k, and the toothed wheel m, slide loosely round upon the shaft g, and when brought in contact and confined by a fixed collar A, as in the machine shown at fig. 415, they constitute two distinct pulleys, one being intended to actuate the spindles, and the other the bobbins. In the web of the wheel in, a small bevel pinion o, is mounted upon an axle standing at right angles to the shaft g, which pinion is intended to take into the two bevel pinions p and q, respectively fixed upon bosses, embracing the shaft in the interior of the boxes k ant 1. Now it being remembered that the pinion q, and its box I, are fixed to the shaft g, and turn with it, if the loose wheel m be independently turned upon the shaft, with a different velocity, its pinion o, taking into q, will be made to revolve upon its axle, and to drive the pinion p, and pulley box k, in the same direction as the wheel m; and this rotatory movement of the box k and wheel m, may he faster or slower than the shaft g, and box 1, according to the velocity with which the wheel in is turned. Having explained the construction of the box pulleys k and 1, which are the peculiar features of novelty claimed under this patent, their office and advantage will be seen by describing the general movements of the machine. The main shaft g, being turned by the band and rigger A, as above said, the train of wheels h, connected with it. drives the shaft i, which at its reverse end has a pinion (not seen in the figure) that actuates the whole series of drawing rollers a. Upon the shaft i there is a sliding pulley r, carrying a band s. which passes down to a tension pulley t, and is kept distended by a weight. This band s, in its descent, comes in contact with the surface of the cone it, and causes the, cone to revolve by the friction of the band running against it. The pulley r is progressively slidden along the shaft i, by means of a rack and weight not shown, but well understood as common in these kind of machines, and which movement of the pulley is for the purpose of progressively shifting the band s from the smaller to the larger diameter of the cone, in order that the speed of its rotatioc may gradually diminish as the bobbins fill by the winding-on of the yarns. At the end of the axle of the cone u a small pinion v is fixed, which takes into the teeth of the loose wheel m, and, as the cone turns, drives the wheel m round upon the shaft g, with a speed dependant always upon the rapidity of the rotation of the cone. Now the box pulley 1, being fixed to the main shaft g, turns with one uniform speed, and by cords passing from it over guides to the whorls f, drives all the spindles and fliers which twist the yarns with one continued uniform velocity; but the box pulley k, 2)6 COTTON MANUFACTURE. being loose upon the ahaft, and actuated by the betel pinions within, as described, is made to revolve by the rotation of the wheel in, independent of the shaft, and with a different speed from the pulley box I; cords passing from this pulley box k, over guides to small pulleys under the bobbins, communicate the motion, whatever it may be, of the pulley box k, to the bobbins, and cause them to turn, and to take up or wind tie yarn with a speed derived from this source, independent of, and different fiom, the speed of the spindle and flier which twist the yarn. It will now be perceived, that these parts being all adjusted to accommodate the taking up movements to the twisting or spinning of any particular quality of yarn intended to be produced, any variations between the velocities of the spinning and taking up, which another quality of yarn may require, can easily be effected, by merely changing the pinion v, for one with a different nulmber of teeth, which will cause the wheel m, and the pulley box k, to drive the bobbins faster or slower, as would be required in winding-on fine or coarse yarn, the speed of the twisting or spinning Jeing the same. The rovings or spongy cords, of areater or less tenuity, made on the bobbin and fly, or tube roving frame, are either spun immediately into firm cohesive yarn, or receive a further preparation process in the stretching frame, which is, in fact, merely a mulejenny, without the second draught and second speed, and therefore need not be described at present, as it will be in its place afterwards. The finishing machines of a cotton mill, which spin the cohesive yarn, are of two classes; 1. the water-twist or throstle, in which the twisting and winding are performed simultaneously upon progressive portions of the roving; and, 2. the mule, in which the thread is drawn out and stretched, with little twist, till a certain length of about 5 feet is extended, then the torsion is completed, and the finished thread is immediately wound upon the spindles into double conical coils called cops. The water-twist frame, so called by its inventor, Sir R. Arkwright, because it was first driven by water, is now generally superseded by the throstle frame, in which the mechanical spinning fingers, so to speak, are essentially the same, but the mode of communicating the motion of the mill-earing to themr is somewhat different. Fig. 418 exhibits a vertical section of the throstle. This machine is double, possessing upon each side of its frame a row of spindles with all their subsidiary parts. The bobbins, filled with rovings from the bobbin and fly, or the tube frame, are set up in the creel a a, in two ranges. b, c, d, are the three usual pairs of drawing rollers, through which the yarn is attenuated to the proper deree of fineness, upon the principles already explained. At its escape from the front rollers, every thread runs through a guide eyelet e of wire, which cives it the vertical direction down towards the sptindlesf, g. The spindles which perform at once and uninterruptedly the twisting and winding-on of the thread delivered by the rollers, are usually made of steel, and tempered at their lower ends. They stand at g in steps, pass at v throueh a brass bush or collet which keeps them upriaht, and revolve with remarkable speed upon tleir axes. The bobbins h, destined to take up the yarn as it is spun, are stuck loosely upon the spindles, and rest independently of the rotation of the spindles upon the copping beam 1, with a leather washer between. Upon the top of the spindles an iron-wire fork, called a fly or flier, i, k, is made fast by a left-hand screw, and has one of its forks turned round at the end into a little ring. The branch of the flier at f is tubular, to allow the thread to pass through, and to escape by a little hole at its side, in order to reach the eyelet at the end of that fork. From this eyelet i, it proceeds directly to the bobbin. By the twirling of the spindle, the twisting of the portion of thread between the front roller d and the nozzle f is effected. The winding-on takes place in the followino way:-Since the bobbin has no other connexion with the spindle than that of the thread, it would, but for it, remain entirely motionless, relatively to the spindle. But the bobbin is pulled after it by the thread, so that it must follow the rotation of the spindle and fly. When we consider that the thread is pinched by the front roller d, and is thereby kept fully upon the stretch, we perceive that the rotation of the bobbin must be the result. Suppose now the tension to be suspended for an instant, while the rollers d deliver, for example, one inch of yarn. The inertia or weight of the bobbin, and its friction upon the coppig beam 1, by means of the leather washer, will, under this circumstance, cause the bobbin to hana back in a state of rest, till the said inch of yarn be wound on by the whirling of the fly i, and the former tension be restored. The delivery of the yarn by the drawing rollers, however, does not take place inch after inch, by starts, but at a certain continuous rate; from whence results a continuous retardation or loitering, so to speak, of the bobbins behind the spindles, just to such.an amount that the delivered yarn is wound up at the same time during the rotation. This process in spinning is essentially the same as what occurs in the fine bobbin and fly frame, but is here simplified, as the retardation regulates itself according to tlie diameter of the bobbin by the drag of the thread. In the fly frame the employmen, COTTON MANUFACTURE, 527 f tlls teiJ.Jn is impossible, because the roving has too little cohesion to bear the strain; andl hence it is necessary to give the bobbins that independent movement of rotation which so complicates this machine. The up and down mnition of the bobbins along the spindles, which is required for [he equal distribution of the yarn, and must have the same range as the length of the bobbin barrels, is performed by the following mechanism. Every copping rail, 1, is made fast to a bar m, and this, which slides in a vertical groove or slot at the end of the frame, is connected by a rod n, with an equal-armed, moveable lever o. The rod p carries a weight r, suspended from this lever; another rod, q, connects the great lever o with a smaller one s, t, upon which a heart-shaped disc or pulley, u, works from below at t. By the rotation of the disc a, the arm t, being pressed constantly down upon it by the reaction, the weight r must alternately rise and fall; and thus the cop!ing rail I must obviously move with the bobbins h up and down; the bobbins upon one side of the frame rising, as those upon the other sink. Strictly ciasidered, this copping motion should become slower as the winding-on proceeds, as in the fly roving frame; but, on account of the smallness of the finished thread, this construction. which would render the machine complicated, is without inconvenience nealecied, with the result merely that the coils of the yarn are successively more sparsely laid on, as thediameter of the bobbin increases. The movement of the whole mach:_e proceeds orom the shaft of a horizofitsa drum, which drives the spindles by means of the endless bands x x. Each spindle is mounted with a small pulley or wharf, w, at its lower part, and a particular band, which goes round that wharf or whorl, and the drum y. The bands are not drawn tense, but hang down in a somewhat slanting direction, being kept distended only by their own weight. Thus every spindle, when its thread breaks, can readily be slopped alone, by applvinz a slight pressure with the hand or knee, the band meanwhile gliding loosely round the whorl. The velocities of rotation of the three drawing rollers are, accordinn to this arrangement, in the proportion of 1: 1: 8; and as their diameters are the same, namely, one inch, the elongation of the yarn in spinning is eight fold. If, for example, the roving was of the number 42, the yarn would become No. 36. The extension of the thread may be changed by changing the wheels of the drawing rollers. To perceive the power of this change, let us put, for example, in the place of the 18-toothed wheel of the back rollers, a wheel with 16 teeth; we shall find that the elongation will amount, in that case, only to 71 times, whence the number of the yarn wouldl come out 32 = 7- X 41. The extension by the throstle is extremely various: it amounts, in some cases, to only 4 irnes; at others to 10, 12, or even 15. The copping motion of the bobbins is produced in consequence of a bevel pinion working in a small bevel wheel upon an upright shaft; while this wileel gives a slow motion by means of a worm screw to the wheel of the heart-shaped pulley u,fig. 418. 418 The driving pulley makes about 600 a.~. -u.........turns in a minute; and as the diameter of the drum y, fig. 418, is six times the diameter of the spindle wharves w, it will give 3600 turns to the spindle in that time. If the pulley be driven faster, for example, 700 times in a minute, it will increase the revolutions of the spindles to 4200. The _ 1 ~ ~ t I degree of twist which will be thereby imparted to the yarn, depends, with like speed of spindles, upon the rate at which the soft /; yarn is delivered by the drawing-rollers; -lt i for the quicker this delivery the quicker is the windinn-on, and the less twist goes into a given length of yarn. If, for example, V) the front rollers d turn 24 times in a A=)_ ____1 s minute, giving out of course 72 inches of lA~dej r~-g g N, yarn in this time, upon which the 3600 = ~-= r) revolutions of the spindle are expended, _ | d/ *" l there will be 50 twists to every inch of - arn. By chanrin. the wheel-work of fig. 418, or by sticking greater or smaller wharves upon the spindles, the proportion between their velocity and that of the drawing rollers, and thence the degree of twist, can be modified at pleasure. The number of spindles in a throstle fiame 12 feet long is about 60 on each side. The drawing rollers are coupled together as in the bobbin and fly frame, so that each row forms one continuous cylinder. There is a complete roller beam on each side' each of the rollers of the front row is pressed by its top rollers with a weight of ten 35 D28 COTTON MANUFACTURE. twelve pounds; but those of the middle and back rows bear weights of only one pound In the throstles, there is a guide bar which traverses a small way horizontally to the left and right, in front of the roller beam, to lead the thread along different points of the rollers, and thus prevent the leather of the top ones from being grooved by its constant pressure in one line. For the service of 240 spindles, in two double frames, one young woman and an assistant piecer are sufficient. They mend the broken ends, and replace the empty bobbins in the creel with full ones, and the full bobbins of the throstle by empty ones. The average quantity of yarn turned off in a week of 69 hours i~ about 24 hanks per spindle of 30's twist. Throstle yarn is of a firm wiry quality, adapted to the warps of fustians and other strong stuffs, as well as to the manufacture of stockings and sewing thread. There are many modifications of the throstle system besides the one above described; the most celebrated of which are Danforlh's, called the American throstle, Montgomery's, and Gore's. I must refer for an account of them to my work entitled "The Cotton Manufacture of Great Britain," where they are minutely described and illustrated with accurate figures. Mule-spinning.-The general principles of the mule have been already stated. This machine is so named -because it is the oflspring, so to speak, of two older machines, the jenny and the water-fiame. A mule is mounted with fi-om 240 to 1000 spindles, and pins, of course, as many threads.Fig. 419 represents the Fig". 419 represents the original jenny of Har4190 ^. B. greaves, by which one i~t 419/ I~person was enabled to spin from 16 to 40 threads A 0 at once. The soft cords l______: b ~~~ of rovings wound in double conical cops upon _ _Ly U iz11\\'~i — " —i" skewers were placed in -- -' — w't ithe inclined frame at c; the spindles for first \I j H twisting and then winding-on the spun yarn were set upright in steps and bushes at A, being.... If I urnished near their lower ends with whorls, and endless cords, which were driven by passing round the longrevolving drum of tin plate E. D is the clasp or clove, havin a handle for lifting its upper jaw a little way, in order to allow a few inches of the soft roving to be 420 introduced. The cornpound clove D being now pushed forward upon its fi'oction wheels to A, was.KE A- 1i. I next gradually drawn, t ^- e* |L Xc <~ ~ w _Xbackward, while the spin_TYTT.~~~ ~~u f l: lY ldles were made to revolve with proper speed by the right hand of the opera3 tive turning the fly-wheel 13 ^ Z l } Z:13 B. Whenever one stretch was thereby spun, the clove frame was slid home towards A; the spindles being simultaneously whirled slowly to take up the yarn, which was laid on in a conical cop by the du, depression of the faller wire at A with the spinner's left hand. Fig. 420 is a diagram of Arkwright's original I I.? i1' Y Y......I water frame spinningZ machine, called after. wards the water - twist COTTON MANUFACTUIE. 529 frame. The rovings mounted upon bob 421 ^,bins in the creel A A, have their ends lei through between the three sets of twin rollers below B B, thence down through _ —:~_ i ~ ~, a d \ the eyelet hooks upon the end of the fliers -'- At's \ of the spindles c, and finally attached tc their bobbins. The spindles being driven by the band D D upon their lower part, continuously twist and wind the finished yarn upon the bobbins; constituting the first unremitting automatic machin, for spinning which the world ever saw., Contrast with the above admirable systern, the primitive cotton wheel of India, as represented in the annexed figure 421. By the aid'f mechanical finoers, one English____g ^^^^,_ man at Iis mule can turn off daily more yarn and of far finer quality than 200 of Ihe most diligent spinsters of Hindostan. Fig. 422 is a transverse section of the mule. in which its principal parts are shown, A ffli- 91 422; 5' * |I\......\ l 3 3A The machine consists of two main parts; a fixed one corresponding in some mea. sure to the water-frame or throstle, and a moveable one corresponding to the jenny. The first contains in a suitable frame the drawing roller-beam and the chief moving machinery: the second is called the carriage, in which the remainder of the moving mechanism and the spindles are mounted. The frame of the fixed part consists of two upright sides, and two or more intermediate parallel bearings, upon which the horizontal roller beam a, the basis of the drawing rollers is supported. b, c, d, are the three ranges of fluted iron rollers; e, f, g, are the upper iron rollers covered with leather; h, the wooden wiper-rollers covered with flannel, which being occasionally rubbed with chalk, imparts some of it to the pressure rollers beneath, so as to prevent the cotton filaments adhering to them. The rollers are made through. _____________________________________ 530 COTTON MANUFACTURE. put the whole length of the mule in portions containing six flutings, which are coupled together by squared ends fitted into square holes. The skewers upon which the bobbins containing the rovings from the bobbin and fly Dr stretching frame are set up, are seen at al, al, al, arranged in three rows in the treel z. The soft threads unwound from these bobbins, in their way to the drawing rollers, pass first through eyelets in the ends of the wire arms bl, then through the rings or eyes of the guide bar w, and enter between the back pair of rollers. The Lumber of these bobbins is equal to the number of spindles in the mule, and twice as great as the number of fluted portions of the rollers; for two threads are assigned to each portion. The carriage consists of two cast-iron side pieces, and several cast-iron intermediate similar pieces, such as f2, which all tozether are made fast to the planks b2, c2, d2. The top is covered in with the plank k2. The carriage runs by means of its cast-iron grooved wheels, upon the cast-iron railway 12,which is fixed level on the floor. The spindles stand upon the carriage in a frame, which consists of two slant rails 2, x2, connected by two slender rods y2, and which frame may be set more or less obliquely. The lower rail carries the brass steps for the points of the spindles be; upon the upper rail brass slips are fixed pierced with holes through which the tops of the spindles play. The spindles are as usual made of steel, perfectly straight, turned truly round, and are all arranged in one plane. To each of them a small wooden or cast-iron whorl g2 is made fast. They are distributed into groups of 24, and the whorls are arranged at such different heights, that only two of them in each group are upon a level with each other. A small brass head h2, which every spindle has beneath the upper slant rail of the frame x2, prevents their sitting down into the step, during their rotatin, or sliding off their cop of yarn, c3 are drums, mounted in the carriage in a plane at right angles to the plane in which the spindles are placed. At top they have a double groove for a cord to run in, and the motion which they receive from the great fly wheel, or rim of the mule (not visible in this view) they impart to the spindles. Such a drum is assigned to every 24 spindles; and therefore a mule of 480 spindles contains 20 drums. In the middle of the carriage is seen the horizontal pulley k3, furnished with three grooves,, which stands in a line with the drums c3. The motion is given to the drums c3, upon the right hand half of the carriage, by a single endless band or cord which proceeds from the middle groove of the pulley k3. The rotation of the spindles is produced by a slender cord, of which there are 12 upon each drum C3; because every such cord goes round the drum, and also every two wharves which stand at the same level upon the spindles. It is obvious that the drums, and consequently the spindles, must continue to revolve as long as the main rim of the mule is turned, whether the carriage be at rest or in motion upon its railway. If we suppose the carriage to be run in to its standing point, or to be pushed home to the spot from which it starts in spinning, its back plank d-2 will strike the post q3 upon the fixed frame, and the points of the spindles will be close in front of the roller beam. The rollers now begin to turn and to deliver threads, which receive immediately a portion of their twist from the spindles; the carriage retires from the roller beam with somewhat greater speed than the surface speed of the front rollers, whereby the threads receive a certain degree of stretching, which affects most their thicker and less twisted portions, and thereby contributes greatly to the levelness of the yarn. When the carriage has run out to the end of its course, or has completed a stretch, the fluted rollers suddenly cease to revolve (and sometimes even beforehand, when a second stretch is to be made), but the spindles continue to whirl till the fully extended threads have received the proper second or after-twist. Then the carriage must be put up, or run back towards the rollers, and the threads must be wound upon the spindles. This is the order of movements which belong to the mule. It has been shown how the rotation of the spindles is produced. Fbr winding-on the yarn the carriage has a peculiar apparatus, which we shall now describe. In fiont of it, through the whole extent to the right hand as well as the left, a slender iron rod, ds, runs horizontally along, in a line somewhat higher than the middle of the copping portion of the spindles, and is supported by several props, such as 5. Upon each end of the two rods, d5, there is an arm, go; and betwixt these arms an iron wire, called the copping wire, fs, is stretched, parallel with the rod d5. For the support of this wire, there are several slender bent arms h5 extended from the rod ds at several points betwixt the straight arms go. The rod ds has, besides, a wooden handle at the place opposite to where the spinner stands, by which it can be readily grasped. This movement is applied at the left division of the machine, and it is com municated to the right by an apparatus which resembles a crane's bill. The two arms, g5, in the middle of the machine, project over the rods ds, and are connected by hinges with two vertical rods j5, which hang together downwards in like manner with two arms,;5 proceeding from a horizontal axis ks. COTTON MANUFACTURE. 531 By means of that apparatus the yar is wound upon the spindles in the following tanner. As long as the stretching and twisting go on, the threads form an obtuse anale with the spindles, and thereby slide continually over their smooth rounded tips during their revolution, without the possibility of coiling upon them. When, however, the spinning process is completed, the spinner seizes the carriage with his left hand and pushes it back towards the roller beam, while with his right hand he turns round the handle of the rim or fly wheel, and consequently the spindles. At the same time, by means of the, handle upon the rod d5, he moves the copping-wiref5, so that it presses down all the threads at once, and places them in a direction nearly perpendicular to the spindles; as shown by the dotted line y5. That this movement of the copping wire, however, may take place without injury to the yarn, it is necessary to turn the rim beforehand a little in the opposite direction, so that the threads may get uncoiled from the upper part of the spindles, and become slack; an operation called in technical language the backing off. The range upon which the threads should be wound, in order to form a conical cop upon the spindle, is hit by depressing the copping wire to various angles, nicely graduated by an experienced eye. This faller wire alone is not, however, sufficient for the purpose of winding-on a seemly cop, as there are always some loose threads which it cannot reach without breaking others. Another wire called the counter-faller, 1, must be applied under the threads. It may be raised to an elevation limited by the angular piece p5; and is counterpoised by a very light weight m5, applied through the bent lever n5, which turns upon the fulcrum os. This wire, which applies but a gentle pressure, gives ten:;un to all the threads, and brings them regularly into the height and range of the fallei fs. This wire must be raised once more, whenever the carriage approaches the roller beam. At this instsan a new stretch commences; the rollers begin again to revolve, and the carriage resumes its former course. These motions are performed by the automatic machinery. There is a little eccentric pulley mechanism for moving the guide beam to and frc with the soft yarns, as they enter between the back rollers. On the right hand end of the back roller shaft, a worm screw is formed which works into Vhe oblique teeth of a pinion attached to the end of the guide beam. in which there is a series of holes for the passage of the threads, two threads being assigned to each fluted roller. In the flat disc of the pinion, an eccentric pin stands up which takes into the jointed lever upon the end of the guide beam, and, as it revolves, pushes that beam alternately to the left and the right by a space equal to its eccentricity. This motion is exceedingly slow, since for each revolution of the back roller, the pinion advances only by one tooth out of the 33 which are cut in its circumference. After counting the number of teeth in the different wheels and pinions of the mule, or measuring their relative diameters, it is easy to compute the extension and twist of the yarns; and when the last fineness is given to ascertain their marketable value. Let the ratio of speed between the three drawing rollers be 1: 1-32: 7.; and the diameter of the back and middle roller three quarters of an inch: that of the front roller one inch; in which case the drawing is thereby increased 1- times, and 7~ X 1 =- 10. If the rovings in the creel bobbins have been No. 4, the yarn, after passing through the rollers, will be No. 40. By altering the change pinion (not visible in this view) the fineness may be changed within certain limits, by altering the relative speed of the rollers. For one revolution of the great rim or fly wheel of the mule, the front roller makes about 6 tenths of a turn, and delivers therefore 22*6 lines or 12ths of an inch of yarn, which, in consequence of the tenfold draught through the rollers, corresponds to 2'26 lines of roving fed in at the back rollers. The spindles or their whorls make about 66 revolutions for one turn of the rim: The pulleys or grooved wheels on which the carriage runs, perform 0'107 part of a turn while the rim makes one revolution, and move the carriage 24*1 lines upon its rails, the wheels being 6 inches in diameter. The 22'6 lines of soft yarn delivered by the front rollers will be stretched 11 lines by the carriage advancing 24'1 lines in the same time. Let the length of the railway, or of each stretch, be 5 feet, the carriage will complete its course after 30 revolutions of the rim wheel, and the 5 feet length of yarn (of which 56.- inches issue from the drawing rollers, and 3- inches proceed from the stretching) is, by the simultaneous whirling of the spindles, twisted 1980 times, being at the rate of 33 twists for every inch. The' second twist, which the threads receive after the carriage has come to repose, is regulated according to the qualit; of the cotton wool, and the purpose for which the yarn is spun. For warp yarn of No. 40 or 50, for example, 6 or 8 turns of the rim wheel, that is, from 396 to 528 whirls of the spindles for the whole stretch, therefore from 7 to 9 twists per inch will be sufficient. The finished yarn thus receives from 40 to 42 twists per inch. One spinner attends to two mules, which face each other, so that he needs merely turn round in the spot where he stands, to find himself in the proper position for the nther mule. For this reason the rim wheel and handle, by which he operates, are not 532 COTTON MANUFACTURE. placed in the niddle of the length of the machine, but about two fifths of the spindles are to the righ hand and three fifths to the left; the rim wheel being towards his right hand. The ca.riace of the one mule Is in the act of going out and spinning, while that of- the other is finishing its twist, and being put up by the spinner. The quantity of yarn manufactured by a mule in a given time, depends directly upon the number of the spindles, and upon the time taken to complete every stretch of the carriage. Many circumstances have an indirect influence upon that quantity, and particularly the degree of skill possessed by the spinner. The better the machine, the steadier and softer all its parts revolve, the better and more abundant is its production. When the toothed wheels do not work truly into their pinions, when the spindles shake in their bushes, or are not accurately made, many threads break, and the work is much injured and retarded. The better the staple of the cotton wool, and the more careful has been its preparation in the carding, drawing, and roving processes, the more easy and excellent the spinning will become: warmth, dryness, cold, and moisture have great influence on the ductility, so to speak, of cotton. A temperature of 65~ F., with an atmosphere not too arid, is found most suitable to the operations of a spinning mill. The finer the yarn, the slower is the spinning. For numbers from 20 to 36, from 2 to 3 stretches of warp may be made in a minute, and nearly 3 stretches of weft; for numbers above 50 up to 100, about 2 stretches; and for numbers from 100 to 150, one stretch in the minute. Still finer yarns are spun more slowly, which is not wonderful, since, in the fine spinning mills of England, the mules usually contain upwards of 500 spindles each, in order that one operative may manage a great number of them, and thereby earn such high wages as shall fully remunerate his assiduity and skill. In spinning fine numbers, the second speed is given before the carriage is run out to the end of its railway; during which course of about six inches. is made to move very slowly. This is called the second stretch, and is of use in minltng the yarn level by drawing down the thicker parts of it, which take on the twist less readily than the thinner, and therefore remain softer and more extensible. The stretch may therefore be divided into three stages. The carriage first moves steadily out for about 4 feet, while the drawing rollers and spindles are in full play; now the rollers stop, but the spindles go on whirling with accelerated speed, and the carriage advances slowly about 6 inches more; then it also comes to rest, while the spindles continue to revolve for a little longer, to give the final degree of twist. The acceleration of the spindles in the second and third stages, which has no other object but to save time, is effected by a mechanism called the counter, which shifts the driving band, at the proper time, upon the loose pulley, and, moreover, a second band, which had, till now, lain upon its loose pulley, upon a small driving pulley of the rim-shaft. At length, both bands are shifted upon their loose pulleys, and the mule comes to a state of quiescence. The SELF-ACTOR MULE, or the IRON MAN, as it has been called in Lancashire, is an invention to which the combinations among the operative spinners obliged the masters to have recourse. It now spins good yarn up to 40s with great uniformity ana promptitude, and requires only juvenile hands to conduct it, to piece the broken yarns, to replace the bobbins of rovings in the creel, and to remove the finished cops from the spindles. The self-acting mules were first constructed, I believe, by Messrs. Eaton, formerly of Manchester, who mounted ten or twelve of them in that town, foilr at Wiln, in Derbyshire, and a few in France. From their great complexity and small productiveness, the whole were soon relinquished, except those at Wiln. MI. de Jong obtained two patents for self-acting mules, and put twelve of them in operation in a mill at Warrington, of which he was part proprietor; but with an unsuccessful result. I saw the debris of one of M. de Jong's self-actors in the factory of M. Nicholas Schlumberger, at Guebwiller, in Alsace, where the machine had been worked for three months, without advantage, under the care of the inventor, who is a native of that valley. The first approximation to a successful accomplishment of the objects in view, was an invention of a self-acting mule, by Mr. Roberts, of Manchester; one of the principal points of which was the mode of governing the winding-on of the yarn into the form of a cop; the entire novelty and great ingenuity of which invention was universally admitted, and proved the main step to the final accomplishment of what had so long been a desideratum. For that invention a patent was obtained in 1825, and several headstocks upon the principle were made, which are still working successfully. In 1830, Mr. Roberts obtained a patent for the invention of certain improvements; and by a combination of both his inventions, he produced a self-acting mule, which is generally admitted to have exceeded the most sanguine expectations, and which has been extensively adopted. There are probably, at present, upwards of half a million of spin. dies of Messrs. Sharp, Roberts, and Co.'s construction, at work in the United Kingdom, anol giving great satisfaction to their possessors. The advantages of these self-actors fr- the following: COTTON MANUFACTURE. 53,2 The saving of a spinner's wages to each pair of mules, piecers only being required, as one overlooker is sufficient to manage six or eight pairs of mules. The production of a greater quantity of yarn, in the ratio of from 15 to 20 per cent. The yarn possesses a more uniform degree df twist, and is not liable to be strained during the spinning, or in winding-on, to form the cop; consequently, fewer threads are broken in these processes, and the yarn, from having fewer piecings, is more regular. The cops are made firmer. of better shape, and with undeviating uniformity; and, from being more regularly and firmly wound, contain from one third to one half more yarn than cops of equal bulk wound by hand; they are consequently less liable to injury in packing or in carriaoe, and the expense of packages and freight (when charged by measurement) is considerably reduced. From the cops being more regularly and firmly wunnd, combined with their superior formation, the yarn intended for warps less frequently breaks in winding or reeling, consequently there is a considerable saving of waste in those processes. Secondly, the advantages connected with weaving. The cops being more regularly and firmly wound, the yarn, when used as weft, seldom breaks in weaving; and as the cops also contain a greater quantity of weft, there are fewer bottoms, consequently there is a very material saving of waste in the process of weaving. From those combined circumstances, the quality of the cloth is improved, by being more free from defects caused by the breakage of the warp or weiL, as well as the selvages being more regular. The looms can also be worked at greater zed; and, from there being fewer stoppazes, a greater quantity of cloth may be produced. That the advantages thus enumerated, as derivable from the use of self-acting mules, have not been overrated, but, in many instances, have been considerably exceeded, I have, by extensive personal inquiry and observation, had ample opportunity of ascertainina. Statement of the quantity of yarn produced on Messrs. Sharp, Roberts, and Co.'s selfacting mules, in twelve working hours, including the usual stoppages connected with spinning, estimated on the average of upwards of twenty mills:No. of Yarn. No. of Twist. No. of Weft. 16 - - 41 hanks - - 47 hanks per spindle. 24 - - 4- - - - 4 - 32 - - 4 - - - 4- - 40 - - 3 - - - 4 - Of the intermediate numbers the quantities are proportionate. Results of trials made by Messrs. Sharp, Roberts, and Co., at various mills, to ascertain the comparative power required to work self-acting mules, in reference to handmules, during the spinning, up to the period of backing off. Particulars of the trials referred to, and their results:At what Mill, and the Description of No. and kind Total Forre Mule. of Yarn. |J i^ ~~ Employed in o:^ __'> -5 Spinning. Messrs. Birley and Kirk. Weft. Ins. lbs. lbs. Self-acting mule, 360 sps. - - 30 to 34 12 58 30 5463 *Hand-mule, 180 sps. - - - ditto 15 36 26 3X6692 Messrs. Leech and Vandrey. Twist. t Self-acting mule, 324 sps. - 36 12 70 36 7912 Hand-mules, 324 sps. - - - 36 29 58 161 7273 Messrs. Duckworth, Co. Twist. Self-acting mule, 324 sps. - - 40 12 62 33 6421 Hand-mule, 324 sps. - - - 40 47 36 15- 6646 The mode adopted to make the trials was as follows, viz.: A force, indicated by weight in pounds, was applied to the strap working upon the, The trial was disadvantageous for the hand-mules, being two for 360 spindles. t The trial was disadvantageous for the self-acting mules, being driven by a very short and light veruIca stran, the hand-mul., having a long horizontal strap. 534 COTTON MANUFACTURE. driving-pulley of the respective mules, sufficient to maintain the motion of the mule whilst spinning, which weight, being multiplied by the length of strap delivered by each revolution of the pulley, and again by the number of revolutions made by the pulley whilst spinning, gave the total force in pounds, applied to the respective mules whilst spinning; for instance, suppose a mule to be driven by a pulley 12 inches diameter (3'14 feet in circumference), such pulley making 58 revolutions during the spinning as above, and that it required a force equal to 30 lbs. weight to maintain the motion of the mule, then 30 lbs. X 3-14 feet circumference of pulley X 58 revolutions in spinning = 5,463 lbs. of force employed during the spinning, to the period of backing off. Mr. James Smith, of Deanstone cotton works in Scotland, obtained a patent for the invention of a self-aclor, in February, 1834. He does not perform the backing-off by reversing the rotation of the spindle, as in common mules, or as in Mr. Roberts', but by elevating the counterfaller wire, which, being below the ends of the yarn or thread, along the whole extent of the carriage, thereby pulls off or strips the spiral coils at the point of the spindle, instead of unwinding them, as of old. This movement he considers to be of great importance towards simplifying the machinery for rendering the mule self-acting; and the particular way in which he brings the stripper into action is no doubt ingenious, but it has been supposed by many to strain the yarn. He claims as his invention the application and adaptation of a mangle wheel or mangle rack to the mule, for effecting certain successive movements, either separately or in conjunction; he claims that arrangement of the carriages of a pair of mules, by which the stretch is caused to take place over part of the same ground by both carriages, and thereby the space required for the working of the pair of mules is greatly dimi2ished; and he claims the application of a weight, spring, or friction, for balancing the tension of the ends of the threads. A patent was granted, in April, 1835, to Mr. Joseph Whitworth, engineer in Man chester, for some ingenious modifications of the mechanism of the mule, subservient to automatic purposes. His machinery is desianed, first, to traverse the carriage in and out, by means of screws or worm-shafts, which are placed so as to keep the carriage parallel to the drawing rollers, and prevent the necessity of squaring bands, hitherto universally employed: secondly, his invention consists in an improved manner of working the drums of a self-acting mule by gear; thirdly, in the means of effecting the backing off; fourthly, in the mechanism for working the faller-wire in building the cops; and fifthly, in the apparatus for effecting the winding of the yarns upon the spindles. As regards the throstles and doubling frames, his improvements apply, first, to the peculiar method of constructing and adapting the flyers and spindles, and producing the drag; and, secondly, to the arrangement of the other parts of the doubling machinery. See LACE-MAKING, SINGEING, TEXTILE FABRIC, THREAD MANUFACTURE, and WEAVING. We extract the following from the Circular of Hermann Cox and Co., dated 19th July, 1852. Exportfrom 1st January to 5th May, as follows: 1852. 1851. Exportations of Yarn - - - 50,399,189 lbs. 42,630,812 lbs. Manufactured Goods - 509,350,295 yds. 493,915,720 yds. consequently a considerable surplus on both over last year; the official return till 5th June, just out, again shows an increase, viz.: 1852. 1851. txportations of Yarn - - - 63,418,111 lbs. 54,634,370 lbs. Manufactured Goods - 649,341,927 yds. 630,581,674 yds. The following is a return of exports from Hull, from 1st January till 30th June Manufactured Twist. Other Yarn. Cotton Goods. Raw Cotton. 1852. - 33,182 bales. 12,115 bales. 11,536 bales. 65,186 bales. 1851. - 31,601,, 9,634,, 11,347,, 33,054, COTTON. 535 AMERICA. 1351. 1852. Stock 1st September in the Ports - - 148,000 bales. 128,000 bales. Receipts till 22d June - - - 2,250,000,, 2,936,000,, 2,398,000,, 3,064,000,, Shipments tc Europe till 22d June - 1,758,000,, 2,263,000,, 640,000,, 801,000,, Deduct Stock 22d June - - - 304,000,, 201,000,, American Consumption for 1851 - - 336,000 bales. 600,000 bales. Last year the American spinners took from the above-named last date till 1st Sept, 137,000 bales. FRANCE. Notwithstanding 96,348 bales larger supply, the stock is still 12,293 bales smallei than last year. 1851. Stock, Imports Total. Deduct Stock, Leaves for 1st January. to 1st July. Total. 1st July. Consumption. Havre - 39,825 210,140 249,965 78,377 171,588 bales. Marseilles - 15,095 26,124 41,219 17,479 23,740,, 54,920 236,264 291,184 95,856 195,328 bales. or 7,512 bales per week. 1852. Havre - 22,767 297,514 320,281 75,271 245,010 bales. Marseilles - 7,661 35,098 42,759 8,292 34,467, 30,428 332,612 363,040 83,563 279,477 bales. or 10,749 bales per week this year against 7,512 bales in the same period last year, ot 7,326 bales average of 1851. REMAINING CONTINENT. We find the consumption of the first six months of 1851 and 1852 to be as follows: i851. Stock, Direct T ta Deduct Stock, Leaves for 1st January. Implorts. o l. 1st July. Consumption. Hamburg - - 6,300 33,730 40,030 6,730 33.300 bales. Bremen. - 89 21,191 21,280 12,133 9,147 Petersburg and Sweden 5,575 7,000 12.575 4,000 8,575 A msterdam - - 1,362 4,888 6.250 2,698 3,552 Rotterdam - - 467 1,912 2,379 1,533 1,046 Antwerp - 4,578 25,173 29,751 8,5(00 21,251 Trieste - - 22,596 79.582 102,178 49,004 53,174 Spain, Portugal, and Italy - 6,000 68,000 74,000 8,000 66,000 46,967 241,476 288,443 92,398 196,045 bales. Add Export from England - 95,3(10, Total -. 291,345 bales. or 11,205 bales per wesk. I. 536 COTTON. 1852. Stock, Direct Total. DeductStock Teaves for 1st January. Imports. 1st July. Con.umption. Hiamburg - - 5,900 65,929 71,829 17,990 53,839 bales. Brelen - - - - 1,664 1 6.303 17,967 3,304 14663 Petersurg and Sweden - 2.000 23,1000 25,000 5,000 20,0l0, Amsterdam - - 2,101 6,890 8.991 4,157 4,834, Rlotterdam - - - 928 11,581 12.509 8,350 4,159, Antwerp - - - 1,196 54.282 55,478 22,0(10 33,478 Trieste - - - - 2,914 72.392 98,3(16 29,857 68,49, Spain, Portugal, and Italy - 4,219 97,000 101,219 9,000 92,219, 347,377 99,658 291,641 bales. Export from England - 147,(00,, Total - - - 438,641 bales. or 16,870 bales per week, against 11,205 bales in the first half of last year, or against 11,664 bales average of the whole period of 1851. The total consumption of all countries according to the preceding statements is as follows: England - - - 39,683 bales, against 29,851 bales, 1851. America - - - - 11,538,, 6,461,, France - - - - 1(1,749,, 7,512, Remaining Continent - - 16,870,, 11,205,, 78,840 55,029 bales per week. To which we, however, consider it advisable to add, that this increase in the consumlption for the first half year (viz., 23,811 bales per week) should not be taken as any cliterion agrainlst the consumption of the same period last year, when it was so niuch restricted through the drooping state of prices, and when spinners were induced to use up their whole stocks. We affirm therefore that this increase of consumption should oily be considered in comparison with the average consumption of the whole of last year, viz.: In England - - - -- 31,973 bales in 1851. America - - - - - - 9,479,, France - - - - - - 7,326, Remaining Continent - - - - 11,664,, 60,442 bales per week. Against - - 78,840,, this year. We have thus far represented the consumption-the extraordinary increase of the same in all countries, without exception, proves how cheap food, with peace, tends to enlarge consumtption; and it remains therefore only to be hoped that the favorable prospects for the ensuing crop be not blighted. It is clearly evident that present prices do not affect the consumption; for the planters they are sufficiently remunerative to induce an extension of the culture, and so provide for the world such stocks as would prevent any ill effect arising from a future small or bad crop. It slhall now be our endeavor to point out the position of stocks in all Europe on the 31st December this year, supposing the consumpltion to continue at its present rate: The American crop -- 3,000,000 bales. Of which were received by the last list of 22d June - 2,936,329,, Remain to receive - - - - - - 63,671,, Stocks in the ports and on shipboard 22d June - - 201,773,, 265,444 The average stock left in the ports during the last six years was about 150,000 bales, but we will take for this year only - - - - - - - 100,000,, Would leave for all Europe - - - 165,444,, Suppose American spinners take nothing more from 22d June till 1st September. COTTON. 537 Brought forward - - 165,444 bale. From America, floating to England - - - 150,000,,,,,,, to other countries -. 100,000,,, India,, to England - - - 100,000 to receive from other countries till 31st December, equal tc last year. England - from Egypt, Brazils, and Sundries - 83,000 Fraince -,, Egypt, Brazils, and Smyrna - 26,000 Trieste, and other Ports,,, Egypt, Brazils, and Smyrna - 40,000 149,000,, Total supply for Eurcpe - - - - 664,444 Add stocks in all Eurcpean ports on 1st July - 900,421,, Total - 1,564,865,, Quantity of American, next ci;p, to be received in England 150,000,, Ditto in Continental ports - - 75,000,, 1,789,685 bales. Therefore, if the present consumption of Europe were to continue to the end of the year, the stock would be only 39,084 in all European ports, not enough for one week Table of^ Imaginary Stocks in Great Britain on 31st December, 1852. The American crop 3- 5,000,000 bales. Of which were received by the last list of 22d June - - 2,936,329,, Remain to receive - - 63,671,, Stocks in the ports and on shipboard 22d June - - 201,773,, 265,444,, The average stock left in the ports during the last six years was about 150,000 bales, but we will take for this year only 100,000 165,444,, We will suppose American spinners to take nothing more till 1st September, and supposing the 32 ships loading for France, and 125 for other ports take only - - 65,444, Would leave for Great Britain - - - - 100,000,, As the stocks in the interior markets are only one third of those of last year, shipments after August must fall very short; but supposing England to receive from 1st September till 31st December - - - - 150,000,, Now floating to England - - - - - 150,000, From India we will suppose - - 100,000,, From Brazils, Egypt, &c., like last year in the same period - 83,000,, Total to receive - 583,000,, Add stock 1st July in Great Britain - - - 17,200,, 1,300,200 bale& Export until 1st July last year was 95,300 bales, for the same period this year 147,000 bales. We have shown that the Continental stocks, notwithstanding so much larger roceipts, are only near on a par with those of last year; this leads us to suppose that our market must later assist those by large exports, but we will take such only equal to last year, viz. - - - - - 121,000 bales. Leaves - - - - 1,179,200, Whereas the present rate of consumption requires till 31st Dec. - 1,031,758 bales. This would leave us a stock at this vear's end of all descriptions of 147,442 bales only, not sufficient for the consumption of four weeks; supposing, however, the consumption to fall to only 33,000 bales per week, the remaining stock would be only 321,000 lales against 494,000 bales at the end of last year. IMPORT AND STOCK OF COTT(21 IN LIVERPOOL-31st JULY, 18052. Delivery. Estimated Stock. Prices. Import. T Description. Import inn J uly.Imot In July, In July, 7 Months, 7 Months, 31st July, 31st July, slat July, 3lst July, Whence. 7 Months, 7 Months, 1851. 1852. 1851. 18512. 1851. 18502. 1851. 1852. 1851. 185-2. 1851. Sea Islatnd 15 a 30 8 a 04 Savannah - 92,886 112,442 119,672 Stained do. 51, 14 4,0 9Y2 Charleston 160,025 135,266 165,303 Upland - - 134,192 148,942 157,133 1,036,596 767,042 513,200 140,000 4,'~ 6, Y 31~ 6 Northern Ports - 181,756 133,930 167,120 Mobile | 4J0 8~ 31~ 511 New Orleans, &c. 870,009 664,164 886,612 New Orleans J 4 Y, 3,0 7,/ Pernambuco - 41,7150 27,086?02,486 Pernambuco 9,040 1,142 6 009 40,170 30,311 13,900 14,T00 6 - Y, 6 70~ Bah ia - - 10,708 11,512 06,614 AracatiandCeo-a 6,2, 7,6 5,0 7 51aranham - 00,279 23,161 09,570 Bahia and Mueeio 6,345 2,745 2,528 20,019 18,722 8,800 10,700 65~ 7 5 Y4 60~ Peruvian - - - 10 47 47 Maranio,501 301 304 to 33,900 60~~ 7~ 50~ Y 7 Demerearn-. 677 368 473'am.} 5'281 3'28l 3,-204 26'509 20'531 20'900 390 5 4 \y'is.-: 3,72,9 6 Sawginueltd do. 5 194 6 4 Y4 5 04 Wcst Indies, &ec, -3,971 0,199 6,8'29 Demerara - - 161 164 35 777 258 50 150 51~ 10 510 6 Y4 Egypc - - 93,559 45,079 62,349 West India, &c. 985 1,085 529 4,501 2,106 5,300 1,0)00 5Y2 9 4)4 5 Y2 Bombay -. 47,090 99,027 225,932 Egyptian - 26,846 8,446 8,123 P0,089 41,759 53,300 35,500 5>,1 10 50~ 9 Madras - --- - 4,595 5,280 Surat aud Madras 2,124 16,124 13,397 109,580 115,772 31,500 79,002 3 40~ 20,1 40~ Calcutta - - 704 1,700 1,700 Bengal - - 100 100 944 1,010 10(0 508 30 )4'-'Y 4Y,~ Total - 185,729 186,029 191,138 1,299,185 999,706 645,050 1 715,750 - - - - - — 1,520,505 1,2600,5786 1,74,983 The sales dtringt the month of July amounted to 277,260 bales, of which 1(09,420 were toiken s10 taken on opeculation and for export, conliisting of 90.510 American, 4.430 Pernambuco, 1,170 0 Bahia, 20 Matlaiilhan, 3,8>l) Egyptian, and 6,490 East 11(110a. The actual export was 15,0U) Amcericatt, 1,60 Brazil, and 1,500 Surat; and front 1st of January to 31st July, 106,300 American, 7,000 Brazil, 260 West India, $00 Egyptian, and 28,600 Surat, &c7. Prices advanced during the ntonth 1d. per lb. H IMPORT, DELIVERY, AND STOCK OF COTTON, IN GREAT BRITAIN, FIRST SEVEN MONThS, 1851 AND 1852. 1S51. 1852. American. Brazil. West Indies. Egyptian. East India. Total. American. Brazil. West Indies. Egyptian. East India. Total. Stock, 1st January - - - 272,710 60,650 1,5108 34,870 143,300 521,120 245,810 49,520 4,310 22,910 172,050 494,600 Import, 7 months - - 1,087,501 61,759 3,428 1 45,539 148,416 1,356,633 1,363,809 I 80,935 5,007 95,734 46,984 1,592,469 1,370.211 130,409 4,928 80,409 291,796 1,877,753 1,609.619 13(,455 9,317 118,644 219,034 2,087,069 Taken for export - - - 83,500 6,6(0 - - 3(!0 46,900 137,300 106,850 7,000 200 310 | 53.950 168,300 1,206,711 123,809 4,928 80,109 044,86 7 1,74(,453 1,50.769 123,455 9,117 118,344 165,084 1,918,769 Estimated stock, 31st July - - 567,000 58,00 2,00 37,000 136,550 0,150, 540,000 43,600 4,000 54.70 72,050 714.350 Taken for consumption - - 719,711 65,(0)9 5,928 42,309 108,346 928.303 962,769 79,855 5,117 63,644 93,034 1,204,419 Or per week - - 23,727 2,143 96 1 1,395 3,572 30(,933 31,739 2,633 169 2,008 3,067 39,706 Total import, 1851 - - - 1,397,112 108,670 8,476 63,833 526,474 1,904,565 Total export, 1851 - - - 151,950 102,(00 200 900 103,450 268,500 Weekly consumption, 1851 - 24,463 2,527 105 1,440 3,738 31,973 Import last 5 months 1851 - 299,611 46,911 15,058 18,294 178,058 547,732 _ COTTON REPORT OF HERMANN COX & CO., IN LIVERPOOL AND LONDON, DATEiD AJGUST 6th, 1852. gales. | Sorts. PresentPrice. Supply. Export. Consumption. On Hand. From Jan. I to Aug. 6. From Jan 1. to Aug. 6. From Jan. 1. to Aug. 6. From Liverpool.alone, On August 6. Jan. 1. This I f~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~rom J an. I to Aug. 6' [ This __ _ -— ___ Good G Good F Good T~s Work. Week Ord. Ord Mil..Mid. air. FairThsWe. —.. 1852. 1851. -1852. 1851. 1852. 185. 1852. 1851. 1852. 1851. 1852. 250 20,210 17,260 Sea Island 15 161-218 19 20 21 11772 4 4 429 10,690 40,4 829.650 Georo _4 ~~10,690 404,940 0829.650 Georgia - - 5 5 31-8 58-8 55-8 6 6 1-4 f1,2 487,74 432,979t 106,788 57,566 948770 715,6CO 534,000 524,800 236,120 6,010 290,039 146,270 Mobile - - 5 583-1657-16 511-166 6 1-4 32,743 865,702 638,578 25,300 727,240 889,060 New Orleans - 51-8 5 1-4 5 1-2 5 3-4 6 3-6 7 j, 2,300 55,770 85,830 Pernam. &c. - 61-2 6 5-8 6 3-4 6 7-8 7 7 1-4 1,503 42,541 28.078 12,320 420 25,520 20,720 Bahia & Maccio 61-4 6 1-2! 6 5-8 6 38-4 7 7 1-8 2,151 18,775 11,435 7,266 5,211 144,400 112,140 42,890 55,350 2 30 1,820 27,580 26.130 Maranhainm - 61-4 61-2 65-8 68 3-4 6 7-8 7 - - 20,217 23,161 129130 5,98;0 87.740 47,950 Egyptische - 5 3-4 6 6 1-2 6 8-4 7 7 1-2 7,117 100,516 46,676 113,0 3,580 169,930 133.910 Surat -..... 41-8 41-4 43-8 41-2 5 - 1.770 5,690 Ma(ras - --—. 4 41-8 4 1-4 3 4 102,76 1 1,269 84,040 94,700 29,130 7,650 3 40 1,300 1,120 Bengal - - 3 1-2 3 5-8 3 3-4 3 7-8 4 4,1-2 - - 704 1,74.00 28,90. I 670 5,240,3 Diverse —4 4,869 3,386 J5,280 8,170,350 1,220 3,970 0 57,060 1,817,270 1,156,970 55,320 1,568,157 |1,288,756 142,961 84,046 1,182,490 925,610 666,230 693,280 3 730 H ___j ~~~~~~~~Weekly Average 38,145 29,859 [ OFFICIAL LIST FROM AMERICA. NEW YORK, JULY 14,1852. NEW A or.K, 3ULY 21, 1852. In Vessels to In Vessels to Exported. -------------------------------- On Hand. Exported. On Hand England. France. North Europe. Overland. Total. England. France. North Europe. Overland. Total. 1852 2,972,024 1,588,637 414,479 164,383 170,370 2,337,869 155,189 1852 2,977,884 1,607,416 417,555 164,383 174,476 2,363,830 127,834 1851 2,286,977 1,301,747 290,597 116,047 128,782 1,837,173 235,549 1851 2,296,126 1,322,340 290,683 117,193 133,032 1,863,248 204,613 685,047 286,-90 123.882 48,36 41,588 500,64 8 6 C__61, I 25,076 |126 2 4,190 41,444 500-S I 8,4 8,9 123.82 4,36 4,8 50,9 8060 ___ 1.8 8,7 2.87 4719. 1,4. 50,8. 7,79_ IMPORT OF COTTON WOOL INTO LIVERPOOL IN TIHE YEAR 1851, AND FOR TIHE EIG1T PREVIOUS YEARS, WITh THE GENERAL IMIORT INTO GREAT j BRITAIN FOR THE LAST TEN YEARS, AND TlE STOCKS OF TlHE DIFFERENT DESCRIPTIONS REMAINING ON HAND ATTIIE CLOSE OF 1850 AND 1851. ~... ~- - __- _ ~~~~~~~~~4a TNIM (S;' ~nthlyp Import. Imported into Liverpool 1843. 1844. 1845. 1846. 1847. 1848. 1849.'~~ ~~~-'rom United States.. 1,286,384 1,158,845 1,37:,9815 93q,921 829,291 1,296.9G3 1,38-2,591 ^ Q ^>2-1 (5 H 1851. 180. Brazil.... 98,586 111,509 110,843 83,950 109,820 100,142 163,530 _________________________________________________________ ______ _______________ l_______ Demerara and Berbice. January - 590,1643 115095 9 5'5 5962 West hIdies.. 15,038 14,851 8,7,54 8,819 5,808 8,887 7,870 Febray - 75,980 6, 788968 215,8 85652 1085042 Est Indies 110,80 142,817 82,539 46,432 122,049 136,1)15 106,968 Feereay 59,9819 4,940 - 83 %18,968 8,552 86,51 108,042 E 48,953 61,326 79,154 59,614 20,732 27,820 71,520 Mlerch - 13639 11,7538 - 3, 37 17,5552 6,848 229,5294 78,132 Eyt c 883 6 2 April - - 113,147 6,824 - 255 15,734 7,881 141,041 224,179 1,___..559,8-29 1,489,3-28 1,853,195 13,14.156 1,087,500 1,566,964 | 1,732,300 May - - 55,853 15,546 - 151 17,990 6,257 296,797 155,345 _ ~ T ~~~~~~~~~~~~~~~~~~~~~~- - 259853 12.4 June - - 185,127 11,582 - 534 5,178 14,821 217,242 115,199 July - - 166,997 7,3-21 - 645 10,297 7,631 19-2,891 171,666 Imparted into Great Britain. 1845. 1846. 1847. 1848.. 1849. 1850. 1851. August - 91,398 7,912 - 238 99,363 6,156 135,067 151,796 * September - 35,30,2 8,718 - 194 51,1118 5,17-2 67,59-2 114.814 -___-______________ Octeber: 31,87 13,918 - 191 39,603 5,173 90,684 84,363 i-rom United States.. 1,49,683 992,497 872,7(85 1,374.342 1,477,220 1,185,202 1,39,887 Nioven-ber - 46,733 7,139 - 732 09,972 3,895 87,471 75,617 Brazil.... 110,851 83,950 110,385 100,185' 163,530 170,155 108,644 December - 87,657 9,248 - 27 8,546 2,726 108,204 124,257 Demerara and Berbice 9,17 13,530 6,668 7,835 1,468 4,666 4,79 W est Indies 9,114 13,530 6,660 7,_____________ _____83 5 9Went4,9d66s.479 Totals 1851 - 1,337,549 108,644 - 3,90-2 23-2,939 65,467 1,748,501 1,553,554 East indies'. 158,857 91,665 222,82 217,572 182,010 309,189 356,437 - East ludies 158,057 91,665 222,PO2 227,572 182,010~~~~~~~~~~~~ 391'93826,49 Te~ ---- ---— 18591 ---- 1,15,85-18,15 —4,55 5 Increase of Tioprt, 1851, Egypt, &te... 852,063 61,688 273-2 9,0333 75720 801-254 67,175 Totals 1850 - 1,1-25,87.5 170.155 -! 4,355 192,535 80,114 increase ^ poi t, 1~5J, _____________________ ^c,^ ^,^,,310' _1,233,2^9 1.73^67 1.904,940 1,746.386 1,902,969" 175F4r7 1,8-9,:-s I.994,310 1,53279 1,75,1162 1,9104,948 1,746,.4 1,5 ----- - ~ ~~~ -75;' ] ] -2, 9 ~ - --—,13 —------ GENERAL IMPORT, CONSUMPTION AND STOCK IN GREAT BRITAIN-FROM 1841 TO 1851, INCLUSIVE. STOCK IN LIVERPOOL. Liverpool. London. n, Total Import. Total Con. Average Total Stlck. RepTnIo H &e..'eekly cen. wIe ekl1's Co(n, 1t SA p r MobileTl P,'nm sis ine -a- Dens4 W.2 InI3 Epem 1 ett 14 1,454,1,.8, 75, 260 67,863 1,397,241 1,19-2,21 20 2, 27 564,534 24 1 Mlayt Sea Orleans Bowed Mobile Pe.Bahia. lran-Dem. W I PS. erga Total. 1843 1,559,829 61247 125,191 1,746,265 1,403,477 06,988 785,952 59 Dec. Island. i Amer. haul. &c. tial. b1 1,589,38 77,778 114,0127 1,681,133 1.44,565 27,03 93,0160 33 July -- --- -- -- -- --- -- ---- --- ---- ---- -- -- 1e45 1,653,195 68,-264 138,369 1,859,828 1568,718 30,168 1,060,270 35 1851 2,330 11,560' 60,480 51,750 36,120 12,30 10,030 7,13 140 3,830 19,83 113,990 340 423,730 1846 1,13336 36,167 73,17 1,24,31 1,56,590 30,49 45,79 1 1827 1,1187,511 81,1'4 64,695 1, 2 11),5180 51,55 451,939 4 1 1850 4,296 130,928 0,140 35,870 261,34 19,435 17,909 31,269 40 778 32,267 89,577 2,370 454,879 1848 1,566,964 69,911 102,392 1,738,967 1.51,656 945 496,050 17 1849 5,410 156,2005 65,3017 51,421 278,332 29,815 26,998 38,359 89 1,435 35,318 57,829 - - 68,175 14 130 1 9 148 1,590,3 30 559,418 18 5,418 I I -~~~~ ~ ~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~- I 1858 1,573,1)34 98,321 82,971 1,746,53386 1,50l-2,063 528, 58S4 5'3-2,02'9 18 1848 6,180 126,160 50,840 52,030235,210 22,070 10,480) 35,660' 60 1,570 1445 72,470: 1,170 393,340 1851 1,748,501 65,780 88,658 1,902,839 1,662,001 31,962 495,104 1 15Y2 GENERAL IMPORT, EXPORT, QUANTITY TAKEN OUT OF THE PORTS FOR CONSUMPTION, AND STOCK, AT THE CLOSE OF 1851, 1850, AND 1849. IMPORT. EXPORT. ANNUAL CONSUMPTION. WEEKLY CONSUMPTION. STOCK. Li-ore Len- (Sian- Oter Toeal. Liverpoel. Len- Gln Ote Total. Liverp. Len. Glas- Other Total. Liverpool. Rn- Glas- Oiher Total, Liverpool. Len- Giss Other Total. peel. don. gemw. Peelts, den. goew. Pelden, gow. Portn, don, gem. Furls. den. gow. Ports. I _ America 1,337,549 1,670 43,368 13,300 1,395,887 153,817 1,450 429 1,001 156,691 1,184,i~92 100 80,145 23,9S0 1,289,157 52,789 2 1,541 40 24,782 236,1120 150 7,544 2,508 546,31 Btrazil - 108,644. - - - - - 108,644 8,944 - - - - - - 8,944 115.,346 - - - - - - 115,346 2,219 - -- -.,219 49,480 40 - - - - 49,520 Dem W.. &c 3,902 630 267 - - 4799 18 180 4,752 810 - - 5,52 91 16 - 17 3,90 10 - - - - I 4,180 East Indian 232,939 63,090 22,308 8,100 326,437 45,355 52,580 - - 2,000 99,935 147,445 5,80 10,100 11,960 175,35 2,835 112 194 l) 3,371 114,330 52,630 4,094 1,0080 172,C54 Egyptian,&c. 65,467 390 1,055 260 67.172 940 - - - - - - 640 76,511 188_... 76,611 1,471 2 - _ - - 1.473 19,830 290 2,916 - - _ 23,036 Totals 1850 1,573,034 90581 59,31 53,65)1 l74s,386 2i>0,97.9 69,688 1,905 1,600 274,182 1,..,.2-o1 1)1,278 80-,24 216,()10 t,502,013 e6,664 1327 1,716 307 58,84 454,79 49,738 f4,S, 5,598 522,059 Tot..al 1849 1,3) 51,499 81,9003)1,150 904,9 18 65,100 2,050 3,800 5,5002881,20 5,009,101 11 1,801 488 30,583 468,179 39,7044,408 7,)08559,41 Totals~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~~~~~~~',2 108'20 11573,'7 Demra,a. and Baic.3 5]20 Totals 1849 1,732,3)0 51,490 108,4 30,150 1,i9 9 188,&i= 63,100 2,850 38 I 0 1 11__ 1881 480 30,5831468,170.. 7,..59 _________________________________________________________________ East_]__di_.....}_158,05'/____ 9 1, 6 65__ __2____________________________________________________] PRICES TIIIRTY-FIRST DECEMBER. Years. Ordin. to Mid. Fair to Good Fair. Good to Fine. Years. Or i. to Mid. Fair to Good Fair. Good to Fine. 1851 Bowed 8,d. @ 4d.11-16 8d. (a) 5 d. 51d. @ 5 d. 1851 Orleans. 3d. 4d. 13-16 5d. (1i 5d. b5d. T?d. 1850 Ditto 6 - 71- 77 -8 8 - 81 1850 Ditto 61 -- 77 8 - 8- 8-9 1849 Ditto 5 - 6} 6] - 61 6] - 61 1849 Ditto 51 - 61 68 - 7 7 -8 1848 Ditto 3- 4 41 - 41 41 - 41 1848 Ditto 31 - 4 4 - 4- 51- 6 1847 Ditto 3 - 4 41 - 4' 5 - 5 1847 Ditto 83 - 4 5 -51 6-7 1846 Ditto 6 - 6z 7~ - 7] 7.- 7 1846 Ditto 5o -7 7| - 7} 8- 8 1845 Ditto 31 - 37 41 - 4 41 - 41 1845 Ditto 3 -- 4 4] - 551 - 6i 1844 Ditto 31 - 3 4- -4 4] 47 -5 1844 Diitto 3 -5 4- - 5 51-7 1843 Ditto 4] - 47 5} -5 5 5} - 5 1843 Ditto 4* - 5 5 - 5} 6 - 7 1842 Ditto 4 -4 5 - 51-5 51 - 6 1842 Ditto 4-5 5 - 51 6 - 7 I - - ^ -- ----- - ^ --- - -- = =. —- --- -------- = - -- --- --- --- -- ---- Q~ 0 _______________________________________________________________________________________ _________ ___________ ___ q COTTON CROP OF TIlE UNITED STATES. I CONSUMPTION. GROWTH. Export to Foreign Ports. Qantity consoumed by, 1851. 1QK(. To Fand in the hand 0 34,90 143,3840 521,120 London, &e. - - - titO - - - 40 60 ~~~~~ 160 53,650 B~~3M Imported froms 1at Jan. to 3slt Dec. 1,506,950 107,69. 5,760 65,340 506,780 1,904,520 01 agow - - 70 1,470 1,340 1,660-1,920 4,090 1d,550 ~~~~~Total supply for 1851 - "- - 1,660,660,176,340 7,2s^0 182,360,478,160 2,425,640 ___ ________________________1 ________ ____ _-_, __________ _____ ____ Sleek en hand, 31at Dec. 1831. - 115,810 49,520 4,310 10,910!172,050 494,600 Total in 1031 - 0,400 65,100 103,000 11,410 49,520 210 4,100 102,010 170,050 494,600 14380 1680 290 7,5 9,1,3,4 Total in 1850 - 4,630 93,340 1134,780 19,940 68,650 40 1,420 |34,920 143,580 121,120 Export to the Continent, &c. - 111,950 11,000 100 060 103,450 168,500 Total in 1849 - 6,050 76,760 171,820 62,680 95,170 90 1,900 38,000 105,870 558,340 Taken for home consumption 1851. 1,171,900 114,820 2,710 78,450 194,660 1,662,540 Total in 1848 - 7,050 58,170 145,820 61,190 68,590 60 2,570 16,920 135,680 496,050 Or average per week - - - 24,458 2,208 52 1,509 3,744 31,971 _ _ _ _ _ __ —--- ----- --- --- _________ ___ ___ ______ __ —- --- -- --- --- --- _ _ 23 Total in 1847 - 7,310 51,930 130,650 49,430 59,20 100,030 2600 125.200 451,940 20,705 3,339 105 1,572 3,33 29,094 I~~~~~~~~~~~~4,3 I I 0I, 0j Weekly average in 1881 075,3 00,72333 1.9 546 COTTON (GUN). COTTON SPINNING. Messrs. Tatham, Cheetham, and Duncan, obtained in 1846 a patent for sundry improvements in apiparatus for cotton spinr.ing. Their first invention applies to the scutcher, a machine by which the cotton is cleansed and lapped in a compact and even sheet or ]E1) upon a roller preparatory to its being fed into the carding engine, and consists in a new arrangement of rollers for compressing or calendering the sheet of cotton previous to its being lapped upon the roller; and also in a new method of weighting the calendering rollers, whereby the pressure is gradually increased as the sheet of cotton approaches the lap. The second part of the invention consists in the employment of an apparatus for collecting the fibres of cotton from the dust which is blown by the fan from the scutcher. The third part of the invention is an improvement upon machinery patented by Tatham & Cheetham in March, 1844, which caused the sliver to be twisted as it is delivered from the carding engine into the tin-can receptacle. The fourth relates to the application of gutta percha tintawan for covering rollers used in the several machines employed in cotton spinning. These substances may be used either alone, or combined with sulphurets, &c. The fifth invention relates to the "flyer" now usually employed in "presser frames." Here the legs or arms of the flyer (being jointed above the.top or elbow) are caused to act upon the bobbin like tongs, and thus dispense with the small spur or level at the bottom of the flyer, called the presser. Through the boss or upper part of the flyer the sliver or roving of cotton passes to the hollow arm. Thie top part and arms are joined together, and swivel upon a central pin or stud. At this joint a co ed spring, exactly sirnilar to the ordinary snuffers-spring, is inserted, one end of which is to be fast to the head, and the other end to the arm of the flyer; whereby the desired elasticity is imparted to the arms, to effect the pressure on the bobbin. Tile lower end of the arm must be smalb ler, to lap one or two folds of the roving around it to create the drag usually obtained by tihe folds around the common press or level.-Newton's Journal, xxxi., p. 77. In cotton spinning machines tile roving and slubbing frames move at a great velocity, and are liable to vibrations, and consequently to much wear and tear, which Mr. Edmund Hartley, of Oldhlam, has tried to remedy by patented contrivances, while the speed is increased. He has also sought to improve the backing off motion in self-actor mules. For description of his invention, see Newton's Journal, vol. xxxvi., p. 300. COTTON (GUN). MA. Sehonbein, the patentee, states that the invention consists in the manufacture of explosive compounds applicable to mining purposes and to projectiles, and as substitutes for gunpowder, by treating and combining matters of vegetable origin with nitric and sulphuric acids. The matter of vegetable origin which he prefers, as being best suited for the purposes of the invention, is cotton, as it comes into this country, freed from extraneous matters; and it is stated to be desirable to operate on the clean fibres of the cotton in a dry state. The acids are nitric acid of from 1-45 to 1'50 specific gravity, and sulphuric acid of 1'85 specific gravity. Tihe acids are mixed together in the proportions of 1 measure of nitric to 3 measures of sulphuric acid, in any suitable or convenient vessel not liable to be affected by the acids. A great degree of heat being generated by the mixture, it is left to cool until its temperature falls to 60~ or 50~ Fahr. The cotton is then immiuersed in it, and in order that it may become thoroughly impregnated or saturated with the acids, it is stirred with a rod of glass or other material not affected by the acids. The cotton should be introduced in as open a state as practicable. The acids are then poured or drawn off, and the cotton gently pressed by a presser of glazed earthenware, to press out the acids, after which it is covered up in the vessel, and allowed to stand for about an hour. It is subsequently washed in a continuous flow of water until thie presence of the acids is not indicated by the ordinary test of litmus paper. To remove any uncombined portions of the acids which may remain after the cleansing process, the patentee dips thie cotton in a weak solution of carbonate of potash, composed of 1 oz. of carbonate of potash to 1 gallon of water, and partially dries it by pressing, as before. The cotton is then highly explosive, and may be used in that state; but, to increase its explosive power, it is dipped in a weak solution of nitrate of potash, and, lastly, dried in a room heated by hot air or steam to about 150~ Fahr. It is considered probable that the use of the solutions of carbonate of potash and nitrate of potash may be dispensed with, although actual experience does not warrant such an omission. The patentee remarks, that nitric acid may be emploved alone in the manufacture of explosive compounds, but that, as far as his experience goes, the article when so manufactured is not so good, and far more costly. When used, care should be taken to employ a much less quantity by weight, to produce the same result, than of gunpowder: and it has been found that three parts by weight of the cotton produce the same effect as eight parts by weight of the Tower, Droof gunpowder. COTTON (GUN). 547 The cotton, when prepared in the manner before mentioned, may be rammed into a piece of ordnance, a fowling-piece, or musket; or may be made up -into the shape of cartridges; or may be pressed, when damp, into moulds of the form, of thle bore of tle piece of ordnance for which it is intended, so that, when dried, it shall retain the required figure; and it may also be placed in caps, like percussion caps, and made to explode by impact. Lastly, the patentee states, that although he prefers the use of cotton, other matters of vegetable origin may be similarly treated with acids to form an explosive compound, and that acids of an inferior specific gravity may be elmployed. COTTON (GUN); spontaneous combustion of, (by Dr. Gladstone).-" Gun-cotton, as commonly produced, especially for preparation of collodiunm, is a mixture of two distinct though analogous substances. The one is designated pyroxyline, and has the formula H I5 In C24 5NO j 20 It leaves no residuum on explosion; is insoluble in ether, &c. The other has received the appellation Cotton-xyloidine, and the formula p i H7 jn C24 { 3, 7O~ It leaves a residue on explosion; is soluble in ether, &c. "Pyroxyline.-This substance is produced only when cotton or cotton-xyloidine is immersed in a mixture of nitric acid, of sp. gr. 1'5, with strong oil of vitrol. Although it contains so large an amount of oxide of nitrogen, I am acquainted with no clear instance in which it has undergone spontaneous decomposition. Specimens obtained by the action of the mixed acids on cotton-xyloidinle have shown no indications of change; and pyroxyline obtained in a compact translucent form, from solution in acetic ether, has also remained unaltered. "Cotton-Xyloidine. —This may be prepared in a state of purity, and ii a pulverulent condition, by dissolving cotton or pyroxyline in nitric acid of about sp. gr. 1'45, and precipitating the substance by water. "Several specimens of tlis compound made from both sources have hitherto suffered no decompositions, but they have been generally kept in the dark. One sample of precipitated cotton-xyloidine placed in a stoppered bottle remained in a cupboard, the door of which was sometimes opened and sometimes closed. After the lapse of about tlree years it suddenly began to evolve nitric oxide and water: the action continued for a few weeks, and then nothing remained but a smnall quantity of a transparent gummy mass of a light brown color, and possessed of a very peculiar odor. Several months produced no further alteration. "This product of decolmposition, which had about the tenacity and consistency of ordinary gum, was not, explosive: when heated in a closed tube, per se, it gave off red fumes, and afterward swelled ip, being carbonized, and evolving enpyreumatic oils. It was found to be insoluble il cold svwater, but whtle boiled in that liquid, it swelled up as a gelatinous mass, and becname disintegrated. There resulted a solution which reddened litmus paper slightly, contaliling, however, no oxalic acid. but a small quantity of another acid, which gave a flocculent white-lead salt, insoluble in excess of acetic acid; tlhe substance in question, though insoluble in cold water, dissolved readily in aqueous solution of potash: yet it appeared to be altered in combining with the alkali, for it was not re-precipitated when the potash was supersaturated by an acid. " Starch-Xyloidine.-Tiis is the well-known substance produced when starch is treated with strong nitric acid, and water is added to the viscid mass. Its composition varies; but it is in general analogous to, if not identical with, that ascribed above to cotton-xyloidine. "A large specimen, freely exposed to the light during more than four years, remained unaltered. " Higher Starch Compound.-When ordinary starch-xyloidine is treated with a mixture of fuming nitric and sulphuric acids, and subsequently wasled, it is found to have greatly increased in weight. The resulting substance is more combustilde than the original xyloidine, and differs from it in several respects, but is not identical with the pyroxyline obtained from woody fibre. "A sample of this product, which had been left eight or nine months in a room where light freely entered, was found wholly decomposed; nitrous fumes and vapor of water had been evolved, leaving a dark sticky residue. This new substance was soluble in vwater and in alcohol; crystallizing from the latter in tufts, wlich under the microscope had a beautiful arborescent appearance. It reimained a couple years or more dissolved in a very small quantity of water. What changes may have taken place in it during that period is unknown, since no proper examination had been previously made, but ifter the lapse of that time, the solution was found to be almost black and strongly acid. 548 COTTON (GUN). When neutralized with an alkali it gave a copious precipitate on the addition of nitrate of silver, and a flocculent salt, or rather mixture of salts, with chloride of calcium which, when dried and heated with hydrate of potash, evolved ammonia. At the bot. tom of the vessel containing the aqueous solution there had grown a compound crystal, transparent and colorless, with the exception of a few brown specks. It had the rhomboidal form which oxalic acid usually assumes, and upon further examination and analysis proved to be that substance. "A small sample of this same starch compound, which had been washed repeatedly with glacial acetic acid for complete purification, and which had been kept constantly in the dark was found to have suffered decomposition, nothing remaining but a viscous acid liquid. When examining these decomposed explosive compounds, I found in my laboratory a bottle filled with a brown sticky mass; the label having been destroyed by evolved acid, it could not be positively identified, but I have good reason to believe it had originally been the higher starch compound: the substance had a strong odor of hydrocyanic acid. Its solution, in either water or alcohol, had a strong acid reaction. It gave no precipitate with chloride of calcium. Flocculent salts containing metallic oxides or baryta, all easily soluble in nitric acid, were readily produced. Its combinations with the alkalis gave dark brown aqueous solutions, from which they separated in an amorphous form on evaporation, but though exceedingly soluble in water, they were precipitated on the addition of alcohol. The mass was probably a mixture of different acids, principally non-azotized, for little nitrogen was discoverable; and although oxalic acid itself was absent, it is by no means improbable that some higher members of the series, Cn Hnl 04 were present. " Nitro-lMannzite.-This substance, first described by MM. Flores Domonte and Menard, is formed when mannite is dissolved in fuming nitric acid, and precipitated by sulphuric acid. Its formula, according to Strecker, is C2i Hs (NO4 ) Oia. It is the only known crystallizable body belonging to this group. "My sample of nitro-mannite kept in a glass tube, generally in the dark, has suffered some decomposition; acid fumes have been given off, but the action has not proceeded far. Sugar Compound.-It is well known that cane-sugar submitted to the action of mixed nitric and sulphuric acids is converted into a pasty explosive substance, readily soluble in alcohol, but insoluble in water, to which, however, it, communicates an intensely bitter flavor. According to the observations of H. Vohl, several different compounds are produced simultaneously in this reaction. Diabetic sugar similarly treated gives a similar substance. " I have kept samples of this product, some of which had been merely kneaded with water until the acid was removed, others regained from solution in alcohol. They have shown little signs of decomposition. " Milk-Sugar Compound.-By the same treatment a substance is obtained from milksugar closely resembling that just described. Like the previous compound, it can be purified by solution in acohol, but does not present itself in a crystalline form. "A sample kept in paper was found to be much decomposed. " Caramel Compound.-I procured a similar compound from pure caramel, prepared by means of absolute alcohol. The caramel having been dried and pounded, was placed in fuming nitric acid: it dissolved; upon the addition of sulphuric acid, a darkcolored oil separated, which became hard and yellow when washed with water. It was soluble in alcohol, but came out from solution without crystallizing, and always of the same color. The compound bore a close resemblance in its various properties to those obtained from sugar. "The sample kept by me has suffered little or no alteration. " Gum Compound.-At least two different substances of this explosive character may be produced by the action of nitric acid on gum. If the gum be treated with the fuming acid, it dissolves into a mucilaginous solution, from which water precipitates a white body, slightly soluble in that liquid, and very soluble in alcohol. A sample of this substance has not yet suffered any decomposition. "If sulphuric acid be added to the solution of gum in fuming acid, it precipitates a white substance resembling that from sugar, but not nearly so soluble in alcohol, and very slightly in ether. Moreover, it is only softened, not melted, by a temperature of 212~ Fahir. No specimen of this compound was preserved. "While treating upon this subject, it may not be amiss to append a few observations upon another decomposition of pyroxyline. When good gun-cotton is heated at a temperature a little exceeding that of boiling water, it becomes brown in color, and is disin. tegrated. The odor of nitrous fumes, along with that of some cyanogen compound, is very perceptible. It thus becomes explosive at a lower temperature than formerly, a fact which may account for some of those hitherto unexplained accidents which have nisen from this article, for it is evident that gun-cotton exposed for some time to a CRANES (TUBULAR). 549 degree of heat quite insufficient under ordinary circumstances to caruse explosion, may yet be eventually dissipated from the formation of this product. "The brown substance thus obtained underwent no visible alteration in the space of four years. When examined lately it was found to be very soluble in water, but insoluble in alcohol or ether. Its aqueous solution tasted somewhat bitter, it reacted slightly acid, no crystals were obtained on evaporation. When boiled with a solution of potash, it evolved ammonia. When mixed with a salt of lead or copper it formed brown flocculent precipitates, but none appeared with a silver or lime salt. The organic substance which fell in combination with oxide of lead, contained a large amount of nitrogen. That portion of the fibre which had not become brown with heat was found to be no longer pyroxyline; when freed from the brown matter by washing with water, and dried, it left little residue on explosion; but on the other hand, it dissolved very readily in ether, alcohol, or cold sulphuric acid; properties of cotton-xyloidine, but not of the original substance. When, however, the manner of its production is considered, we can hardly conceive it identical with a body which would require the introduction of two atoms of hydrogen if formed from pyroxyline. Whether this change which gun-cotton undergoes at a high temperature is at all analogous to the spontaneous decomposition mentioned above, can scarcely be determined, but the presence of azotized compounds in considerable quantity, and of ammonia, rather indicates the reverse. " The rationale of these decompositions is far from being elucidated by the observations here recorded, but as the substances themselves are not now in existence, nor are capable of being procured without long delay, I cannot pursue the investigation further. The only general conclusion which can be drawn appears to be, that several substances of the character above described have a tendency to suffer spontaneous decomposition from being oxidized into non-azotized acids at the expense of the peroxide of nitrogen, NO, they contain, which is reduced to the condition of nitric oxide, NO2, and evolved as such, a portion of water being always given off at the same time." COURT PLASTER is a considerable object of manufacture. It is made as follows: Black silk is strained and brushed over ten or twelve times with the following preparation:-Dissolve I an ounce of balsam of benzoin in 6 ounces of rectified spirits of wine; and in a separate vessel dissolve 1 ounce of isinglass in as little water as may be. Strain each solution, mix them, and let the mixture rest, so that any undissolved parts may subside; when the clear liquid is cold it will form a jelly, which must be warmed before it is applied to the silk. When the silk coated with it is quite dry it must be finished off with a coat of a solution of 4 ounces of Chian turpentine in 6 ounces of tincture of benzoin, to prevent its cracking.* COW DUNG SUBSTITUTE, in calico printing. Sulphate, carbonate and phosphate of lime and soda. CRANES, ITubular, of Mir. W Fairbairn.-Amlong the many happy applications of the hollow-girder system of our great engineer, this is one of the most ingenious. " Fig. 425 is a vertical section of a crane, constructed according to my said invention, and calculated for lifting or hoisting weights up to about 8 tons. Fig. 426 is an elevation of the same; figs. 427, 428, 429, and 430, are cross-sections, on the lines a b, c d, ef, g h; andfig. 431 a transverse vertical section on the line i k. A A is the jib, which in its general outline, is of a crane-neck form, but rectangular in its cross-section, as particularly shown in figs. 428, 429, and 430. The four sides are formed of metal plates, firmly riveted together. Along the edges the connection of the plates is effected by means of pieces of angle iron. The connections of the plates at the cross-joints on the convex or upper side of the jib, are made by the riveting on of a plate, which covers or overlaps the ends of the two plates to be joined; the rivets at this part are disposed as represented in fig. 43t (a plan of the top plates), and known as'chain riveting;' B B is the pillar, which is firmly secured by a base plate p, to a stone foundation B; and fits at top into a cup-shaped bearing c, which is so firmly secured to the side plates of the jib, at or near to the point where the curvature commences, and on which bearing the jib is free to revolve. Fig. 431 is a transverse vertical section of the lower part of the jib, showing the manner of fitting the bearings for the chainbarrel (which is placed in the interior), and the spindles and shafts of the wheel-geel-ing, by which the power is applied there to D, is the chain pulley, which is inserted in an aperture formed in the top of the jib. The chain passing over this pulley, enters the interior of the crane, and is continued down to the chain barrel. E is a pulley or roller, which is interposed about half-way between the chain-pulley and the chain-barrel, for the purpose of preventing the chain rubbing against the plates. Fig. 433 is a plan of the lower plates. *Paris's Pharmacologia. 550 CRANES (TUBULAR). Fig. 434 is a vertical section of another crane constructed upon the same principle as that just described, but calculated for lifting much greater weights (says 20 tons); it differs in having the lower or concave side A A, of the jib strengthened by means of three additional plates B B B, whereby the interior is divided into one large and three nmaller ceils, as shown in figs. 435 and 436, which are cross sections upon the lines a 425 433IN31 =42f 430 1 429 433 432 uowoD o'oou;i-~~o ~u-.,e ~,ao~~o..uor.Fou u~rCor o e......... cT-' l - and c d of fiq. 434-. This arrangement of the celli to strengthen the lower or concave side is advisable, in order to obtain sufficient resistance to the compression exerted by the load lifted, without unnecessarily increasing the weight of the other parts. The tension exerted upon the upper or convex plates does not require so much materials to withstand it; c, is the toe of the jib, which rests in a step formed in the bottom of the cylindrical castings D, which is built into the masonry forming the basis of the machine. E E are two of a set of pulleys, which are mounted between two rings FF, and serve an anti-friction rollers for the upper bearing of the jib. The lowermost of the rings F F, rests upon a set of rollers G G, which are fitted into the top of the casting D, so that as the jib is turned round, the rings F F, and the anti-fiiction rollers which they carry, have perfect freedom to move along with it; n is a platform, upon which the persons working the machine may stand, and which supports a column I, within which there is mounted a spindle K, the lower end of which has keyed to it a pinion L, which gears into a circular rack Zm Ar, bolted to the top of the cylindrical casing D. N is a worm-wheel keyed to the top of the spindle K, into which an endless screw, worked by CRAPE. 551 a hand-wheel, is geered, so that, by turning the hand-wheel, the jib of the crane is made to move round in any required direction. o is the chain-barrel; P the chain-wheel; R R pulleys or rollers which support the chain, and prevent its rubbing against the plates of the jib. "In the cranes and hoisting machines which I have described, the chain-barrels are incl;sed within the jib, and the spindles of the wheel-gearing are also inside; and this 434 i the disposition of those parts, which I prefer; bt it will vi is the disposition of those parts, which I prefer; blat it ill be obvious that they may be also placed outside of the jib, in a manner similar to that generally followed in the con struction of ordinary cranes. And having now described my said invention, and in what manner the same is to be performed, I declare that what I claim is the construction of cranes and other light lifting or hoisting machines, with jibs composed of a series of metal plates, arranged and combined sowas to form a connected series of tubular or cellular compartments, as before exemplified and described," CRAPE. (Crepe, Fr.; Kr'epp, Germ.) A transparent textile fabric, somewhat like gauze, made of raw silk, gummed and twisted at the mill. It is woven with any crossing or tweel. When dyed black, it is much worn by ladies as a mourning dress. Crapes are crisped (crepes) or smooth; the former being double, are used in close mourning, the latter in less deep. White crape is appropriate to young unmarried females, and to virgins on taking the veil in nunneries. The silk destined for the first is spun harder than for the second; since the degree of twist, particularly for the warp, determines the degree of crisping which it assumes after being taken from the oom. It is for this purpose steeped in clear water, and rubbed with prepared wax. __ 552 CRAYONS. Crapes are all wc ven and dyed with the silk in the raw state. They are finished with a stiffening of gium water. Crape is a l3olognese invention, but has been long manufactured with superior excellence at Lyons in France, and Norwich in England. There is now a magnificent fabric of it at Yarmouth, by power-loom machinery. There is another kind of stuff, called crepon, made either of fine wool, or of wool and silk, of which the warp is twisted much harder than the weft. The crepons of Naplea consist altogether of silk. CRAYONS. (Eng. and Fr.; Pastelstifte, Germ.) Slender, soft, and somewhat friable cylinders, variously colored for delineating figures upon paper, usually called chalk drawings. Red, green, brown, and other colored crayons, are made with fine pipe or china clay paste, intimately mixed with earthy or metallic pigments, or in general with body or surface colors, then moulded and dried. The brothers Joel, in Paris, employ as crayon cement the following composition: 6 parts of shellac, 4 parts of spirit of wine, 2 parts of turpentine, 12 parts of a coloring powder, such as Prussianblue, orpiment, white lead, vermilion, &c., and 12 parts of blue clay. The clay being elutriated, passed through a hair sieve, and dried, is to be well incorporated by tritu. ration with the solution of the shellac in the spirit of wine, the turpentine, and the pigment; and the doughy mass is to be pressed in proper moulds, so as to acquire the desired shape. They are then dried by a stove heat. In order to make cylindrical crayons, a copper cylinder is employed, about 2 inches in diameter, and 11 inches long, open at one end, and closed at the other with a perforated plate, containing holes corresponding to the sizes of the crayons. The paste is introduced into the open end, and forced through the holes of the bottom by a piston moved by a strong press. The vermicular pieces that pass through are cut to the proper lengths, and dried. As the quality of the crayons depends entirely upon the fineness of the paste, mechanical means must be resorted to for effecting this object in the best manner. The following machine has been found to answer the purpose exceed ingly well. 44A 49..437 438 A Fig. 437 is a vertical section through the centre of the crayon mill. Fig. 438 is a,iew of tlie mill from above. A, the mill tub, whose bottom B must be a hard flat plate of cast iron; the sides A being of wood or iron at pleasure. In the centre of the bottom there is a pivot c, screwed into a socket cast upon the bottom, and which may be strengthened by two cross bars D, made fast to tie fiame E. F, tile millstone of castiron, concave, whose diameter is considerably smaller than that of the vessel A; it is furnished within with a circular basin of wood G, which receives the materials to be ground, and directs them to the holes a, wlich allow them to pass down between the under part of tie muller, and the bottom of the tub, to undergo trituration. By the certrifugal motion, the paste is driven toward the sides of the vessel, rises CREOSOTE. 553 over the sides of the muller, and comes again through the holes H, so as to be repeatedly subjected to the grinding operation. This millstone is mounted upon an upright shaft I, which receives rotary motion from the bevel-wheel work K, driven by the winch L. The furnace in which some kinds of crayons, and especially the factitious black-lead pencils, are baked, is represented in fig. 439, in a front elevation; and in fig. 440, which is a vertical section through the middle of the chimney. A A, six tubes of greater or less size, according as the substance of the crayons is a better or worse conductor of heat. These tubes, into which the crayons intended for baking are to be put, traverse horizontally the laboratory B of the furnace, and are supported by two plates c, pierced with six square holes for covering the axes of the tubes A. These two plates are hung upon a conmmon axis D; one of them, with a ledge, shuts the cylindrical part of the furnace, as is shown in the figure. At the extremity of the bottom, the axis D is supported by an iron fork fixed in the brickwork; at the front it crosses the plate c, and lets through an end about 4 inches square to receive a key, by means of which the axis D may be turned round at pleasure, and thereby the two plates c, and the six tubes A, are thus exposed in succession to the action of the fire in an equal manner upon each of their sides. At the two extremities of the furnace are two chinneys E, for the purpose of diffusing the heat more equably over the body of the crayons. F, fig. 439, is the door of the fire-place, by which the fuel is introduced; G, Jig. 440, the ash-pit; ii, the fire-place; I, holes of the grate which separate the fire-place fiorn the ash-pit; K, brickwork exterior to the furnace. General Lomet proposes the following composition for red crayons. He takes the softest hematite, grinds it upon a porphyry slab, and then carefully elutriates it. He makes it into a plastic paste with gum arabic and a little white soap, which he forms by moulding, as above, through a syringe, and drying, into crayons. The proportions of the ingredients require to be carefully studied. CRAYONS, lithographic. Various formulae have been given for the formation of these crayons. One of these prescribes, white wax, 4 parts; hard tallow-soap, shellac, of each 2 parts; lamp black, 1 part. Another is, dried tallow soap and white wax, each 6 parts; lamp black, 1 part. This mixture being fused with a gentle heat, is to be cast into moulds for forming crayons of a proper size. CREOSOTE, or the flesh-preserver, from Kpoea and atu,, is the most important of the five new chemical products obtained from wood tar by Dr. Reichenbach. The other four, parcaffine, eupione, picamar, and pittacal, have hitherto been applied to no use in the arts, and may be regarded at present as mere analytical curiosities. Creosote may be prepared either from tar or from crude pyroligneous acid. The tar must be distilled till it acquires the consistence of pitch, and at the utmost till it begins toexhale the white vapors of paraffine. The liquor which passes into the receiver divides itself into 3 strata, a watery one in the middle, placed between a heavy and a light oil. The lower stratum alone is adapted to the preparation of creosote. 1. The liquor, being saturated with carbonate of potash, is to be allowed to settle, and the oily matter which floats at top is to be decanted off. When this oil is distilled, it affords, at first, products lighter than water, which are to be rejected, but the heavier oil which follows is to be separated, washed repeatedly by agitation, with fresh portions of dilute phosphoric acid, to fiee it from ammonia, then left some time at rest, after which it must be washed by water from all traces of acidity, and finally distilled along with a new portion of dilute phosphoric acid, taking care to cohobate, or pour bazk the distilled product repeatedly into the retort. 2. The oily liquid thus rectified is colorless; it contains much creosote, but at the same time some eupiosue, &c. It must therefore be mixed with potash ley at 1'12 sp. grav., which dissolves the creosote. The upione floats upon the surface of that solution, and may be decanted off. Tre alkaline solution is to be exposed to the air, till it blackens by decomposition of some foreign matter. The potash being then saturated with dilute sulphuric acid, the creosote becomes free, when it may be decanted or syphoned off and distilled. 3. The treatment by potash, sulphuric acid, &c., is to be repeated upon the brownish -reosote till it remains colorless, or nearly so, even upon exposure to air. It must be now dissolved in the strongest potash ley, subjected to distillation anew, and, lastly, reJistilled with the rejection of the first products which contain much water, retaining only the following, but taking care not to push the process too far. In operating upon pyroligneous acid, if we dissolve effloresced sulphate of soda in it to saturation, at the temperature of 167~ F., the creosote oil will separate, and float upon the surface. It is to be decanted, left in repose for some days, during which it will part with a fresh portion of the vinegar and salt. Being now saturated while hot, with carbonate of potash, and distilled with water, an oily liquor is obtained, of a pale yellow color. This is to be rectified by phosphoric acid, &c., like the crude product of creosote from tar. 5SS~4 ~ CRUCIBLES. Creosote is apparently composed of 76'2 carbon,'78 hydrogen, and 16'0 oxygen, ti 100 parts. It is an oily-looking liquid, slightly greasy to the touch, void of color, acrid burning taste, and capable of corroding the epidermis in a short time. It possesses a penetrating disagreeable smell, like that of highly smoked hams, and, when inhaled up the nostrils, causes a flow of tears. Its specific gravity is 1-037, at 58~ F. Its consist. ence is similar to that of oil of almonds. It has no action upon the colors of litmus ot turmeric, but communicates to while paper a stain which disappears spontaneously in a few hours, and rapidly by the application of heat. It boils without decomposition at 398~ F., under the average barometric pivrsure, remains fluid at 16~ F., is a non-conductor of electricity, refracts light powerfully, and burns in a lamp with a ruddy smoky flame. When mixed with water at 58~ F. it forms two different combinations, the first being a solution of 1 part of creosote in 400 of water; the second, a combination of 1 part of water with 10 parts of creosote. It unites in all proportions with alcohol, hydric ether, acetic ether, aaptha, eupione, carburet of sulphur, &c. Creosote dissolves a large quantity of iodine and phosphorus, as also of sulphur with the aid of heat, but it deposites the greater part of them in crystals, on cooling. It comr bines with potash, soda, ammonia, lime, baryta, and oxyde of copper. Oxyde of mercury converts creosote into a resinous matter, while itself is reduced to the metallic state. Strong sulphuric and nitric acids decompose it. Creosote dissolves several salts, particularly the acetates, and the chlorides of calcium and:n; it reduces the nitrate and acetate of silver. It also dissolves indigo blue; a remarkable circumstance. Its action upon animal matters is very interesting. It coagulates albumen, and prevents the putrefaction of butchers' meat and fish. For this pur. pose these substances must be steeped a quarter of an hour in a weak watery solution of creosote, then drained and hung up in the air to dry. Hence Reichenbach has inferred that it is owing to the presence of creosote that meat is cured by smoking; but he is not correct in ascribing the effect to the mere coagulation of the albumen, sincefibriae alone, without creosote, will putrefy in the course of 24 hours, during the heats of summer, it kills plants and small animals. It preserves flour paste unchanged for a long time. Creosote exists in the tar of beech-wood, to the amount of from 20 to 25 per cent., and in crude pyrolioneous acid, to that of 1. It ouglht to be kept in well-stoppered bottles, because when left open it becomes pro. gressively yellow, brown, and thick. Creosote has considerable power upon the nervous system, and has been applied to the teeth with advantage in odontalgia, as well as to the skin in recent scalds. But its me. dicinal and surgical virtues have been much exaggerated. Its flesh-preserving quality is rendered of little use, fiom the difficulty of removing the rank flavor which it Imparts. Having been employed by a chemical manufacturer to examine his creosote, and compare it with others with a view to the improvement of his process, I found that the article, as made by eminent houses, differed considerably in its properties. The specific gravities varied in the several specimens as follows: 1, a specimen given me by Messrs. Zimmer and Sell, at their factory in Sachsenhausen, by Frankfort-on-theMaine, had a specific gravity of 1'0524; 2, a sample made in the north of England, sp. gr. 1'057, and its boiling point varied from 370~ to 3S0~ Fahr. Mr. Morson's creosote, which is much esteemed, has a sp. gr. of 1'070, and boils first at 280~, but progressively rises in temperature up to 420c, when it remains stationary. The German creosote was distilled from the tar of the pyrolignous acid maniufacture. Creosote, I believe, is often made from Stockholm tar. Berzelius gives the sp. gr. of creosote at 1 (t37, and its boiling point at 203~ C.==397-4~ F. I deemed it useless to subject to ultimate analysis products differing so considerably in their physical properties. They were all very soluble in potash lye. CROSS-FLUCKANS or FLOOKANS. The name given by the Cornish miners to clay veins of more ancient formation. CRUCIBLES (Crettsets, Fr.; Schmelztiegel, Germ.) are small conical vessels, narrower at the bottom than the mouth, for reducing ores in dociniasy by the dry analysis, for fusing mixtures of earthy and other substances, for melting metals, and compounding metallic alloys. They ought to be refractory in the strongest heats, not readily acted upon by the substances ignited in them, not porous to liquids, and capable of bearing considerable alternations of temperature without cracking; on which account they should not be made too thick. The best crucibles are formed from a pure fire-clay, mixed with finely-ground cement of old crucibles, and a portion of black-lead or gra plite. Some pounded coke may be mixed with the plumbago. The clay should be prepared in a similar way as for making pottery ware; the vessels after being formed must be slowly dried, and then properly baked in the kiln. Crucibles formed of a mixture of 8 parts in bulk of Stourbridge clay and cement, 5 of coke, and 4 of graphite, CRYSTAL. 555 have been found to stand 23 meltings of 76 pounds of iron each, in the Royal Be.rlin foundry. Such crucibles resisted the greatest possible heat that could be produced, in which even wrought iron was melted, equal to 150~ or 155~ Wedgewood; and bore mudden cooling without cracking. Another composition for brass-founding crucibles is the following: i Stourbridge clay; } burned-clay cement; ~ coke powder; | pipe clay. The pasty mass must be compressed in moulds. The Hessian crucibles from Great Almerode and Epeterode are made from a fire-clay which contains a little iron, but no lime; it is incorporated with siliceous sand. The dough is compressed in a mould, dried and strongly kilned. They stand saline and leaden fluxes in docimastic operations very well; are rather porous on account of the coarseness of the sand, but are thereby less apt to crack fiom sudden heating or cooling. They melt under the fusing point of bar iron. Beaufoy in Paris lhas lately succeeded in making a tolerable imitation of the Hessian crucibles with a fire-clay found near N'amur in the Ardennes. Berthier has published the following elaborate analyses of several kinds of crucibles:IIessian. Beaufay. EnOlish fo t for GlaFs Pots Bohemian Glass Pots Silicast Seel Neurs Glass P646 637 652 6re4 680 68 t. Silica - - - 70.9 64-6 63-7 652 67-4 68-0 68-0 Alumina - - 248 34'4 20'7 25-0 32-0 29-0 28-0 Oxyde of Iron - 38 1-0 4-0 7-2 0-8 22 2-0 Magnesia - trace - - tace trace 05 trace Water- - - _ 103 1-0 Wurzer states the composition of the sand and clay in the Hessian crucibles as follows: Clay; silica 10*1; alumina 65-4; oxydes of iron and manganese 1-2; lime 0-3; water 23 Sand; 95-6 2-1 1'5 058 Black lead crucibles are made of two parts of graphite and one of fire clay; mixed with water into a paste, pressed in moulds, and well dried; but not baked hard in the kiln. They bear a higher heat than the Hessian crucibles, as well as sudden changes of temperature; have a smooth surface, and are therefore preferred by the melters of gold and silver. This compound forms excellent small or portable furnaces. Mr. Anstey describes his patent process for making crucibles, as follows: Take two parts of fine ground raw Stourbridge clay, and one part of the hardest gas coke, pre. viously pulverized, and sifted through a sieve of one eighth of an inch mesh (if the coke is ground too fine the pots are very apt to crack). Mix the ingredients together with the proper quantity of water, and tread the mass well. The pot is moulded by hand upon a wooden block, supported on a spindle which turns in a hole in the bench; there is a gauge to regulate the thickness of the melting pot, and a cap of linen or cotton placed wet upon the core before the clay is applied, to prevent the clay from sticking partially to the core, in the taking off; the cap adheres to the pot only while wet, and may be removed without trouble or hazard when dry. He employs a wooden bat to assist in moulding the pot; when moulded, it is carefully dried at a gentle heat. A pot dried as above, when wanted for use, is first warmed by the fire-side, and is then laid in the furnace with the mouth downwards (the red cokes being previously damped with cold ones in order to lessen the heat); more coke is then thrown in till the pot is covered, and it is now brought up gradually to a red heat. The pot is next turned and fixed in a proper position in the firnace, without beine allowed to cool, and is then charged with cold iron, so that the metal, when melted, shall have its surface a little below the mouth of the pot. The iron is melted in about an hour and a half, and no flux or addition of any kind is made use of. A pot will last for fourteen or even eighteen successive meltings, provided it is not allowed to cool in the intervals; but if it cool, it will probably crack. These pots, it is said, can bear a greater heat than others without softening, and will, consequently, deliver the metal in a more fluid state than the best Birmingham pots will. See a figure of the crucible mould under STEEL. CRYSTAL is the geometrical form possessed by a vast number of mineral and saline substances; as also by many vegetable and animal products. The integrant particles of matter have undoubtedly determinate forms, and combine with one another, by the attraction of cohesion, according to certain laws, and points of polarity, whereby they assume a vast variety of secondary crystalline forms. The investigation of these laws belongs to crystallography, and is foreign to the practical purpose of this volurme. In* This crucible had been analyzed before being baked in the kiln. 556 CURRYING OF LEATHER. structions are given under each object of manufacture which requires crystallization how to conduct this process. See BORAX, SALT, &C. CUDBEAR was first made an article of trade in this country, by Dr. Cuthbert Gordon, from whom it derived its name, and was originally manufactured on a great scale by Mr. G. Mackintosh, at Glasgow, nearly 80 years ago. Cudbear or persio is a powder of a violet red color, difficult, to moisten with water, and of a peculiar but not disagreeable odor. It is partially soluble in boiling water, becomes red with acids, and violet blue with alkalis. It is prepared in the same way as archil, only towards the end the substance is dried in the air, and is then ground to a fine powder, taking care to avoid decomposition, which renders it glutinous In Scotland they use the lichen tartareus, more rarely the lichen calcareus, and omphalodes; most of which lichens are imported from Sweden and Norway, under the name of rock moss. The lichen is suffered to ferment for a month, and is then stirred about to allow any stones which may be present to fall to the bottom. The red mass is next poured into a flat vessel, and left to evaporate till its urinous smell has disappeared, and till it has assumed an agreeable color verging upon violet. It is then ground to fine powder. During the fermentation of the lichen, it is watered with stale urine, o. with an equivalent ammoniacal liquor of any kind, as in making archil. CUPELLATION is a mode of analyzing gold, silver, palladium, and platinum, by adaing to small portions of alloys, containing these metals, a bit of lead, fising the mixture in a little cup of bone earth called a cupel, then by the joint action of heat and air, oxydizing the copper, tin, &c., present in the precious metals. The oxydes thus produced are dissolved and carried down into the porous cupel in a liquid state, by the vitrified oxyde of lead. See ASSAY, GOLD, and SILVER. CURRYING OF LEATHER (Corroyer, Fr.; Zurichten, Germ.) is the art of dressing skins after they are tanned, for the purpose of the shoe-maker, coach and harness maker, &c., or of giving them the necessary smoothness, lustre, color, and suppleness. The currier's shop has no resemblance to the tanner's premises, having a quite different set of tools and manipulations. The currier employs a strong hurdle about a yard square, made either of basket twigs, or of wooden spars, fixed rectangularly like trellis work, with holes 3 inches square, upon which he treads the leather, or beats it with a mallet or hammer, in order to soften it, and render it flexible. The head knife, called in French couteau (i revers, on account of the form of its edge, which is much turned over, is a tool 5 or 6 inches broad, and 15 or 16 long; with two handles, one in the direction of the blade, and the other perpendicular to it, for the a\\\\x441 P^P0^purpose of guiding the t<2Na=EMe^~ ~edge more truly upon \4 JR % ^ 447 the skin. The pommel (paumelle) is so called -^S4 r0!3442 ~\\~ -,,'~ ~ because it clothes the I ^\ ^ \ X'' P 1 palm of the hand, and J ~,OH-^j-~~ A d ^^^s performs its functions. Zb6~~~ a Ad^vw/^^^.^*^ ^^ {It is made of hard wood, and is of a rectangular /ws^ // \ ^shape, 1 foot long, 5 inches broad, flat above and rounded below. It is furrowed over the roundi/, p G< I~ ed surface with transverse y F //1 A 11 parallel straight grooves., K,: ~, _' \ 1 1 E * These grooves are in section sharp-edged isosppr and 9 \ v.-celes triangles..Figs. 441 and 442, repre. sent the pommel in an ppt t and under view. The flat surface is provided with a leather strap for securing t to the hand of the workman. Pommels are made of different sizes, and witl grooves of various degrees of fineness. Cork pommels are also used, but t:ey are r ot grooved. Pommels serve to give grain arid pliancy to the skins. The stretching iron, fig. 443, is a flat plate of iron or copper, fully a fourth of an inch thick at top, and thinning off at bottom in a blunt edge, shaped like the arc of a circle of large diameter, having the angles a and b rounded, lest in working they should penetrate the leather. The top cis mounted with leather to prevent it from hurting the hands. A copper stretching knife is used for delicate skins. The workman holds this tool nearly perpendicular, and scrapes the thick places powerfully with his two hands, esnecially those where some tan or flesh remains. He thus equalizes the thickness of CURRYING OF LEATHER. 557 the skin, and renders i; at the same time more dense and uniform in texture, This tool is of very general use in currying. The round knife, figs. 444 and 445 (lunette in French), is a circular knife from 10 to 12 inches in diameter, with a round 4 or 5 inch hole in its centre, for introducing the hands and working it. It is concave, as shown in the section fig. 445, presenting the form of a spherical zone. The concave part is that applied to he'kin Its edge is not perfectly straight; but is a little turned over on the side opposite to the skin, to preven' 444 445 it from entering too far into the lea. ther. The urrier first -lopes off with the head knife from the edges, a por& D M I tion equal to what he afterwards reHI^- / I moves with the round one. By this division the work is done sooner and 446 \ _ J / more exactly. All the rileo )r greased ^~^ ___________ _________skins are dressed with the round knife. v — _nz- -— ) -" — The cleaner is a straight two-handled knife two inches broad, of which mere are two kinds, a sharp-edged and a blunt one. Fig. 446. The mace is made of wood, having a handle 30 inches long, with a cubical head or mallet; upon the two faces of which, parallel to the line of the handle, there are 4 pegs of hard wood turned of an eg-shape, and well polished, so as not to tear the moistened leather when it is strongly beat and softened with the mace. The horse or trestle, fig. 447, consists of a strong wooden frame, A B c D, which serves as & leg or foot. Upon the middle of this frame there are two uprights, E F, and a strong cross beam, G, for supporting the thick plank H, upon which the skins are worked. This plank may be set at a greater or less slope, according as its lower end is engaged in one or other of the cross bars, I I I I, of the frame. In the figure, a skin K is represented upon the plank with the head knife upon it, in the act of being pared. A cylindrical bar fixed horizontally at its ends to two buttresses projecting from the wall, serves by means of a parallel stretched cord, to fix a skin by a coil or two in order to dress it. This is accordingly called the dresser. Tr.e tallow cloth is merely a mop made of stout rags, without the long handle; of which there are several, one for wax, another for oil, &c. Stron-toothed pincers with hook-end handles, drawn together by an endless cord, are employed to stretch the leatl er in any direction, while it is being dressed. The currier uses clamps like the letter U, to fix the edges of the leather to his table. His polisher is a round piece of hard wood, slightly convex below, with a handle standing upright in its upper surface, for seizing it firmly. He first rubs with sour beer, and finishes with barberry juice. Every kind of tanned leather not intended for soles or such coarse purposes, is generally curried before being delivered to the workmen who fashion it, such as shoemakers, coachmakers, saddlers, &c. The chief operations of the currier are four:1. Dipping the leather, which consists in moistening it with water, and beating it with the mace or a mallet upon the hurdle. He next applies the cleaners, both blunt and sharp, as well as the head knife, to remove or thin down all inequalities. After the leather is shaved, it is thrown once more into water, and well scoured by rubbing the grain side with pumice stone, or a pidce of slaty grit, whereby it parts with the bloom, a whitish matter, derived from the oak bark in the tan pit. 2. Applying the pommel to give the leather a granular appearance, and correspondent flexibility. The leather is first folded with its grain side in contact, and rubbed strongly with the pommel, then rubbed simply upon its grain side; whereby it becomes extremely flexible. 3. Scraping the leather. This makes it of uniform thickness. Tltc workman holds the tool nearly perpendicular upon the leather, and forcibly scrapeb the thick places with both his hands. 4. Dressing it by the round knife. For this purpose he stretches the leather upon the wooden cylinder, lays hold of the pendent under edge with the pincers attached to his girdle, and then with both hands applies the edge of the knife to the surface of the leather, slantingly from above downwards, and thus pares off the coarser fleshy parts of the skin. This operation requires great experience and dexterity; and when well performed improves greatly the look of the leather. The hide or skin, being rendered flexible and uniform, is conveyed to the shed or drying house. where the greasy substances are applied, which is called dubbing (daubing) or stuffing. The oil used for this purpose is prepared by boiling sheep-skins or doe-skins, in cod oil. This application of grease is often made before the graining board or pommel is employed. Before waxing, the leather is commonly colored by rubbing it with a brush dipped into a composition of oil and lamn black on the flesh side, till it be thoroughly black; it is 558 CUTLERY then black-sized with a brush or sponge, dried, tallowed with the proper cloth, and slicked upon the flesh with a broad, smooth lump of glass; sized again with a sponge; and when dry, again curried as above described. Ciirrying, leather on the hair or grain side, termed black on the grain, is the same in the first operation with that dressed on the flesh, till it is scoured. Then the first black is applied to it while wet, by a solution of copperas put upon the grain, after this has been rubbed with a stone; a brush dipped in stale urine is next rubbed on, then an iron slicker is ased to make the grain come out as fine as possible. It is now stuffed with oil. When dry, it is seasoned; that is. rubbed over with a brush dipped in copperas water, on the grain, till it be perfectly black. It is next slicked with a good grit-stone, to take out the wrinkles, and smooth the coarse grain. The grain is finally raised with the pommel or graining board, by applying it to the leather in different directions. When thorouwhly dry, it is grained again in two or three ways. Hides intended for covering coaches are shaved nearly as thin as shoe hides, anc blacked upon the grain. CUTLERY. (Coutellerie, Fr.; Messerschmidwaare, Germ.) Three kinds of stee. are made use of in the manufacture of different articles of cutlery, viz., common steel, shear steel, and cast steel. Shear steel is exceedingly plastic and tough. All the edge tools which require great tenacity without great hardness are made of it, such as table knives, scythes, plane-irons, &c. Cast steel is formed by melting blistered steel in coveix crucibles, with bottle glass, and pouring it into cast-iron moulds, so as to form it into ingots; these ingots are then taken to the tilt, and drawn into rods of suitable dimensions. No other than cast steel,an assume a very fine polish, and hence all the finer articles of cutlery are made of it, sueh as the best scissors, penknives, razors, &c. 2'ormerly cast steel could be worked only at a very low heat; it can now be made so as to be welded to iron with the greatest ease. Its use is consequently extended to making very superior kinds of chisels. plane-irons, &c. Forging of table knives. -Two men are aenerally employed in tle forging of table knives; one called the foreman or maker, and the other the striker. The steel called common steel is employed in making the very common articles; but for the greatest part of table knives which require a surface free from flaws, shear steel is generally preferred. That part of the knife termed the blade, is first rudely formed and cut off. It is next welded to a rod of iron about 2 inch square, in such a manner as to leave as little of the iron part of the blade exposed as possible. A sufficient quantity of the iron now attached to the blade, is taken off from the rod to form the bolster or shoulder, and the tang. In order to make the bolster of a given size, and to give it at the same time shape and neatness, it is introduced into a die, and a swage placed upon it; the swage has a few smart blows given it. by the striker. This die and swage are, by the workman, called prints. After the tangs and bolster are finished, the blade is heated a second time, and the foreman gives it its proper anvil finish; this operation is termed smithiig. The blade is now heated red-hot, and plunged perpendicularly into cold water. By this means it becomes hardened. It requires to be tempered regularly down to a blue color: in which state it is ready for the grinder. Mr. Brownill's method of securing the handles upon table-knives and forks, is, by lengthening the tangs, so as to pass them completely through the handle, the ends of which are to be tinned after the ordinary mode of tinninr iron; and, when passed through the handle, the end of the tang is to be spread by beating, or a small hole drilled through it, and a pin passed to hold it upon the handle. After this, caps of metal, either copper plated or silver, are to be soldered on to the projecting end of the tang, and while the solder is in a fluid state, the cap is to be pressed upon the end of the handle and held there until the solder is fixed, when the whole is to be cooled by being immersed in cold water. Mr. Th )mason's patent improvements consist in the adaptation of steel edges to the bladets of gold and silver knives. These steel edges are to be attached to the other netal, of whatever quality it may be, of which the knife, &c. is made, by means of solder, in the ordinary mode of effecting that process. After the edge of steel is thus attached to the gold, silver, &c.. it is to be ground, polished, and tempered by immersion in cold water or oil after being heated. This process being finished, the other parts of the knife are then wrought and ornamented by the engraver or chaser, as usual. A patent was obtained in 1827, by Mr. Smith of Sheffield, for rolling out knives at one operation. In the ordinary mode of making knives, a sheet of steel being provided, the blades are:ut out of the sheet, and the backs, shoulders, and tangs, of wrought iron, are attached to CUTLERY. 559 the steel blades, by welding at the forge. The knife is then ground to the proper shape, and the blade polished and hardened. Instead of this welding process, the patentee proposes to make the knives entirely of steel, and to form them by rolling in a heated state between massive rollers; the shoulders or bolsters, and the tangs for the handles being produced by suitable recesses in the peripheries of the rollers; just as railway rails are formed. When the knife is to be made with what is called a scale tang, that is, a broad flat tang, to which the handle is to be attached in two pieces, riveted on the sides of the tang, the rollers are then only to have recesses cut in them, in a direction parallel to the axis for formine the bolster. The plate of steel, having been heated, is to be pressed between the two rollers, by which the blades and the parts for the scale tangs will be pressed out flat and thin, and those parts which pass between the grooves or recess will be left thick or protuberant, forming the bolster for the shoulder of the blade. But if the tangs are to be round in order to be fixed into single handles, then it will be necessary also to form transverse grooves in the rollers, that is, at right angles to those which give shape to the bolsters, the transverse grooves corresponding in length to the length of the intended tang. When the plates of steel have been thus rolled, forming three or more knives in a breadth, the several knives are to be cut out by the ordinary mode of what is called slitting, and the blades and shoulders ground, hardened, and polished in the usual way. Forks are generally a distinct branch of manufacture from that of knives, and are purchased of the fork makers by tL. manufacturers of table knives, in a state fit for receiving the handles. The rods of steel from which the forks are nade, are about Aths of an inch square. The tang and shank of the fork are first roughly formed. The fork is then cut off, leaving at one end about 1 inch of the square part of the steel. This part is afterwards drawn out flat to about the length of the prongs. The shank and tang are now heated, and a proper form given to them by means of a die and swage. The prongs are afterwards formed at one blow by means of the stamp; this machine is very similar to that used in driving piles, but it is worked by one man. It consists of a large anvil fixed in a block of stone nearly on a level with the ground. To this anvil are attached two rods of iron of considerable thickness, fixed twelve inches asunder, perpendicularly to the anvil, and diagonally to each other. These are fastened to the ceiling. The hammer or stamp, about 100 lbs. in weight, having a groove upon either side corresponding to the angles of the upright rbds, is made to slide freely through its limited range, being conducted by its two iron supporters. A rope is attached to the hammer, which goes over a pulley on the floor of the room above, and comes down to the person who works the stamp: two corresponding dies are attached, one to the hammer, and the other to the anvil. That part of thi fork intended to form the prongs, is heated to a pretty white heat and placed in the lower die, and the hammer containing the other die is made to fall upon it from a height of about 7 or 8 feet. This forms the prongs and the middle part of the fork, leaving a very thin substance of steel between each prong, which is afterwards cut out with an appropriate instrument called a fly-press. The forks are now annealed by surrounding a large mass of them with hot coals, so that the whole shall become red-hot. The fire is suffered gradually to die out, and the forks to cool without beina disturbed. This process is intended to soften, and by that means to prepare them for filing.. The inside of the prongs is then filed, after which they are bent into their proper form and hardened. When hardened, which is effected by heating them red-hot and plunoing them into cold water, they are tempered by exposing them to the degree of heat at which grease inflames. See STAMPS. Penknives are generally forged by a single hand, with the hammer and the anvil sim ply. The hammer in this trade is generally light, not exceeding 3- lbs. The breadth of the face, or the striking part, is about one inch; if broader, it would not be convenient for striking so small an object. The principal anvil is about 5 inches, and 10 upon the face, and is provided with a groove into which a smaller anvil is wedged. The smaller anvil is about 2 inches square upon the face. The blade of the knife is first drawn out at the end of the rod of steel, and as much more is cut off along with it as is th( uight necessary to form the joint. The blade is then taken in a pair of tongs, and heated a second time to finish the joint part, and at the same time to form a temporary tang for the purpose of driving into a small haft used by the grinder. Another heat is taken to give the blade a proper finish. The small recess called the nail-hole, used in opening the knife, is made while it is still hot by means of a chisel, whicn is round on one side, and flat upon the other. Penknives are hardened by heating the blade red-hot, and dipping them into water up to the shoulder. They are tempered by setting them side by side, with the back downwa:-ds upon a flat iron plate laid upon the fire, where they are allowed to remain till they are of a brown or purple color. b60 CUTLER The blades of pocket knives, and all that come under the denomination of spring knives, are made in the same way. The forging of razors is performed by a foreman and striker, as in making table knives. They are generally made of east steel. The rods, as they come from the tilt, are about ~ inch broad, and of a thickness sufficient for the back of a razor. There is nothing peculiar in the tools made use of in forging razors: the anvil is a ilttle rounded at the sides, which affords the opportunity of making the edge thinner, and saves an immense labor to the grinder. Razors are hardened and tempered in a similar manner to penknives. They are, however, left harder, being only let down to yellow or brown color. The forging of scissors is wholly performed by the hammer, and all the sizes are made by a single hand. The anvil of the scissor-maker weighs about 11 cwt.; it measures, on the face, about 4 by 11 inches. It is provided with two grates or grooves for the reception of various little indented tools termed by the workman bosses; one of these bosses is employed to give proper figure to the shank of tho scissors; another for forming that part which has to make the joint; and a third is made use of for giving a proper figure to the upper side of the blade. There is also another anvil placed on the sane block, containing two or three tools called beak-irons, each consisting of an upright stem about 6 inches high, at the top of which a horizontal beak projects; one of these beaks is conical, and is used for extending the bow of the scissors; the other is a segment of a cylinder with the round side upwards, containing a recess for giving a proper shape and smoothness to the inside of the bow. The shank of the scissors is first formed by means of one of the bosses, above described, leaving as much steel at the end as will form the blade. A hole is then punched about 1 inch in width, a little above the shank. The blade is draw'i out and finished, and the scissors separated from the rod a little above the hole. It is heatod a third time, and the small hole above mentioned is extended upon the beak-irons so as to form the bow. This finishes the forging of scissors. They are promiscuously made in this way, without any other guide than the eye, having no regard to their being in pairs. They are next annealed for the purpose of filing such parts of them as cannot be ground, and afterwards paired. The very large scissors are made partly of iron, the blades being of steel. After the forging, the bow and joints, and such shanks as cannot be ground, are filed. The rivet hole is then bored, through which they are to be screwed or riveted together. This common kind of scissors is only hardened up to the joint. They are tempered down to a purple or blue color. In this state they are taken to the grinder. Grinding and polishing of cutlery.-The various processes which come under this denomination are performed by machinery, moving in general by the power of the steamengine or water-wheel. Grinding wheels or grinding mills are divided into a number of separate rooms; every room contains six places called troughs; each trough consists of a convenience for running a grindstone and a polisher at the same time, which is generally occupied by a man and a boy. The business of the grinder is generally divided into three stages, viz., grinding, glazing, and polishing. The grinding is performed upon stones of various qualities and sizes, depending on the articles to be ground. Those exposing much flat surface, such as saws, fenders, &c., require stones of great diameter, while razors, whose surface is concave, require to be ground upon stones of very small dimensions. Those articles which require a certain temper, which is the case with most cutting instruments, are mostly ground on a wet stone; for which purpose the stone hangs within the iron trough, filled with water to such a height that its surface may just touch the face of the stone. Glazing is a process following that of grinding: it consists in giving that degree of lustre and smoothness to an article which can be effected by means of emery of the various degrees of fineness. The tool on which the glazing is performed, is termed a glazer. It consists of a circular piece of wood, formed of a number of pieces in such a manner that its edge or face may always present the endway of the wood. Were it made otherwise, the contraction of the parts would destroy its circular figure. It is fixed upon an iron axis similar to that of the stone. Some glazers are covered on the face with leather, others with metal, consisting of an alloy of lead and tin; the latter are termed caps. In others, the wooden surface above is made use of. Some of the leather-faced glazers, such as are used for forks, table knives, edge tools, and all the coarser polished articles, are first coated with a solution of glue, and then covered with emery. The surfaces of the others are prepared for use by first turning the face very CIDER. 561 true, then filling it with small notches by means of a sharp-ended hammer, and lastly filling up the interstices witll a collpound of tallow and eimery. Tlhe pulley of the glazer is so much less tlarn tlhat of the stone, that its velocity is more than double, having in general a surface-speed of ],500 feet in a second. Tine process of polishling onsists in giving the most perfect polish to the different articles. Nothing is subljected to this operalion but what is made of cast steel, and lias been previously hard{ned and tempered. Thle polisher consists of a circular piece of wood covered with buff leather, tlhe surface of which is covered fiom time to time, wlile in use, wvith the crocus of iron, called also colcothar of vitriol. The polisher requires to run at a speed much short of that of the stone, or the glazer. Whlatever may be its diameter, the surface must not move at a rate exceeding'0 or 80 feet in a second. CYANATES; saline compounds of cyanic acid with the bases potash, soda, ammonin, baryta, &e. The first is prepared by calcining at a dull red heat, a mixture of ferro-cyanide of potassium (prussiate of potash) and black oxide of manganese. The cyanates have not hlitherto been applied to any use in thle arts. CYANHYDRIC ACID; another name for the hydrocyanic or prussic acid. See PRUSSIAN BLUE and PRussIC ACID. CYANIDES; compounds of cyanogen with the metals; as qyanide of potassiaum, sodium, barium, calcium, iron, mercury. Tlie last is the only one of importance in a manufacturing point of view, since from it prussic acid is often made. CYANIDES, FERRO. Double compounds of cyanogen Nwitl iron, and of cyanogen with another metal, such as potassium, sodium, barium, &c. Tlhe ordinary yellow prussiate of potash has this constitution, and is called the ferro-cyanide. CYANIDE OF POTASSIUM. This salt, so muech used 1now in the electrotype processes, is prepared, according to Liebig's formula, by mixing 8 parts of pounded prussiate of potash, sharply dried, witl 3 parts of pure carbonate of potlish, fusing the mixture in an iron crucible, by a moderate red heat, and keeping it so, till tle glass or iron rod with which the fluid mass should be occasionally stirred, comes out covered with a white crust. The crucible is tlen to be renloved fiom tle fire; and after the disengaged iron has fallen to tle bottom, the supernatant fluid, still obscurely red hot, is to be poured off upon a clean surface of iron or platinum. After concretion and cooling, the white saline mass is to be pounded while hot,. and then kept ill a well-stopped bottle. It consists of about only 60 per cent. of cyanide of potassiun, and 1 of cyanate of potash. For most purposes, and the analysis of ores, the latter ingredient is no ways detrimental. It contains much of other potash salts. CYANOGEN. A gaseous compound of'two prime equivalents of charcoal = 12, and ane of azote = 14 = 26; hydrogen being the radix, or 1. It consists of two volumes of vapor of carbon, and one volume of azote, condensed into one volume; and has therefore a density equal to the sum of the weights of these three gaseous volumes = 1-815. Cyanogen is readily procured by exposing the cyanide of mercury to a dull red heat in a retort; the gas is evolved and may be collected over mercury. Its smell is very sharp and penetrating; it perceptibly reddens tincture of litmus; it is condensable bl pressure at a low temperature into a liquid; and by a still Trf ater degree of cold, it is solidified. When a lighted taper is applied to a mixture of cyanoen and oxygen, an explosion takes place; carbonic acid is formed, and the azote is set at liberty. For a connected view of the various compounds of cyanogen employed in the arts, see PRUSSIAN BLUE. CIDER (Cidre, Fr.; Rpfelwein, Germ.); the vinous fermented juice of the apple. The ancients were acquainted with cider and perry, as wP iearn from the following passage of Pliny the naturalist: "Wine is made from the Syrian pod, from pears and apples of every kind." Book xiv. chap. 19. The termr cider or cidre in French, at first written sidre, is derived from the Latin word sicera, which denoted all other fermented liquors except grape wine. Cider seems to have been brought into Normandy by the Moors of Piscay, who had preserved the use of it after coming into that country from Africa. It was afterwards spread through some other provinces of France, whence it was introduced into England, Germany, and Russia. It is supposed that the first growths of' Nornmandy afford still the best specimens of cider. Devonshire and Herefordslire are the counties of England most famous for this beverage. Strong and somewhat elevated ground, rather dry, and not exposed to the air of the sea, or to high winds, are the best situations for the growth of the cider apple. The firit should be gathered in dry weather. The juice of apples is composed of a great deal of water; a little sugar analogous to that of the grape; a matter capable of causing fermentation with contact of air; a pretty large proportion of mucilage, with malic acid, acetic acid, and an azotized matter iri a very small quantity. The seeds contain a bitter substance and a little essential oil; the pure parenchyma or cellular membrane constitutes 37 562 CIDER. not more than two per cent. of the whole. After the apples are gathered, they are left in the barn-loft for fifteen days or upwards to mellow; some of them in this ease, how. ever, become soft and brown. This degree of maturation diminishes their mucilage, and develops alcohol and carbonic acid; in consequence of which the cider suffers no injury. There is always, however, a little loss; and if this ripening goes a little further it is very apt to do lharm, notwithstanding the vulgar prejudice of the country people to the contrary. Too much care, indeed, cannot bp taken to separate the sound from the spoiled apples; for the latter merely furnish ian acid leaven, give a disagreealle taste to the juice, and hinder tlhe cider from filinnr, by leaving in it a certain portion of the parenchyma, which the gelatinous matter or the fermllentation has diffused through it. Unripe apples sholld be separated from the ripe also, for they possess too little saccharlum to be properly susceptille of the vinous feirmentation. In France, where cider-making is most scientifically practised, it is prepared by crushipg tie apples in a mill with revolvinr edle-stones, turned in a circular stone cistern by one or two horses. When the fruit is half nrashled, about one fifth of its weight of river water is added, or the water of lakes. Tie latter has been found by experience to be preferable to other water. In some places a mill composed of two cast-iron fluted cylinders, placed parallel to each other under the bottom of a hopper, is eimployed for crushing the apples. One of the cylinders is turned by a winch, and communicates its motion in the opposite direcrion by means of the flutings working into each other. Each portion of the fruit must be passed thrice through this rude mill in order to be sufficiently mashed; and the same quantity of water must be added as in the edge stone mill. After the apples are crushed they are usually put into a large tub or tun for 12 or 24 hours. This steeping aids the separation of the juice, because the fermentative motion which tak 3s place in the mass breaks down the cellular membranes; but there is always a loss of alcohol' carried off by the carbonic acid disengaged, while the skins and seeds develop a disagreeable taste in the liquid. The vatting millgt be suppressed if the apples were so comminuted as to give out their juice more readily. With slight modifications, the process employed in rasping and squeezing the beet-roots might in my opinion be applied with great advantage to the cider manufacture. See SUGAR. After the vattina, the mashed fruit is carried to the press and put upon a square wicker fiame or into a hair baw, sometimes between layers of straw, and exposed stratum super stratumn to strong pressure till what is called a cheese or cake is formed. The mass is to be allowed to drain for some time before applying pressure, which ought to be very gradually increased. The juice which exudes vith the least r-ossure affords the best cider; that which flows towards the end acquires a disagreeable taste from the seeds and the skins. The must is put into casks with large bungholes, where it soon begins to exhibit a tumultuous fermentation. The cask must be comrpletely filled, in order that all the light bodies suspended in the liquid when floated to the top by the carbonic acid may flow over with the froth; this means of clearing cider is particularly necessary with the. weak kinds, because it cannot be expected that these matters in suspension will fall to the bottom of the casks after the motion has ceased. In almost every circumstance besides, when no saccharine matter has been added to the must, that kind of yeast which rises to the top must be separated, lest by precipitation it may excite an acid fermentation in the cider. The casks are raised upon awawntrces or stillions, in order to place flat tubs below them to receive the liquor which flows over with the froth. At the end of two or three days, for weak cilers which are to be drunk somewhat sweet, of 6 or 10 days or more fr stronger ciders, with variations for the state of the weather, the fermentation will be sufficiently advanced, and the cider may be racked off into other casks., Spirit puncheons preserve cider better than any other, but in all cases the casks should be well seasoned and washed. Sometimes a sulphur match is burned in them before introducing the cider, a precaution to be generally recommended, as it suspends the activity of the fermentation, and prevents the formation of vinegar. The cider procured by the first expression is called cider without water. The,ake remaining in the press is taken out, divided into small pieces, and mashed anew, adding about half' the weight of water, when the whole is carried back to the press and treated as above described. The liquor thus obtained furnishes a weaker cider which will not keep, and therefore must be drunk soon. The cake is once more mashed up with water, and squeezed, when it yields a liquor which may be used instead of water for moistening fresh ground apples. The processes above described, although they have been long practised, and havf,Terefore the stamp of ancestral wisdom, are extremely defective. Were the apples ground with a proper rotatory rasp which would tear all their cells asunder, and the mash put through the hydraulic press in bags between hurdles of wicker-work, the juice would be totained in a state of perfection fit to make a cider superior to many wines DAGUERREOTYPE. 563 An experimental process of this kind has been actually executed in France upon a con. siderable scale, with tlhe best results.. The juice had the file flavor of the apple, was fermented by itself without any previous fermentation in- the mash, and afforded an excellent strong cider, which kept well. When the.must of the apples is weak or sour, good cider cannot be made from it without the addition of some saccharine matter. The syrup into which potato farina is convertible by diastase (saccharine ferment), see STARCH and SUGAR, would answer well fur enriching poor apple-juice. The value of apples to produce this beverage of good quality is proportionate to the specific gravity of their juice. M. Couverchel has given the following table, illustrative of that proposition.Juice of the green renette, queen apple (reinette vert) - -1094 English renette - - -- 1080 Red renette - - 1072 Mulsk renette - - - - - 1069 Fobtillet ra - - - - - 1064 Orange apple - - - - - 1063 Reiectte of Caux - - - - 1060 Watert -. - 1'000 Cider apples may be distributed into three classes-the sweet, the bitter, and the sour. The second are the best; they afford a dellser jriice, richer in sugar, Whlichl clarifies well, and when fermllented keeps a long tile; the juice of sweet alpples is difficult to clarify; but thait of the sour ones makes bal cider. Late apnlles lare in general to be preferred. With regard to the proper soil for raising apple-trees, the reader may consult with advantage ani able essay upon "The Cultivation of Orcllards and the laking of Cider and Perry," by Frederick Falknler, Esq., in the fourth volume of the Royal Agricultural Jourial. HIe adverts judiciously to the inecessity of the presence of alkaline and. earthy bases in the soils of all deciduous trees, and especially of suich as produce acid fruits. I1 November, 2340) ilogramnmes of apples (2- tons English, nearly) are supposed to afford 1000 litres (220 galloins) of pure cidel; atid 600 litres of a smua ll cider maide with the marc mixed wit I water and pressed. Buit lmay persons mnix all together, and thus manufacture 1600 litres out of the above weiglrt of frtlit. Inl France, the fermiented liquor, as soon as it is clear, is often racked off ilito casks colitaiinig tile fumies of burning sulphur, whereby it ceases to ferlmelit, alld lreserves mluch of its sugar undecomposed. It is soon afterwards bottled. Average cider should yield 6 per cent. of alcohol on distillation. D. DAGUERREOTYPE. This new and most ingenious invention, for producing pictures by the action of light, is due to MA. Daguerre and A5. Niepee, two Frenclhmen. It was purchased from them by thle French goverilnent for the benefit of the nation at large; but was made the sublject of an exclusive patent in this country by M. Daguerre, as our government never pulichases anly scientific invention. The fixation of the images, formed in the focus of the camera obscura, is made on very smooth surfaces of pure silver plated on copper. The process is divided into five oijerations. 1. The first consists in polishing and cleaning the silver surface, by fric. tion with cotton fleece imbued with olive oil, upon the plate, previously dusted ovex with very finely-ground dry pumice-stone out of a muslin bag. The hand of the operator should be moved round in circles, of various dimensions. The plates should be laid upon a sheet of paper solidly supported. The pumice must be ground to an impalpable powder upon a porphyry slab with water, and then dried. The s-urface is next to be rubbed with a dossil of cotton, slightly moistened with nitric acid, diluted with sixteen parts of water, by applying the tuft to the mouth of the phial ot acid, and inverting it for a moment. Two or three such dossils should be used in succession. The plate is lastly to be sprinkled with pumice powder or Venetian tripoli, and rubsd clean with cotton. The next step is to heat the plate by placing it in a wire frame (fig. 449), with the silver surface uppermost, over a spirit lamp, meanwhile moving it so as to act equally on every part of the plate. In about five minutes a whitish coating will indicate that this operation is completed. The plate must now be laid upon a flat metal or marble slab to cool it quickly. The white surface is to be brightened by rubbing it with cottonand punice powder. It must be once more rubbed with the cotton imbued with acid, and afterward dried by friction with cotton and pumice; avoiding to touch 564 DAGUERREOTYPE. the plate with th3 fingers, or with the part of the cotton held in them, or to breathq upon the plate, since spots would thereby be produced. After cleaning with cotton alone, the plate is ready for the next operation. 2. Here the following implements are required: 1, the b6x represented in figs. 450 and 451; 2, the thin board or frame, fig. 452; fcur small metallic bands of the same a 453 a "7 -ld ~ 449 458 451 a, 1a 4 dc 455 d t=b c. A6 d', d a d a " " r=3!/*~, -- \d d d di A~: — mletals as the plates, also shown in fig, 452, a small handle and a box of small nails or tacks, and a phial of iodine. After fixing, by the metallic bands and the small nails, the plate upon the thin board, with the silver uppermost, several particles of iodine are then to be spread in the dish d, at the bottom of the box, figs. 450, and 451. The thin board with the plate, is next placed, with the silver beneath, upon small supports at the four corners of the bhx, and its cover is applied. The plate must be left in this position till the surface of the silver acquires a fine golden hue, caused by the vapors of the iodine rising through the gauze cover of the dish, and condensing upon it; but it should not be allowed to assume a violet tint. The room should be darkened, and no heat should be employed. When the box is in constant use it gets impregnated with iodine, and acts more uniformly and rapidly; but in general states of the atmospheric temperature this operation will be effected in about twenty minutes. If the purple color be produced, the plate must be repolished, and the whole process repeated. The plate with its golden hue is to be introduced with its board into the frame, figs. 453, 454,455, which is adapted to the camera obscura. During this transfer the light must not be suffered to strike upon the surface of the plate; on which account, the camera obscura may be lighted briefly with a small wax taper. 3. The plate is now submitted to the third operation, that of the camera obscura, figs. 456 and 448, and with the least possible delay. The action of this machine is obviously quicker the brighter the light which acts upon it; and more correct, according as the focus is previously accurately adjusted to the place of the plate, by moving backwards and forwards a roughened pane of glass, till the focal point be found; and the plate is to be inserted precisely there, see figs. 453, 454, 455. This apparatus exactly replaces the ground glass. While the prepared plate is being fastened, the camera must be closed. The darkening shutters, b b, of the apparatus are opened by means of the two semicircles, a a. The plate is now in a proper position to receive and retain the impression of the image of the objects presented the moment that the camera is opened. Experience alone can teach the proper length of time for submitting the plate to the concentrated rays of light; because that time varies with the climate, the seasons, and the time of day. More time should not be allowed to pass than what is necessary for fixing a distinct impression, because the parts meant to be clear would be apt to become clouded. 4. The fourth is the operation with quicksilver, which must follow as soon as possible the completion of the third. Here a phial of quicksilver, a spirit-lamp (the apparatus represented in figs. 457 and 458), and a glass funnel with a long neck, are required. The funnel is used for pouring the mercury into the cup c, placed in the DAGUERREOTYPE. 56~ bottom of the apparatus, so as to cover the bulb of the thermometer f. No daylight must now be admitted, but that of a small taper only should be used by the operator in conducting the process. The board with the plate is to be withdrawn from the 460 4 5//9 1 A 0 456 458 L 457 L.~-~_ is___I___ camera, and inserted into the grooves of tihe blackened board, b, fig. 45 Th6is blac3 camera, and inserted into the grooves of the blackened board, b, Jig. 457. This black board is laid back into the box at an angle of 450 with the horizon; the prepared metal surface h being placed undermost, so that it may be viewed through the side glass g; and the cover, a, of the box must be put down gently, to prevent any par' tides of mercury from being thrown about by the agitation of the air. Tile whole being thus prepared, the spirit-lamp is lighted, and placed under the cup containing the mercury, and left there until the thermometer indicates a temperature of 140~ Fahr., when the lamp is to be removed. The heat should in no case be permitted to exceed 167~ F. The impression of the image of nature is now actually made upon the plate; but it is yet invisible; and it is only after a lapse of several minutes that faint tracings of the objects begin to be seen through the peep-glass by the momentary gleam of a taper. The plate should be left in the box till the thermometer has cooled to 113~ F., when it is to be taken out. After each operation, the interior of the apparatus, and the black board or frame, should be carefully wiped, in order to remove every particle of mercury. The picture may now be inspected in a feeble light, to see how far the process has succeeded. The plate, freed from the metallic bands, is to be placed in a box, provided with a cover and grooves, to exclude the light, till it is made to undergo the fifth and last operation, which may be done after any convenient interval of time without detriment, provided the plate be kept in the dark. The following articles are now required: 1, strong brine, or a weak solution of hyposulphate of soda; 2, the apparatus represented in figs. 459 and 460; 3, two troughs of tin-plate; 4, a jug 6f distilled water. The object of this process is to fix the photogenic picture. One of the bG6f DAGUERREOTYPE. troughs is to be filled with brine to the depth of an inch, and the other with pur'e water, both liquids being heated somewhat under the boiling pitch. The solution of hyposullhite of soda is preferable, and does not need to b)e warm. The plate is to be first immersed in the pure water for a mnoment, and transferred immediately to the saline solution, and moved to and fro in it to equalize the action of the liquor. Whenever the yellow tint of the iodine is remloved, the plate is to be lifted out by the edges, and dipped straightway in the water-trough. The apparatus offigs. 459, and 460, is then brought into use, with a vessel filled with distilled water, hot, but not boiling. The plate, when lifted out of tlhe water-trough, is to be placed immediately on tho inclined llane e; and without allowing it time to dry, is to lie floated over with the hot distilled water from tile top, so as to carry off all the saline nmatter. As the quicksilver wlhich traces tlie images will not bear touching, the silvered plate should be secured by a cover of glass, made tight at the edges by pasting paper round them. Infig. 451, which is a plan view of the icdinle-box apparatus, c is an interior cover; d is tle iodine-dish; e is the thin board to wlhich the silvered plate is fixed, as shown at fiq. 450; g is tile cover of tle box; h i are small rods, at tile four corners of the inclined lining, k, of tile box, to supplort the lid c; j is a gauze of wire-cloth cover, to diffuse tile iodine vapor; k is the wooden lining, sloping'ke a hopper; d d, in fig. 454, are buttons to fasten tlie board on tlhe doors; e slhows t.ie thickness of the frame; fis tlhe silvered plate. In fig. 461, a is tile ground gluss of tlie canlera; b is a mirror inclined about 45~ to tile horizon, by means of the rod 1. Tile image of the object is easily brought inito focus by movirig forward or backward tie sliding-box d, in laying hold of it witli both hands by tlie projections a, fig. 454. When tie focus is adjusted, tlie tihumbscrew, it, fixes the whole. Tile mirriror is kept closed by two hooks at f, wlIicl take into snrall eyes at g. Tire frame and grounld glass plate are withdrawn and replaced bty the frame carrying the prepared plate, as represented in fig. 448, with tihe shading doors, b, open in tlie camerra. Tllese doors and tile sliding-box d are lined with black velvet. Tile object glass is achro(,iatic and periscopic, tile concave being outside in tile camera; its diameter is about 3' inilies, and focus about 13 inches. A diaphragm is placed before the olject glass, at 38 inclles fronl it, and its aperture may be closed by a plate moving in a livot. This carmera reverses ltie objects from left to right; but this lmay be obviated by placinlg a plane mirror on the outside beyond tlie aperture of tlhe dilaphragml, as at f, fig. 456, where it is fixed by means of a screw, k. Loss of light is therely occasioned. Fig. 457 is an upright section, and fig. 458, a front elevation of the mercurial apparatus. a, tile cover; b, the black board, witll grooves to receive the board, h; c, the cup of quicksilver; d, the spirit-lainlp; e, a small cock, throulgh whi.ch the quicksilver may be run off, if tlie apparatus be laid to one side; f, tihe thermomleter; g, a glass window; h, tlhe board bearing the metallic plate; 1, a stand for tlhe spirit-lanmp, which is held by the ring k, so that its fllame may strike the bottom of the cup. The whole of tlhe inside of tile apparatus should be blackened and varnished. Fig. 459 is a front view of tlhe lwashing apparatus rnadle of tin p1late, varnished. The plates, to be wasledl, are laid on the anguilar ledge, d; e is a ledge to conduct the water to the receptacle c.'2g. 460 is a side view of tlhe waslhing alpparatus. The patent was enrolled in February, 1840. (See XNeiton's Journal, C. S. xvi., 1.) Mr. Rich eard Bead ving purchased from M. Daguerre a license to practise his invention above described, received fromr a foreirgner a colnlimni(cation of certain improvements, for wlhich lie obtained a patent in June, 1840. Tihe first of these is the substitution of a concave reflecting lirrior for the lens in tile caRnera obscura. Fig. 462 represents in section a slight wooden box, a a, open at tlie front, opposite to the person sitting for tlie portrait. In tile back part of tile box a co!cave mirror, b, is placed, to reflect tlie rays coming fiomn the person. A small framne, c, is fixed to an adjustable pedestal, d, winich slides in grooves in the bottom of the box, for tlie purpose of being set at tihe focal point of tie mirror. In tlis frame, c, a polished surfaice is first to be placed for trial, to receive the iniage correctly, as observed by the operator, by looking through tie opening, e, in tlie top of the box. The prepared silvered plate is now substituted in tile exact place for thie trial one. Tlhe luminous impression being made, the slide, d, is withdrawn, and the plate removed; carefully shut up in a box from- the light. Tile second olbject of this patent is making the prepared surface nore uniform, by passing two plartes, witlh their silvered faces in contact, several times between hardened rollers, annealing them at a low red heat after each passage. His third object is to use a compound of bromine and iodine, instead of tlhe lattel alone, for coating tie silver; which increases its sensibility to light, thereby shortening and improving tlie operation of taking likenlseses. e also reconnmends to use a combination of iodine with nitric acid. Finally, IMr. Beard finds that by placing a screen of any desired color behind the sitter, the appearance of his Daguerreotype portrait ie irsproved. (Newton's Journal, xxiii., 112.) DAGUERROTYPE. 537 M. A. J. P. Claudet, who had also purchased a license from M. Daguerre, obtained a patent in December, 1841, for certain improvements upon tie original process. His first object is to give the front of the camera obscura such an aperture as to admit the largest object-glass intended to be used; and of such he provides a series of difi ferent dimensions, each attached to its board, that may be fitted by a slide to the fron of the camera. One of the greatest difficulties in the Daguerrotype process was the impossibility of ascertaining the precise moment at which the light had produced, on the prepared plate, the effect requisite for the vapor of mercury to bring out the image. By apply. ing that vapor to the plate while the silver surface is being acted upon by the light, the operator is enabled to see when his picture is complete. Another advantage of this joint operation is, that thb effect of the mercury upon those parts of the plate which have been acted upop by the light, are more perfect when caused to take place immediately under the luminous influence. Hence, instead of using the distinct box with the cup of quicksilver, he places a cup containing that metal in the camera ob. scura, with its spirit-lamp, and exhales the vapors there. When the mercury has risen to the proper temperature, the aperture of the object-glass is thrown open, and the!;ht, reflected from the object to be delineated, is allowed to operate. He watches the effect through an opening in the side of the camera, where he views the prepared plate by the light of a lantern passing through a piece of red or orangecolored glass in the (other) side of the camera. Whenever the light and mercury, by their simultaneous action, have produced a good image, the object-glass is covered, and the silver plate, with its picture, removed, in order to be washer and finished. I. Claudet embellishes his Daguerrotype portraits by placing behind the sitter screens of painted scenery, which furnish pleasing back grounds. He specifies also various kinds of artificial illumination, to I2 used in the absence of solar light. (Newton's Journal, C. S. xx. 430.) According to M. Barnard, Daguerre's iodized plate should be exposed for half a minute to the action of chlorine, mixed with a large proportion of common air; whereby it becomes so sensitive, that the pictorial impression is produced in the short space of time necessary for removing and replacing the screen of the camera. The mercury is afterward employed; as also the hyposulphite wash. Daguerrotype pictures are colored by dusting over them powders of proper hues, which are immediately washed by passing the plate through water. What remains of the color after this ablution does not seem in the least to injure the appearance or alter the form of the imo.ge. It would seem that those parts of the picture which were at first black, retain, after being washed, a larger proportion of the coloring matter than the lighter parts. Several valuable improvements seem to have been made in Vienna upon the Da guerrqtype process; and among others, the mode of using chloriodine. The best form of box for applying the chloriodic vapor is square, with its bottom of plate Olass, supported a little above the table by feet, a thumb-screw being one of them, in order to give a certain inclination to the glass plate for spreading the chloriodine over it uniformly. A sheet of white paper being laid beneath the box, enables the operator to see whether the liquid chloriodine is properly distributed. There is a groove round the top of the box, into which the ledge of the lid fits tight. A thermom. eter is placed in the box. VcoigtlalJ's lenses consist of two achromatic object-glasses placed apart; the first nearest the object, having an aperture of 18 lines; the second one of 19 lines; the solar fo. cus of the two Is 5j;nches. A system of lenses of so short a focus with so large aper. tures affords from 11 to 12 times more illumination than Daguerre's original apparatus did. The finest p)rtraits can be produced in the course of from 10 to 30 seconds with this arrangement. Suce,t apparatus, elegantly made in brass, costs only 120 gulden, or about 10 guineas. Voigtland has recently made a camera with two object-glasses, as above arranged, each having an aperture of 37 lines, and a combined focus of 12 inches. By means of this instrument, portraits 5- inches in size can be made. The landscapes produced in them are very beautiful. Its price is 144 gulden, about 12 guineas. Along with the above apparatus, a box with a bottom of amalgamated copper is used for applying the vapor of mercury. By peculiar methods of polishing the silvered copper plate, peculiar tones and tints may be given to the picture. The olive-oil and pumice-powder are indispensable for t-emoving the scratches from the plate and to render its surface uniform. If a delicate blue tone be desired, the plate should be a second time polished with silphuric ether and washed tripoli; and a third time with dilute nitric acid and Paris red, rubbing the plate lastly with a peace ofwashleather and crocus. But if a brownish black tone be wished for, a like series of operations is to be gone through, only instead of the ether ind tripoli, spirit of ammonia and Vienna lime is to be used. a68 DAMIASCUS BLADES. To give the plate the utmost sensibility to lilght, a film of iodine should be given in the first place. If with dry iodine, this should be strewed, then covered with cotton, and lastly with a sheet of paper, and the plate above the last, but not so as to touch it This may be done also with a solution of 1 part of iodine in 6 of spirits of wine, pu into a saucer, which is laid on the bottom of the box, and covered with gauze. The plate is to be removed whenever it has acquired a faint brazen tint. By this means the plate receives the impressions of light so well as to produce good contrasts between the white and the dark places. The application of bromine afterward causes a rapid reception of the image, and occasions the deep black shades of an object. The best form is brome water, made by dissolving the bromine in a little distilled water, and then addin. more, when it is wanted, till the solution acquires a straw-yellow color. A delicate thermometer being put into the box, the solution'is to be spread uniformly on its glass bottom, the plate being laid on above and covered up, while the time of expo sure must'3e counted by seconds, with a clock or watch. If the temperature be 41~ F., the time should be 258 seconds. 50~ 230 590 201 680 158 77~ 113 By attending to these instructions, exact results may be always obtained. A second mode of experimenting is with bromiodine; prepared by dissolving I part of bromine in an alcoholic solution of 5 parts of iodine; and diluting this mixture with water, till it acquires the color of Bavarian beer. The action of this application upon the plate is so rapid as hardly to leave time for consideration. It must be watched every instant till the dark gold yellow tint appear, when it is ready for the camera. The best time of day f'ir Daguerrotype operations is from an hour after the sun rises till he comes within 45~ of the meridian, and not again till he has passed the meridian by 45~. When the sitting is too long, the parts which should be pure white become of a dirty blue tint, and the dark parts become brown. The picture is burnt, so to speak. Chloride of gold applied to the picture has the effect of fixing and enlivening the tints. A small grate being fixed by a clamp to the edge of a table, the plate is laid upon it with the image uppermost, and overspread evenly with solution of chloride of gold, by means of a fine broad camel-hair brush, without letting any drop over the edge. A spirit lamp is now brought under the plate, and moved to and fro till a number of small steam bubbles appear upon the image. The spirit lamp must be immediately withdrawn. The remainder of the chloride solution must be poured back into the phial, to be used on another occasion. It is lastly to be washed and examined. This operation has been repeated three or four times with the happiest effect, of giving fixity and force to the picture. It may then be wiped with cotton without injury. By dusting various pigment powders from small cotton-wool dossils upon the picture, previously coated with an alcoholic solution of copal, and nearly dry, the appearance of a colored miniature has been very successfully imitated. The varnish must be applied delicately with one stroke of a broad brush of badger hair.* DAGUERREOTYPE ENGRAVING. Thia new art, patented by M. A. F. J. Claudet on the 21st November, 1843, is established on the following facts. A mixed acid, consisting of water, nitric acid, nulr'te of potash, and conmmon salt, in certain proportions, being poured upon a Daguerreotype picture, attacks the pure silver, forming a ellloide of that metal, but does not affeet the white parts, which are produced by the mercury of the picture. This action does not last long. Water of ammonia; containing a little chloride of silverin solution, dissolves the rest of that chloride, which is Jehen washed away, leaving the naked metal to be again attacked, especially with the aid of heat. The metallic surface should have been perfectly purified by means of alcohol and caus. tic potass. For the rest of the ingenious but complex details, see )Neezton's Journal, C. S., vol. xxv., p. 112. DAI-LINE, tie same as Inuline, the fecula obtained from elecampane, analogous in many respects to starch. It is not employed in the arts. DAMASCUS BLADES, are swords or scymitars, presenting upon their surface a variegated appearance of vzatering, as white, silvery, or black veins, in fine lines, or fillets; fibrous, crossed, interlaced or parallel, &c. They are brought from the East, being fabricated chiefly at Damascus, whence their name. Their excellent quality has become proverbial; for whlich reason these blades are much sought after by military men, and ta7' high priced. Tie oriental processes have never been satisfactorily described; but if late years methods have been devised in Europe to imitate tie fabric very well. k ee Praktischc Anweisung zum Daguerrotypiren, Leipzig, &c. 1843. DAMASK. 569 Clouet and Hachette pointed out the three following processes for producing Da rascus blades: 1, that of parallelfillels; 2, that by torsion; 3, the mos ic. The first, which is still pursued by some French cutlers, consists in scooping out with a graving tool the faces of a piece of stuff composed of thin plates of different hinds of steel These hollows are by a subsequent operation filled up, and brought to a level with the external faces, upon which they subsequently form tress-like figures. 2. The method of torsion which is more generally employed at present, consists in formitng a bundle of rods or slips of steel, which are welded together into a well-wrought bar, twisted several times round its axis. It is repeatedly forged, and twisted alternately; after which it is slit in the line of its axis, and the two halves are welded with their outsides In contact; by which means their faces will exhibit very various configurations. 3. The mosaic method consists in preparing a bar, as by the torsion plan, and cutting this bar into short pieces of nearly equal length, with which a fagot is formed and welded together; taking care to preserve the sections of each piece at the surface of the blade. In this way, all the variety of the design is displayed,'corresponding to each fragment of the cut bar. The blades of Clouet, independently of their excellent quality, their flexibility, and extreme elasticity, have this advantage over the oriental blades, that they exhibit in the very substance of the metal, designs, letters, inscriptions, and, gener ally speaking, all kinds of figures which had been delineated beforeiand. Notwithstanding these successful results of Clouet, it was pretty clear that the watered designs of the true Damascus cimeter were essentially different. M. Briant has at last completely solved this problem. He has demonstrated that the substance of the oriental blades is a cast-steel-more highly charged with carbon than our European steels, and in which, by means of a cooling suitably conducted, a crystallization takes place of two distinct combinations of carbon and iron. This separation is the essential condi. tion; for if the melted steel be suddenly cooled in a small crucible or ingot, there is no damascene appearance. If an excess of carbon be mixed with iron, the whole of the metal will be converted into steel; and the residuary carbon will combine in a new proportion with a portion of the steel so formed. There will be two distinct compounds; namely, pure steel, and carbureted steel or cast-iron. These at first being imperfectly mixed will tend to separate, if while still fluid they be left in a state of repose; and form a crystallization in which the particles of the two compounds will place themselves in the crucible in an order determined by their affinity and density conjoined. If a blade forged out of steel so prepared be immersed in acidulous water, it will display a very distinct Damascus appearance; the portions of pure steel becoming black, and those of carbureted steel remaining white, because the acids with difficulty disengage its carbon. The slower such a compound is cooled, the larger the Damascus veins will be. Travernier relates that the steel crucible ingots, like those of wootz, for making the true oriental Damascus, come from Golconda, that they are of the size of a halfpenny roll, and when cut in two, form two swords. Steel combined with manganese forges easily, but it is brittle when cold; it displays however the Damascus appearance very stron(gly. A mixture of 100 parts of soft iron, and 2 of lamp black, melts as readily as ordinary steel. Several of the best blades which M. Br6ant presented to the Sociiet d'Encouragement are the product of this combination. This is an easy way of making cast-steel without previous cementation of the iron. 100 parts of filings of very gray cast-iron, and 100 parts of like filings previously uxydized, produced, by their fusion together, a beautiful damascene steel, fit for forcing into white arms, sabres, swords, &c. This compound is remarkable for its elasticity, an essenial qualiiy, not possessed by the old Indian steel. The greater the proportion of the oxydized cast-iron, the tougheris the steel. Care should be taken to stir the materials during their fusion, before it is allowed to cool; otherwise they will not afford a homogeneous damasc. If the steel contains much carbon it is difficult to forge, and cannot be drawn out except within a narrow range of temperature. When heated to a red-while it crumbles under the hammer; at a cherry-red it becomes hard and brittle; and as it progressively cools it becomes still more unmalleable. It resembles completely Indian steel, which European blacksmiths cannot forge, because they are ignorant of the suitable temperature for working it. M. Breant, by studying this point, succeeded in forging fine blades. Experience has proved that the orbicular veins, called by the workmen knots or thorns (ronces), which are seen upon the finest Eastern cimeters, are the result of the manner of forging them, as well as the method of twisting the Damascus bars. If these be drawn in length, the veins will be longitudinal; if they be spread equally in all directions, the stuff will have a crystalline aspect; if they be made wavy in the two directions, undulated veins will be produced like those in the oriental Damascus. DAMASK is a variegated textile fabric, richly ornamented with figures of flowers, 570 DAMASKEENING. fruits, landscapes, animals, &c., woven in the loom, and is by far the mou't rich, eckgant and expensive species of ornamental weaving, tapestry alone excepted. The name is said to be derived from Damascus, where it was anciently made. Damask belongs to that species of texture which is distinguished by practical men by the name of tweeling, of which it is the richest pattern. The tweel of damask is usualil half that of full satin, and consequently consists of eight leaves moved either in regulal succession or by regular intervals, eight leaves being the smallest number which will ad. mit of alternate tweeling at equal intervals. In the article CARPET, two representations have been given of the damask draw.r loom. The generic difference of tweeling, when compared with common cloth, consists in the intersections, although uniform and equidistant, being at determinate intervals, and not be. tween the alternate threads. Hence we have specimens of tweeled cloth, where the intersections take place at the third, fourth, fifth, sixth, seventh, eighth, or sixteenth interval only. Tihe threads thus deflecting only from a straight line at intervals, -reserve more of their original direction, and a much greater quantity of materials can be combined in an equal space, than in the alternate intersection, where the tortuous deflection, at every interval, keeps them more asunder. On this principle tweeled cloths of three and four leaves are woven for facility of combination alone. The coarser species of ornamented cloths, known by the names of dornock and diaper, usually intersect at the fifth, or half satin interval. The sixth and seventh are rarely used, and the intersection at the eighth is distinguished by the name of satin in common, and of damask in ornamental tweeling. It will further be very obvious, that where the warp and woof cross only at every eighth interval, the two sides of the cloth will present a diversity of appearance; for on one side the longitudinal or warp threads will run pai'allel from one end of a web to the other, and, on the other, the threads of woof will run also parallel, but in a transverse direction across the cloth, or at right angles to the former. The points of intersection being only at every eighth interval, appear only like points; and in regular tweeling these form the appearance of diagonal lines, inclined at an angle of 45~ (or nearly so) to each of the former. The appearance, therefore, of a piece of common tweeled cloth is very similar to that of two thin boards glued together, with the grain of the upper piece at right angles to that of the under one. That of an ornamental piece of damask may, in the same manner, be very properly assimilated to a piece of veneering, where all the wood is of the same substance and color, and where the figures assume a diversity of appearance from the ground, merely by the grain of the one being disposed perpendicularly to that of the other. See TEXTILE FABRIC. From this statement of the principle, it results that the most unlimited variety of figures will be produced, by constructing a loom by which every individual thread of warp may be placed either above or below the woof at every intersection; and to effect this, in boundless variety, is the object of the Jacquard mounting; which see. The chief seat of this manufacture is probably the town and neighborhood of Dunfernlinc, in Fifeshire, and Lisburn and Ardoyne, near Belfast, where it is considered as the staple, having proved a very profitable branch of traffic to the manufacturer, and given employment to many industrious people. The material used there is chiefly linen; but many have been recently woven of cotton, since the introduction of that article into the manufacture of cloth has become so prevalent. The cotton damasks are considerably cheaper than those of linen; but are not considered either so elegant or durable. The cotton, also, unless fiequently bleached, does not preserve the purity of the white color nearly so well as the linen. DAMASKEENING; the art of ornamenting iron, steel, &c., by making incisions upon its surface, and filling them up with gold or silver wire; chiefly used in enriching sword blades, guards, and gripes, locks of pistols, &c. Its name shows the place of its origin, or, at least, the place where it has been prac* tised in the greatest perfection; viz., the city of Damascus, in Syria; though M. Felibien attributes the perfection of the art to his countryman, Cursinet, who wrought under the reign of Henry IV. Damaskeening is partly mosaic work, partly engraving, and partly carving. As mosaic work it consists of pieces inlaid; as engraving, the metal is indented, or cut in intaglio; anl as carving, gold and silver are wrought into it in relievo. There are two ways of damaskeening; in the first, which is the most'beautiful, the artists cut into the metal with a graver, and other tools proper for engraving upon stel, and afterwards fill up the incisions, or notches, with a pretty thick silver or gold wire. In the other, which is only superficial, they content themselves to make hatches, or strokes across the iron, &c., with a cutting knife, such as is used in making slmaL files. As to the first, it is necessary for the gravings or incisions to be made in the dove DECOMPOSITION. 571 tail form; that the gold or silver wire, which is thrust forcibly into them, may adhere the more stronaly. As to the second, which is the more usual, the method is this: —Having heated the steel till it chances to a violet, or blue color, they hatch it over and across with the knife; then draw the ensign or ornament intended, upon this hatching, with a fine brass point or bodkin. This done, they take fine gold wire, and conducting or chasing it according to the figures already designed, they sink it carefully into the hatches of the metal with a copper tool. DAMASSIN is a kind of damask, with gold and silver flowers, woven in the warp ant! woof; or occasionally with silk organzine. DAMPS, in mining, are noxious exhalations, or rather gases, so called from the German dampf, vapor. There are two principal kinds of mine gases, the fire-damp, or carbureter hydro.zen, and the choke-damp, or carbonic acid gas. See MINES. DAPHNINE; the bitter principle of the Daphne dlpina. DATOLITE. A mineral composed of silica, lime, and boracic acid. DECANTATION (Eng. and Fr.; dbgiessen, Germ.) is the act of pouring off the clear supernatant fluid from any sediment or deposite. It is mucn employed in the chemical arts; and is most conveniently effected by a syphon. DECOCTION (Eng. and Fr.;.Jbkochung, Germ.) means either the act of boiling a liquid along with some organic substance, or the liquid compound resulting from that act. DECOMPOSITION (End. and Fr.; Zerseflzng, Germ.) is the separation of the constituent principles of any compound body. The following table, the result of important researches recently made by M. Persoz, Professor of Chemistry at Strasburgh, shows the order in which decompositions take place among the successive substances. Nitric Acid. Muriatic Acid. Oxyde of Magnesium Oxyde of Magnesium Silver - Cobalt - Cobalt - Nickel - Nickel Protox. of Mercury Protox. of Cerium - Cerium Oxyde of Zinc Oxyde of Zinc Protox. of Manganese Protox. of Manganese Oxyde of Lead - Iron - Cadmium - Uranium - Copper - Copper - Glucinum - Tin - Alumiim Oxyde of Glucinum - Uranium - Alumium - Chromium - Uranium Protox. of Mercury - Chromium Oxyde of Mercury - Iron Iron - Tin - ismuth - Bismuth - Antimony By means of the cupric oxyde we may separate, 1, the ferric oxyde from the mangancas oxylde; 2, the cobaltic, nickelic, zincic and cerous oxvdes from the uranic, ferric, chromic, and alurninic oxydes; 3, the ferrous oxyde from the chromic oxyde, when dissolved in the muriatic acid. In boiling a muriatic solution of the cobaltic, nickelic, and manganous oxydes, with the mercuric oxyde, the first two oxydes alone are precipitated. Alumina separates the cadmic oxyde from the bismuthic oxyde, the stannous oxyde from the stannic oxyde, and the stannous oxyde from the antimonic acid. The cupric oxyde separates also by precipitation, the aluminic, uranic, chromic, titanic, and vanadic oxydes from all the oxydes which are precipitable in the state of sulphuret, by hydrosulphuret of ammonia. As an example of this mode of analysisDissolve pech-blende in aqua regia, precipitate its copper by sulphureted hydrogen, boil the liquid along with nitric acid, in order to transform all the uranium into uranic acid. Next boil it along with cupric oxyde, which precipitates only the uranic and ferric oxydes. Redissolve the precipitate in nitric acid, and boil the solution with mercuric oxyde, which does not precipitate the ferric oxyde. Finally, separate the copper and the mercury from the uranium, by means of sulphureted hydrogen. In this process we may substitute plumbic oxyde for the cupric oxyde, and succeed equally well. Knowledae, like the above, of the elective affinities and habitudes of chemical bodies, simple and compound, imparts to its possessor an irresistible power over the unions and 572 DEPOSITION OF METALS. disunions of the elements, which he can exercise with certainty in effecting innumerable transformations in;he arts. DECREPITATION (Eng. and Fr.; Verknistern, Germ.) is the crackling noise. attended with the flying asunder of their parts, made by several salts and ninerals~ when heated. It is caused by the unequal sudden expansion of their substance by the heat. Sulphate of baryta, chloride of sodium, calcareous spar, nitrate of baryta, and many more bodies which contain no water, decrepitate most violently, separating at the natural joints of their crystalline structure. Some chemists have preposterously enough ascribed the phenomenon to the expansion of the combined water into steam. What a specimen of inductive philoo6phy! DEFECATION (Enr. and Fr.; Klaren, Germ.), the freeing from dregs or impurities. DEFLAGRATION (Enr. and Fr.; Verpufuneg, Germ.), the sudden blazing up of a combustible; as of a charcoal or sulphur when thrown into melted nitre. DELPHINIA. The vegeto-alkaline principle of the Delphinium staphysagria, or stavesacre. It is poisonous. DELIQUESCENT (Zerfiessen, Germ.) is said of a sc.id which attracts so much moisture from the air as to become spontaneously soft or liquid; such as potash and muriate of lime. DEPHLEGMATION is the process by which liquids are deprived of theil Eatery par. ticles. It is applied chiefly to spirituous liquors, and is now nearly obsolete, as involving the alchemistical notion of a peculiar principle called phlegm. DEPHLOGISTICATED; deprived of phlogiston, - formerly supposed to be the common combustible principle. It is nearly synonymous with oxygenated. The idea originally attached to the word having proceeded from false logic, the word itself should never be used either in science or manufactures. DEPILATORY (Depilatoire, Fr.; Etlthaarensmittel, Germ.) is the name of any substance capable of removing hairs from the human skin without injuring its texture. They act either mechanically or chemically. The first are commonly glutinous plasters formed of pitch and rosin, which stick so closely to the part of the skin where they are applied, that when removed, they tear away the hairs with them. This method is more painful, but less dangerous than the other, which consists in the solvent lction of a menstruum, so energetic as to penetrate the pores of the skin, and destroy the bulbous roots of the hairs. This is composed either of caustic alkalis, sulphuret of baryta, or arsenical preparations. Certain vegetable juices have also been recommended for the same purpose; as spurge and acacia. The bruised eggs of ants have likewise been prescribed. But the oriental rusmna yields to nothing in depilatory power. Gadet de Gassincourt has published in the Dictionnaire des Sciences Medicales, the following recipe for preparing it. Mix two ounces of quicklime with half an ounce of orpiment or realgar, (sulpliuret of arsenic;) boil that mixture in one pound of strong alkaline ley, then try its strength by dipping a feather into it, and when the flue falls off, the rusma is quite strong enough. It is applied to the human skin by a momentary friction, followed by washing with warm water. Such a caustic liquid should be used with the greatest circumspection, beginning with it somewhat diluted. A soap is sometimes made with lard and the above ingredients; or soft soap is combined with them; in either case to form a depila. tory pommade. Occasionally one ounce of orpiment is taken to eight ounces of quicklime, or two to twelve, or three to fifteen; the last mixture being of course the most active. Its causticity may be tempered by the addition of one eighth of starch or rye flour, so as to form a soft paste, which being laid upon the hairy spot for a few minutes, usually car. ries away the hairs with it. The rusma should never be applied but to a small surface at a time, for independently of the risk of corroding the skin, dangerous consequences might ensue from absorption of the arsenic. DEPOSITION OF METALS. Felted fabrics have been coated with metals of various kinds, by means of electricity, in the following way:-A plate of copper, for example, as a dye or matrix, is coated on one side with a resinous, non-conducting varnish, and on the other with graphite or plumbago, and the cloth is strained over it, and cemented to it. The matrix being immersed in a solution of sulphate of copper, and connected with a zinc pole of a galvanic battery; while another plate of copper is immersed in the solution and connected with the copper pole of the battery, the deposition of the metal upon the matrix commences. When the surface of the matrix is covered with a thin film of copper, the depositing metal begins to penetrate the interstices of the cloth, and if the operation is continued sufficiently long, will appear in small globules at the other side. As soon as the required thickness of metal has been deposited, the matrix is removed from the solution, and the cloth separated therefrom. The surface of the metallic coating will be either plain or ornamented, according as the DEXTRINE, 673 surface of the matrix is prepared, whether with a raised or sunk pattern. An the metallic deposit may be afterward gilt or otherwise ornamenled. Other details are given in the specification of MI. Julius Schatlaendcr. —ewton', s Journal, C. S., xxv., 96. DESICCATING APPARATUS. The useful problem of depriving timber of its moisture has received a complete solution by Messrs. Davison & Symington, who in November, 1843, patented a method of transmitting currents of air highly heated (by an arrangement similar to those employed in the hot blast of iron-smelting), through casks made of green wood, or through chamnbers in which the deals or planks are piled up. The same means iave since been found effective for cleansing old tainted beer tuns, or wine hogsheads, of their fermtentative qualities; and hence they are now very generally had recourse to in breweries. A fan or other blowing machine is used for propelling the heated air. Mechanical fiiction with chains or otherwise is used in conjunction with the ventilating process. tIesiccuinq System. " When we first noticed this system we instanced its application to the seasoning of beer casks, as the most striking exemplification of its efficacy which then offered itself to our observation; but though we have been fully borne out in our views of the importance of that application, by the subsequent adoption of Messrs. Davison & Symington's plans in some of the largest breweries in the kingdom, this turns out to be, after all, but one of the least of the triumphs which the system has aceheved. From the seasoning of casks the patentees have gone on, step by step, till they now undertake seasoning of wood and wooden articles:f every description; and give fair promise of benefiting largely, not only every art and manufacture of which wood is an element, but the public at large. We have been obligingly permitted by them to inspect and make extracts from their'Dry Seasoning Book,' and some of shese extracts afford the best possible proofs of the advantages derivable from this desiccatilg system. They are records of work actually done-not by way of experiment merely, but in the ordinary course of an established and fast increasing trade. Each extract shows, first, the weight of the wood when sent in to be seasoned; next, the daily dimiinution in weight produced by the desiccating process; and lastly, the total quantity of moisture expelled-moisture which if allowed to remain in the wood could tend only to produce rot and decay. The extracts give also, in the case of planks, the degree of shrinkage in width produced. Some of the results are exceedingly startling. Mahogany is reduced in weight by desiccation 24'4 per cent., and pine planks 34'5. The woods least affected are fir and white deal, which lose 12'50 per cent. The degree of shrinkage produced is still imore remarkable; amounting, in both the cases noticed, to no less than three fourths. It will be observed, moreover, that all these effects are produced in the course of a few days, some ten or twelve at most, while by the ordinary mode of drying they could hardly be accomplished in as many months" -M-r. Robertson, in his Mechanics' Magazine. We need scarcely add that the less noisture there is left in wood, the greater its strength-the more complete its fitness for every purpose to which it can be applied. DETONATION. See FULMINATING, for the mode of preparing detonating powder for the percussion caps of fire-arms. DEUTOXIDE literally means the second oxide, but is usually employed to denote a compound containing two atoms or two prime equivalents of oxygen to one or more of a metal. Thus we say deutoxide of copper, and deutoxide of mercury. Berzelius has abbreviated this expression by adopting the principles of the French nomenclature of 1787; according to which the higher stage of oxidizement is characterized by the termination ic, and the lower by ous, and he writes accordingly cupric and mercuric, to designate the deutoxides of these two metals; cuprous and mercurous to designate their protoxides. I have adopted this nomenclature in the article DECO.IPOSITION, and in some other parts of this 1)ictionary, as being short and sufficiently precise. DEXTRINE is a matter of a gummy appearance into which the interior substance of the molecules of starch are converted, through the influence of diastase or acids. It derives its names from the circumstance e that it turns, more than any other body, the plane of polarization to the right hand. It is white, insipid, without smell, transparent, in thin plates, friable, with a glassy fracture when well dried. It is not altered by the heat of boiling water, but at 280~ F. it becomes brown, and acquires the flavor of toasted bread. It is not colored by iodine, like starch, it does not form mucic acid with the nitric as.common gum does, and it is transformed into grape sugar, when heated along with dilute sulphuric acid or di,;tase. Dextrine is much employed by tile French pastrycooks and confectioners: it ib a good s'lbstitute for gum arabic in medicine. For the conversion of potato or other starch into dextrine, by the action of diastase, see BREWTNG. This Qubst ance has exactly the same chemical composition as starch, consisting of 24 atoms of carbon, 20 of hydrogen, and 10 of oxygen (Dumas); but it is distinguished 574 DIAMOND. from starch by its solubility in cold water, like gum, and not being affected by iodine British gum, as it is called, or roasted starch, is merely dextrine somewhat discolored a sul)stance apparently used for the paste on the Queen's head post office letter stamps. A process discovered by M. Payen, and patented in France by M. Henze, for making dextrine, consists in moistening one ton of dry starcn with water containing 41 lbs. of strong nitric acid. The starch thus uniformly wetted, is mlade up into small bricks or loaves, and dried in a stove: It is then rubbed down into a coarse powder, and ex posed in a stove-room to a stream of air heated to about 160( F. Being now triturated, sifted, and heated in a stove to about 228~ F., it forms a perfect dextrine of a fair color, because the acid acts as a substitute for the higher leat, used in making the British gum. Such an article makes a fine dressing for muslin and silk goods, and is mich employed in French surgery, for making a stiff paste support to the bandages of frao tured litlmbs. DIAMOND. Since this body is merely a condensed forn of carbon, it cannot in a;isnmical classification be ranked among stones; but as it forms in commerce the most precious of the gems, it claims our first attention in a practical treatise on the arts. Diamonds are distinguishable by a areat many peculiar properties, very remarkable and easily recognised, both in their rough state, and when cut and polished. Their most absolute and constant character is a degree of hardness superior to that of every mineral, whence diamonds scratch all other bodies, and are scratched by none. Their peculiar adamantine lustre, not easy to define, but readily distinguishable by the eye from that of every other gem, is their most obvious feature. Their specific gravity is 3'55. Whether rough or polished, diamonds acquire by fuiction positive electricity, but do not retain it for more than half an hour. The natural form of diamonds is derivable from an octahedron, and they never present crystals having one axis longer than the other. Theirstructure is very perceptibly lamellar, and therefore, notwithstanding their great hardness. they are brittle and give way in the line of their cleavage, affording a direct means ol arriving at their primitive form, the regular octahedi on. The diamond possesses either single or double refraction, according to its different crys. talline forms; its refractive power on light is far greater than it ought to be in the ratio of its density; the index of refraction being 2'44, whence Newton long ago supposed it tc consist of inflammable matter. Its various forms in nature present a circumstance peculiai to this body; its faces are rarely terminated by planes, like most other native crysthls, but they are often rounded off, and the edges between them are curved. When these secondary faces are attentively examined with a lens, we remark that they are marked with strive, sometimes very fine and almost imperceptible, but at others well defined; anti that these strice are parallel to the edges of the octahedron, and consequently to those of the plates that are applied on the primitive faces of this figure. Diamonds are usually colorless and transparent; when colored, their ordinary tint ver-es upon yellow, or smoke-yellow, approaching sometimes to olackish-brown. Green diamonds are next to yellow the most common; the blue possess rarely a lively hue, but they are much esteemed in Scotland. The rose or pink diamonds are the most valued of the colored kind, and exceed sometimes in price the most limpid; though generally speaking the latter are the most highly prized. The Geological locality of the diamond seems to be in diluvial gravel, and among conglomerate rocks; consisting principally of fragments of quartz, or rolled pebbles of quartz mixed with ferruginous sand, which compose sometimes hard aggregated masses. This kind of formnation is called cuscalho in Brazil. Its accompanying minerals are few in number, being merely black oxyde of iron, micaceous iron ore, pisiform iron ore, fragmente of slaty jasper, several varieties of quartz, principally amethyst. In Mr. Heuland's splendid collection there was a Brazilian diamond imbedded in brown iron ore; another in the same, belonging to M. Schuch, librarian to the Crown Piincess of Portugal; nd in the cabinet of M. Eschwege there is a mass of brown iron ore, containing a diamond in the drusy cavity of a green mineral, conjectured to be arseniate of iron. From these facts it may be inferred with much probability that the matrix or original repository of thi diamond of Brazil is brown iron ore, which occurs in beds of slaty quartzose micaceoun iron ore, or in beds composed of iron-glance and magnetic iron ore, both of which art apparently subordinate in that country to primitive clay slate. The loose earth containing diamonds lies always a little way beneath the surface G1o the soil, towards the lower outlet of broad valleys, rather than upon the ridges of tih ndjoining hills. Only two places on the earth can be adduced with certainty as diamond mines, vi rather districts; a portion of the Indian peninsula, and of Brazil. India has been celebrated from the most remote antiquity as the country of diamonds, Its principal mines are in the kingdoms of Golconda and Visapour, extending fron DIAMOND. 575 Cape Comorin to Bengal, at the foot of a chain of mountains called the Orixa, which appear to belong to the trnp-rock formation. In all the Indian diamond soils, these gems are so dispersed, that the} are rarely found directly, even in searching the richest spots, because they are enveloped in an earthy crust, which must be removed before they can be seen. The stony matter is therefore broken into pieces, and is then, as well as the looser earth, washed in basins scooped out on purpose. The gravel thus washed is nllected, spread oit on a smooth piece of ground, and left to dry. The diamonds art now recornised by their sparkling in the sun, and are picked out from the stones. The diamond mines of Brazil were discovered in 1728, in the district of Serro-do. Frio. The ground in which they are imbedded has the most perfect resemblance to that of the East Indies, where the diamonds occur. It is a solid or friable conglomerate, consisting chiefly of a ferruginous sand, which encloses fragments of various malnitude of yellow and bluish quartz, of schistose jasper, and grains of gold disseminated with olizist iron ore; all mineral matters different fiom those that constitute the neighboring mountains; this conglomerate, or species of pudding-stone, almost always superficial, occurs sometimes at a considerable height on the mountainous table-land. The most celebrated diamond mine is that of Mandarga, on the Jicitonhonha, in the district of Serro-lo-Frio to the north of Rio Janeiro. The river Jigitonhonha, three times broader than the Seine at Paris, and from 3 to 9 feet deep, is made nearly dry, by drawing the waters off with sluices at a certain season; and the cascalho or diamond-gravel is removed from the channel by various mechanical means, to be washed elsewhere at leisure. This cascalho, the same as the matrix of the gold mines, is collected in the dry season, to be searched into during the rainy; for which purpose it is formed into little mounds of 15 or 16 tons weight each. The washing is carried on beneath an oblong shed, by means of a stream of water admitted in determinate quantities into boxes containing the cascalho. A negro washer is attached to each box; inspectors are placed at regular distances on elevated stools, and whenever a negro has found a diamond, he rises up and exhibits it. If it weighs 17: carats, he receives his liberty. Many precautions are taken to prevent the negroes from secreting the diamonds. Each squad of wvrkmen consists of 200 negroes, with a surgeon and an almoner or priest. The flat lands on either side of the river are equally rich in diamonds over their whole surface, so that it becomes very easy to estimate what a piece of ground not yet washed may produce. It is said that the diamonds surrounded with a greenish crust are of the first water, or are the most limpid when cut. The diamonds received in the different mines of the district are deposited once a month in the treasury of Tejuco; and the amount of what was thus delivered from 1801 to 1806, may be estimated at about 18 or 19 thousand carats per annum. On the banks of the torrent called Rio Pardo, there is another mine of diamonds. The ground presents a great many fiiable rocks of pudding-stone, distributed in irreuu-:ar strata. It is chiefly in the bed of this stream that masses of cascalho occur, peculiarly rich in diamonds. They are much esteemed, particularly those of a ureenish-blue color. The ores that accompany the diamond at Rio Pardo differ somewhat fron those of the washing grounds of MIandanga, for they contain no pisiform iron ore; but a great many pebbles of slaty jasper. This table land seems to be very high, probably not less'lan 5500 feet above the level of the sea. Tocava, a principal village of Minas Novas, is 34 leagues to the northeast of Tejuco, n an acute angle of the confluence of the Jigitonhonha and the Rio Grande. In the bed of the streamlets which fall westward into the Jigitonhonha, those rolled white topazes are found which are known under the name of minas novas with blue topazes, and aquamarine beryls. In the same country are found the beautiful cymophanes or crvsoberyls so much prized in Brazil. And it is from the cantons of Indaia and Abaite that the largest diamonds of Brazil come; yet they have not so pure a water as those of the district of Serro-do-Frio, but incline a little to the lemon yellow. Diamonds are said to come also from the interior of the island of Borneo, on the banks of the river Succadan, and from the peninsula of Malacca. It is known that many minerals become phosphorescent by heat, or exposure to the sen's lizht. Diamonds possess this property, but all not in equal degree, and certain precautions must be observed to make it manifest. Diamonds need to be exposed to the tunbeam for a certain time, in order to become self-luminous; or to the blue rays of the prismatic spectrum, which augment still more the faculty of shining in the dark. Diamonds susceptible of phosphorescence exhibit it either after a heat not raised to redness, or the electric discharge. They possess not only a great refractive power in the mean ray of light, but a high dispersive agency, which enables them tc throw out the most varied and vivid colors in multiplied directions. Louis de Berquemn discovered, in 1476, the art of cutting diamonds by rubbing them 576 DIAMOND. against one another, and of polishing them with their own powder. These operations may be abridged by two methods: 1. ly availing ourselves of the direction of the larninae of the diamond to split them in tht directioni, and thus to produce several facets. This process is called cleaving the dianlond. Some, which appear to be macle crystals, resist this mechanical division, and are called diamonds of nature. 2. by sawing the diamonds by means of a very delicate wiie, coated with diamond powder. Diamonds take precedence of every gem for tile purpose of dress and decoration; and hence the price attached to those of a plire water increases in so rapid a proportion, that, beyond a certain term, there is no rule of commlllercial valuation. The largest diamond that is known seems to be that of the Rajah of Mattan, in the East Indies. It was of tile purest water, and weighs 367 carats, or at the rate of 4 grains to a carat, upward of 3 ounces troy. It is shaped like an egg, with an indented hollow near the smaller end; it was discovered at Landak about 100 years ago; and though the possession of it has cost several wars, it remained in the Malttan family for 90 years. A governor of Batavia, after ascertaining the qualities of the gem, wished to be the purchaser, arnd offered 150,000 dollars for it, besides two war brigs with their guns and ammuniition, together with a certain number of great guns, lnd a quantity of powder and shot. But this diamond possessed such celebrity in Iilldia, being regard as a talisman involving the fortunes of the Rajah and his farmily, that lie refused to part with it at any price. The Mogul diamond passed into the plossessio of the ruling family of Kabul, as has been invariably affirmed by the melmbers of tllat f-amily, and by the jewellers of Delhi and Kabul. It has been by both eparties identified with the great diamond, now known under the name of the KH-I-N'ooR, olr mzountain of light, which was displayed by its present proprietor, her Majesty the Queen, at tile recent Great Exhibition. It is now being properly cut by skilful Dutch artists, under the charge of Messrs. Garrard, jewellers in London, in order to bring out all its lustre, and remove some superficial specks or clouds. The weight of it has been of old various stated. The diamond possessed, in the time of the traveller Tavernier, by the emperor of Mogul, a kingdom now no more, weighl'd 279 carats, and was reckoned worth upwards of 400,0001. sterling. It was said to have lost the half of its original weight in the cutting. After these prodigious gems, tile next are:-l. That of the emperor of Russia, bought by the late empress Catharine, which weighs 193 carats. It is said to be of the size of a pigeon's egg, and to have been bought for 90,0001., besides an annuity to the Greets merchant of 40001. It is reported that,he above diamond formed one of the eyes of the famous statue of Sheringan, in the temple of Brama, and that a French grenadier, who had deserted into the Malabar servre, found the means of robbing the pagoda of this precious ern; and escaped with it to Madras, where he disposed of it to a ship captain for 2,0001., who resold it to a Jew for 12,0001. From him it was transferred for a large sum to the Greek merchant. 2. That of the emperor of Austria, which weighs 139 carats, and has a slightly yellowish hue. It has, however, been valued at 100,0001. 3. That of the king of France, called the Regent or Pitt diamond, remarkable for its form and its perfect limpidity. Although it weighs only 136 carats, its fine qualities have caused it to be valued at 160,0001., though it cost only 100,0001. The largest diamond furnished by Brazil, now in possession of the crown of Portugal, weighs, according to the highest estimates, 120 carats. It was found in the streamlet of Abaite, in a clay-slate district. The diamonds possessed of no extraordinary magnitude, but of a good form and a pure water, may be valued by a certain standard rule. In a brilliant, or rose-diamond of regular proportions, so much is cut away that the weight of the polished gem does not exceed one half the weight of the diamond in the rough state; whence the value of a cut diamond is esteemed equal to that (t' a similar rough diamond of double weioht, exclusive of the cost of workmanship. The weight and value of diamonds are reckoned by carats of 4 grains each; and the comparative value of two diamonds of equal quality but different weights, is as the squares of these weights respectively. The average price of rough diamonds that are worth working is about 21. for one of a single carat; but as a polished diamond of one carat must have taken one of 2 carats, its price in the rough state is double the square of 21., or 8/. Therefore, to estimate the value of a wrought diamond, ascertain its weight in carats, double that weight, anti multiply the square of this product by 21. Hence, a wrought diamond of 1 carat is wothl ~ 8 2 - 32 3 - 72 4 - 128 5 - 200 6 - 288 DIAMOND. 577 ~ of 7 carats is worth 392 8 - 512 9 - 612 10 - 800 20 - 3200, beyond which weight the prices can no longer rise in this geometrical progression, fromt the small number of )lpurchasers of such expensive toys. A very trifling spot or flaw of any kind lowers exceedingly the commercial value of a diamond. Diamonds are used not only as decorative gems, but for more useful purposes, as for cutting glass by the glazier, andt all kiinds of arld stones by the lapidary. On the structure of the glazier's diamond we possess some very interesting observations and reflections by Dr. Wolliston. Ile remarks, that thle hardest substances brought to a sharp point scratch glass, indeed, but do not cut it, and that diamonds alone possessed that lro'perty; which hle ascriles to the. peculiarity of its crystallization in rounded faces and curvilinear edges. For glass-cutting, those rough diamonds are always selected which are sharply crystallized, hence called diamond sparks; but cut diamonas are never used. The inclination to be given to a set diamond in cutting glass is comprised within very narrow limits; -nd it ought, moreover, to be inoved in the direction of one of its angles. The curvilinear edge adjoining the curved faces, enteriag as a wedge into the furrow opened up by itself, thus tends to separate the parts of the glass; and in order that the crack which causes the separation of tile vitreous pal,.Jes may take place, the diamond must be held almost perpendicular to the surface of the glass. The Doctor proved this theory by an experiment. It, by suitable cutting with the wheel, we make the edges of a spinel ruby, or corundum telesie (sapphire) curvilinear, and the adjacent faces curved, these stones will cut glass as well as a glazier's diamond, but being less hard than it, they will not preserve this property so long. He found that upon giving the surface of even a fragment of flint the same shape as that of the cutting diamond, it acquired the same property; but, from its relative softness, was of little duration. The depth to which the fissure caused by the glazier's diar'ond penetrates, does not seem to exceed the two-hundredth of an inch. I shall here introduce Mr. Milburn's valuable observations or, the choice of rough diamonds, as published in his work on Oriental Commerce. The color should be perfectly crystalline, resembling a drop of clear spring water, in the middle of which you will perceive a strong light, playing with a great deal of spirit. If the coat be smooth and bright, with a little tincture of green in it, it is not the worse, and seldom proves bad, but if there is a mixture of yellow with green, then beware of it; is a soft greasy stone, and will prove bad. If the stone has a rough coal, so that you can hardly see through it, and the coat be white and look as if it wre rough by art, and clear of flaws or veins, and no blemish cast in the body of the stone Wwhich may be discovered by holding it against the light), the stone will prove good. It often happens that a stone will appear of a reddish hue on the outward coat, not unlike the color of rusty iron, yet by looking through it against the light, you may observe the heart of the stone to be white (and if there be any black spots, or flaws, or veins in it, they may be discovered by a true eye, although the coat of the stone be the same), and such stones are generally good and clear. If a diamond appears of a greenish bright coat, resembling a piece of green glass, inclining to black, it generally proves hard, and seldom bad; such stones have -been known to have been of the first water, and seldom worse than the seconll; but if any tincture of yellow seems to be mixed with it, you may depend on its being a very bad stone. All stones of a milky cast, whether the coat be bright or dull, if ever so little inclining to a bluish cast, are naturally soft, and in danger of being flawed in the cutting; and though they should have the good fortune to escape, yet they will prove dead and milky, and turn to no account. All diamonds of cinnamon color are dubious; but if of a bright coat mixed with a little green, then they are certainly bad, and are accounted arnong the worst of colors. You will meet with a great many diamonds of a rough cinnamon-colored coat, opaque; this sort is generally very hard, and, when cut, contain a great deal of life and spirit but the color is very uncertain; it is sometimes white, sometimes brown, and sometimes of a fine yellow. Rough diamonds are frequently beany, that is, look fair to the eye, yet are so full of veins to the centre, that no art or labor can polish them. A good diamond should never contain small spots of a white or gray color of a nebulous form; it should be free from small reddish and brownish grainis, that sometimes occur on their surface. or in their interior. A good diamond should split readily in the direction of the cleavage; it sometimes happens, however, that the folia are curved, as is the case in twin 38 578 DIAMOND DUST. crystals. When this happens, the stone does not readily cut and polish, and is there fore of inferior value. In the cut and polished gem, the thickness must always bear a certain proportion to the breadth. It must not be too thin nor thick; for, when too thin, it loses much of its fire, anrd app-ars not unlike glass. The term carate is said to be derived frotrn the name of a bean, the produce of a specie? of erytkhina, a native of the district of Shangallas, in Africa, a famous mart of gold-dust. The tree is called ketara, a word signifying sun in the language of the country; because it bears flowers and fruit of a flame, color. As the dry seeds of this pod are always of nearly uniform weight, tile savages have used them fronl time immemorial to weigh gold. Tile beans were transported into India, at an ancient period, and have been long employed there for weighing diamllonds. Tile carat of tile civilized world is, in fact, an imaginary weight, consisting of 4 nominal grains, a little lighter than 4 grains troy (poids de marc); it requires 74 carat grains and,-1- to equipoise 72 of the otiler. In valuing a cut diamond, we must reckon that one half of its weight i.as been lost in the lapidary's hands; whence its weight in this state should be doubled before we calculate its price by the general rule for estimating diamonds. The French multiply by 48 the square of this weight, and ihey call ite rodulct in francs.he value of the diamond. Thus, for example, a cut diamond of 10 carats would be worth (10 X 2)9 X 48=19,200 francs, or 768/., allowing only 25 francs to the pound sterling. The diamond mines of Brazil have brought to its government, front. the year 1730 till 1814, 3,023,000 carats; being at the average rate annually of 36,000 carats, or a little more than 16 lbs. weight. They have not been so productive in the later years of that period; for, according to Mr. Mawe, between 1801 and 1806, only 115,675 carats were obtained, being 19,279 a year. The actual expenses incurred by the government, during this interval, was 4,419,700 francs; and, deductinz the pro. duction in gold fromn the washings of the diamond gravel, or cascalho, it is found that the rough diamonds cost in exploration, per carat, 38 francs 20 c., or nearly 31s. British money. TIle contraband is supposed to amount to one third of the above legitimate trade. Brazil is almost the only country where diamonds are mined at the present day; it sends annually to Europe front 25 to 30 thousand carats, or fiom 10 to 161 lbs. DIAMONDS, cutting of. Although the diamond is the hardest of all known substances, yet it may be split by a steel tool, provided a blow be applied; but this requires a perfect knowledge of the structure, because it will only yield to such means in certain directions. This circumstance prevents the workmrn;. from forming facettes or planes generally, by the process of splitting; he is therefore obiged to resort to the process of abrasion, which is technically called cutting. The process of cutting is effected by fixing the diamond to be cut on the end of a stick, or handle, in a small ball of cement, that part which is to be reduced being left to project. Another diamond is also fixed in a similar manner; and the two stones being rubbed against each other with considerable force, they are mutually abraded, flat surfaces, or faceltes, being thereby produced. Other facettes are formed by shifting the diamonds into fresh positions in the cement, and when a suffici,.nt number are produced, they are fit for polishing. The stones, when cut, are fixed for this purlose, by imbedding them in soft solder, contained in a small copper cup, the part, or facette, to be polished, being left to protrude. A flat circular plate of cast-iron is then charged with the powder produced during the abrasion of the diamonds; and by this means a tool is formed which is capable of producing the exquisite lustre so much admnired on a finely-polished gem. Those diamonds that are unfit for working, on account of the imperfection of their lustre or color, are sold, for various purposes, under the technical name of Bort. Stones of this kind are frequently broken in a steel mortar, by repeated blows, until they are reduced to a fine powder, which is used to charg;e metal plates, of various kinds, for the use of jewellers, lapidaries, and others. Bort, in this state of preparation, is incapable of polishing any gems; but it is used to produce flat surfaces on rubies and other precious stones. Fine drills are made of small splinters of bort, which are used for drilling small holes in rubies, and other hard stones, for the use of watch-jewellers, gold and silver wiredrawers, and others, who require very fine holes drilled in such substances. These drills are also used to pierce holes in china, where rivets are to be inserted; also for piercing noles in artificial enamel teeth, or any vitreous substances. however hard. DIAMOND DUST. The demanld for diamond dust within a few years has in creased very materially, on account of the increased demand for all articles thalt are wrought by it, such as cameos, intaglios, &c. Recently there has been a discovery made of the peculiar power of diamond dust upon steel; it gives the finest edge to all D AS'ASE. 57~ kinds of cutlery, and threatens to displace the hone of Hungary. It is well known that in cutting a diamond (tlie liardest substance in nature), the dust is placed on the teeth of the saw-to which it adheres, and thus prevents the instrument from making its way through the gem. To this dust, too, is to be attributed solely tle power of man to mnake brilliants from roughl diamonds; from the dust is obtained the perfection of the geometrical symmetry, whllich is one of the chief beauties of the mineral, and also that adaanlltine polish, which inothing can injure or affect, save a substance of its own nat ure. IDIAMOND MICROSCOPES were first suggested by Dr. Goring, and have been well executed by Mr. Pritchllard. Previous to grinding a diamond into a spherical figure, it should be ground flat and parallel upon both sides, that by looking through it, as opticians try flint glass, we lay see whether it has a double or triple refractive power, as many have, which would render it useless as a lens. Aniong the 14 different crystalline formns of the diamondl, prolbably the octahedron and the cube are the only ones that will give a single vision. It will, in many cases, be advisable to grind d'amond lenses plano-convex, both because I-his figure gives a low sphlerical aberration, and because it saves the trouble of grinding one side of the gem. A concave tool of cast iron, paved with diamond powder, lihamnlered into it by a hardened steel punch, was employed by Mr. Pritchard. Tlis ingenious artist succeeded in completinlg a double convex of equal radii, of about 5_ of an inch focus, bearing an aperture of 1 of an inch with distinctness upon olpique ol)jects, and its entire diameter upon transparent ones. This lens gives vision with a trifling chromatic aberration; in other respects, like Dr. Goring's Alniciani reflector, ti). without its darkness, its light is said to be superior to th;at of anly comrpound microscople whatever, actingi with the same power, anld the same angle of iaperture. Tile advantage of seeing an olject without aberration by the interposition of only a single nulagnifier, instead of looking at a picture of it with an eye-glass, is evident. We thus lhave a simple direct view, whereby we shall see more accurately and minutely the real texture of objects. DIAPER, is the name of a kind of clolh, used chiefly for table linen. It is known among the French by the name of toilefonurr, and is,rnalmelnted with the most extensive ntaures of any kind of tweeled cloth, excepting damask. The mounting of a loom for working diaper is, in principle, much the same as a draw-loom, but the figures being less extensive, the mounting is more simple, and is wrought entirely by the weaver, without the aid of any other person. As tweeled cloths, of any number of leaves, are only interwoven at those intervals when one of the leaves is raised, the woof above, and the warp below, is kept floating or flushed, until the intersection takes place. of consequence, the floating.yarn above appears across the fabric, and that below longitudinally. This property of tweeled cloths is applied to form the ornamenlal figures of all kinds of tweeled goods, merely by reversing the floating yarn when necessary. In the simpler patterns, this is effected by a few additional leaves of treddles; but when the range of pattern becomes too great to render this convenient, an apparatus called a back harness is employed, and the cloth woven with this mounting is called diaper. Diapers are generally five-leaf tweels; that is to say, every warp floats under four threads of woof, and is raised, and of course interwoven with the fifth. This is done either successively, forming diagonals at 45~ upon the cloth, or by intervals of two threads, which is called the broken tweel. The latter is generally, if not universally, adopted in the manufacture of diaper. The reason of preferring the broken to the regular tweel, where ornaments are to be formed, is very obvious. The whole depending upon reversed flushing to give the appearance of oblique or diagonal lines, through either, would destroy much of the effect, and materially injure the beauty of the fabric. The broken tweel, on the contrary, restores to the tweeled cloth a areat similarity of appearance to plain, or alternately interwoven fabrics, and at the same time preserves the facility of producing ornaments by reversing the flushing. The simplest kinds of reversed tweels will he found described under TEXTILE FABRICS. DIASTASE. This curious substance, extracted by water fiom crushed malt, and precipitated fiom that infusion by alcohol, as is described under FERMENTATION, has been made the subject of new researches by M. Guerin Varry. Tile conclusions deducible from his interesting experiments are the following:1. One part of diastase, dissolved in 30 parts of cold water, put with 408 parts of potato starch out of contact of air, did not exercise the slightest action upon this substance in the course of 63 days, under a temperature varying from 68~ to 79~ Fahr. 2. Two parts of diastase do not in the course of an hour cause the globules of three parts of starch to burst, at a temperature approaching very nearly to that of the hot water which bursts them into a paste. It follows that diastase acts no part in the process of germination, towards eliminating the teguments of the starch, or transforming its interior portion into sugar, and a gummy matter assimilated by plants. b88 DIES FOR STAMPING. 3. Diastase liquefies and saccharifies the paste of starch without absorption or disengagement of gas; a reaction which takes place equally in vacuo as in the open air. 4. 100 parls of starch iade into a paste with 39 times their weight of water, mixed with 6'13 parts of diastase dissolved in 40 parts of water, and kept for an hour between 140~ and 149~ Fiahr., afforded 86-91 parts of sugar. 5. A paste containing 100 parts of starch, and 1393 parts of water, put in contact with 12'25 parts of diastase dissolved in 367 parts of cold water, having been maintained at 68~ Fhlr. during 24 hours, produced 77-64 parts of sugar. 6. The preceding experiment, repeated at the temperature of melting ice, afforded at the end of 2 hours, I'82 parts of sugar. 7. The most favorable proportions and circumstances for the production of a great quantity of sugar, are a slight excess of diastase or barley malt (at least 25 per cent. of the latter), about 50 parts of water to one of starch, and a temperature between 140~ and 1490 Fahr. It is of the greatest consequence for the saccharification to take place as speedily as possible, so that the sugar produced may not be left in contact with muchl gummy matter (dextrine), in which case the diastase will not convert the latter into sugar. In fact, the liquefaction and saccharification should proceed simultaneously. 8. The sugar of starch prepared either with diastase, or sulphuric acid, crystallizes in cauliflowers, or in prisms with rhomboidal facets. It has the same composition as sugar of grapes. 9. Diastase even in excess does not saccharify the gummy matter dissolved in the water along with the starch-sugar, but when the gumi is insulated, it is convertible almost entirely into sugar. 10. Gum arabic, cane sugar, and beer yeast, suffer no change fiom diastase. 11. A watery solution of diastase readily decomposes on keeping, either in contact or out of contact of air. 12. When starch-sugar, whether obtained by means of diastase or sulphuric acid, is submitted to the spirituous fermentation, the sum of the weights of the alcolol, carbonic acid, and water of crystallization of the sugar, is less than the weight of the sugar by about 38 per cent. This difference proceeds in a great measure from the formation of some acetic acid, lactic acid, volatile oil, and probably some other unknown products in the act of fermentation. DIDYM. A new metal, found in oxide of cerium, and so called as being associated in that ore as a twin brother of lanthanum. DIES FOR STAMPING. (Coins, Fr.; Minzstampeln, Germ.) The first circumstance that claims particular attention in the manufacture of dies, is the selection. of the best kind of steel for the purpose, and this must in some measure be left to the experience of the die-forger, who, if well skilled in his art, will be able to form a tolerably correct judgment of the fitness of the metal for the purpose, by the manner in which it works upon the anvil. It should be rather fine-grained than otherwise, and above all things perfectly even and uniform in its texture, and free from spots and patches finer or coarser than the general mass. But the very fine and uniform steel with a silky fracture, which is so much esteemed for some of the purposes of cutlery, is unfit for our present purpose, fiom the extreme facility with which it acquires great hardness by pressure, and its liability to cracks and flaws. The very coarse-grained or highly crystalline steel is also equally objectionable; it acquires fissures under the die-press, and seldom admits of being equally and properly hardened. The object, therefore, is to select a steel of a medium quality as to fineness of texture, not easily acted upon by dilute sulphuric acid, and exhibiting a uniform texture when its surface is washed over with a little aqua-fortis, by which its fieedom from pins of iron, and other irregularities of composition, is sufficiently indicated. The best kind of steel being thus selected, and properly forged at a high heat into the rough die, it is softened by very careful annealing, and in that state, having been smoothed externally, and brought to a table in the turning lathe, it is delivered to the engraver. The process of annealing the die consists in heating it to a bright cherry red, and suf fering it to cool gradually, which is best effected by bedding it in a crucible or iron po, of coarsely-powdered charcoal, that of animal substances being generally preferred. In this operation it is sometimes supposed that the die, or at least its superficial parts, becomes super-carbonized, or highly-converted steel, as it is sometimes called; but experience does not justify such an opinion, and I believe the composition of the die is scarcely, certainly not materially, affected by the process, for it does not remain long enough in the fire for the purpose. The engraver usually commences his labors by working out the device with small steel tools, in intaglio; he rarely begins in relief (though this is sometimes done); and having ultimately completed his design, and satisfied himself of its general effect and 1. ___________________________________________________________ __________________________________________________________ DIES FOR STAMPING. 581 correctness, by impressions in clay, and dabs, or casts in type metal, the die is ready for the important operation of hardening, which, from various causes, a few of which I shall enumerate, is a process of much risk and difficulty; for should any accident non occur, the labor of many months may be seriously injured, or even rendered quite useless. The process of hardening soft steel is in itself very simple, though not very easily explained upon mechanical or chemical principles. We know by experience that it is a property of this highly valuable substance to become excessively hard, if heated and suddenly cooled; if, therefore, we heat a bar of soft malleable and ductile steel red hot, and then suddenly quench it in a large quantity of cold water. it not only becomes hard, but fragile and brittle. But as a die is a mass of steel of' considerable dimensions, this hardening is an operation attended by many and peculiar difficulties, more especially as we have at the same time to attend to the careful preservation of the engraving. This is effected by covering the engraved face of the die with a protecting face, composed of fixed oil of any kind, thickened with powdered charcoal: some persons add pipe-clay, others use a pulp of garlic, but pure lamp-black and linseed oiL answer the purpose perfectly. This is thinly spread upon the work of the die, which, if requisite, may be further defended by an iron ring; the die is then placed with its face downwards in a crucible, and completely surrounded by pcr;dered charcoal. It 1iY heated to a suitable temperature, that is, about cherry red, and in that state is taken out with proper tongs, and plunged into a body of cold water, of such magnitude as not to become materially increased in tempPr iture; here it is rapidly moved about, until all noise ceases, and then lel' in the water till quite cool. In this process it should produce a bubbling and hissing noise; if it pipes and sings, we may generally apprehend a crack or fissure. No process has been found to answer better than the above simple and common mode of hardening dies, though others have had repeated and fair trials. It has been proposed to keep up currents and eddies of cold water in the hardening cistern, by means of delivery-pipes, coming from a height; and to subject the hot die, with its face uppermost, to a sudden and copious current of water, let upon it from a large pipe, supplied from a high reservoir; but these means have not in any way proved rjore successful, either in saving the die or in giving it any good qualities. It will be recollected, from the form of the die, that it is necessarily only, as it were, case-hardened; the hardest strata being outside, and the softer ones within, which envelop a core, something in the manner of the successive coats of an onion; an arrangement which we sometimes have an opportunity of seeing displayed in dies which have been smashed by a violent blow. The hardening having been effected, and the die being for the time safe, _ome fur. ther steps may be taken for its protection; one of these consists in a -ery mild kind of tempering, produced by putting it into water, gradually raised to tie boiling point, till heated throughout, and thei suffering it gradually to cool. This operation renders the die less apt to crack in very cold weather. A great safeguard is also obtained by thrusting the cold die into a red-hot iron ring, which just fits it in that state, and which, by contracting as it cools, keeps its parts together under considerable pressure, preventing the spreading of external cracks and fissures, and often enabling us to employ a split or die for obtaining punches, which would break to pieces without the protecting ring. If the die has been successfully hardened, and the protecting paste has done its duty, by preserving the face from all injury and oxydizement, or burning, as it is usually called, it is now to be cleaned and polished, and in this state constitutes what is technically called a MATRIX; it may, of course, be used as a multiplier of medals, coins, or impressions, but it is not generally thus employed, for fear of accidents happening to it in the coining press, and because the artist has seldom perfected his work upon it in this state. It is, therefore, resorted to for the purpose of finishing a PUNCH, or steel impression for relief. For this purpose a proper block of steel is selected, of the same quality, and with the same precautions as before, and being carefully annealed or softened, is turned like the matrix, perfectly true and flat at the bottom, and obtasely conical at top. In this state, its conical surface is carefully compressed by powerful and proper machinery upon the matrix, which, being very hard, soon allows it to receive the commencement of an impression; but in thus receiving the impression, it becomes itself so hard by condensation of texture as to require, during the operation, to be repeatedly annealed, or softened; otherwise it would split into small superficial fissures, or would injure the matrix; much practical skill is therefore required in taking this impression, and the punch, at each annealing, must be carefully protected, so that the work may not be injured. Thus, after repeated blows in the die-press, and fretquent annealing, the impression 582 DIGESTER. from the matrix is at length perfected, or brought comt letely up, and having been retouched by the engraver, is turned, hardened, and collared, like the matrix, of wlhich it is now a complete impression in relief, and, as we have before said, is called a punch. This punch becomes an inexhaustible parent of dies, without further reference to the orizinal matrix; for now by impressing upon it plugs of soft steel, and by pursuing with them an exactly similar operation to that by which the punch itself was obtained, we procure impressions from it to any amount, which of course are fac-similes of the matrix, and these dies being turned, hardened, polished, and, if necessary, tempered, are employed for the purposes of coinage.'he distinction between striking medals and common coin is very essential, and the work upon the dies is accordingly adjusted to each. Medals are usually in very high relief, and the effect is produced by a succession of blows; and as the metal in which they are struck, be it gold, silver, or copper, acquires considerable hardness at each stroke of the press, they are repeatedly annealed during the process of bringing them up. In a beaurtful medal, which Mr. Wyon some time since completed for the Royal Navy College, the obverse represents a head of the King, in very bold relief; it required thirty blows of a very powerful press to complete the impression, and it was necessa.y to anneal each medal after every third blow, so that they went ten times into the fire for that purpose. In striking a coin or medal, the lateral spread of the metal, which otherwise would ooze out as it were fiom between the dies, is prevented by the application of a steel collar, accurately turned to the dimensions of the dies, and which, when left plain, gives to the edge of the piece a finished and polished appearance; it is sometimes grooved, or milled, or otherwise ornamented, and occasionally lettered, in which case it is made in three separate and moveable pieces, confined by a ring, into which they are most accurately fitted, and so adjusted that the metal may be forced into the letters by its lateral spread, at the same time that the coin receives the blow of the screw-press. Coins are generally completed by one blow of the coining-press. These presses are worked in the Royal Mint by machinery, so contrived that they shall strike, upon an average, sixty blows in a minute; the blank piece, previously properly prepared and annealed, being placed between the dies by part of the same mechanism. The number of pieces which may be struck by a single die of good steel, prperly hardened and duly tempered, not unfrequently amounts at the Mint to between three and four hundred thousand, but the average consumption of dies is of course much greater, owing to the variable qualities of steel, and to the casualties to which the dies are liable: thus, the upper and lower die are often violently struck together, owing to an error in the layer-on, or in that part of the machinery which ought to put the blank into its place, but which now and then fails so to do. This accident very commonly arises from the boy who superintends the press neglecting to feed the hopper of the layer-on with blank pieces. If a die is too hard, it is apt to break or split, and is especially subject to fissures, which run from letter to letter upon the edoe. If too soft, it swells, and the collar will not rise and fall upon it, or it sinks in the centre, and the work becomes distorted and faulty. He, therefore, who supplies the dies for an extensive coinage has many accidents and difficulties to encounter. There are eight presses at the Mint, fiequently at work for ten hours each day, and the destruction of eight pair of dies per day (one pair for each press) may be considered a fair average result, though they much more frequently fall short of, than exceed this proportion. It must be remembered that each press produces 3600 pieces per hour, but, making allowance for occasional stoppages, we may reckon the daily produce of each press at 30,000 pieces; the eight presses, therefore, will furnish a diurnal average of 240,000 pieces. DIGESTER is the name of a strong kettle or pot of small dimensions, made very strong, and mounted with a safety valve in its top. Papin, the contriver of this apparatus, used it for subjecting bones, cartilages, &c. to the solvent action of high-pressure steam, or highly heated water, whereby he proposed to facilitate their digestion in the stomach. This contrivance is the origin of the French cookery pans, called atuoclaves, because the lid is self-keyed, or becomes steam-tight by turning it round under clamps or ears at the. sides, having been previously ground with emery to fit the edge of the pot exactly. In some autoclaves the lid is merely laid on with a fillet of linen as a lute, and then secured in its place by means of a screw bearing down upon its centre from an arched bar above. The safety valve is loaded either by a weight placed vertically upon it, or by a lever of the second kind pressing near its fulcrum, and acted upon by a weight which may be made to bear upon any point of its graduated Irm. Chevreul has made a useful application of the digester to vegetable analysis. His instrument consists of a strong copper cylinder, into which enters a tight cylinder ot DISTILLATION. 58S silver, having its edge turned over at right angles to the axis of the cylinder, so as tc form the rim of the digester. A segment of a copper sphere, also lined with silver stops the aperture of the silver cylinder, being applied closely to its rim. It has a conical valve pressed with a spiral spring, of any desired force, estimated by a steelyard. This spring is enclosed within a brass box perforated with four holes; which may be screwed into a tapped orifice in the top of the digester. A tube screwed into another hole serves to conduct away the condensable vapors at pleasure into a Woulfe's apparatus. DIMITY is a kind of cotton cloth oiminally imported from India, and now manufactured in great quantities in various parts of Britain, especially in Lancashire. Dr Johnson calls.it dimmity, and describes it as a lind of fustian. The distinction between fustian and dimity seems to be, that the former designates a common tweeled cotton clotl of a stout fabric, which receives no ornament in the loom, but is most frequently dyed after being woven. Dimity is also a stout cotton cloth, but not usually of so thick a texture; and is ornamented in the loom, either with raised stripes or fancy figures, is seldom dyed, but usually worn white, as for bed and bed-room furniture. Tile striped dimities are the most common, they require less labor in weaving than the others; and the mounting of the loom being more simple, and consequently less expensive, they can be sold at much lower rates. See TEXTILE FABRICS, for articular details of the plan of mounting them. DISINFECTION OF CLOTHING, (Jessrs. Davison and Symington's patent vrocess). -The absorption of noxious effluvia by clothes or soft and porous articles of mr.;chandise, has been long recognised as a fact by men who have directed special attention to this subject. The use of the various liquid disinfectants, which have of late been proposed, is not applicable to articles of clothing; and the common practice of baking clothes in ovens is liable to lead to their destruction, owing to the impossibility of regulating the temperature to which it is necessary to expose them. The only plan which combines economny with certainty of disinfection, is that which has been patented by Messrs. Davison and Symington, and which is now extensively employed in various manufactures. This plan consists in exposing the articles of clothing in a large chamber to rapid currents of air heated to a temperature insufficient to injure them, i. e. varying from 200) to 250~. We have had an opportunity of witnessing this process as applied to certain branches of manufacture, and the results were of the most satisfactory kind. In the case of infected clothing, it is obvious, that while a high temperature tends to destroy the animal poisons, a rapid current of air, constantly passing through the chamber, tends to carry them off. The temnperature of tile current of air can be so regulated that common albumen is speedily dried into a yellow transparent solid, without coagulation, or if necessary, the heat may be increased from 400~ to 5003, according to the nature of tile articles which are exposed. Dr. Copland has already directed the attention of the profession to tilis process, and observes that, "the great advantage of this method is its easy applicability to all kinds, and to any number of objects and articles without injury to their textures or fabrics." From an inspection of one of these chambers, when thle tem)perature of the current of air was 116~, we can state that the process of Messrs. Davison and Symington for the drying and disinfecting of the clothing of cholera and fever patients, will be far more efficacious than the common plan of washing and baking. In our opinion, an apparatus of this kind, fitted up in large hospitals, infirmaries, prisons and workhouses, as well as all quarantine stations, would be admirably adapted to prevent the diffusion of infectious diseases. DISTILLATION (Eng. and Fr.; Brantlu'einbrennerei, Germ.) means, in the commercial language of this country, the manufacture of intoxicating spirits; under which are comprehended the four processes, of mashivg the vegetable materials, cooling the worts, exciting the vinous fermeltation, and separating by a peculiar vessel, called a still, the alcohol combined with more or less water. This art of evoking the fiery demon of drunkenness from his attempered state in wine and beer, was unknown to the ancien. Greeks and Romans. It seems to have been invented by the barbarians of the north of Eur pe, as a solace to their cold and humid clime; and was first made known to the eollthern nations mn the writings of Arnoldus de Villa Nova, and his pupil, Raymond Lnlly of Majorca, who declares this admirable essence of wine to be an emanation of the Divinity, an element newly revealed to man, but hid from antiquity, because the human race were then too young to need this beverage, destined to revive the energies of modern decrepitude. He further imagined that the discovery of this aqua,itae, as it was called, indicated the approaching consummation of all things-the end of this world. However much he erred as to the value of this remarkable essence, he truly predicted its Vast influence upon humanity, since to both civilized and savage nations it has realized greater ills than were threatened in the fabled box of Pandora. 584 DISTILLATION. I shall consider in this place the first three of these subjects, reserving for the artlcie STILL an account of the construction and use of that apparatus. Whiskey, from the Irish word Usquebaugh, is the British name of the spirituous liquor manufactured by our distillers, and corresponds to the Eau de vie of the French and the Branntwein of the Germans. It is generated by that intestine change which grape juice and other glutino-saccharine liquids spontaneously undergo when exposed tc the atmosphere at common temperatures; the theory of which will be expounded under the article FERMENTATION. The production of whiskey depends upon the simple fact, that when any vinous fluid is boiled, the alcohol, being very volatile, evaporates first, and may thereby be separated from the aqueous vegetable infusion in which it took its birth. Sugar is the only substance which can be transformed into alcohol. Whatsoever fruits, seens, or roots afford juices or extracts capable of conversion into vinous liquor, either contain sugar ready formed, or starch susceptible of acquiring the saccharine state by proper treatment. In common languages tho intoxi.atine liquor obtained fiom the sw-J.t juices of fruits is called wine; and that fromr the infusions of farinaceous seeds, beer; though there is no real difference between them in chemical constitution. A similar beverage, though probably less palatable, is procurable from the Juices and;, "usions of many roots, by the process of fermentation. Wine, cider, beer, and fermented wash of every kind, when distilled, yields an identical intoxicating spirit, which differs in these different cases merely in flavor, in consequence of the presence of a minute quantity of volatile oils of different odors. I. The juices of sweet fruits contain a glutinous ingredient which acts as a ferment in causing their spontaneous change into a vinous condition; but the infusions of seeds, even in their germinated or malted state, require the addition of a glutinous substance called yeast, to excite the best fermentation. In the fabrication of wine or beer for drinking, the fertnentative action should be arrested before all the fruity saccharum is decomposed; nor should it on any account be suffered to pass into the acetous stage; whereas for makina distillery wash, that action should be promoted as long as the proportion of alcohol is increased, because the formation of a little acetic acid is not injurious to the quality of the distilled spirit, but rather improves its flavor by the addition of acetic ether, while all the undecomposed sugar is lost. Distillers operate upon the saccharine matter from corn of various kinds in two methods; in the first they draw off a pure watery extract from the grain, and subject this species of wort to fermentation; in the second they ferment and distil the infused mass of grains. The former is the practice of the distillers in the United Kingdom, and is preferable on many accounts; the latter, which is adopted in Germany, Holland, and the north of Europe, is less economical, nmore uncertain in the product, and affords a cruder spirit, in consequence of the fetid volatile oil evolved firom the husks in the still. The substances employed by the distillers may be distributed into the following classes:1. Saccharine juices. At the head of these stands cane-juice, which fresh from the mill contains fromn 12 to 16 per cent. of raw sugar, and like the must of the grape enters into the vinous fermentation without the addition of yeast, affording the species of spirit called Rum, which is possessed of a peculiar aroma derived fiom an essential oil in the cane. An inferior sort of rum is fabricated from molasses, mixed with the skimmings anl washings of the sugar pans. When molasses or treacle is diluted wilh twenty times its weight of warm water, and when the mixture has cooled to 78~ F., if one tweifth of its weight of yeast be added, fermentation will speedily ensue, and an ardent spirit will be generated, which when distilled has none of the aroma of rum; proving this to reside in the immediate juice or substance of the cane, and to be dissipated at the high temperature employed in the production of molasses. Though the cane juice will spontaneously undergo the vinous fermentation, it does so more slowly and irregularly than the routine of business requires, and therefore is quickened by the addition of the lees of a preceding distillation. So sensible are the rum distillers of the advantage of such a plan, that they soak woollen cloths in the yeast of the ferment. ing vats, in order to preserve a ferment from one sugar season to another. In Jamaica and some other of our colonies, 50 gallons of sstnt wash or lees are mixed with 6 gallons of molasses, 36 gallons of su(ar-pan skimmings (a substance rich in aroma), and 8 gallons of water; in which mixture there is about one twelfth part of solid sacelarum. Those who attend more to the quality than the quantity of their rum, will use a smaller proportion of the spent wash, which is always empyreumatic, and imparts more or less of its odor to the spirit distilled from it. The fermentation is seldom complete in less than 9 days, and most commonly it requires from 12 to 15; the period being dependant upon the capacity of the fermenting tun, and the quality of its contents. The liquid now becomes clear, the froth having fallen to the bottom, and few bubbles cf Las are extricated from it, while its specific gravity is reduced from 1*050 down tc )3992. The sooner it is subjected to distillation after this period, the better, to prevenl DISTILLATION. 585 the loss of alcohol by the supervention of the acetous stage of fermentation, an accident very liable to happen in the sugar colonies. The crude spirit obtained from the large single s ill at the first operation, is rectified in a smaller still. About 114 gallons of rum, proof strength, specific gravity 0-920, are obtained fiom 1200 gallons of wash. Now these 1200 oallons weigh 12,600 lbs., and contain nearly one eighth of their weioht of sugar=1575 lbs.; which should yield nearly its own weight of proof spirit, whose bulk is=]9725=1712 pound measures=171'2 gallons; whereas only 114 are obtained; proving the processes to be conducted in a manner far from economical, even with every reasonable allowance. Mr. Edwards gives the following estimate: "The total amount of sweets from an estate in Jamaica which makes 200 hogsheads of sugar, is 16,666 gallons. The wash set at the rate of 12 per cent. sweets should return 34,720 gallons of low wines, which should give 14,412 gallons of rum, or 131 puncheons of 110 gallons each." By my own experiments on the quantity of proof spirit obtainable from molasses by fermentation (afterwards to be detailed), one gallon of sweets should yield one gallon of spi it; and hence the above 16,666 gallons should have afforded the same bulk of rumn. But here we are left somrewhat in the dark, by not knowing the specific gravity of the rum sp'oken of by Mr. Edwards. The only light let in upon us is when he mentions rum oilproof, that is, a spii it in which olive oil will sink; indicaling a density nearly the same with our actual excise proof, for olive oil at 60~ F. has the specific gravity 0-919. When a solution of sugar of the proper strength is mixed with wine lees, and fermented, it affords a spirit by distillation not of the rum, but of the brandy flavor. The sweet juices of palm trees and cocoa nuts, as also of the maple, and ash, birch, &c., when treated like cane juice afford vinous liquors nomn which ardent spirits, under various names. are obtained; as arrack, &c.; the quantity being about 50 pounds of alcohol of 0'825 for every 100 pounds of solid saccharine extract present. Honey simiiarly treated affords the metheelin so much prized by our ancestors. Good whey, freed from curd by boiling, will yield 4 per cent. of spirit of wine. when fermented with the addition of a little yeast. 2. The juices of apples, pears, currants, and such fruits, afford by fermentation quan. tities of alcohol proportional to the sugar they contain. But the quality of the spirit is much better when it is distilled from vinous liquids of a certain age, than fiom recently fermented must. Cherries are employed in Germany, and other parts of the Continent, for making a high-flavored spirit called Kirsrh-wasser, or cherry water. The frilly ripe fruit is crushed by a roller press, or an edge-stone mill, along with the kernels; the pulp is fermented in a mass, the liquid part is then drawn off, and distilled. More or less prussic acid enters fiom the kernels into this spirit, which renders it very injurious, as a liquor, to many constitutions. I was once nearly poisoned by swallowing a wine glass of it in the valley of Chamouni. The ripened red fruit of the mountain ash constitutes a good material for vinous fermentation. The juice being mixed with some water and a little yeast, affords when well fermented, according to Hermstaedt, 12 pounds, or gallons, of alcohol fiom 2 bushels of the ripe berries. 3. Many roots contain sugar, particularly beet, from which no less than 7 per cent. of it may be extracted by judicious means. Hermstaedt recommends to mash the steam boiled clean roots, and add to the paste two thiids of its weight of boiling water, and a thirtieth of its weight of around malt, mixing the materials well, and then leaving them three hours in a covered vessel. Tile mixture must now be passed through a wire sieve, with meshes of one third of an inch square each; the residuum is washed with a little cold water, and, when the temperature has fallen to 77~ F., the proper quantity of yeast must be added, and the fermentation suffered to proceed in a covered tun. In 5 or 6 days it will be complete, and will afford by distillation,.from 100f pounds of beet root, about 10 or 12 pounds of proof spirits. Carrots and parsnips, when similarly treated, yield a considerable quantity of alcohol. II. drdenf spirits or whiskey from fecula or starchy materials. I have already pointed out, in the article BEER, how the starch is transformed into a saccharine condition, by malting and mashing; and how a fermentable wort may be obtained from starchy meal. By like operations may all vegetable substances, which consist chiefly of starch, become materials for a whiskey distillery. To this class belong all the farinaceous grains, potatoes, and the pods of shell fruits, as beans, vetches, horsechestnuts, acorns, &c. 1. Whiskey from corn. All those species of corn which are employed in breweries answer for distilleries; as wheat, rye, barley, and oats; as well as buckwheat, and maize or Indian corn. The product of spirits which these different grains afford, depends upon the proportion of starch they contain, including the small quantity of uncrystallizable sugar present in them. Hermstaedt, who has made exact experiments upon the subject, reckons a quart (Prussian or British) of spirits, containing 30 per cent. of the absolute alcohol of Richtcr, for 2 pounds of starch. Hence 100 pounds of starch should yield _. 586 DISTILLATION. 35 pounds of alcohol; or 4*375 gallons imperial, equal to 7'8 gallons of spirits, ex- isZ proof 100 pounds of the following grains afford in spirits of specific gravity 0.9427, conr taining 45 per cent. of absolute alcohol, (= 9 of British proof,) the following quantities:Wheat, 40 to 45 pounds of spirits; rye, 36 to 42; barley, 40; oats, 36; buckwheat, 40; maize, 40. The mean of the whole may be taken at 40 pounds, equal to 4} gallons imperial, of 0-9427 specific gravity = 3:47 gallons, at excise proof. The chief difference in these several kinds of corn consists in their different bulks under the same weight; a matter of considerable importance; for since a bushel of oats weighs little more than the half of a bushel of wheat, the former becomes for some purposes less convenient in use than the latter, though it affords a good spirit. Barley and rye are the species of grain most commonly employed in the European distilleries for making whiskey. Barley is mostly taken either partly or altogether in the malted state; while the other corns are not malted, but merely mixed with a certain proportion of barley malt to favor the saccharine fermentation in the mashing. It is deemed preferable to use a mixture of several sorts of grain, instead of a single one; for example, wheat with barley and oats; or barley with rye and wheat; for the husks of the oats diffused through the wheat flour and rye meal keep it open or porous when mashed, and thus favor the abstraction of the wort; while the gluten of the wheat tends to convert the starch of the barley and oats into sugar. When the whole of the grain, however, is malted, a much more limpid wort is obtained than fiom a mixture of malt with raw grain; hence the pure malt is preferable for the ale and porter brewer, while the mixture affords a larger product, at the same cost of materials, to the distiller. When barley is the only grain employed, from one thiid to one sixth of malt is usually mixed with it; but when. wheat and rye are also taken, the addition of from one eighth to one sixteenth of barley malt is sufficient. Oats are peculiarly proper to be mixed with wheat, to keep the meal open in the mashing. Tie following are the proportions used by some experienced Scotch distillers. 250 bolls, containing 6 bushels each, being used for a mashing, consist of, 25 bolls of oats, weighing 284 lbs. per boll, or 47- lbs. per bushel; 42 malt 240 40 25 rye 320 53 158 barley 320 531 250 mean 48From each boll, weighing 291 Ibs., 14 imperial gallons of proof whiskey are obtamea on an average; equivalent to 11-2 gallons at 25 over proof. The malting for the distilleries is to be conducted on the same principles as for the breweries, but the malt ought to be lightly kiln-dried, and that preferably at a steam heat, instead of a fire, which is apt to give an empyreumatic smell to the grain that passes into the spirit;. For ruch pers-ns, indeed, as rel'sh the srmell of bt.rned turf, called l eat-reek in Scotland, the malt should be dried by a turf fire, whereby the whiskey will acquire that peculiar odor. But this smell, which was originally prized as a criterion of whiskey made from pure malt, moderately fermented and distilled with peculiar care, has of late years lost its value, since the artifice of impregnating bad raw grain whiskey with peat-smoke has been extensively practised. Dr. Kolle, in his treatise on making spirits, describes a malting kiln with a copper plate heated with steam, 18 feet long, and 12 feet broad, on which a quantity of malt being( spread thin, is changed every 3 or 4 hours, so that in 24 hours he turns out upwards of 28 cwt. of an excellent and well kilned article. The malt of the distiller should be as pale as possible, because with the deepening of the color an empyreumatic principle is generated. When Indian corn is the subject of distillation, it must be malted in the same way as described in the article BEER. According to Hermstaedt, its flour may be advantageously nwixed with the crushed malt in the mash tun. But its more complete dissolution may be accomplished by Siemen's mode of operating upon potatoes, presently to be described. 1. Mashing. Barley and raw grain are ground to meal by millstones, but malt is mereil crushed between rollers. If only one tenth or one eighth of malt be used with nine tenths or seven eighths of barley, some husks of oats are added, to render the mash miixture more drainable. When 40 bushels of barley and 20 of malt form one mashing, flour 600 to 700 gallons of water, heated to 150~ F., are mixed with these 60 bushels in the mash tun. DISTILLATION. 587 and carefully incorporated b; much manual labor with wooden cars, or in great concern, by the mechanical apparatus used in the breweries. This agitation must be continued for 2 or 3 hours, with the admission from time to time of about 400 additional gallons of water, at a temperature of 190~, to counteract the cooling of the materials. But since the discovery of diastase, as the best heat for saccharifying starch is shown to be not hilger than 160~ F., it would be far better to mash in a tun, partially, at least, steam incased, whereby we could preserve the temperature at the appropriate degree for generating the greatest quantity of sugar. If the wort be examined every half-hour of the mashing period, it will be found to become progressively sweeter to the taste, thinner in appearance, but denser in reality. The wort must be drawn off from the grains whenever it has attained its maximum density, which seldom exceeus 150 lbs. per barrel; that is, 360 -- 150 = 1-42, or 4^ 3',0 per cent. As the corn of the distiller of raw grain has not the same porosity as the brewer's, the wort cannot be drawn off from the bottom of the tun, but through a series of holes at the level of the liquor, bored in a pipe stuck in at the corner of the vessel About one third only of the water of infusion can thus be drawn off from the pasty mass. More water is therefore poured on at the temperature. of 1900, well mixed by agitation for half an hour, then quictly infused for an hour and a half, and finally drawa off as before. Fully 400 gallons of water are used upon this occasion, and nearly as much liquor may be drawn off. Lastly, to extract from the grains everything soluble, about 700 gallons of boiling hot water are turned in upon them, thoroughly incorporated, then left quietly to infuse, and drawn off as above. This weak wort is commonly reserved for the first liquor of the next mashing operation upon a fresh quantity of meal and malt. The English distiller is bound by law to make his mixed worts to be let down into the fermenting tun of a specific gravity not less than 1 050, nor more than 1 090; the Scotch and Irish distillers not less than 1-030, nor more than 1-080; which numbers are called, gravity 50, 90, 30, and 80, respectively. With the proportion of malt, raw grain, and water, above prescribed, the infusion first drawn off may have a strength = 20 per cent. = spec. grav. 1-082, or 73 lbs. per barrel; the second of 50 lbs. per barrel, or 14 per cent.; and the two together would have a strenoth of 61-2 lbs. per barrel = 17 per cent., or spec. grav. 1-070. From experiments carefully made upon a considerable scale, it appears that no more than four fifths of the soluble saccharo-starchy matter of the worts is decomposed in the best regulated fermen. tations of the distiller from raw grain. For every 2 lbs. so decomposed, 1 lb. of alcohol, spec. gray. 0-825, is generated; and as every gallon of spirits of the spec. grav. 0-909 contains 4-6 lbs. of such alcohol, it will take twice 4-6 or 9-2 lbs. of saccharine matter to produce the said gallon. To these 9-2 lbs., truly transmuted in the process, we must add one fifth, or 1-84 lbs., which will raise to 11-04 the amount of solid matter employed in producing a 2allon of the above spirits. Some distillers mash a fourth time; and always use the feeble wort so obtained in mashing fresh Drain. 2. As the imperfect saccharine infusion obtained from raw grain is much more acescent than the rich sugary solution got from malt in the breweries, the distiller must use every precaution to cool his worts at quickly as possible, and to keep them clear from any acetous taint. The different schemes of cooling worts are considered under BEEA and REFRIGERATION. As the worts cool, a quantity of starchy matter is precipitated, but it is all carefully swept along into the fermenting tun, and undoubtedly contributes to increase the production of alcohol. During the winter and tempelate months, when the distilleries are most actively at work, the temperature at which the worts are set is usually about 70~ F. When much farinaceous deposite is present, the heat may be only 65~, because, in this case, a slow fermentation seems to favor the conversion of that starch into sugar. In some German distilleries a little chalk is mixed with the worts, to ch.lek acidity. 3. Tie fermentation. The yeast added to the worts as a ferment, ought to be the best top barm of the London porter breweries. About 1 gallon of it is requisite for every 2 bushels of meal and malt worked up in the mashing process; and of this quantity only a certain propor. tion is introduced at the beginning; the remainder being added by degrees, on the second and third days. Should the fermentation flag, a little more may be added on the fourth or fifth day and the contents of the tun may be roused by an agitator. About 8 or 9 gallons may be introduced four days in succession to the quantity of worts extracted from 60 bushels of the farinaceous materials; or the third day's dose may be intermitted, and joined to the fourth on the subsequent day. 588 DISTILLATION. Great diversity and no little caprice prevail among distillers in respect of the periods ol administering the yeast; but they.hould be ooverned very much by the appearance of the fermentation. This process continues from nine to twelve or even fourteen days, according to circumstances; the tuns being left quite open during the first five days, but being covered moderately close afterwards to favour the full impregnation of the liquor with carbonic acid, as a fermenting agent. In consequence of the great attenuation of the wort by the generation of so much alcohol, no good body of yeast continues to floal on the surface, and what is formed is beat down into the liquor on purpose to promote the fermentation. The temperature of the wash gradually increases till towards the end of the fourth day, when it attains its maximum height of about 25~ above the pitch of 55~ or 60~ at which it may have been set. The time of the greatest elevation of tem. perature, as well as its amount, depends conjointly upon the quality of the yeast, the nature of the saccharo-starchy matter, and the state of the weather. It is highly probable that the electrical condition of the atmosphere exercises a considerable influence upon fermentation We know the power of a thunder-storm to sour vinous fluids. An experimental inquiry into the relation between electricity and fermentation, could not fail to prove both curious and profitable. The dimunition of the density of the wort is carefully watched by the distiller, as the true criterion of the success of his process. This alleaialion, as he calls it, is owing partly to the decomposition of the sugar, which communicate(d its gravity to the solution, and partly to the introduction of the lighter alcoholic particles. Were a?' the saccharostarchy matter resolved into gaseous compounds, the wort would become water; Dut since a part of it remains ulndecomposed, and a portion of alcohol is produced at the expense of the decomposed part, the decree of attenuation becomes a somewhat complicated probler in a theoretical point of view; the density due to the residuary sugar being masked and counteracted by the spirit evolved. Could the alcohol be drawn off as it is formed, the attenuation would probably become greater, because the alcohol checks the fermentative action, and eventually stops it, before all the saccharum is decomposed. After the wash has taken its highest degree of temperature, not much more spirit is found to be generated; were this therefore removed by proper means, the remaining vegetable matter would undoubtedly yield a further product of alcohol. In the attenuation of raw-grain wash, the specific gravity seldom arrives at 1-000; but most commonly stops short at 1-002 or 1'004. When the vinous fermentation comes to an end, the acetous is apt to commence, and to convert a portion of the alcohol into vinegar; a result which is easily ascertained by the increasing specific gravity, sour smell, and acidulous reaction of the wash upon litmus paper, which remains after the paper is heated, showing that the red color is not caused by carbonic acid. Fermentation proceeds with more uniformity and success in the large tuns of the distiller, than in the experimental apparatus of the chemist; because the body of heat generated in the former case maintains the action. But I have succeeded in obviating this inconvenience in operating upon 80 or 90 gallons, by keeping up the temperature, when it begins to flag, by transmitting hot water through a recurved pipe plunged into the tun. We have already mentioned that one gallon of spirits, one in ten over-proof, is upon the average generated from 11-04 lbs. of starch sugiar; hence we conclude that one pound water-measure of spirits at proof (= -1_ imperial gallon) is produced from one pound of the saccharum. Malt whiskey.-The treatment and produce of malt distilleries are in some respects different from those of raw grain. Having been professionally employed by the proprietors of both, I am prepared to state the peculiarities of the latter, by an example. 500 bushels of ground malt are first mashed with 9000 gallons of water, heated to the temperature of 160~ F.: 6000 gallons of worts are drawn off into the coolers, and let down into the fermentinr tun at 68~. From 3 to 4 per cent. of a mixture of London porter yeast with quick Scotch barm are added, and well stirred through the mass. At the enOl of two or three days, in general, the fermentation is finished. On the residuary grains of the malt, fiom 4500 to 5000 gallons of water at 1SO' are run, which after proper mashing as before, are drawn off; then 4500 more are poured on, the drainage of which is added to the second. Both of these together, constituting 9000 gallons, are heated next day, and employed for the mashing of 500 bushels of fresh malt. During the fermentation, the wash which was set at the spec. grav. 1'065, comes down to water = 1'000. The wash is distilled in two stills, appropriated to it, of about 800 gallons capacity each, provided with a rotatory chain apparatus for preventing the lees from adhering to the bottom of the still. Into about 800 gallons of wash 8 lbs. of soap are put. The liquor obtained at this first distillation is called low wines. These low wines are redis. tilled in the spirit stills; the first and last portions of liquid being more or less blue oi lmiky in color, and rank in flavor, are run into a separate receiver called thefaints-backj DISTILLATION. 589 while the middle portion, constituting in a well-managed distillery, from three fourths to four fifths of the whole, are received into the spirit-back. The faints are mixed with a'arje quantity of water, and relistilled, in order to free them from the fetid oil derived from the husks of the grain. The interception of this noxious oil may be best effected by a self-regulating bath, between the capital of the still and the refrigeratory, as will be explainledl in treating of STILLS. The capitals of the common Scotch stills are made from 15 to 20 feet high, in order to prevent the chance of the wash boiling over into the worm; and they are, towards the beginning of the process, struck from time to time with a rod, and by the sound emitted it is known whether they be empty, partially filled, or in danger of an overflow; in which case the fire is damped, by a spout near the lurnace door, connected by a leather pipe with an elevated reservoir of wa'vr. When very pure spirits are wished for, a third or even a fourth distillation is had recourse to; there being a quantity of water mixed each time with the spirit in the still, to prevent its acquiring a harsh alcoholic flavor. According to some experienced distillers from raw drain, the mashing temperature of the first liquor should not exceed 140~ F.; whereas with Irat;t may be safely and beneficially 165~ or 170~. When rye is used instead of malt, 90 bushels of it are mixed -'(th 190 bushels of raw grain, constituting 280 bushels in whole, for the mashing of which 5200 gallons of water are required. An hour and a half more time is necessary for settling the mashing of the above mixture, than of grain alone. Gin is made in this way. The distiller of malt whiskey calculates on obtaining two gallons of proof spirits from ane bushel of malt, in average years. The highest yield is 20 gallons per quarter of 8 bushels; and the lowest is 16, when the malt and fermentation are indifferent. The best temperature to set the fermenting tun with malt wash is about 70~ or 72~ F. When malt is 5s. the bushel, 6 bushels at 30s. will yield 12 gallons of proof spirits. These cost therefore 2s. 6d. per gallon for the malt; to which must be added 3d. per bushel for the amount of malt duty not returned, or 1lI. on the gallon; this added to the Scotch duty of 3s. 4d. the gallon, makes the price altogether os. lld.; besides the expenses in fuel, yeast, labor, and rent, which may be estimated at 8ftd. per gallon. But 3d. may be deducted for what is paid by the dairymen for the spent wash and grains. The total cost, therefore, exclusive of use of capital, is 6s. 5d. per gallon in Scotland. The following is the work of a Scotch distillery, where good malt whiskey was made. One bushel of the malt weighed 35 lbs., or the boll, = 6 bushels, 210 lbs. In mashing each boll of malt, 110 gallons of water were run on it at 160~ F. As soon as the fermenting tun of 3000 gallons capacity was charged with the wash at from 64~ to 74~ F., 2 gallons per cent. of barm were added. When the wash had become attenuated from 1.060 to 1*010, another aallon of barm was'introduced. Tile temperature of the fermenting wash sometimes rises to 96~, which is, however, an extreme case, and not desirable. When the bubbles of carbonic acid mount in rapid succession, it is reckoned an excellent sign. If the tun be small, and stand in a cool apartment, it should be started at a higher temperature than in the reverse predicament. Should the fermentation be suffered to flag, it is in tgeneral a hopeless task to,estore vigorous action. Some try the addition of bus, that is, of some wort brought into a state of rapid fermentation in a tub, by a large proportion of yeast, but seldom with much success. Indeed, the law prohibits the addition of any wort to the tun at a later period than 24 hours after it is set; so that if bubs are used afterwards, the distiller is apt to incur a penalty. The maximum quantity of proof spirits obtained on the great scale at any time from raw grain mixed with from one fourth to one eighth of malt, seems to be 22 gallons per quarter. By the British laws a distiller is not allowed to brew and distil at the same time; but he must work alternately, one week, for instance, at fermentation, and next week at distillation. In fermenting solutions of sugar mixed with good yeast, the attenuation has been carried down to 0*984, and even 0'982, that is, in the language of the excise, 16 and 18 degrees below water, from 1'060, the density at which it was originally set in the tun. This was excellent work done on the scale of a great distillery nearly 30 years ago, when distillation from sugar was encouraged, in consequence of bad corn harvests. In an experiment which I made in 1831, for the information of a committee of the ffouse of Commons, on the use of molasses in the breweries and distilleries, I dissolved I cwt. of raw sugar in water, so as to form 741 gallons, inclusive of 2 gallons of yeast. The specific gravity of the mixture was 1-0593 on the 31st of March. By the 6th of April, that is, in 6 days, the gravity had sunk to 0'992, or 8 degrees under water, which was reckoned a good attenuation, considering the circumstances and the small quantity operated upon. By distillation it afforded at the rate of 14-875 gallons of proof spirits for 100 gallons of the wash. * ~90 ~DT9P!S' ILLATION. When the distillers first worked from sugar, they only obtained upon an average freor 1 cwt. 10-09 gallons imp. of proof spirit; but they afterwards got no less than 11' f! imp. gallons. The following experiment, which I made upon the fermentation of West India molasse? into spirits, for the information of the said committee, may prove not uninteresting to my readers. 150 Ibs. were dissolved in water and mixed with 2 gallons of yeast, weighing exactly 20 lbs. The wash measured 70 gallons, and had a spec. gravity of 1-06:17 at 60~ F. In two days the gravity had fa!len to 1-0055; in three days to 10022; and in five days to 1-00l. The temperature was Kept up at from 80~ to 90~ F., during the last two days, iy means of a steam pipe, to favor the fermentation. The product of spirits was 11 gallons, and -- of a gallon. Now 150 lbs. of the above molasses were found to contain of solid matter, chiefly uncrystallizable, 112 lbs. And as 112 Ibs. of sugar are estimated by the revenue laws to afford by fermentation 1.12 galllns imp. of proof spirit, the result of that experiment upon molasses must be considered satisfactory, bearing in mind that the saccharine s- stance in molasses has been not only partially decomposed by heat, but is mixed with some of the glutinous or extractive mattel of the cane. Since the alteration of the excise laws relative to distillation in 1825 and 1826, when permission was given to set the wort at lower gravities, the quantity of spirits produced from I quarter of corn has been much increased, even up to fully 20 gallons; and the proportion of malt has been much diminished. The latter was soon reduced from tiree sevenths malt, and four sevenths harley, or two fifths malt and three fifths barley, to one fifth of malt and now to one tenth or even one sixteenth. A discussion having lately taken place in Ireland between certain persons connected \ith the distilleries and the officers of the excise, whether, and to what extent, raw grain worts would pass spontaneously into the vinous fermentation, the Board in London requested me to superintend a series of researches in a laboratory fitted up at their office, to settle this important point. I shall content myself here with giving the result of one experiment, out of several, which seems to me quite decisive. Three bushels of mixed grains were taken, consisting of two of barley, one half of oats, and one half of malt, which, being coarsely ground by a hand-mill, were mashed in a new tun wilh 24 gallons of water at 155~. The mash liquor drawn off amounted to 18 gallons, at the density of 1'0165; and temperature of 82~ F. Being set in a new tun, it began to ferment in the course of 12 hours, and in 4 days it was attenuated down to gravity 1'012. This yielded, upon distillation in low wines, 3-22 gallons, and by rectification, in spirits, 3-05; while ihe quantity equivalent to the attenuation by the tables was 3-31, being an excellent accordance in such circumstances. The inquisitorial regime imposed by lawupon our distilleries, might lead a stranger to imagine that our legislators were desirous of repressing by every species of annoyance the fabrication of the fiery liquid which infiriates and demoralizes the lower population of these islands. But alas! credit can be given them for no such moral or philanthropic motive. The necessity of the exchequer to raise a great revenue, created by the wasteful expenditure of the state, on the one hand, and the etffrts of fraudulent ingenufity on the other, to evade the payment of the high duties imposed, are the true origin of that regitne. Examinations in distilleries are constantly making by the officers of excise. There is a survey at 6 o'clock in the morning, when the officers take their accounts and gauges, and make calculations which occupy several hours. At 10 o'clock they again survey, going over the whole premises, where they continue a considerable time, frequently till the succeeding officer comes on duty; at 2 in the afternoon another survey takes place, but not by the same people; at 6 in the evening the survey is repeated; at 10 there comes another survey by an officer who had not been engaged in any of the previous surveys of that day. He is not relieved till 6 o'clock next morning. In addition to these regular inspections, the distilleries are subject to frequent and uncertain visits of the surveyor and general surveyor. "We are never," says Mr. Smith, the eminent distiller of Whitecllapel, " out of their hands."* Before the fermented wort goes into the still, a calculation is made of the quantity of wash drawn from the wash back, and which is first pumped into what is called the wash charger. If the quantity in the wash charger exceeds the quantity in the wash back, the distiller is charged upon the higher quantity; if it contains less, he must pay according to the wash back, as being the larger quantity. When the quantity of wash i, all transferred to the charger, the discharge cock of the wash charger is unlocked, and the wash is allowed to be drawn off from the charger into the still, the charging and discharging cock of the still being locked by the officer. There can be no transfer of wash but through the pumps, which are locked also. The first distillation from the wash is worked into the low-wine receiver, which is also a locked up vessel; then of * Report of Committee on Molasses, 2198. DISTILLATION. 591 those low w'nes, the strength and quantity are ascertained by the excise. The account -f them affords a comparison with the quantity which the contents of the wash-x.tk had been estimated to produce; they are then pumped from the low wine receiver, through pumps previously locked into the low wine charger, which is also a locked up vessel; fiom the locked up charger, after the officer has done his duty regarding it, they are allowed to be drawn off into the low wine still, which is adistillation of the second extraction; then that low wine still works into another locked up cask, called the spirit receiver, for the receiving of raw spirits; when that distillation is finished, the officer, attending again on regular notice for that purpose, takes the quantity and strength of the spirits therein, and upon the quantity so ascertained he charges the duty. In distilling low wines, one portion of them goes into the spirit receiver, and a portion into what is called the faint receiver, which is another locked up vessel. These faints are in the next distillation united with the low wines, from the succeeding wash-back on their second distillation, and are worked together; the united produce of these goes partly into the spirit cask, and partly back again into the faint cask. The operation is thus continued till all the backs in the house are emptied. There is a kind of ardent spirits manufactured in Holland, vulgarly called Dutch gin, Hollands, and sometimes geneva, from genievre, the French for juniper, a plant with the essential oil of whose berries it is favored. One cwt. of ground malt mixed with two cwts. of rye meal are mashed for two hours, with about 450 Gallons of water at the temperature of 1609 F. The mash drawn off is reduced with cold water till the liquid part has the density of 45 lbs. per barrel, = specific Gravity 1-047; and is then put all together into the fermenting back at the temperature of 80~ F. One or two gallons of yeast are added. The fermentation soon becomes so vigorous as to raise the heat to 900 and urwards, but it is not pushed far, being generally over in two days, when the oravity of the wash still indicates 12 pounds of saccharum per barrel. By this moderate attenuation, like that practised by the contraband distillers of the Highlands of Scotland, it is supposed that the fetid oil of the husks is not evolved, or at least in very small quantity. The grains are put into the alembic along with the liquid wash, and distilled into low wines, which are rectified twice over, some juniper berries and hops being added at the last distillation. But the junipers are sometimes bruised and put into the mash. The produce of worts so imperfectly fermented, is probably little more than one half of what the British distiller draws from the same quantity of grain. But the cheapness of labor and of,grain, as well as the superior flavor of the Skiedam spirits, enables the Dutch distiller to carry on his business with a respectable profit. In opposition to the above facts, Dubrunrtaut says that about one third more spirits is obtained in Holland from grain than in France, because a very calcareous spr'ing water is employed in the mashing operation. Were this account well founded, all that the distillers of other countries would have to do would be merely to introduce a portion of chalk into their mash tuns, in order to be on a par with the Dutch. But the statement is altogether a mistake. In the vine countries, the inferior wines or those damaged by keeping, as also a fprmented mash of the pressed grapes, mixed with water, are distilled to form the 6(u. de vie de Cognac of the French, called Brandy in this country. It contains less essential oil, and that of a more agreeable flavor, than corn spirits. See BRANDY. Berzelius says that there are distillers who are guilty of putting a little arsenious acid into the still; that the spirits contain pretty frequently traces of arsenic, which may be detected by adding to them a little muriatic acid, then evaporating off the alcohol, and passing a current of sulphureted hydrogen gas through the residuary liqruid, which will give it the characteristic orpinent yellow tinge, arsenic being present. Copper, which is sometimes introduced into distilled grain, or even malt spirits, in consequence of the soap employed in the process of distillation, may be detfeer-,r] best by the brown precipitate which it occasions with ferroprussiate of potash. No arsc,i t is ever used in this country. When damaged grain has been mashed in making whiskey, a peculiar oily substance makes its appearance in it. On approaching the nostrils to such whiskey slightly heated, this volatile matter irritates the pituitary membrane and the eyes rely powerfully. These Spirits have exactly the smell of an alcoholic solution of cyanogene; they intoxicate more powerfully than pure alcohol of equal strength, and produce even temporary phrensy, with subsequent sickness and disordered functions. This volatile body is not cvanogene, though it oe so like it, for it forms no such combinations as cyanogene does. It may be extracted from diluted alcohol by agitating it with an unctuous oil,and then distilling the oil along with water. At the end of 3 or 4 months, this volatile matter disappears in a great measure, even when the spirits impregnated with it are enclosed in well-corked bottles; obviously from its undergoing a spontaneous decomposition. It may be preserved mxnch longer in the state of a watery solution. When acetic ether is added to well purified or clean spirits, such as the distillers call * Thomas Smith, Esq., of Whitechapcl Road, in Report of Molasses Committee, Part It. p. 149. 592 DISTILLATION. silent whiskey, it gives it somewhat of the flavor of brandy. For this purpose, also, the spirits are rectified from bruised prunes, or the lees of the cognac distilleries, whereby they acquire additional flavor. The astringent taste of old brandy is imitated by the introduction of a little catechu into the British spirits. Burned sugar is employed as a coloring in these imitations. IV. Of making whiskey from potatoes.-This root, in certain localities where it abounds at a moderate price, is an excellent material for fermenting into alcohol. When sound, it possesses fromn 20 to 25 per cent. of solid substance, of which starch constitutes at least three fourths; hence 100 pounds contain from 16 to 22 pounds of starch susceptible of being saccharified. In the expressed juice there is a small quantity of tartaric acid. Previously to mashing, potatoes must be first well washed in a horizontal cylindrical cage revolving partially in a trough of water, as will be described in tiating of the manufactire of sugar from beet root. They must be then boiled in a close vessel with steam, provided with a perforated bottom a few inches above the real one. The top has an opening with a cover fitted tightly to it; through that the potatoes are intr-tduced; and immediately above the false bottom there is a similar aperture through which the boiled potatoes are taken out. The steam-pipe enters at the top, runs down the side a little way, and terminates in a widened mouth. The large lids are secured by cross bars, the small hole by folds of linen. In the lower valve there are two small holes closed with pins, for inserting a wire to feel whether the potatoes be sufficiently boiled. If so, the steam is immediately stopped off, the lower lid is removed, and the potatoes pulled out with a hook into a 465 tub. They must be imme~Jc ^&s,a~S2> cdiately made into a homoge464 neous paste before they get tI m D _ _ cold. Fig. 464 represents, in plan, or horizontal section, the apparatus used in France for 91E A X, this purpose. A B are two E G c......c.. cylinders covered with wire... m n / — =-1: - _ __ cloth, but open at the ends; 1 _ -|1IIIl- - — = H c c and D D are two pieces of ei tl ^S 1 \ - D __d_-_=: = rh wood fixed on the two axes, t5 II-~-n ^i" l _ __ 1 |_in the form of two cones, with Lj Kt% U ji -F A E;A the adjoining surfaces truncated; upon which, as also upon iron rings E F, of the -same diameter, made fast to the axes, the wire cylinder rests. Of the two wheels G H, the smaller has 18, the greater has 21 teeth. Tile diameter of each cylinder is 14 inches, the length 18. Above and between the two cylinders, there is a hopper for the reception of the boiled potatoes. This machine triturates 1200 pounds of potatoes per hour. Their paste must be forthwith mashed with some ground wheat or barley, and a proportion of malt; then be set a fermenting. As in the above mode of trituration, the potatoes are apt to cool to such a degree as to obstruct their ready admixture with water, it is better to make them into a paste in the vessel in which they are steamed. The apparatus contrived by Siemens fully answers this end. It consists essentially of a tub A, represented in Jig. 465, in section. It is cylindrical, and made of planks from 3 to 4 inches thick, joined firmly and steam-tight; the upper and under ends being well secured with iron hoops. The lower part is about 2 inches more in diameter than the upper. About a foot from the bottom, in a circular groove, a cast iron partition w, or disc full of holes, is made fast, which serves the purpose of a scarce, the apertures being an inch asunder; above, from 8 to J_ of an inch in diameter, and below, scooped out to half an inch. This disc is half an inch thick in the edges, and five fourths of an inch in the middle. Through the female screw a in the top of the cylinder, there passes the screwed rod b, one and a half inches thick, provided at top with a strong cross bar c c, for lurning it round. The under end of this rod has a square piece terminating in a short screw, upon which a wrought iron cross is secured by means of a screw nut, so as to stand at right angles to the rod. This cross is composed of two distinct arms; of which one of them is mounted on the upper side with little knives an inch and a half long; the other, upon the unde: side, with a wire brush, that may be made to rub against the perforated cast iron disc. On the side of the cylinder at E, fig. 465, there is a narrow aperture provided with a bung secured by a cross bar, and near the bottom at H there is another like it. Both openings serve for taking out the residuary matter. Through the opening E, the above two arms are introduced; and secured to the square of the rod by the screw nut. In the top there is an opening, Dn DISTILLATION. 593 for putting in the potatoes which may be shut in the same way. From the lid theri likewise issues a lateral tube F, which terminates in a tubful of water, for condensing the waste steam. G is the tube connected witl the steam boiler, for conducting the steam into the space under the iron disc w. With this apparatus the potatoes are prepared as follows: when the screw rod is sc fixed that the cross touches the disc, the cylinder is to be filled with washed potatoes to within one foot of the top, leaving them so(me space to expand. The orifice D is to be then closed, and the steam admitted. When the potatoes are boiled enough, two laborers lay hold of the lever handles c c, of the screw rod b, and turn it round with the effect of screwing up the spiked cross, and of triturating the potatoes; an operation which may be still more effectually done by screwing it down again. The potato paste is now let off by the plug hole H. into the tub L, where it is mixed with about 30 per cent. of boiling water, and one thousandth part of potash, made caustic with quicklime, in order to dissolve the albuminous n:atter coagulated by the heat, and give complete fluidity to the n ass. The alkali also neutralizes the tartaric acid present. The mashed matter must now be mixed with the crushed malt diffused through 40 or 50 pounds of cold water for every 100 pounds of potatoes, which lowers the temperature to lo"~. The wort must be then diligently stirred during two hours; mixed with 40 or 50 pounds of cold water for 100 pounds of potatoes, and, when reduced to the temperature of 77~, put into the fermenting tun along with the proper quantity (3 or 4 per cent.) of yeast. As potatoes readily pass into the acetcus fermentation, the admixture of the malt, the mashing, and the cooling should be rapidly perfoimed, while the utmost cleanliness must be observed. The fermentation is brisk, probably from the agency of the albumen. and furnishes a good head of barm, which answers well for the bakers; 100 pounds of potatoes yield from 18 to 20 pounds measure of spirits, nine elevenths of our excise proof; or about 16 pounds measure of proof, = about 1'.allons. It has been observed that after the month of December potatoes begin to.ield a smaller product of fermented spirits; and when they have once sprouted or germinated, they afford very little indeed. From the difficulty of keeping and transporting potatoes, distillation from them, even though our laws now permit it, can never become general till some plan be adopted for overcoming these disadvantages. A scheme of this kind, however, has been successfully piactised in Vienna, which consists in subjectiln the washed potatoes to strong pressure in a perforated chest by a hydraulic or screw press, wheieby they lose about three fourths of their weight, and may then be readily dried into a white flour, that may be kept for several years without injury, and transported to considerable distances with comparative ease. This flour, mixed with a moderate quantity of ground malt, and saccharified by mashing with water, at the temperature of 1670 F., becones capable of affording a sweet wort convertible by fermentation either into beer or whiskey. Horse-chestnuts, accordina to Hermstaedt, are an eligible material for producing alcohol, as 128 pounds of them afford 100 pounds of meal; which 100 pounds yield, by proper treatment, 34 pounds of spirits5 containing 36 per cent. of absolute alcohol, by Richtr's tables. Barlry to the extent of 10 pounds per 190 should be ground up with them, after they have been boiled in a steam apparatus, not only for the purpose of softening them, but freeing them from their bitter astringent matter. Acorns are pro ductive of alcohol by similar treatment. The best means hitherto discovered for depriving bad whiskey of its nauseous smell and taste is to pass it throuah well burned and coarsely pulverized charcoal, distributed as follows in a series of cylindrical casks. Each vessel must have a double bottom, the false one being perforated with conical holes, and placed a few inches above the true. Upon this perforated board a layer of chopped clean straw, one inch thick, is laid; and over the straw, a stratum of small river gravel, the size of large peas. This is to be covered with a pretty thick stratum of the charcoal, previously freed fiom dirt and dust by washing; upon which a piece of close canvass is to be spread, and pressed down by a thin bed of river sand. The cylinder or cask should be filled with these successive layers to within two inches of its top, and it is then to be closed air-tight. Irrmtdialely below the head, a rounr orifice is pierced in the side, for receiving an overflow tube, which is either screwead ectangularly to another elbow pipe, or is bent (awhen of block tin) so as to enter tight into an orifice beneath the false bottom of the second cylinder or cash. In this way, the series may be continued to any desired number of vessels; the last discharging the purified spirit into the store-back. The foul spirit must be made to flow into the bottom space of the first cylinder down through a pile in communication with a charging-back placed upon such an elevated level as to give sufficient pressure to force the spirits up through the series of filters; the supply-pipe being provided with a regulating stop-cock. The spirit may be filtered downwards through sand and cloth in 39 594 DOCIMACY. its final passage to the receiver. It has been found, with very crude spirits, that'eight successive cylinders were required to deprive them entirely of the rank flavor. Fiq. 466 represents one form of the worm-safe, which iis a. contrivance for permitting trivance for permitting the distiller tv observe and note at any period of the ~Ja; N\~ ~ distillation the alcoholic strength or tht,; /^0IX!\\ ~ specific gravity of his spirits, without access to the still or the means of pur.. m!a __,,I __ _ _ _=__ vy loining the product before it has paid duty. c I ~ ) |21t{4 0 11 3 lJ^ l The nose-pipe of the worm-tub terminates I X i in, and is firmly cemented to the side co the glass globe, a, from whose bottom the dis. N i s jcharge-pipe descends vertically, but has a T%1y ~ /> sstot cock upon it, and a branch small pipe b, turned up parallel to the former. This Ib Ad /is> branch is surmounted with a glass cylinder, \ /, / c, which, when the stop-cock is opened, gets filled with the spirits, and then receives a hydrometer to show the gravity of the fluid. The stop-cock mechanism is so contrived, 466 i //athat only one full of the small glass cylinder can be obtained at a time. The following is the gross produce of the excise duties on British distilled spirits for the United Kingdom annually from 1830 to 1840 inclusive: 1E31, 5,196,1751.; 1832, 5,163,3731.; 1833, 5,258,5721.; 1834, 5,287,032/.; 1835, 5,073,2761.; 1836, 5,. 485,8831.; 1837, 5,006,697t.; 1838, 5,451,7921.; 1839, 5,363,290/.; 1840, 5,208,0401. The net produce is very nearly the same. In 1838, 26,486,543 millions of gallons paid Jutv; in 1839, 25,190,843; and in 1840, 21,859,337. See RuM, SPIRITS, and STILL. DIVIDIVI, is an indigenous production of Jamaica. Mr. Rootsey obtained a mean produce of 6'625 grs. of leather from 60 grs. of dividivi, while the same quantity of the best Aleppo galls yielded only a mean. produce of 4-625. Hence it appears from Sir Humphry Davy's estimate, that the 60 grs. of dividivi contain 3'0475 grs. or 5'079 per cent. of tannin and 60 grs. of galls, on 2-12704 grains, or 345 per cent. Sixty grs. of oak bark yielded only 1'75 grnins of leather; whence it follows that it contains but 0-805 of a grain of tannin to the draehm, or not more than 13-4166 DOCIMACY, from the Greek A'Kitpa0w, I prove (Doc;.nasie, Fr.; Probierkunst, Germ.); is the art by which the nature and proportions of an ore are determined. This analytical examination was originally conducted in the dry way, the metal being extracted from its mineralizers, by means of heat and certain fluxes. But this method we.s eventually found to be insufficient and even fallacious, especially when volatile metals were in question, or when the fluxes could absorb them. The latter circum. stance became a very serious evil, whenever the object was to appreciate an ore that wai to be worked at great expense. Bergmann first demonstrated, in an elaborate disser. tation, that the humid analysis was much to be preferred; and since his time the dry way has been consecrated chiefly to the direction of metallurcic operations, or, at least, it has been employed merely in concert with the humid, in trials upon the small scale. After discovering an ore of some valuable metal, it is essential to ascertain if its quantity and state of combination will justify an adventurer in working the mine, and smelting its products. The metal is rarely found in a condition approaching to purity; it is often disseminated in a mineralizing gangue far more bulky than itself; and more fiequently still it is combined with simple non-metallic substances, such as sulphur, carbon, chlorine, oxygen, and acids, more or less difficult to get rid of. In these compound states its distinctive characters are so altered, that it is not an easy task either to recognise its nature, or to decide if it can be smelted with advantage. The assayer, without neglecting any of the external characters of the ore, seeks to penetrate, so to speak, into its interior; he triturates it to an impalpable powder, and then subjects it to the decomposing action df powerful chemical reagents; sometimes with the aid of alkalis or salts appropriate to its nature, he employs the dry way by fire alone; at others, he calls in the solvent power of acids with a digesting heat; happy, if after a serie.s of labors, long, varied, and intricate, he shall finally succeed in separating a notable proportion of one or more metals either in a pure state, or in a form of corn. bination such, that from the amount of this known compound, he can infer, with precision, the quantity of fine metal, and thereby the probable value of the mine. The blow-pipe, skilfully applied affords ready indications of the nature of the metallic DONARIUM. 595 tonstituents, and is therefore usually the preliminary test. The separation of tlhe several constituents of the ore can be effected, however, only by a chemist, who j-,ins to the most extensive knowledge of the habitudes of mlineral substances, much experience, sagacity, and precision, in the conduct of analytical operations. Under the individual metals, as also in tile articles METALLURGY, MINES, and ORES, I have endeavored to present such a copious and correct detail of docismastic processes, as will serve to guile the intelligent student llhrough tllis most mysterious labyrinth of nature and art. DONARIUM, a recently discovered metal.-Dr. Bergellanni received through Mr. Krantz a mineral from Brlerig in Norway, which is found in the samle zircon-syenite that contains wxhllerite and eukolite, and lie discovered in it the oxide of a new metal comlbined with silicic acid. This metal he calls Donarium, after the god Donar, and he assigns to it the syrmbol Do. The silicate of the oxide of donarium, Do2 03 Si 03 -2 H O, is yellowish red, in some fragmlents passing into brown, in others into yellow; when scratched or powdered, it is light orange. In thin films it is almost transparent, the thicker ones translucid. Some pieces have a distinctly laminated structure, in others thie fracture is more flat, or conchoidal. Its hardniess is tbetween that of fluor spar and apatite; its spec. grav.=5'397. Smtall films heated in a platina spoon break'own into a dark browin mlass, which reassumes an orange color when cold: the larger pieces lose their transparency. By heating it in a glass tube, watery vapor is driven off. Fragments hleld by the platina forceps in the flame of a slpirit lamp decrepitate. Heated by the blowpipe on charcoal,:t does not melt, a slight vitrification being sometimles olbserved on the edges, perhaps in consequence of tlhe intermixture of some foreign substance. Fused with soda, the silicic acid is dissolved. Tile other constituients are seen in the non-transparent mass, by tile help of a glass, as small yelfow particles. Borax yields a yellow bead, which is colorless when cold. Tile phosphates piroduce in the external part of the flame a reddish glass, which is colorless when cold; in the inner part of the flame the bead becomes yellow, and when cold is colorless. Tile mineral is readily and completely decomposed by acids, and yields when treated by hydrochloric acid a clesr an(d transparent gelatinlous matter. At the same time some carbonic acid is evolved. The color of the solution is deep yellow, like that of a concentrated solution of iron. The miineral is also affected by diluted acids, even by tartaric acid. After having been exposed to a strong heat, the essential parts of the mineral are no longer acted upon even by concentrated acids. The analysis showed the presence of lime, water, and the new oxide, also some traces of magnesia, manganese, carbonate of soda, and iron. Tlhe oxide of donarilun belongs to the class of earthy bodies, and ranks next to zirconia and yttria. The hydrate, which is thrown down by ammoinia of a beautiful white color, becomes yellow, and at last yellowish red, losing its hvdrate water in the air. By heat the latter is completely removed, and the oxide, which is insoluble in muriatic acid, can be perfectly deprived by this acid of the contained iron. The analysis showed the constituents to be:Silicic acid - -- 17'695 Oxide of donarium - - - - - - 71'247 Carbonate of lilte - - - - - - 4042 Oxide of iron - - - - -- 0'310 Magnesia and oxide of manganese - - - - 0214 Potash and a little soda - - - - - - 0303 Water - - - -6900 100'741 The metal is obtained as a black powder, by treating the oxide with potassium. If the alkaline solution be directly poured off and tile powder washed with water, it can be kept for fiom 24 to 36 hours under water without alteration; but if it remains under hot water, a yellowish gray mass is gradually formed, in consequence of oxidation. The black metallic powder forms heavy flocculi, which soon conglomerate anld are easily separated by filtration. When in the dried state they assume a metallic lustre when tubbed with an agate; and then can be preserved in this condition for several hours, even in a damp atmosphere, without developing any smell. The specific gravity is nearly =7-35. The powder thrown into a flame burns with a reddish light, and yields the red oxide(; so also, if the black powder le heated in a platina spoon, it burns, and moreover appears to glow, but only transitorily. Neither cold nor boiling muriatic acid affects the metal; nitric acid acts not when cold, and but slowly when heated; nitro-muriatic acid readily produces the red oxide, of which a small portion is d ssolved; by the application of a few arons of sulphuric acid a sulphate is formed, While at the same time the smell of sulphurous acid is perceived. The grayish yellow 596 DRYING HOUSE. substance produced by potash water, quickly forms, when heated by itself or moistened with nitric acid, the r(d oxide. This powder also, when thrown into the flame of a spirit lamp, glows. ]4ydrated Oxide of Donarium.-The precipitate produced by ammonia fiom the muriatic solution of the mineral is, by long digestion wili sulplluric acid, converted into sulphate of the oxide of donarium, and fromn this the hydrated oxide is precipitated by ammonia. The voluminous precipitate, dried at ordinary temperatures, forms yellow gummy masses, the powder of which is reddish. In this condition the substance represents tie pure hydrated oxide, which, like oxide of iron, probably combines with different proportions of water. The water is expelled by a slight increase of temperature. The hydrate is dissolved by all acids at common temperatures, and more so when heated. If muriatic acid be employed, no chlorine is developed. Oxide of Donaritom is obtained by heating the hydrate to redness. Its sp. gray. is 5'576, color deep red; its forn heavy glittering scales. Finely powdered it is orange; darker when strongly heated, and lighter again when cold. Mluriatic acid, nitric acid, aqua regia, and even fluoric acid, have no effect upon the oxide which has been heated to redness. By the continued action of concentrated sulphuric acid it is rendered soluble, if it be afterward mixed with much water. If the oxide, however, be exposed only to that temperature which expels the water from the hydrate, it is slightly acted upon by muriatic acid, without the development of chlorine. DORNOCK is a species of figured linen of stout fabric, which derives its name from a town in Scotland, where it was first manufactured for table-cloths. It is the most simple in pattern of all the varieties of the diaper or damask style, and therefore the goods are usually of coarse quality for common household wear. It receives the figure by reversing the flushing of the warp and woof at certain intervals, so as to form squares, or oblong rectangles upon the cloth.'The most simple of these is a succession of alternate squares, forming an imitation of a checlrer board or mosaic work. The coarsest kinds are generally woven as tweels of three leaves, where every thread floats over two, and is intersected by the third in succession. Some of the finer are tweels of four or five leaves, but few of more; for the six or seven leaf tweels are seldom or never used, and the eight leaf tweel is confined almost exclusively to damask. See TEXTILE FABRIC. DRAGON'S BLOOD, (Sanq dracon, Fr.; Drachenblii, Germ.) is a resinous substance, which comes to us sometimes in small balls about the size of a pigeon's egg, sometimes in rods like the finger, and sometimes like irregular cakes. Its color, in lump, is dark brown red; in powder, bright red; friable; of a siining fracture; sp. gray. 1'196. It contains a little benzoic acid, is insoluble in water, but dissolves readily in alcohol, ether, and oils. It is brought from the East Indies, Africa, South America, as the produce of several trees, the Draccena Draco, the Pterocarpus santalinus, Pterocarpus Draco and the Calamuns Rotang. Dragon's blood is used chiefly for tinging spirit and turpentine varnishes, for preparing gold lacquer, for tooth tinctures and powders, for staining marble, &c. According to Herbenger, it consists of 9-07 parts of red resin, 2 of fat oil, 3 of benzoic acid, 1'6 of oxalate, and 3'7 of phosphate of lime. DRUGGET is a coarse, but rather slight, woollen fabric, used for covering carpets, and as an article of clothing by females of the poorer classes. It is now-a-days nearly superseded by coarse cotton goods. DRYING IIOUSE. An apartment fitted up in a peculiar manner for drying calicoes and other textile fabrics. Mr. Southworth, of Sharples, a Lancashire bleacher, obtained a patent, in 1823, for the following ingenious arrangement, which has been since generally adopted, with certain modifications, in most of our extensive bleaching and printing works. Fig. 467 is a section of the drying-house, where a is a furnace and boiler for the purpose of generating steam; it is furnished with a safety valve in the tube b, at top, and from this tube the steam main c passes down to the floor of the basement story. From this main, a series of steam-pipes, as dl, extend over the surface of the floor, and from them heat is intended to be diffused for the purpose of warming the drying-house. Along the middle of the building a strong beam of timber e e extends, and is supported by cast-iron pillars; from this beam to bearings on the side walls, a series of rails are carried in a cross direction, over which rails the wet cloth is to be hung in folds, and the steam or evaporation emitted in drying is allowed to escape through apertures or ventilators in the roof. The mode in which the cloth is delivered on to the rails, on either side of the beam, will be best understood by reference to the delivering carriage, which is shown with its rollers partly in section. The wet cloth is first to be coiled upon a roller, and then placed in the carriage, as mtf, with its pivots bearing upon inclined planes. The carriage is to be placed at the DRYING MACHINE. 597 commencement of tile rails, running upon the middle beam, and also upon the sidebearings or railways extending along the side walls of tile building, parallel to and upon a level with the same beam. It is made to travel by means of an endless band 467 &; 7.k)i' -p 9 passing over two riggers, g and h, in fig. 467, and over pulleys and a band-wheel attached to the carriage, as will be explained. The rigger g, which moves this endless band, is actuated by bevel geer, seen at i, which is put in motion by a pinion at the end of a revolving shaft leading from a steam engine. In the same fig., k k is tile endless band passing over a pulley under the band-wheel and over the pulley n, by which it will be perceived that the traversing of tile band, as described, would cause these pulleys and wheels to revolve. On tile axle of the bandwheel m, there is a drum against which the roll of wet cloth f presses, and as this drum revolves, the roll of wet cloth is, by its friction, made to turn in a contrary direction, and to deliver off the cloth on to the periphery of the drum, whence it passes over a roller and descends to the rails. Upon the end of tile axle of the band wheel m, tliere is a pinion which takes into the teeth of tile large wheel, and upon the axle of tills large wheel there is a pinion that actuates tile internediate wheel which turns another toothed wlheel. This last-mentioned toothed wheel takes into cogs upon tile side railway, and lence, as tile train of wheels moves round, the carriage to which the wheels are attached is slowly impelled forward. As soon as the wlieels begir to move, and the carriage to advance, the wet cloth begins to uncoil, and to pass down over the first roller; a small roller attached to the carriage, as it passes over the rails in succession, holds tile cloth against each rail for a short space of tine, and prevents it flrom slipping, by which means the cloth descends in folds or loops between the rails, and is thereby made to hang in a series of folds or loops, as shown in the figu're. It will be perceived that as tlhe pivots of the cloth rollerf bear upon inclined planes, the roller will continually slide down as the cloth dininishes in bulk, keeping in contact with the drum, and delivering the cloth from the roller on to the several rails, as described. In order to stop the carriage in any part of its course, or to adjust any of the folds of the cloth, a man is usually placed upon the platform travelling with the carriage, over which he has perfect comlmand. Tilis apparatus may be also employed for taking tlhe clotli when dried off the rails; in which case the carriage must be made to travel backward, and by first guiding the end of the cloth on to tlie rollerf, and then putting the wheels in a retrograde motion, the cloth will be progressively coiled upon. the roller f? in a similar way to that by which it was uncoiled. DRYING MACHINE (CENTRIFUGAL), (Hydro-extracteur; Macchine d essorer, Fr.)-By tilis contrivance, Pentzoldt was enabled to deprive all kinds of wet clotlies in a few minutes of their moisture, without compression or heat. Kelly, a dyer, and Alliott, a bleecher, hiave since obtained a patenrt for the above machine with improvements. Fig. 468 represellts a partial section of the machine. A, A, is the flamle; B, the vertical shaft turningl in the step a, fixed on tile bridge b. This shaft bears on its upper part a friction cone c, firom which it receives its movement of rotation,' _______________ 598 DRYING MACHINE as will be shown presently; c is a drum containing two concentric compartments d e of the form represented in the figure; this drum moves freely upon the shaft B, and 468. K I rests when it is not in motion upon two conical projections f, g, which formr part of the shaft. These two compartments are each composed mainly of mecial, and their sides consist of tined iron wire coiled circularly at very small distar ces from each other, and soldered together crosswise by small slips of metal. The top, which covers the inner compartment d, is secured by bolts and screws to a circle of iron which retains tile wire sides of the same metal, but tllat which serves as a cover to the little compartment e, in which alone the goods are placed, is disposed so that it may be removed with ease, when these are to be introduced or withdrawn. It is furnished with an outer and inner border, disposed so that when the top is fixed the inner border presses upon the convex circumference of the ceetiral compartment, while the exterior border falls oatside of the edges of the other compartment. While the machine is at work, the second plate is maintained in its place by pins or bolts, not shown in the figure. The sides of the outer compartment d, are connected with the bottom by means of a prolongation of cross bands of metal wlieh ninite the wires anld are riveted or soldered to the two outer plates. Tlre wires of the interior compartment are attached by an iron hoop, to which they are riveted and soldered, and are united to the bottom plate by means of a rim upon this plate; a rim somewhat flattened upon the sides which are riveted and soldered. D, is a regulator suspended in tlhe inner compartmlent d, and whose two branches A, h, are loaded. Tlese two branches having roolm to dlay around tlhe bolts which serve as points of attachment, and which are fixed to tlhe upper plate, terminate in kneed Ibrancles whose extremities rest upon a rope g, wlich projects fiom the sliaft. E, is an exterior envelope secured to tlhe frame A, A. It encloses tlhe whole drum except at top, and serves to cat;cl tile water thrown out of the goods. At y lthere is a stopcock for tlie dischlarge of tins water, and the bottom contains besides tlhe end of a pipe by which hot air is introduced. Tile vertical sliaft B receives a movement of rotation and carries with it tlie drum. The more rapid this movement is tlhe more does tlhe cerntrifugal force tend to expel thle water contained in tire clothes or yarn to be dried. But as this force might also displace tile ceenrali slhaft, if thie weight was not rightly distrilmuted in tlie drum, and cause the dislocation of tlhe machine when the great velocity requisite for quick drying is given to it, the regulaltor D is tested to prevent accident. The branches of this regulltor spre;la wider tlhe more tlie velocity is increased, and raise consequently tile drum c above tile conical enlargements, which permsits tile drum to be somewhat misplaced and to rectify its position conformalhly to tlie inequalities of its load, so thlat its centre of gravity may always coincide with its centre of rotation. The drum is connected with the shaft as is shown in z, leaving it free to take tle requisite adjustment. To hinlder it fronm rising too suddenly, a spiral spring k is fixed over tlle sbiaft immediately alove tile conical enlargement q. Tn order to maintain the eqluilibrium more certainly, the apparatus is surromunded with a hollow crown F, half filled with water, and if during tile revolution of tlie macline tlre weight of the goods preldomillates on one side, that of thle water which accumulates on tlre other side serves tlie more to counterbalance it. Tlhe effect of this crown may be increased by dividing it DUNGiNG. 599 into two compartments or more. G, is a large pipe by which steam or hot air is intro. duced into the belly of the drum, which is pierced in this place with a great number of small. holes to receive it. The rotary movement is transmitted to the drum in the following way. I is a conical disc mounted upon the extremity of a shaft which actuates the cone a and the shaft B by means of friction; L is a cone fixed upon the extremity of the shaft. K L "is another cone of the same dimension, but whose base fionts the top of the other and which is placed on the shaft K" commanded by the prime mover. M is the belt which embraces the two cones, and whose lateral displacement, effected by means of a fork, permits the velocity of the machine to be regulated at pleasure. N is the pulley which directly receives the movement. In place of a single friction disc I, another may be employed, if judged necessary, and placed between the two, an additional fiiction pole in order better to equalize the friction. In this case the disc and additional cone should turn freely upon their own shafts. We may also adopt another arrangement for the bottom of the vertical shaft. The shaft immediately above the step is surrounded by a loose rim, around which a certain quantity of lead shot, or other granular matter, is conttained in the rim in the box which serves for the step. The top of this box is nierecd with an opening, into which, when the machine is at r'est, a cord connected with the shaft sinks, controlled by tle shaft, and when the drum.s raised by the action of the regulator D, this cord quits its place, which allows the shaft to displace the shot a little, and to take a position conformably to the point of the centre of gravity. But after all great attention should be paid to the proper working of the machine. DUCTILITY (Streckbarkeit, Germ.) is the property of being drawn out in length without breaking, possessed in a pre-eminent degree by go.' and silver, as also by'many other metals, by glass in the liquid state, and by many semifluid resinous and gur.my substances. The spider and the silk-worm exhibit the finest natural Exercise of ductility upon the peculiar viscid secretions from which they spin their threads. When a body can be readily extended in all directions under the hammer, it is said to be malleable, and when into fillets under the rolling press, it is said to be laminable. Table of the ductility and malleability of Metals. Metals ductile and Brittle metals Metals in the order Metals in the order of malleable in alphabetical in of their wire-drawing their lamninable order. alphabetical order. ductility, ductility. Cadmium. Antimony. Gold. Gold. Copper. Arsenic. Silver. Silver. Gold. Bismuth. Platinum. Copper. Iron. Cerium.? Iron. Tin. Iridium. Chromium. Copper. Platinum. Lead. Cobalt. Zinc. Lead. Magnesium. Columbium. Tin. Zinc. Mercury. Iridium. Lead. Iron. Nickel. Manganese. Nickel. Nickel. Osmium. Molvbdenum. Palladium.? Palladium.? Palladium. Osmium. Cadmium.? Cadmium.? Platinum. Rhodiun. Potassium. Tell uriurn. Silver. Titanium. Sodium. Tungsten. Tin. Uranium. Zinc. There appears to be, therefore, a real difference between ductility and malleability; for the metals which draw into the finest wire are not those which afford the thinnest leaves under the hammer or in the rolling press. Of this fact iron affords a eood illustration. Among the metals permanent in the air, 17 are ductile and 16 are brittle. But the most ductile cannot be wire-drawn or laminated to any considerable extent without being annealed from time to time during the progress of the extension, or rather the sliding of the particles alongside of each other, so as to loosen their lateral cohesion. DUNGING, in calico-printing, is the application of a bath of cowdung, diffused through hot water, to cotton goods in a particular stage of the manufacture. Duneing and scouring are commonly alternated, and are two of the most important steps in the process. The operation of dunoing has fcr its objects:1. To determine:he entire combination of the aluminous sub-salts with the stuffs, by 600 DUNGING sepiarating almost all the acetic acid which was not volatilized in the stove-drying of the mordant. 2. To dissolve and carry off from the cloth a portion of the thickening matters. 3. To separate from the cloth the part of the mordant that is uncombined, and merely mixed mechanically with the gum or starch. 4. To prevent, by the peculiar action of the dung, the uncombined mordant, as well as the acetic acid with which the bath is apt to get loaded, from affecting the blank parts of the cloth, or being injurious to the mordant. The aluminous base or mordant on the cloth, r.i:re or less neutralized by the dunging is next subjected to the dash-wheel or filling mill, where by the stream of water tht ren.ainder of the thickening and other impurities are washed away. No very exact analysis has been made of cowdung. Morin's, which is the most recent and elaborate, is as follows -- Water -. - 70-00 Vegetable fibre -24-08 Green resin and fat acids - - - 1-52 Undecomposed biliary matter - - 060 Peculiar extractive matter (bubuline) - - 1-60 Albumen - - - - 040 Biliary resin- - - - 180 According to MI. Koechlin's practical knowledge on the great scale, it consists of a moist fibrous vegetable substance, which is animalized, and forms about one tenth of its weight; 2. of albumen; 3. of animal mucus; 4. of a substance similar to bile; 5. of muriate of soda, muriate and acetate of ammonia, phosphate of lime and other salts; 6. of benzoin or musk. Probably the hot water in which the calico-printer diffuses the dune exerts a powerful solvent action, and in proportion as the uncombined mordant floats in the bath it is precipitated by the albumen, the animal mucus, and the ammoniacal salts; but there is reason to think that the fibrous matter in part animalized or covered with animal matter, plays here the principal part; for the great affinity of this substance for the aluminous salts is well known. All practical men are aware that the affinity of cotton for alumina is increased by its combination with oil or animal substances, to such a degree as to take it from the dung bath; which would not be possible without this combination. It would therefore appear that the principal function of dunging is to hinder the uncombined mordant, diffused in the dung bath, from attaching itself to the unmordanted portion of the cloth, as already observed; for if we merely wished to abstract the thickening stuffs, or to complete by the removal of acetic acid the combination of the aluminous base with the goods, dung would not be required, for hot water would suffice. In fact, we may observe, that in such cases the first pieces passed thronuh the boiler are fit for dyeing; but when a certain number have been passed through, the mordant now dissolved in the water is attracted to the white portions of the cloth, while the free acid impoverishes the mordanted paits, so that they cannot afford good dyes, and the blank spaces are tarnished. The cowdung may be in some measure replaced by bran, but not with perfect success. The former both answers the purpose better and is cheaper. The bran is only preferred for the most delicate yellows, for cochineal pinks and lilachs, to which the dung may sometimes impart a greenish cast. It is to be presumed that the action of the bran in this process has much analogy with that of the dung, and that the, ligneous fibre is the.most active constituent; with which the gluten and mucilage co-operate, no doubt, in ceizing the aluminous salts. It seems to be ascertained that the mordant applied to the cloth does not combine en. tirely with it durina the drying; that this combination is more or less perfect according to the strength of the mordants, and the circumstances of the drying; that the operation of dunginr, or passing through hot water, completes the combination of the cloth with the aluminous base now insoluble in water; that this base may still contain a very minute quantity of acetic acid or sulphate of alumina; that a long ebullition in water impoverishes the mordant but a little; and that even then the liquid does not contain anl perceptible quantity of acetate or subsulphate of alumina. The manner of immersing the goods, or passing them throuah the dung bath, is an important circumstance. They should be properly extended and free from folds, which is secured by a series of cylinders. The cistern is from 10 to 12 feet long, 41 feet wide, and 6 or 8 feet deep. The piece passes alternately over the upper rollers and under rollers near the bottom. There are two main squeezing rc lers at one end, which draw the cloth through between them. Wheneve he goods come out of the bath they are put into the dasn-wheel DYEING. 601 rne immersion should take place as fast as possible, for the moment the hot water penetrates Cle mordanted cloth, the acetic acid quits it; and, therefore, if the immersion wa, made slowly or one ply after another, the acid as well as the uncombined mordant become free, would spread their influence, and would have time to dissolve the aluminous subsalts now combined with the cloth; whence inequalities and impoverishment of the colors would ensue. It is difficult to determine the number of pieces which may be passed through a given quantity of' dung and water. This depends upon the state of the mordants, whether they are strong or acid, and on the quantity of the surface covered with the figures. The number varies usually from 20 to 60 pieces, for from 240 to 300 gallons of water and 6 gallons of dung. The time of the immersion varies with the concentration of the mordants, and the nature of their thickening. The temperature must be regulated by the same circumstances; for starch or flour paste a much warmer bath is needed than for gum. The heat varies usually from 130~ to 212~ F. When the printing is heavy and the thickening is starch or flour, the goods are usually twice dunged, with two washings between the two dungs. A strong acid mordant is more difficult to dung and to wash than a, neutral mordant, especially when it is to receive the madder dye. Sometimes a little chalk is added to the bath, when the goods have been padded in an acid mordant. Too much (ung is injurious to weak mordants, as well as to pinks. It has also been Lemarked that a mordant whep neutralized does not produce as brilliant tints, especially yellows. The latter are obtaineu of a finer shade when, instead of dunging, they are exposed for an hour in a stream of water, provided its temperature is not too low. In winter they are passed through a slightly chalky water, then washed at the wheel, and dyed in quercitron or weld. A very able and learned memoir upon this subject, by M. Penot, Professor of Chenistry, appeared in the Bulletin of the Society of Mulhausen, in October, 1834, with an ingeniols commentary upon it, under the title of a Report by M. Camille Kcechlin, in March, 1835. Experience has proved that dunging is one of the most important steps in the process of calico printing, and that if it be not well performed the dyeing is good for nothing. Before we can assign its peculiar function to the dung in this case, we must know its composition. Fresh cow's dun(l is conmonly neutral when tested by litmus paper; but sometimes it is slightly alkaline, owing, probably, to some peculiarity in the food of the animal. The total constituents of 100 parts of cow dung are as follows: Water, 69'58; bitter matter, 0'74; sweet substance, 0-93; chlorophylle, 0-28; albumine, 0-63; muriate of soda, 0'08; sulphate of potash, 0-05; sulphate of lime, 0'25; carbonate of lime, 0-24; phosphate of lime, 0'46; carbonate of iron, 009; woody fibre, 26-39; silica, 0'14; loss, 0 14. In dunging calicoes the excess of uncombined mordant is in part attracted by the soluble matters of the cow's dung, and forms an insoluble precipitate, which has no affinity for the cloth, especially in presence of the insoluble part of the dung, which strongly attracts alumina. The most important part which that insoluble matter plays, is to seize the excess df the mordants, in proportion as they are dissolved by the water of the bath, and thus to render their reaction upon the cloth impossible. It is only in the deposite, therefore, that the matters carried olf fr( n the cloth by the dung are to be found. M. Camille Kcechlin ascribes the action of cow dung chiefly to its albuminous constituent, combining with the alumina and iron, of the acetates of these bases dissolved by the hot water of the bath. The acids consequently set free, soon become evident by the test of litmus paper, after a few pieces are passed through, and require to be got rid of either by a fresh bath or by adding chalk to the old one. The dung thus serves also to fix the bases on the cloth, when used in moderation. It exercises likewise a disoxydlating power on the iron mordant, and restores it to a state more fit to combine with coloring matter. DYEING, (Teinture, Fr.; Fdrberei, Germ.) is the art of impregnating wool, silk, cotttn, linen, hair, and skins, with colors not removable by washing, or the ordinary usage to which these fibrous bodies are exposed when worked up into articles of furniture or raiment. I shall here consider the general principles of the art, referring for the particular dyes, and peculiar treatment of the stuffs to be dyed; to the different tinctorial substances in their alphabetical places; such as cochineal, indigo, madder, &c. Dyeing is altogether a chemical process, and requires for its due explanation and practice an acquaintance with the properties of the elementary bodies, and the laws which regulate their combinations. It is true that many operations of this, as of other chemical arts, have been practised from the most ancient times, long before any just views were entertained of the nature of the changes that took place. Malnkind, equally in the rudest an' most refined state, have always sought to gratify the love of distinction 302 DYEING. by staining their dress, sometimes even their skin, with gaudy colors. Moses speaks ot raiment dyed blue, and purple, and scarlet, and of sheep s-kins dyed red; circumtlanret whicoi indicate no small degree of iinctorial skill. He enjoins purple stuffs for the works of the tabernacle and the vestments of the high priest. In the article CALICO PRINTING, I have shown from Pliny that the ancient Egyptians cultivated that art with some degree of scientific precision, since they knew the use of mordants, or these substances which, thouoh they may impart no color themselves, yet enable white robes (caadida vela) to absorb coloring drugs (colorer sorbendibus medi. camentis). Tyre, however, was the nation of antiquity which made dying its chief occupation and the staple of its commerce. There is little doubt that purple, the sacred symbol of royal and sacerdotal dignity, was a color discovered in that city, and that it contributed to its opulence ant grandeur. Homer marks no less the value than the antiquity of this dye, by describing his heroes as arrayed in purple robes. Purple habits are mentioned among the presents made to Gideon by the Israelites from the spoils of the kings of Midian. The juice employed for communicating this dye was obtained from two differenl kinds of shell-fish, described by Pliny under the names of purpura and buccirum; and was extracted from a small vessel, or sac. in their throats, to the amount of only one drop from each animal. A darker and inferior color was also procured by crushing the wh, le substance of the buccinum. A certain quantity of the juice collected fror a vast number of shells being treated with sea-salt was allowed to ripen for three days; after which it was diluted with five times its builk of water, kept at a moderate heat for six days more, occasionally skimmed, to separate the animal membranes, and when thus clarified was applied directly as a dye to white wool, previously prepared for this purpose by the action of lime-water, or of a species of lichen called fucus. Two operations were requisite to communicate the finest Tyrian purple; the first consisted in plunging the wool into the juice of the purpura: the second, into that of the buccinum. Fifty drachms of wool requiried one hunlred of the former liquor, and two hundred of the latter. Sometimes a preliminary tint was given with coccus, the kermes of the present day, and the cloth received merely a finish from the precious animal juice. The colors, though probably not nearly so brilliant as those producible by our cochineal, seem to have been very durahle, for Plutarch says, in his Life of.l/exander, (chap. 36,) that the Greeks found On the treasury of the King of Petsia a large quantity of purple cloth, which was as heautiftul as at first, though it was 190 years old. The difficulty of collecting the purple juice, and the tedious complication of the dyeing process, made the purple wool of Tyie so expensive at Rome, that in the time of Augustus a pound of it cost nearly 30/. of our money.t Notwithstanding this enormous price, such was the wealth accumulated in that capital, that many of the leading citizens decoraied themselves in purple attire, till the emperors arrogated to themselves the privilege of wearing purple, and prohibited its use to every other person. This prohibition operated so much to discourage this curious art as eventually to occasion its extinction, first in the western and then in the eastern empire, where, however, it existed in certain imperial manufacturies till the eleventh century. Dyeing was little cultivated in ancient Greece; the people of Athens wore generally wooliendresses of the natural color. But the Romans must have bestowed some pains upon this art. In the iames of the circus parties were distinguished by colors. IFcur of these are described by Pliny, the green, the orange, the gray, and the white. The followins ingredients were used by their dyers. A crude native alumn mixed with copperas, copperas itself, blue vitriol, alkanet, lichen rocellus, or archil, broom, madder, woad, nutgalls, the seed of pomegranate, and of an Eayptian acacia. Gage, Cole, Plumier, Reaurnmr, and Duhamel have severally made researches concernin. the coloring juices of shell-fi-h caught on various shores of the ocean, and have succeeded in forming a purple dye, but they found it much inferior to that furnished by other means. The juice of the buccinum is at first white; it becomes by exposure to air of a yellowish green bordering on blue; it afterwards reddens, and finally changes to a deep purlple of considerable vivacity. These circumstances coincide with the minute description of the manner of catching the purple-dye shell-fish which we possess in the work of an eye-witness, Eudocia Macrembolitissa, daughter of the Emperor Constantine VIII., who lived in the eleventh century. The moderns have obtained fiom the New World several dye-drugs unknown to the ancients; such as coclineal, quercitron, Brazil wood, logwood, annatto; and they have * "Among' other things, there was purple of Hernnione (?) to the amount of five thousand talents. tPlutarch's Lives, translated by Langhoine, Wranghail's edition, vol. v. p. 240.) Horace celebrates the,aconlau dye in the following lines:Nee Laconicas mihi Trahunt honestin purpuras clientae. (Carm. lib. ii., Ode 18.) * Plil-y says that a pound of the double-dipped Tyrian purple was sold in Rome for a hundred crownla DYEING. 602 liscovered the art of using ndigo as a dye, which the Romars knew only as a pigment, But the vast superiority of our dyes over those of former times must be ascribed princi pally to the employment of pure alum and solution of tin as mordants, either alone or mixed with other bases; substances which give to our common dye-stuffs remarkable depth, durability, and lustre. Another improvement in dyeing of more recent date is the application to textile substances of metallic compounds, such as Prussian blue, chrome yellow, manganese brown, &c. Indigo, the innoxious and beautiful product of an interesting tribe of tropical plants, which is adapted to form the most useful and substantial of all dyes, was actually denounced as a dangerous drug, and forbidden to be used, by our parliament in the reign of Queen Elizabeth. An act was p:issed authorizing searchers to burn both it and lo —wood in every dye-house where they could be found. This act remained in full force till the time of Charles II.; that is, for a great part of a century. A foreigner L ight have supposed that the legislators of England entertained such an affection for their native woad, with which their naked sires used to dye their skins in the old times, that they would allow no outlandish drug to come in competition with it. A most instructive book might be written illustrative of the evils inflicted upon arts, manufactures, and commerce, in consequence of the ignorance of the legislature.* Colors are not, properly speaking, material; they are impressions wnich we receive from the rays of light refected, in a decomposed state, by the surfaces of bodies. It it well known that a ahite sunbeam consists of an indeterminate number o. Jitferently colored rays, which being separated by the refractive force of a glass prism, orml the solar spectrum, an image distinguishable into seven sorts of rays; the red, orange, yellow, green, blue, indigo, and violet. Hence, when an opaque body appears colored, for example, red, we say that it reflects the red rays only, or in greatest abundance, mixed with more or less of the white beam, which has escaped decomposition. According to this lranner of viewing the coloring principle, the art of dyeing consists in fixing upon stuffs, by means of corpuscular attraction, substances which act upon light in a different manner from the surfaces of the stuffs themselves. The dyer ought, therefore to be familiar with two principlles of optics; the first relative to the mixture of colors, and the second to their simult taneous contrast. Whenever the different colored rays, which have been separated by the pai3m, are totally reunited, they reproduce white light. It is evident, that in this composition of light, if some rays were left out, or if-the colored rays be not in a certain proportion, we should not have white light, but light of a certain color. For example; if we separate the red rays from the light decomposed by a prism, the remaining colored rays will form by their combination a peculiar bluish green. If we separate in like manner the orange rays, the remaining colored rays will form by their combination a blue color. If we separate from the decomposed prismatic light the rays of greenish yellow, the remaining colored rays will form a violet. And if we separate the rays of yellow bordering on orange, the remaining colored rays will form by their union an indigo color. Thus we see that every colored light has such a relation with another colored light that, by uniting the first with the second, we reproduce white light; a relation which we express by saying that the one is the complement of the other. In this sense, red is the complementary color of bluish green; orange, of blue; greenish yellow, of violet; and orange yellow, of indigo. If we mix the yellow ray with the red, we produce orange the blue ray with the yellow, we produce green; and the blue with the red, we produce violet or indigo, according as there is more or less red relatively to the blue. But these tints are distinguishable from the orange, green, indigo, and violet of the solar spectrum, because when viewed through the prism they are reduced to their elementary compound colors. If the dyer tries to realize the preceding results by the mixture of dyes, he will succeed only with a certain number of them. Thus, with red and yellow he can make orange; with blue and yellow, green; with blue and red, indigo or violet. These facts, the results of practice, have led him to conclude that there are only three primitive colors; lle red, yellow, and blue. If he attempts to make a white, by applying red, yellow, and blue dyes in certain quantities to a white stuff, in imitation of the philosolher's experiment on the synthesis of the sunbeam, far from succeeding, he will deviate still further from his purpose, since the stuff will by thew dyes become so dark colored as to appear black. The fact must not, however, lead us to suppose that in every case where red, yellow, and blue are applied to white cloth, black is produced. In reality, when a little ultramarine, cobalt blue, Prussian blue, or irdigo, is applied to goods with the view of giving them the best possible white, if only a certain proportion be used, the goods will appear whiter after this addition than before it. What happens in this case? The violet blue * A'uthor, in Penny Cyclopedia. 604 DYEING. forms, with the brown yellow ot the goods, a mixture tending to white, or less color4 tlan the yellow of the goods and the blue together were. For the same reason, a mix ture of Prussian blue and cochineal pirk has been of' late years used in the whitening or the azuring of silks, in preference to a pure blue; bfr on examining closely the color.i the silk to be neltralized, it was found by the relations of the complementary colors, thai the violet was more suitable than the indigo blue formerly used. The dyer should know, that when he applies several different coloring matters to stuffs, as yellow and blue, for example, if they appear green, it is because the eye cannot distinguish the points which reflect the yellow from those which reflect the blue; and that, consequently, it is only where the distinction is not possible, that a mixture or combination appears. When we examine certain gray substances, such as hairs, feathers, &c., with the microscope, we see that the gray color results from black points disseminated over a colorless or slightly colored surface. In reference to compound colors, this instrument might be used with advantage by the dyer. The dyer should be acquainted also with the law of the simultaneous contrast of colors. When the eye views two colors close alongside of each other, it sees them:iiiering most in their optical composition, and in the height of their tone, when the two are not equally pale or full-bodied. They appear most different as to their optical composition, when the complementary of the one of them is added to the color of the other. Thus, put a green zone alongside of an orange zone; the red color complementary of green, being added to the orange, will make it appear redder; and in like manner the blue, complementary of orange, beina added to the green, will make it appear more intensely blue. In order to appreciate these differences, let us take two green stripes and two orange stripes, placing one of the green stripes near one of the orange: then place the two others so that the green stripe may be at a distance from the other green stripe, but on the same side, and the orange at a distance from the other orange, also on the same side. As to the contrast in the height of the tone, we may satisfy ourselves by taking the tones No. 1, No. 2, No. 15, and No. 16, from a graduated pallet of reds: for example, by placing No. 2 and No. 15 close alongside, putting No. 1 at a distance from No. 2 on the same side, and No. 16 at a distance from No. 15 on the same side,-we shall see (if the pallet is sufficiently lowered in tone) No. 2 equal to No. 1, and No. 15 equal to No. 16; whence it follows that No. 2, by the vicinity of No. 15, will appear to have lost some of its color; while No. 15 will appear to have acquired color. When black or gray figures are printed upon colored grounds, these figures are of the color complementary of the around. Consequently, in order to judge of their color, we must cut out spaces in a piece of gray or white paper, so as to allow the eye to see nothing but the figures; and if we wish to compare figurres of the same color, applied upon grounds of different colors, we can judge rightly of the figures only by insulating them from the grounds. The relations of dyeing with the principles of chemistry, constitute the theory of the art, properly speaking; this theory has for its basis, the knowledge-1. of the species of bodies which dyeing processes bring into contact; 2. of the circumstances in which these species act; 3. of the phenomena which appear during their action; and 4. of the prop. erties of the colored combinations which are produced. These generalities may be speci. fied under the ten following heads:1. The preparation of the stuffs to be dyed, whether fibres, yarn, or cloth; under the heads of ligneous matter, cotton, hemp, flax; and of the animal matters, silk and wool. 2. The mutual action of these stuffs, and simple bodies. 3. The mutual action of these stuffs, and acids. 4. The mutual action of these stuffs, and salifiable bases, as alumina, &c. 5. The mutual action of these stuffs, and salts. 6. The mutual action of these stuffs, and neutral compounds not saline. 7. The mutual action of these stuffs, and of one or more definite compounds. 8. Of dyed stuffs considered in reference to the fastness of their color, under the influence of heat, light, water, oxygen, air, boilings with soap, and reagents. 9. Of dyeing, considered in its connexions with chemistry. 10. Of dyeing, considered in its relations with caloric, mechanics, hydraulics, and optics. 1. The preparation of stuffs. The operations to which stuffs are subjected before dyeing, are intended-1. to sepa. rate from them any foreign matters; 2. to render them more apt to unite with the coloring tinctures which the dyer proposes to fix upon them, in order to give them a more agreeable, or more brilliant aspect, or to lessen their tendency to assume a soiled appearance by use, which white surfaces so readily do. The foreign matters are either naturally inherent in the stutfs, or added to themn i the spinning, weaving, or other DYEING. 605 Manipulation of manufacture. The ligneous fibres must be freed from the colored azo. t.Lel varnish on their surface, from a yellow coloring matter in their substance, from sonie lime and iron, from chlorophyile or leaf-green, and fiom pectic acid; all natural combinations. Some of these principles require to be oxygenized before alkaline leys can cleanse them, as I have stated in the article BLEACHING, which may be consulted in reference to this subject. See also SILK and WOOL. A weak bath of soda has the property of preparing wool for taking on a uniform dye, but it must be well rinsed and aired before being put into the dye-vat. 2. M.itual action of stuffs and simple bodies. Stuff; chemically considered being composed of three or four elements, already in a state of reciprocal saturation, have but a feeble attraction for simple substances. We know in fact, that the latter combine only with each other, or with binary compounds, and that in the greater number of cases where they exert an action upon more complete compounds, it is by disturbing the arrangement of their elements, and not by a resulting ~ffinity with the.whole together. 3, 4. Although stuffs may in a general point of view be considered as neutral in relation to coloring reagents, yet experience shows that they are more disposed to comnl'ne with acid than with alkaline compounds; anri that consequently their nature seems to be more alkaline than acid. By steeping dry wool or other stuff in a clean state in an alkaline or acid solution of known strength, and by tes'ina the liquor after.ie stuff is taken out, we shall ascertain whether there be any real affinity between them, by the solution being rendered more dilate in consequence of the abstraction of alkaline or acid particles from it. Wool and silk thus immersed, abstract a portion of both sulphuric and.,uriatic acids; but cotton and flax imbibe the water, with the rejection of a portion of the acid. The acid may be again taken from the stuffs by washing them with a sufficient quantity of water. 5. The affinity between saline bodies and stuffs may be ascertained in the same way as that of acids, by plunging the dry stuffs into solutions of the salts, and determining the density of the solution before the immersion, and after withdrawing the stuffs. Wo, 1 abstracts alum fiom its solution, but it gives it all out again to boiling water. The sulphates of protoxyde of iron, of copper, and zinc, resemble alum in this respect. When silk is steeped for some time in solution of protosulphate of iron, it abstracts the oxyd, gets thereby dyed, and leaves the solution acidulous. Wool put in contact with cream of tartar decomposes a portion of it; it absorbs the acid into its pores, and leaves a neutral salt in the liquor. The study of the action of salts upon stuffs is at the present day the foundation of the theory of dyeing; and some of them are employed immediately as dye-drugs. 6. Mutual action of stuffs, anl neutral compounds not saline. Several sulphurets, such as those of arsenic, lead, copper, antimony, tin, are susceptible of being applied to stuffs, and of dyeing them in a more or less fast manner. Indigo, hematine, breziline, carmine, and the peculiar coloring principles of many dyes belong to this division. 7. Mutual action of goods with one or more definite compounds, and dye-stuffs. I sha'l consider here in. a theoretical point of view, the most general results which a certain number of organic coloring matters present, when applied upon stuffs by tile dyer. Indigo. This dye-drug, when tolerably good, contains half its weight of indigotine. The cold vat is prepared commonly with water, copperas, indigo, lime, or sometimes carbonate of soda, and is used almost exclusively for cotton and linen; immersion in aciduoated watei is occasionally had recourse to for removing a little oxyde of iron which attaches itself to the cloth dyed in this vat. The indigo vat for wool and silk is mounted exclusively with indigo, good potashes of commerce, madder, and bran. In this vat, the immediate principles with base of carbon and hydrogen, such as the extracts of madder and bran, perform the disoxydizing function of the copperas in the cold vat. The pastel vats require most skill and experience, in consequence of their complexity. The greatest difficulty occurs in keeping them in a good condition, because they vary progressively as the dyeing goes on, by the abstraction r: the indigotine, and the modification of the fermentable matter employed to disoxygenate the indigo. The alkaline matter also changes by the action of the air. By the successive additions of indigo, alkali, &c., this vat becomes very difficult to manage with profit and success. The great affair of the dye - s tie proper addition of lime; too much or too little being equally injurious. Sulphate of indigo or Saxon blue is used also to dye silk and wool. If the wools be ill sorted, it will show their differences by the inequalities of the dye. Wool dyed in this bath put into water saturated with sulphureted hydrogen, becomes soon colorless, owing to the disoxygenation of the indigo. The woollen cloth, when exposed to the air for some'ime resumes its blue color, but not so intensely as before. 806 DYEING. The properties of hematine explain the mode of using logwood. When Etuffs arc dyed in the infusion or decoction of this wood, under the influence of a base which acts upon the hematine in the manner of an alkali, a blue dye, bordering upon violet, is obtained. Such is the process for dyeing cotton and wool a logwood blue by means of verdigris, crystallized acetate of copper, and acetate of alumina. When we dye a stuff yellow, red, or orange, we have always bright tints; with blue, we may have a very daik shade, but somewhat violet; the proper black can be obtained only by using the three colors, blue, red, and yellow, in proper proportions. Hence we can explain how the tints of yellow, red, oranee, blue, green, and violet, may be browned, by applying to them one or two colors which along with themselves would produce black; and also we may explain the nature of that variety of blacks and grays which seems to be indefinite. Nutgalls and sulphate of iron, so frequently employed for the black dye, give only a violet or bluish gray. The pyrolianite of iron, which contains a brown empyreumatic matter, gives to stuffs a brown tint, bordering upon greenish yellow in the pale hues, and to chestnut brown in the daik ones. By galling cotton and silk, and giving them a bath of pyrolignite of iron, we may, after some alternations, dye them black. Galls, logwood, and a salt of iron, produce merely a very deep violet blue; but by boiling and exposure to air, the hematate of iron is changed, becoming red brown, and favors the production of black. Galls and salts of copper dye stuffs an olive drab, logwood and salts of copper, a violet blue; hei.:' their combination should nroduce a black. In using sumach as a substitute for galls, we should take into account the proportion of yellow matter it contains. When the best possible black is wanted "ipon wool, we must give the stuff a foundation of indigo, then pass it into a bath of lgwood, sumach, and proto-sulphate of iron. The sumach may be replaced by one third of its weizht of nutgalls. 8. Of dyed stuffs considered in reference to the fastness of their colors, when exposed to water, light, heat, air, oxygen, boiling, and reagenls. Pure water without air has no action upon any properly dyed stuff. Heat favors the action of certain oxygenized bodies upon the carbonaceous and hydrogenous constituents of the stuff; as is seen with regard to chromic acid, and peroxyde of maneanese upon cotton goods. It promotes the solvent action of water, and it even affects some colors. Thus Prussian blue applied to silk, is reduced to peroxyde of iron by long boiling. Lioht without contact of air affects very few dyes. Oxygen, especially in the nascent state, is very powerful upon dyes. See BLEACHING, The atmosphere in a somewhat moist state affects many dyes, at an elevated tim perature. Silk dyed pink, with safflower, when heated to 400~ F., becomes of a dirty white hue in the course of an hour. The violet of logwood upon alumed wool becomes of a dull brown at the same temperature in the same time. But both stand a heat of 300( F. Brazil red dye, turmeric, and weld )ellow dyes, display the same phenomena. These facts show the great fixity of colors commonly deemed tender. The stufft become affected to a certain degree, under the same circumstances as the dyes. The alterability even of indio in the air is shown in the wearing of pale blue clothes; in the dark blue cloth there is such a body of color, that it resists proportionally longer; but the seams of coats exhibit the effect very distinctly. In silk window curtains, which have been long exposed to the air and light, the stuff is found to be decomposed, as well as the color. Boiling was formerly prescribed in France as a test of fast dyes. It consisted in putting a sample of the dyed goods in boiling water, holding in solution a determinate quantity of alum, tartar, soap, and vinegar, &c. Dufay improved that barbarous test, He considered that fast-dyed cloth could be recognised by resisting an exposure of twelve hours to the sunshine of summer, and to the rmidnight dews; or of sixteen days in winter. In trying the stability of dyes, we may offer the following rules:That every stuff should be exposed to the light and air; if it he intended to be worn abroad, it should be exposed also to the wind and rain; that carpets, moreover, should be subjected to friction and pulling, to prove their tenacity; and that cloths to be washed should be exposed to the action of hot water and soap. In examining a piece of dyed cotton goods, we may proceed as follows:Suppose its color to be orange-brown. We find first that it imparts no color to boilina water; that protochloride of tin takes out its color; that plunged into a solution of ferropruissiate of potash it becomes blue; arid that a piece of it being burned, leaves a residuum of peroxyde of iron; we may thence conclude that the dyeing matter is peroxyde of iron. Suppose we have a blue stuff which may have been dyed either with indigo or with Prussian blue, and we wish to know what it will become in use. We inquire first into the nature of the blue. Hot water slightly alkaline will be colored blue by it, if DYEING. 607 it has been dyed with sulphate of indigo; it will not be colored if it was lyed in the indigo vat, but it will become yellow by nitric acid. Boiling water, without becoming colored itself, will destroy the Prussian blue dye; an alkaline water will convert its color into an iron rust tint; nitric acid, which makes the indigo dye yellow, makes that of Prussian blue green. The liquor resulting from boiling alkaline water on the Prussian blue cloth. will convert sulphate of iron into Prussian blue. 9. Division. Of dyeing viewed in its relation to chemistry. The phenomena of dyeing have been ascribed to very different causes; by some they were supposed to depend upon mechanical causes, and by others upon the forces from which chemical effects flow. Hellot, in conformity with the first mode of explanation, thought that the art of dyeing consisted essentially in opening the pores in order to admit coloring matters into them, and to fix them there by cooling, or by means of a mordant imagined to act like a cement. Defay in 1737, Berrmarun in 1776, Macquer in 1778, and Berthollet in 1790, had recourse to chemical affiniiies, to explain the fixation of the coloring principles upon stuffs, either without an intermedium, like indig, walnut peels, annotto; or by the intervention of an acid) a salifiable base, or a salt, which were called mordants. When bodies present phenomena which we refer to an attraction uniting particles of the same nature, whether simple or compound, to form an aggregate, or to an affinity which unites the particles of different natures to form them into a chemical compound, these bodies are in apparent contact. This happens precisely in all the cases cf the mutual action of bodies in an operation of dyeing; if their pariicles were not in apparent contact, there would be absolutely no change in their respective condition. When we see sttffs and metallic oxydes in apparent contact, form a mutual union of greater or less force, we cannot therefore help referring it to affinity. We do not know how many d5 es nay be fixed upon the same piece of cloth; but in the operations of the dye-house.uficiently complex compounds are formed, since they are always stuffs, composed of three or four elements, which are combined with at. least binary acid or basic compounds; with simple salts compounded themselves of two immediate principles at least binary; with double salts composed of two simple salts; and finally with organic dyestuifs containing three or four elements. We may add that different species belonging to one of these classes, and different species belonving to different classes, may unite simultaneously with one stuff. The union of stuffs with coloring matters appears, in general, not to take place in definite proportions; though there are probably some exceptions. We may conclude this head by remarking, that, besides the stuff an l the coloring matter, it is not necessary, in dyeing, to distinguish a third body, under the name of mordaelt; for the idea of mordant does not rest upon any definite fact; the body to which this name has been given being essentially only one of the immediate principles of the colored combination which we wish to fix upon the stuff. 10. Division. Of dyeing in its relation with caloric, mechanics, hydraulics, pneumatics, and optics. Dyeing baths, or coppers, are heated directly by a furnace, or by means of steam conducted in a pipe from a boiler at a certain distance from the bath. In the first case, the vessels are almost always made of copper; only, in special cases, for the scarlet and some delicate silk dyes, of tin; in the second case, they are of copper, iron, or wood. A direct fire is more economical than heating steam pipes, where the' e is only one or two baths to heat, or where the labors are often suspended. Madder and indigo vats, when heated by steam, have it either admitted directly into the liquor, or made to circulate through pipes plunged into it, or between the copper and an exterior iron or wood case. See the end of this article. Everything else beinz equal, dyeing with heat presents fewer difficulties towards obtainin? an evenly color, than dveing in the cold; the reason of which may be found in the o'llowinz facts:-The air a'lherinz to the surface of stuffs, and that interposed between uhe fibres of their constituent yarns, is more easily extricated in a hot bath than a cold ane, and thus allows the dre liquor to penetrate more easily into their interior: in the second place, the currents which take place in a hot bath, and which tend incessantly to rentler its contents unifrnrm, by renewing continually the strata of liquid in contact with the stuff, contribute mainly to render the dyeing evenly. In cold dyeing, it is necessary to;:'r up the bath from time to time: and when goods are first put in, they must be carefllly dipped, then taken out, pressed, and wrung, several times in succession till they be unitormly moistened. The mechanical relations are to be found in the apparatus employed for wincing, siring, and pressing the goods, as we have described under CALICO PRINTING and BANDANA. The hydraulic relations refer to the wash-wheels and other similar apparatus, of which an account is given under the same articles. The optical relations 608 DYEING. have been already considered. In the sequel of this article an automatic dyeing vat wil be described. 1 ne extracts of solutions of native dye-stuffs may be divided into two classes, in reference to their habitudes with the oxygen of the atmosphere; such as continue essentially unaltered in the air, and such as suffer oxydation, and thereby precipitate a determinate coloring matter. The dyes contained in the %,atery infusions of the different vegetable and animal substances which do not belong to the second class, are feebly attached to their solvents, and quit them readily for any other bodies that possess an attraction for them. On this principle, a decoction of cochineal, loowood, brazil wood, or a solution o( sulphate of indigo, by digestion with powdered bone black, lose their color, in conse. quence of the coloring particles combining by a kind of capillary attraction with the porous carbon, without undergoing any change. The same thing happens when wellscoured wool is steeped in such colored liquids; and the color which the wool assumes by its attraction for the dye, is, with regaid to most of the above colored solutions, but feeble and fugitive, since the dye may be again abstracted by copious washing with simple water, whose attractive force therefore overcomes that of tth wool. The aiu of a hioh temperature, indeed, is requisile for the abstraction of the color from the wool and the bone-black, probably by enlarging the size of the pores, and increasing the solvent power of the water. Those dye-baths, on the contrary, whose coloring matter is of the nature of extractive cr apotheme, form a faster combination with stuffs. Thus the yellow, fawn, and brown dyes, which contain tannin and extractive, become oxygenated by contact of air, and insoluble in water; by which means they can impart a durable dye. When wool is impregnated with decoctions of that kind, its pores get charged by capillarity, and when the liquid becomes oxygenated, they remain filled with a color now become insoluble in water. A similar change to insolubility ensues when the yellow liquor of the indigo vat gets oxydized in the pores of cotton and wool, into which it had been introduced in a fluid state. The same change occurs when protosulphate of iron is converted into perstllphate, with the deposition of an insoluble peroxyde in the substance of the stuff. The change here effected by oxydation can, in other circumstances, be pioduced by acids which have the power of precipitating the dye-stuff in an insoluble state, as happens with decoction of fustic. Hence we perceive that the dyeing of fast colors rests upon the principle, that the colors dissolved in the vat, during their union with the stuff, should suffer such a change as to become insoluble in their former nenstruum. The more this dye, as altered in its union wilh the stuff, can resist other menstrua or agents, the faster it will be.'I;is is the essential difference between (yeing and painting; or applying a coat of pigment devoid of any true affinity for the stuface. If we mix a clear infusion of a dye with a small quantity of a solution of an earthy or metallic salt, both in water, the limpid liquids soon become turbid, and there gradually subsides sooner or later, according to the nature of the mixture, a colored precipitate, consisting of the altered dye united with a basic or subsalt. In this compound the coloring matter seems to act the part of an acid, which is saturated by a small quantity of the basis, or in its acid relationship is feeble, so that it c in also combine with acids, being in reference to them a base. The decomposition of a salt, as alum, by dyes, is effected principally through the formation of an insoluble subsalt, with which the color combines, while a supersalt remains in the bath, and modifies, by its solvent reaction, the shade of the dyed stuff. Dyed stuffs may be considered as composed of the fibrous body intimately associated with the coloring matter, the oxyde, and acid, all three constituting a compound salt. Many persons have erroneously imagined, that dyed goods contained none of the acid employed in the dye bath; but they forget that even potash added to alum does not throw down the pure earthy basis, but a subsalt; and they should not ascribe to coloring matter a power of decomposition at all approaching to that of an alkali. Salts, containing strong acids, saturate a very large quantity of coloring matter, in proportion to their place in the scale of chemical equivalents. Mere bases, such as pure alumina, and pure oxyde of tin, have no power of precipitating coloring matter; when they seem to do so, they always contain some acid. Such salts, therefore, as have a tendency to pass readily into the basic state, are peculiarly adapted to act as mordants in dyeing, and to form colored lakes. Magnesia affords as fine a white powder as alumina, and answers equally well.to dilute lakes, but its soluble salts cannot be employed to form lakes, iecause they do not pass into the basic state. This illustration is calculated to throw much light upon dyeing processes in general. The color of the lake depetAls very much upon the nature of the acid, and the basis of the precipitating salt. If it be white, like alumina and oxyde of tin, the lake'vill have, more or less, the color of the dye, but brightened by the reflection of white DYEING. 60i fight from the basis; while the difference of the acid occasions a difference in the h:ie. The colored bases impart more or less of their color to the lakes, not merely in virtue of theii own tints, but of their chemical action upon the dye. Upon these principles a crimson precipitate is obtained from infusions of cochineal by alum and salt of tin, which becomes scarlet by the addition of tartar; by acetate of lead, a violet blue precipitate is obtained, which is durable in the air; by muriate of licie, a pink brown precipitate falls, which soon becomes black, and at last dirty green; by the solution of a ferruginous salt, the precipitates are dark violet and black; and,:n like manner, all other salts with earthy or metallic bases, afford diversities of shade fwith cochineal. If this dye stuff be dissolved in weak water of ammonia, and be precipitated with acetate of lead, a green lake is obtained, which, after some time, will become green on the surface by contact of air, but violet and blue beneath. Hence it appears, that the shade of color of a lake depends upon the iegree of oxydation or cleange of the color caused by the acid of the precipitating salt, upon the degree of oxydation or color of the oxyde which enters into union with the dye, and upon its quantity in reference to that of tie coloring principle. Such lakes are the difficultly soluble salts which constitute the dyeing materials of stuffs. Their particles, however, for the purposes of dyeing, must oxist in a state of extremely fine division in the bath liquor, in order that they mav oeneuv..e along v'"h it into the minute pores of textile fibres, and fill the cavities observed by means of the microscope in the filaments of wool, silk, cotton, and flax. I have examined these stuffs with an achromatic microscope, and find that when they are properly dyed with fast colors, the interior of their tubular texture is filled, or lined at least, with coloring matter. When the bath contains the coloring particles, so finely divided that they can pass throlgh filtering paper, it is capable of dyeing; but if the infusion mixed with its mordant be flocculent and ready to subside, it is unfit for the purpose. In the latter case, the ingredients of the dye have already become aggregated into compounds too coherent and too gross for entering into combination with fibrous stuffs. Extractive matter and tannin are particularly liable to a chartne of this kind, by the prolonged action of heat in the bath. Hence, also, an alkaline solution of a coloring matter affords no useful dye bath, when mixed with the solution of a salt having an earthy or metallic basis. These circumstances, which are of frequent occurrence in the dye-house, render it necessary always to have the laky matter in a somewhat soluble condition, and to effect its precipitation within the pores of the stuffs, by previously impregnating them with the saline solutions by the aill of heat, which facilitates their introduction. When a mordant is applied to any stuff, the portion of it remaining upon the surface of the fibres should be removed; silce, by its combination with the coloring matter, it would be apt to form an external crust of mere pigment, which would block up the pores, obstruct the entrance of the dye into the interior, and also exhaust to no purpose the dyeing power of the bath. For this reason the stuffs, after the application of the mordant, are drained, squeezed, washed, and somretimes (particularly with cotton and linen, in calico printing) even hard dried in a hot stove. The saline mordants, moreover, should not in general possess the crystallizing property in any considerable decree, as this opposes their affinity of composition for the cloth. On this account the deliquescent acetates of iron and alumina are more ready to aid the dyeing of cotton than copperas and alum. Alum is the great mordant employed in wool dyeing. It is frequently dissolved in water, holding tartar equal to one fourth the weiglt of the alum in solution; by which alddition its tendency to crystallize is diminished, and the resulting color is brightened. The alum and tartar combine with the stuff without suffering any change, and are decomposed only by the action of the coloring matters in the dye bath. The alum operates solely in virtue f its sulphuric acid and earthy basis; the sulphate of potash present in that salt being rather injurious. Hence, if a sulphate of alumina free from iron coutll be readily obtained, it would prove a preferable mordant to alum. It is also probable, for the reasons above assigned, that soda alum, a salt much less apt to crystallize tlian potash or ammonia a'um, would suit the dyer very well. In order to counteract the tendency of common alum to crystallize, and to promote its tendency to pass into a basic salt, one eighth part of its weight of potash is added to its solution, or the equivalent in chilk or soda. We shall conclude this account of the general principles of dyeing, with Mr. Delaval's observations on the nature of dyes, and a list &f the different substances used in dyeing, in reference to the colors produced by them. Sir Isaac Newton supposed colored matters to reflect the rays of light; some bodies:eflecting the more, others the less, refrangible rays most copiously; and this he conceived to he the true, and the only reason of their colors. Mr. Delaval, however, proved, in the 2d vol. of the " Memoirs of the Philosophical and Literary Society of Manchester," that, " in transparent colored substances, the coloring substance does not reflect any 40 510 DYEING. light; anc. that when, by intercepting the light which was transmitted, it is hindered from passing through substances, they do not vary from their former color to any other color, but become entirely black;" and he instances a considerable number of colored liquors, none of them endued with reflective powers, which, when seen by transmitted hsht, appeared severally in their true colors; but all of them, when seen by incident light, appeared black; which is also the case of black cherries, black currants, black berries, &c., the juices of which appeared red when spread on a white ground, or other-.vise viewed by transmitted instead of incident light; and he concludes, that bleached linen, &c., " when dyed or painted with vegetable colors, do not differ in their manner of acting on the rays of light, from natural vegetable bodies; both yielding their colors by transmitting throneh the transparent colored matter the light which is reflected from the white ground:" it being apparent, from different experiments, "that no reflecting power resides in any of their components, except in their while matter only," and that transparent colored substances, plnced in situations by which transmission of light through them is intercepted, exhibit no color, but become entirely black." The art of dyeing, therefore, (acco'ling to M r. Delaval,) "consists principally in covering white substances, fiomn which light is strongly reflected, with transparent colored media, which, according to their several colors, transmit more or less copiously the rays reflected from the while," since " the transparent media themselves reflect no light; and it is evident that if they yielded their colors by reflecting, instead of transmitting the rays, the whiteness or color of the ground on which they are applied, would not in anywise alter or affect the colors which they exhibit." But when any opnaone basis is interposed, the reflection is doubtless made by it, rather than by the substance of the dyed wool, silk, &c., and more especially when such basis consists of the while earth of alum, or the white oxyde of tin; which, by their strong reflective powers, greatly augment the lustre of colors. There are, moreover, some opaque coloring matters, particularly the acetous, and other solutions of iron, used to stain linen, cotton, &c., which must necessarily themselves reflect, instead of transmitting the light by which their colors are made perceptible. The compound or mixed colors, are such as result from the combination of two differ. ently colored dye stuffs, or from dyeing stllff with one color, and. then with another. The simple colors of the dyer are red, yellow, blue, and black, with which, when skil. fully blended, he can produce every variety of tint. Perhaps the dun or fawn color might be added to the above, as it is directly obtained from a great many vegetable sub. stances. 1. Red with yellow, produces orange; a color which, upon wool, is given usually with the spent scarlet bath. To this shade may be referred flame color, pomegranate, caluchin, prawn, jonquil, cassis, chamois, cafe au lait, aurora, mariaold, orange peel, nnordoris, cinnamon, gold, &c. Snuff, chestnut, musk, and other shades are produced by substituting walnut peels or sumach for bright yellow. If a little blue be added to orange, an olive is obtained. The only direct orange dyes are annotto, and subchromate of lead; see SILK and WOOL Dyeing. 2. Red with blue produces purple, violet, lilach, pigeon's neck, mallow, peach-blossom, bleu de roi, lint-blossom, amaranth. 3. Red with black; brown, chocolate, marone, &c. 4. Yellow with blue; green of a great variety of shades, such as nascent green, gay green, grass green, spring green, laurel green, sea green, celadon green, parrot green, cabbage green, apple green, duck green. 5. Mixtures of colors, three and three, and four and four, produce an indefinite divet sity of tints; thus red, yellow, and blue, form brown olives, and greenish grays; in which the blue dye ought always to be first given, lest the indigo vat should be soiled by other colors. Red, yellow, and Aray, (which is a aradation of black,) give the dead-leaf tint, as well as dark orange, snuff color, &c. led, blue, and gray, give a vast variety of shades; as lead gray, slate gray, wood-pigeon gray, and other colors, too numerous to specify. See BROWN DYE. The following list of dyes, and the coloring substances which produce them, may prove useful. ked. Cochineal, kermes, lac, madder, archil, carthamus or safflower, brazil wood logwood, periodide of mercury, alkanet. Yellow. Quercitron. weld, fustic, (yellow wood,) annotto, sawwort, dyer's broom, tur meric, fustet, (rhuv colinus,) Persian and Avignon berries, (rhamnus ilectorius,) willow, peroxyde of iron chromate of lead, (chrome yellow,) sulphuret of arsenic, hydrosulphuret of antimony; nitric acid on silk. Blue. Indigo, woad or pastel, Prus.ian blue, turnsole or litmus, logwood with a salt st copper. DYEING. 611 Black. Galls, sumach, logwood, walnut peels, and other vegetables which contain tannin and gallic acid, along with ferruainous mordants. The anacardium of India. Geen. These are produced by the blue and yellow dyes skilfully combined; with the exception of the chrome green, and perhaps the copper green of Schweinfurt. Orange. Annotto, and mixtures of red and yellow dyes; subchromate of lead. Brown. See the remarks at the beginning of this article; BROWN in its alphabetical place; CALICO PRINTING, CATECHU, and MANGANESE. Fawn, Dun, or Root. Walnut peels, sumach, birch-tree, henna, sandal wood. See CALICO PRINTING, for a great variety of these dyes. Figs. 469 and 470 represent in a cross and longitudinal section the automatic dyeing steam copper, st generally employed in the well-appointed factories of Lancashire. A is the long reel, composed at each end of six radial iron arms or spokes, bound at their outer ex469 tremities with a six-sided wooden frame; these two terminal hexagons are connected by long wooden laths, seen above and below A in fig. 470. - shows A^^^^1 A the sloping border or ledge of the copper. B and c 0 A.^J' ~ are rollers laid horizontally, for facilitating the con< -.r^f^ y, ^tinuous motion of the series of pieces of goods F s. J__f-&k / stitched together into an endless web, which are f= -r-e- -: -made to travel by the incessant rotations of the reel. lFFI~ [ l ed 2Immediately above the roller B in fig. 469, all the spare foldings of the web are seen resting upon the sloping wooden grating, which guides them onwards 1 l \ I in the direction indicated by the arrow. The dye stuffs are put within the middle grating, like a hencoop, marked G. Each copper is 6 feet long, 3X feet wide, 31 feet deep, exclusive of the top ledge, 9 s L}3 B j ~ 119 C /l inches high. Such steam coppers are usually erected in pairs, and moved by a common horizontal bevel wheel seen at D in fig. 470, fixed upon a vertical shaft, 470 A shifted into gear by a wheel at its top, with one of the driving shafts of the factory. Upon each side of D, the two steam pipes fo' supplying the right and left hand coppers are seen; each provided with a stop cock for admitting, regulating, or cutting off the steam. These steam pipes descend at E E, the horizontal branch having several orifices in its upper surface. The horizontal shaft in a line with the axes of the reels, and which turns them, is furnished upon each side with a clutch for putting either of the reels into or out of gear, that is to say, setting it a going, or at rest, in a i.'ment by the touch of a forked lever. The steam pipe of distribution E lies horizontally near the bottom of the middle coop, as shown under G in fig. 469, and sends up the steam through its numerous orifices, among the dye-stuffs and water by which it is covered. Thus the infusion or decoc. 612 EAU DE COLOGNE. tion ia continually advancing in the copper, during the incessant locor, tion of the endless web. The horizontal pipe traverses the copper fiom end to end, and is not stopped short in the middle. Each of these coppers can receive two, three, or more parallel pieces of goods at a time, the reel and copper being divided into so many corn partments by transverse wooden spars. E. EARTHS. (Terres, Fr.; Erden, Germ.) Modern science has demonstrated that the substances called primitive earths, and which prior to the great electro-chemical career of Sir H. Davy, were deemed to be elementary matter, are all compounds of certain metallic bases and oxygen, with the exception of silica, whose base, silicon, being analogous to boron, has led that compound to be regarded as an acid; a title characteristic of the part it extensively performs in neutralizing alkaline bodies, in mineral nature, and in the processes of art. Four of tle earths, when pure, possess decided alkaline properties, being more or less soluble in water, having (at least 3 of them) an acrid alkaline taste, changing the purple infusion of red cabbage to green, most readily saturating the acids, and affording thereby neutro-saline crystals. These four are baryta, strontia, lime (calcia), magnesia. The earths proper are five in number; alumirna, glucina, yttria, zirconia, and thorina. These do not change the color of infusion of cabbage or tincture of litmus, do not readily neutralize acidity, and are quite insoluble in water. The alkalis are soluble in water, even when carbonated; a property which distinguishes them from the alkaline earths. Lithia must for this reason be considered to be an alkali. See the above substances in their alphabetical places. EAU DE COLOGNE. This well-known perfume is a solution of different volatile oils in pure strong spirit. The principal condition for the preparation of a fine water, is the employment of a spirit quite devoid of fusel-oil (oil of grain), and of all foreign odor. In respect to the proportion and kind of oils employed, we have numerous formulae. It is of importance that these oils, which are usually purchased of the druggists of the south of France, should be of the finest quality, and that no oil should be used in sufficient quantity to allow of its peculiar odor being recognisable in the mixture. The oils are to be dissolved in spirit, and the mixture allowed to stand for some weeks (or still better for some months) to improve its odor. Distillation does not effect this; on the contrary a fresh distilled water requires to be kept a much longer titme. Distillation is indeed objectionable, for on account of the great volatility of the spirit, the oils in part remain behind in the still. Distillation can improve the odor only when the less volatile oil has been used in too great a quantity, and we wish to obtain a better proportion. Before all things, we should employ a pure, old, strong spirit, and not too much of, nor a too strongly smelling oil. The different sorts of volatile oil which are obtained from varieties of citrons, oranges, and lemons, in different states of maturity, are the most important; and, therefore, it is most important to ascertain their purity and goodness. Forster gives the following formula for the preparation of a fine eau de Cologne: Take of rectified spirit 82 per cent. of Tralles (=sp. gr. 0'855), 6 (wine) quarts; essence of oranges, essence of bergamot, essence of citron, essence of limette, and essence of petits grains, of each, jj; essence of cedro, essence of cedrat, essence de Portugal, and essence de neroli, of each ass; oil of rosemary, 3ij; and oil of thyme, 3j. Otto gives the following formula for a good eau de Cologne: Rectified spirit of 86 per cent. of Tralles (=( — 846 sp. gr.), 200 (wine) quarts; oil of citrons, lb. iv; oil of bergamot, lb. ij; oil of neroli, 51b.; oil of lavender, b. ss; oil of rosemary, - lb.; and spirit of ammonia, sss. Mix. Don'tdistil. This preparation has long possessed great celebrity, in consequence chiefly of the numerous virtues ascribed to it by its venders; and is resorted to by many votaries of fashion as a panacea against ailments of every kind. It is, however, nothing more than aromatized alcohol, and as such, an agreeable companion of the toilet. Numerous fictitious recipes have been offered for preparing eau de Cologne; the following may be reckoned authentic, having been imparted by Farina himself to a friend. Take 60 gallons of silent brandy; sage, and thyme, each 6 drachms; baln-mint and spearmint, each 12 ounces; calamus aromaticus, 4 drachms; root of angelica, 2 drachms camphor, 1 drachm; petals of roses and violets, each 4 ounces; flowers of lavender, 2 ounces; flowers of orange, 4 drachms; wormwood, 1 ounce; nutmegs, cloves, cassia, lignea, mace, each 4 drachms. Two oranges and two lemons, cut in pieces. Allow the whole to macerate in the spirit during 24 hours, then distil off 40 gallons by the heat of a water bath. Add to the product: Essence of lemons, of cedrat, of balm-mint, of lavender, each 1 ounce 4 drachms; EBULLITION. 61 i neroli and essence of the seed of anthos, each 4 drachms; essence of jasmtn, 1 olnce; of bergamot, 12 ounces. Filter and preserve for use. Cadet de Gassincourt has proposed to prepare eau de Cologne by the following recipe: Take alcohol at 82~ B., 2 quarts; neroli, essence of cedrat, of orange, of lemon, of bergamot, of rosemary, each 24 drops; add 2 drachms of the seeds of lesser cardamoms, distil by the heat of a water bath a pint and a half. When prepared as thus by simple mixture of essences without distillation, it is never so good. EAU DE LUCE, is a compound formed of the distilled oil of amber and water of ammonia. EBULLITION. (Eng. and Fr.; Kochen, Germ.) When the bottom of an open vessel containing water is exposed to heat, the lowest stratum of fluid immediately expands, becomes therefore specifically lighter, and is forced upward by the superior gravity of the superincumbent colder and heavier particles. The heat is in this way diffused through the whole liquid mass, not by simple communication of that power from particle to particle as in solids, called the conduction of caloric, but by a translation of the several particles from the bottom to the top, and the top to the bottom, in alternate succession. This is denominated the carrying power of fluids, being colmmon to both liquid and gaseous bodies. These internal movements may be rendered very conspicuous and instructive, by mingling a little powdered amber with water, contained in a tall glass cylinder, standing upon a sand-bath. A column of the heated and lighter particles will be seen ascending near the axis of the cylinder, surrounded by a hollow column of the cooler ones descending near the sides. That this molecular translation )r locomotion is almost the sole mode in which fluids get heated, may be demonstrated by placing the middle of a pretty long slass tube, nearly filled with water, obliquely over an argand flame. The upper half of the liquid will soon boil, but the portion under the middle will continue cool, so that a lump of ice may remain for a considerable time at the bottom. When the heat is rapidly applied, the liquid is thrown into agitation, in consequence of elastic vapor being suddenly generated at the bottom of the vessel, and being as suddenly condensed at a little distance above it by the surrounding cold columns. These alternate expansions and contractions of volume become more manifest as the liquid becomes hotter, and constitute the simmering vibratory sound which is the prelude of ebullition. The whole mass being now heated to a pitch compatible with its permanent elasticity, becomes turbulent and explosive under the continued influence of fire, and emitting more or less copious volumes of vapor, is said to boil. The further elevation of temperature, by the influence of caloric, becomes impossible in these circumstances with almost all liquids, because the vapor carries off from them as much heat in a latent state as they are capable of receiving from the fire. The temperature at which liquids boil in the open air varies with the degree of atmospheric pressure, being higher as that is increased, and lower as it is diminished. Hence boiling water is colder by some degrees in bad weather, or in an elevated situation, with a depressed barometer, than in fine weather, or at the bottom of a coal-pit, when the barometer is elevated. A high column of liquid, also, by resisting the discharge of the steam, raises the boiling point. In vacuo, all liquids boil at a temperature about 124~ F. lower than under the average atmospheric pressure. For a table of elasticities, see VAPOR. Gay Lussac has shown that liquids are converted into vapors more readily, or with less turbulence, when they are in contact with angular or irregular, than with smooth surfaces; that they therefore boil at a heat 2~ F. lower in metallic than in glass vessels, probably owing to the greater polish of the latter. For example, if into water about to boil in a glass matrass, iron filings, ground glass, or any other insoluble powder be thrown, such a brisk ebullition will be instantl determined as will sometimes throw the water out of the vessel; the temperature at the same time sinking two degrees F. It would thence appear that the power of caloric, like that of electricity, becomes concentrated by points. The following table exhibits the boiling heats, by Fahrenheit's scale, of the most important liquids:Ether, specific gravity 0-7365 at 48 - - - - - - 100 Carburet of sulphur - - - 113 Alcohol, sp. grav. 0-813 - - - - Ure - - - 173-5 Nitric acid, 1-500 - - - - Dalton - - 210 Water - - - - - -- 212 Baturated solution of Glauber salt - - Biot - - 2133 do. do. Acetate of lead - - do. - - 2152 do. do. Sea salt - - - do. -- 2241 do. do. M'lriate of lime, - - Ure - - 285 do. do. do. 1 + water 2, do. - - 230 do. do. do. 35-5 -- do. 64-5, do. - 235 614 EBULLITIOl ALCOHOLMETER. Saturated solution of Muriate of lime 405-+-water 59'5 Ure, - - 240 Muriatic acid, sp. gray. 1')94 Dalton, - - - 232 do. do. 1127 - - do. - - - 22 Nitric acid, do. 1-420 - - do. - - 248 do. do. 1'30 - do. - - - 236 Rectified petroleum - - - Ure, - - - 306 Oil of turpentine - - - - do. - - - 316 Sulphuric acid, sp. gray. 1'848 - - Dalton, - - 600 do o. d 8 o. 1 10 - o. - - 473 do. do. 1780 - - do. - - - 435 do. do. 1-700 - - do. - - 374 do. do. 1650 - - do. - - 350 do. do. 1-520 - - do. - - - 290 do. do. 1 408 - do. - - - 260 do. do, 1'300 - do. - - - 240 Phosphorus - - - do. - - - 554 Sulphur - - - - do. - - - 570 Linseed oil - - - - do. - - - 640 Mercury - - - Dulong,- - - 662 do. - - Crighton, - - 656 Saturatd solution of Acetate soda, containing 60 per cent. Griffiths, - 256 do. Nitrate of soda, 60 do. - 246 do. Rochelle salt, 90 do. - 240 do. iNitre, 74 do. - 238 do. AMuriate of ammonia, 50 do. - 236 do. Tartrate of potash, 68 do. - 234 do. Muriate of soda, 30 do. - 224 do. Sulphate of magnesia, 57-5 do. - 222 do. Borax, 52'5 do. - 222 do. Phosphate of soda,? do. - 222 do. Carbonate of soda,? do. - 220 do. Alum, 52 do. - 220 do. Chlorate of potash, 40 do. 218 do. Sulphate of copper, 45 do. - 216 471 EBULLITION ALCOIIOLMETER. That the boiling temlperature of water is increased by holding neutro~'~/~./ ~ ~^ - ~ saline and saccharine substances in solution has bteen long known, and has been the subject of many experiTlents, made partly with the view of ascertaining firom that temperature tle proportion of the salt or sugar, and partly with the view of obtaining a practical liquid batth. But it seems to have been reserved II for the Abb6 Brossard-Vidal, of Toulon, to have \ discovered that the boiling temperature of alcoholic liquors is, in most cases, proportional to the quantity of alcohol, irrespectively of the quantity of neutrosaline or saccharine matter dissolved in them. When, however, such a quantity of dry carbonate of potash, or sugar, is added to a spirituous liquor as to abstract or fix in the solid state a portion of the wauer F ~F I'present, then the boiling temperature of that mixture will be lowered in proportion to the concentration of the alcohol, instead of being raised, as would be the case with water so mixed. But, generally speakIj 1I |||ing, it may be assumed as a fact, that the boiling point of an alcoholic liquor is not altered by a moderate addition of saline, saccharine, or extractive matter. On this priiciple, M. Brossard-Vidal constlructed the instrument represented in fig. 471, for Kijj iiilw determining by that temperature the proportion of I I BlT! tr alcohol present. His clief olject was to furnish the revenue boards of France with a means of estimating directly the prol)ortion of alcohol in wines so as to detect the too comtnon practice of introji i l ducing brandy into their cities and towns under the i;^'H "it^'IIt'^t' fimask of wine, and thereby comnitting a fratud ul)on I *'1 the octroi; as the duty on spirits is much higher ___. _ _. Mthan on wines. EBULLITION ALCOHOLMETER. 615 The above instrument consists of a spirit-lamp, surmounted by a small boiler, into which a large cylindric glass bulb is plunged, having an upright stem of such calibre, tlhat the quicksilver contained in them may, by its expansion and ascent when heated, raise before it a little glass float in the stem, which is connected by a thread with a similar glass bead, that hangs in the air. The thread passes round a pulley, which turning with the motion of the beads causes the index to move along the graduated circular scale. The rumbers on this scale represent per centages of absolute alcohol, so that tlhe number'opposite to which the index, stops, when the liquor in the cylinder over the lamp boils briskly, denotes the per centage of alcohol in it. That instrument was placed in my hands three years ago by Mr. Field, who had obtained a patent in this country for determining thereby the strength of spirituous liquors. I have made a great many experiments on the boiling points of alcohol at various successive degrees of watery dilution,, i IcoE E and verified tile general utility of the contriv472 ance; but I found the construction of the inH 10 BR'S t l I 1 strumcnt subject to general defects. The mass S 94- 5- S6 Z j so great as to occasion -some loss of alcohol in ii 0 E2 _ - _ M the course of the experiment; the length of the t,,,o~ g, -2 so: thread was liable to be affected by the moisture of tie air; it occasionally failed to move the 70t -1o ppulley with sufficient delicacy on account of fiO I~ 60_ I II-0 friction, and when the spirit in the lamp got I O0 5J I r - heated in its case, it flared up and burned tlhe _ _ tl^ |^ thread, thus rendering the apparatus useless till ~ t ff@ a fresh thread was experimentally adjusted to the beads. On these accounts I renounced the construetion of M. Vidal, and adopted the more simple and direct form of indication represented in fig. 47 2. It consists, 1, of a flat spirit-lamp A, surrounded by a saucer for containing cold water ]-dS llffilI Ito keep the lamp cool, slould many experiments require to be made in succession; 2, of the||I A aifi' A 1 boiler B, wlich fits by its bottom cage c, upon!_ it \' the case of the lamp, At the point c, is seen 5E thile edge of the damper-plate for modifying the ()r - e flame of tle lamp, or extinguishing it when the c1 ~ i:::j |l experiment is completed. D is the thermometer, made with a very minute bore, in the manner of the Iev. Mr. Wollaston's instrument for measuring the height of a mountain by the A I x I boiling point of water on its summit. The bott'L lj|tom of the scale in the ebullition thermometer, -' —' jis marked p for proof on tile leftside, and 100 (of proof spirit) on the right side. It corresponds to 178'6 Fahr. very nearly, or the boiling point of alcohol of 0-920 specific gravity. The following table gives the boiling points corresponding to the indicated densities:Temp. Fahr. Specific gravity. Temp. Fahr. Specific gravity. 178-6 - - 09200 P. 185-6 - - 09665 50 U. P. 179-75 - - 0-9321 10 U. P. 1890 - - 0'9729 60,, 180-4 -- 0-9420 20,, 191-80 - - 09786 70,, 181-00 - - 0.9516 30,, 1964 - - 09850 80,, 183 40.- - 0960 40,, 202-0 - - 0-992 90,, The above table is the mean of a great many experiments. When alcohol is stronger that; 0-92, or tile excise proof, its boiling point varies too little witl its progressive increase of strength, to render that test ap)plicable in practice. In fact, even for proof spii'it;, or spirits approaching in strength to proof, a more exact indication may be obtained by diluting them with their own bulk of water, before ascertaining their strength, and then doubling it. The boiling point of any alcoholic liquor is apt to rise if the heat be long-continucd, aFnd thereby to lead into error in using this instrument. This source of fallacy may be in a great measure avoided by adding to the liquor in the little boiler about a tea. spoonful (thirty-five grains) of common culinary salt, which las the curious effect of arresting the mercury in the thermometer at the true boiling point of the spirit, wine, 01 EEBULLITION ALCOHOLMETEh. or beer, to enable a correct reading to be had. The small measure marked M, holde the requisite quantity of salt. The therlmometer is at first adjusted to an atmospheric pressure of 29'5 inches. When that pressure is bigher or lower, both water and alcohol boil at a somewhat higher or lower temperature. In order to correct the error which would hence arise in the indications of this instrument under different states of the weather, a barometrical equation is attached by means of the subsidiary scale E, to the thermoneter D. Having stated tile principles and the construction of the ebullition alcoholmeter, I shall now describe the mode of its application. First.-Light the spirit lamp A. Second.-charge the boiling vessel B, with the liquid to be tested (to within an inch of the top), introducing at the same time a paper of the powder; then place the vessel a (the damper plate being withdrawn) on to the lamp A. Third.-Fix the thermometer D on the stem attached to B, with its.bulb immersed in the liquid. Thle process will then be in operation. The barometrical scale indicated on the thermometer is opposite the mean boiling point of water. Prior to commencing operat, ns for the day, charge the boiler B with water only, and fix tlie instrument as directed; wlen the water boils freely, the mercury will become stationary in the stem of thie thermormeter, opposite to the true barometrical indication at the time. Should the mercury stand at the line 29'5, this will le thl height of the barometer, and no correction will be required; but should it stand at any otler line, above or below, then the various boiling points will bear reference to that boiling point. In testing spirituous or fermented liquors of any kind, when the mercury begins to rise out of the bulb of the thermometer into the stem, push the damper-plate half-way in its groove to moderate the hleat of the flamne. When the liquor boils freely, the mercury will become stationary in tile stem; and opposite to its indication, on the left, the under-proof per-centage of spirit may be read off at once, if the barometer stand tlhat day at 29'5 inchles; while on the right hand scale, thle per centage of proof spirit is shown; being the difference of the former number froml 100. The damper-plate is to be immediately pushed home to extinguish the flame. The alcoholmeter will by itself only indicate the per centage of alcohol contained in any wine, but by the aid of tlie hydrometer, the proportionate quantity of saccharumn in all wines may be readily and easily determined. Tlie hydrometer will show the specific gravity of tllhe liquid upon reference to table No. 1, annexed. In testing a sample of wine, first take the specific gravity, and suppose it to be 989, then clharge the boiler of tihe alcoholmeter with the wine, as directed, and at the boiling point it indicates the presence of alcohol at 69'6 per cernt.UP, whose specific gravity will be found to be 979; deduct that gravity from the gravity of the bulk, or 989, and 10 will remain, which 10 degrees of gravity, upon reference to the wine table, will be found to represent 25 lbs. of saccharine or attractive matter in every 100 gallons, combined with 30 SO th gallons of proof spirit. Sike's hydrometer will only show the sp. gr. of liquids lighter than water (or 1000) and for wines in general use, thle gravities being ligllter tlhan that article, will answer every purpose; but tlere are wines whose gravities are heavier than water, such as mountain, tent, rich Malagas, lachrymse Clristi, &c., to embrace which additional weights to the hydrometer will be required, as for cordialized spirits, &c. In testing a sample of rich mountain, its sp. gr. was found to be 1039, or 39 degrees heavier than water, that wine at the boiling point indicated the alcohol 72'5 per cent. "P; but 980 sp. gr. deducted from 1039 leaves 59 degrees of sp. gr.; against 59 of the wine tables will be found 147-5 or 1471 lbs. of saccharine or extractive matter, combined with 271 galloins of proof spirit to every 100 gallons. Should the barometer for the day show any other indication above or below the standard of 29'5, tile thermometer scale will then only show the apparent strength, and reference must be had to thle small ivory indicator, F, it being the counterpart of the barometrical scale of the thermoneter; thus should the barometer indicate 30, place 30 of the indicator against the boiling point of the liquid, and opposite the line of 29'5 will be found the true strength. Ex.amiple 1. Barometer at 30.-Suppose the mercury to stop at the boiling-point 72-UP, place 30 of the indicator against 72 on the thermometer, and the line of 29'5 will cut 69 6-uw', tile true streng4th. Elxample 2. Barometer at 29.-Suppose the mercury to stop at the same point, 72 up, place 29 of the indicator against 72 on the thermometer, and tile line 29'5 will cut 74-3-u, the true strength. For inalted Liquors.-To all brewers and dealers in fermented liquors, the principle by its application, will supply a great desideratum, as it will not only show the alcohow reated in the wort by the attenuation, as well as the original weight of the wort prioi - 1 No. I. TABLE OF SPECIFIC GRAVITIES, by Sikes's IHydrometer, adapted to Field's Patent Alcoholmeter for Cordialized Spirits. Ij ______ -' 0 ~~TEMPERATURE 60~. SPECIFIC GRAVITY OF WATER 1000~. L 60 * 70 80 90 100 110 120 130 140 150 160 170 180 W\Tt. S. G. Wt. S. G. Wt. S. G. Wt. S. |. WVt. S. G. Wt. S. G. Wt. S. G. Wt. S. G. Wt. S. G. Wt. S. G. Wt. S. G. Wt. S. G. Wt.'S. G: G 60 922 70 942 80 961 90 981 100 1000 110 1020 120 1041 130 1063 14011085 150 1107 160 1129 170 1152 180 1175 I 1 924 1 943 1 963 1 93 1 1002 1 1022 1 1 1044 1 1065 1 1087 1 1109 111131 111155 1 1178 2 926 2 945 2 965 2 985 2 1004 2 1024 2 1046 2 1067 2 1089 21 111 2 1134 2 1157 2 1180!z! I 3 928 3 947 3 967 3 987 3 1006 I 3 1026 3 1048 3 1069 311091 31113 311136 31159 31182 4 930 4 949 4 969 4 989 4 1008 4 1029 4 1050 4 1071 411093 411116 41139 41162 411185 0 5 932 5 951 5 971 5 991 5 1010 5 1031 5 1052 5 1074 51096 5 1118 51141 5 1164 5 1187 6 934 6 953 6 973 6 993 6 1012 6 1033 6 1054 6 1076 61098 61120 6 1113 6 1166 61189 H 7 936 7 955 7 975 17 995 7 1014 7 1035 7 1056 7 1078 711100 711123 71145 71168 71191 8 938 8 957 8 977 8 997 8 1016 8 1037 8 1058 8 1080 8 1102 81125 811148 811171 8 1194 9 940 9 959 9 979 9 999 9 1018 9 1039 9 1061 9 1082 911104 9 1127 911150 9 1173 91196 10 942 10 961 10 981 10 1000 10 1020 10 1041 10 1063 10 1085 10 1107 10 1129 10 1152 10 1175 10 1199 The foregoing Table, which shows the Specific Gravity on the bulk of the mixture, bears reference to thle Table (No 2) of the Alcoholmeter following. |i _~~~~~~~~~~~~~~~~~~~~~~~~~~~~719.J _~ 618 EBULLITION ALCOHOLMETER. No. 2. TABLE, showing the lbs. of Sugar per Gallon in Cordialized Spirits, with Per-Centaget to be added to the indicated Strength, per the Alcoholmeter. Diff'r.ce of 10 15 20 25 30 35 40 45 50 Difference of Gravity. Gravity. 4 oz. 6 oz. 8 oz. 10 oz. 12 oz. 14 oz. oz. oz. Ibs. of Sugar or 25 371 50 61 75 87 10 1-2 1-4 Llbs. of Sugar per Gallon. to 100. to 100 to 100. to 100. to 100. to 100. per Gallon. 3p. Grav. Per Cent. Per Cent. Sp. Grav. if Spirit of Spirit. of Spirit. of Spirit. 920 Pf. 1'6 2-5 3-4 4'4 5'3 6-2 7-1 8'1 90 Pt. 920 923 2'5 1'6 2-5 3'3 4-3 5-2 6-1 6'9 7-8 8-8 2'5 923 926 5' 1-5 2 4 3'2 4'2 5-0 5'9 6'8 7 7 8-6 5' 926 929 7-5 1-5 2-3 3-2 4'1 4-9 5'8 6-6 7-5 8 4 7-5 929 932 10' 1-4 2-2 3-1 4'0 4-8 5'7 6'5 7-4 8-2 10' 932 935 12'5 1-4 2-2 3-1 3'9 4'7 5'5 6-3 7-2 8-0 12-5 935 938 15' 1-4 2-1 3-0 3'8 4'6 5-4 6-2 7 0 7 8 15- 938 940 17-5 1'3 2-1 2'9 3'7 4-5 5-3 6 0 6-8 7-6 17-5 940 943 20' 1'3 2-0 2'8 3'6 44 5'22 -9 6-7 7-5 20' 943 945 22'5 1'3 2-0 27 3'5 4-3 50' 5-7 6-5 73 225 945 948 25' 1-2 1-9 2'6 3 4 4-1'8 5-5 6-3 7 0 25' 948 950 27-5 1-2 1-9 2'5 3'3 4'0 47 5.3 61 6-8 27-5 950 952 30' 11 1-8 2'4 31 3-8 4'- 5-1 58 65 30' 952 954 325 1-1 1-7 2 3 3-0 3-6 4 3 4-8 5-5 6-2 32-5 954 956 35' 1-0 1-6 2-2 2'9 3-5 4 1 4-6 5-3 60 35- 956 958 37-5 1-0 1 6 2-1 2-8 3 4 3-9 4-4 5-1 5 8 37-5 958 960 40' *9 1-5 2-0 2-7 3-2 3 8 4 3 4-9 5-5 40' 960 962 42'5 5.9' 0 2'6 3-1 3'6 4-1 4'7 5-3 42-5 962 964 45'- 9 14 1-9 2-5 3-0 35 4 40 46 5-1 45' 964 965 47-5 *8 1-4 1-9 2 4 2-9 3-4 3 9 4-4 4-9 47-5 965 967 50(' 8 1I3 1-8 2-3 2-8 3 3 3-8 4 3 4-8 50' 967 969 52-5 7'2 1-7 2-2 2-6 3'1 3 6 4-1 4-5 52-5 969 970 55- -7 1-2:-6 2 0 2-4 2-9 3-4 38 4-2 55' 970 972 57-5.6 1 1 1-5 1-9 2-2 2-7 3-1 3-5 3-9 57-5 972 973 60- -6 1 0 1-4 1-8 2-1 2-5.29 3-3 3-6 60' 973 974 62-5'6 1 13 1-7 2-0 2'4 2 7 3-1 3'4 62-5 974 976 65' -5'9 1-2 1-5 1-8 2-2 2-5 2-8 3-1 65' 976 977 67-5'5'8 1-1 1-4 1-7 2-0 2-3 2-6 2-9 67-5 977 979 70' -4 -7 10 1 3 1-5 1'8 2-1 2-4 2-6 70' 979 980 72-5 -4 7.9 11 1-3 1 6 1 21 2-3 72'5 980 982 75''*3'6'8 1-0 1-2 1'4 1-6 1-8 2-0 75' 982 983 77 -5 3'5'7.9 1-0 1 2 1 4 1-6 1-8 77'5 983 984 80' -2'4'6'8 9 1'0 1-2 1-4 1 -6 80' 984 986 82-5 -2'3'5 7'8 *9 1-0 1'2 1-4 82'5 986 988 85.- "2 2.4'6'7 *8.'9 1 0 1-2 85' 9S8 99 875 2 6 9 1 87'1 2 3 6 -5 990 992 90..1 1 2'4'5 *6 -7'8 -9 90' 992 994 92-5 - -.1'2 3 4 5.6 -7 -8 92-5 994 996 95' - - *- -2 -3'4 *5 -6 -7 95' 996 998 97.5 - -- 2 3 4.5 6 97'5 998 to fermentation, but it will indicate the value of malt liquors in relation to their cornponent parts. It will likewise be a ready means of testing the relative value of worte foml sugar compared with grain, as well as being a guide to the condition of stock beers and ales. To ascertain the strength of malt liquors and their respective values, the instrument has been supplied with a glass saceharotneter, testing-glass, and slide-ruie. Commence by charging the testing-glass With the liquid, then insert the saccharometer, to ascertain its present gravity or density per barrel, and at whatever number i} floats, that will indicate the number of pounds per barrel heavier than water. Example 1.-Suppose the saccharorneter to float at the figure 8, that would indicate 8 lbs. per barrel; then submit the liquid to the boling test, with the salt as before directed, and suppose it should show (the barometrical differences being accounted for) 90-uP, that would be equivalent to 10 per cent. of proof alcohol. Refer to the slide-rule, EBULLITION ALCOHOLMETER. 619 and place A on the slide against 10 on the upper line of figures, an& facing B on the lower line will be 18, thus showing that 18 lbs. per barrel have beer decomposed tc constitute that per centage of spirit; then, by adding the 18 lbs. to the present 8 lbs. per barrel, the result will be 26 lbs., the original weight of the wort after leaving the copper. Example 2.-The saccharometer marks 10 lbs. per barrel, and at the boiling point it indicates 88-UP, equivalent to 12 gallons of proof spirit per cent.; place A against 12, an(l opposite B will be 211 lbs. per barrel, when, by adding that to the 10 lbs. present, 381 lbs. will be the result. To ascertain the relative Value,-Suppose the price of the 26 Ibs. beer to be 36s. per barrel, and the 311 lbs. beer to be 40s. per barrel, to ascertain which beer will be the cheapest, place 26 on the opposite side of the rule against 36, and opposite 311 lbs. will be 43s. 7d., showing that the latter beer is the cheapest by 3s. 7d. per barrel. By taking an account of the malt liquors by this instrument prior to stocking, it may be ascertained at any time whether any alteration has taken place in their condition, either by an increase of spirit by after fermentation and consequent loss of saccharum, or whether by an apparent loss of both, acetous fermentation has been going on towards the ultimate loss of the whole. This instrument will likewise truly indicate the quantity of spirit per cent. created in distillers' worts, whether in process of fermentation or ready for the still, the only difference will be in the allowances on the slide-rule. N.B.-Tlhe saccharometers applicable to the foregoing rules for beers, ales, &c., have been adjusted at the temperature 60~ Fahrenheit, and will be found correct for general purposes; but where extreme minuteness is required, the variation of temperature must be taken into account, therefore for every 10 degrees of temperature above 60, 3-ths of a pound must be added to the gross amount found by the slide-rule; on the contrary, for every 10 degrees below 60, -3;ths of a pound must be deducted. For cordialized Spirits.-The operation in this instance is somewhat different from that of beers which have the alcohol created an the original wVorts; whereas, in cordialized spirits, gins, &c., the alcohol is the original, and the saccharine matter, or sugar, is an addendum. If 100 gallons of spirit are required at a given strength, say 50 per cent. under proof 50 gallons of proof spirit, with the addition of 50 gallons of water, would effect tlat object, and upon testing it by the alcohollneter, it would be found as correct as by the hydrometer. But in cordializing spirit it is different, for to the 50 gallons of proof spirit, 50 gallons of sugar and water would be added, thereby rendering the hydrometer useless, except for taking the specific gravity of the bulk, and, according to the quantity of sugar present, so a relative quantity of water must have been displaced; and as the sugar has no reducing properties, the alcoholmeter will only show the strength of the cordial in relation to the water contained in it, as the principle indicates, irrespectively of saccharine or extractive matter present. Suppose, in making 100 gallons of cordial at 50-uP, 3 Ibs. of sugar are put to the gallon, or 300 lbs. to the 100 gallons, that 300 lbs., displacing 1yS6i7th gallons of water only 31l33-th gallons of water instead of 50 have been applied; the sugar, without reducing p)roperties, making up the bulk of 100 gallons, which is meant to represent 50 per cent. Up. The alcoholmeter will only show at the full point of ebullition the alcoholic strength in relation to the water in the 100 gallons of the mixture, or 35 per cent. -P, leaving If per cent. to be accounted for on the bulk. As the quantity of sugar present must be determined before that per centage can be arrived at, a double object will be effected by so doing, namely, eliciting in all instances the quantity of sugar present, as well as the per centage of spirit to be accounted for. Example 1. —In taking the sp. gr. of a cordial, suppose it to be found 1076, then submit the liquid to the boiling point, and having ascertained the per centage of alcohol, and it proves to be 35-up, the sp. gr. of alcohol at that, strength will be found to be 956; deduct 956 from the sp. gr. of the bulk, or 1076, and 120 will remain; refer that to its amount on the head line of table No. 2, namely, 120, under which will be found 3, representing 3 lbs. of sugar to the gallon; and by running the eye down its column to oppositethe alcoholic strength indicated (35 up) will be found 14'9, which represents the per centage of water displaced by the sugar, and which amount of 14'9, added to the 35 per cent. ascertained, makes the total upon the bulk 49-9 per cent.-up, with 3 lbs. of sugar to the gallon. For Gins, &c.-Example 3. In taking the sp. gr., suppose it to be found 957; then submit to the boiling point, and it proves to be 14-UP, whose sp. gr. is 937, which, deducted from 957, leaves sp. gr. 20; on the head-line of table No. 2, under 20, will be found j, or i lb. of sugar to the gallon, and on running the eye down to opposite - J 620 ELAINE. 14-"r, will be found 380, which, added to the 14, makes the total on the bulk 17 pel Kent.-up, with 50 lbs of sugar to the 100 gallons. To chemists for their tilcetures, &c., this instrument will be found essentially useful. N.B.-Care must be taken that the mercury is entirely in the bulb of the thermo. meter before it is fixed on the stem for operation, and in all cases (except for water) the salt must be used. Conclusion.-Wines are peculiarly subject to be mystified by adulterations of various kinds. It will prove of great advantage to the public when the relative quantity of frlit, or saccharum, and alcohol requisite to constitute the normal wine of each species io v-ell ascertained. Some beers possess a remarkable narcotic power, by which they cause drowsiness alnd stupor without corresponding previous exhilaration. Suh beverages may justly be suspected of having been sophisticated with occulus indicus, opium, or some analogous drug; and this suspicion may become certainty, if they be shown by the alcoholmeter to contain only a few per cents. of fermented spirit. The instrument in its complete state is made and sold by Mr. Joseph Long, Little Tower Street. The tables, of which the above is only a portion, and the barometric indic:tor, have been constructed by him and Mr. Atlee. EDGE TOOLS. Mr. James Bouydell welds iron and steel together in such a manner that when cut up to form edge tools, the steel will constitute a thin layer to form the cutting edge. Ie piles a slab or plate of steel upon two or more similar plates of iron, heats in a furnace to a good welding heat, and then passes between grooved or other suitable rollers, to convert it into bars; the steel being in a thin layer either on one of the outer surfaces of the bar, or between two surfaces of iron according to the kind of tool to be made therefrom. The bars thus produced are cut up and manufac tured into the shape of the desired articles by forging. If the cutting edge is to extend but a short distance, the steel is applied only near one edge of the pile. In this nmanner hatchets, adzes, choppers, knives of all kinds, scissors, scythes, chisels, gouges, &c., may be economically manufactured; the steel being used merely for forming the edge, while the requisite stiffness of the tools is obtained by the iron. The compound bars which have the steel on one side are suitable for chisels and other tools, which have a cutting edge on one side, the iron being ground away when making or sharpening the tool. Mr. B. manufactures spades on a somewhat similar plan. — ewton's Journal, vol. xxvi. p. 183. See CUTLERY and STEEL. EDULCORATE, (Edulcorer, Fr.; Aus.iissen, Germ.) is a word introduced by the alchemists to signify the sweetening, or rather rendering insipid, of acrimonious pulv-rulent substances, by copious ablutions with wrater. It means, in modern language, the washing away of all particles soluble in water, by agitation, or trituration with this fluid, and subsequent decantation or filtration. EFFERVESCENCE. (Eng. and Fr.; Aufbrausen, Germ.) When gaseous matter is suddenly extricated with a hissing sound during a chemical mixture, or by the application of a chemical solvent to a solid, the phenomenon, from its resemblance to that of simmering or boiling water, is called effervescence. The most familiar example is afforded in the solution of sodiac powders; in which the carbonic acid gas of sesqui carbonate of soda is extricated by the action of citric or tartaric acid. EFFLORESCENCE, (Eng. and Fr.; Verwittern, Germ.) is the spontaneous conversion of a solid, usually crystalline, into a powder, in consequence either of the abstraction of the combined water by the air, as happens to the crystals of sulphate and carbonate of soda; or by the absorption of oxygen and the formation of a saline compound, as in the case of alum schist, and iron pyrites. Saltpetre appears as an efflorescence upon the ground and walls in many situations. EGGS, HATCHING. See INCUBATION, ARTIFICIAL. EIDER DOWN, is a kind of precious down, so called because it is obtained from the Eider-duck. These birds build their nests among nrecipitous rocks, and the female lines them with fine feathers plucked from her breast, among which she lays her five eggs. The natives of the districts frequented by the eider-ducks let themselves down by cords among the dangerous cliffs, to collect the downs from the nests. It is used to fill coverlets, pillows, cushions, &c. ELAINE is the name given by Chevreul to the thin oil, which may be expelled from tallow, and other fats, solid or fluid, by pressure either in their natural state or after being saponified, so as to harden the stearine. It may be extracted also by digesting the fat.n 7 or 8 times its weiirt of boiling alcohol, spec. grav. 0-798, till it dissolves the whole. Upon cooling the solution, the stearine falls to the bottom, while the elaine collects in a layer like olive oil, upon the surface of the supernatant solution reduced by evaporation to one eighth of its bulk. If this elaine be now exposed to a cold temperature, it will deposit its remaining stearine, and become pure. See FAT, OILS, and STEARINE. ELASTIC BANDS. 621 ELASTIC BANDS. (Tissus Elastiques, Fr.; Federharz-zeige, Germ.) The manu facture of braces and garters, with threads of caoutchouc, either naked or covered, seeins to have originated, some time aco, in Vienna, whence it was a few years since imported into Paris, and thence into this country. At first the pear-shaped bottle of Indian rubber was cut into long narrow strips by the scissors; a single operative turning off only about 100 yards in a day, by cutting the pear in a spiral direction. He succeeded next in separating with a pair of pincers the several layers of which the bottle was composed.. Another mode of obtaining fine threads was to cut them out of a bottle which had been rendered thin by inflation with a forcing pumrp. All these operations are facilitated by previously steepine the caoutchouc in boiling water, in its moderately inflated state. More recently, machines have been successfully employed for cutting out these filaments, but for this purpose the bottle of caoutchouc is transformed into a disc of equal thickness in all its parts, and perfectly circular. This preliminary operation is executed as follows: 1. the bottle, softened in hot water, is squeezed between the two plates of a press, the neck having been removed beforehand, as useless in this point of view; 2. the bottle is then cut into two equal parts, and is allowed to con.,olidate by cooling before subjecting it to the cutling instrument. When the bottle is strong enough, and of.variable thickness in its different points, each half is submitted to powerful pressure in a very strong cylindrical mould of metal, into which a metallic plunger descends, which forces the caoutchouc to take the form of a flat cylinder with a circular base. The mould is plunged into hot water during the compression. A stem or rod of iron, which goes across the hollow mould and piston, retains the latter in its place, notwithstanding the resilience of the caoutchouc, when the mould is taken from the press. The mould being then cooled in water, the caoutchouc is withdrawn. The transformation of the disc o' caoutchouc into fine threads is performed by two machines; the first of which cuts it into a riband of equal thickness in its whole extent, running in a spiral direction from the circumference to the centre; the second subdivides this riband lengthwise into several parallel filaments much narrower but equally thick. The following figs. 473, 474, 475, represent the machine for cutting the spiral riband. The disc D, placed horizontally, turns round its vertical axis, so as to present its 473 C 474 cl srtiCT, - ~~~475 ~ ~ ~ ~ I1 (475 a periphery to the edge of a knife c, formed like a circular blade, Whose plane is perpea dicular to that of the bases of the disc. This knife turns round its centre, which is fixed. The rotatory motion of the disc forces the knife to penetrate further and further into its mass, and the motion of the knife itself makes it cut the riband more easily. It is obvious, that if the disc alone revolve, the motionless knile could act only by pressure, and would meet with an enormous resistance. A third movement becomes necessary. In proportion as the disc is diminished by the removal of the spiral band, the centre of this disc must advance upon the knife, in order that the riband may have always the same breadth. The inspection of fig. 475 will make the accordance of the three motions intelligible. The knife c is placed upon a shaft or axis A, which carries a pulley, round which a belt or cord runs which drives the whole machine. This knife is six inches in diameter. In order that by being kept cool it may cut the caoutchouc better, it is plunged at its lower part into a trough B, full of water; a stopcock R, serves to empty this trough. The shaft A bears a pinion p, which takes into a wheel R, placed upon the shaft A'; upon which there is cut a worm or endless screw, v, v. This worm bears a nut E, 622 ELECTIVE AFFINITY which advances as the screw turns, and carries with it a tie L, which in its turn pushes the disc D, carried upon a shonlder constantly toward the knife. This shoulder is guided by two ears which slide in two grooves cut in the thickness of the table. The diameter of the pinion p is about one fifth of that of the wheel R; so that the arbor A turns five times less quickly than the arbor A'; and the fineness of the screw v contributes further to slacken the movement of translation of the disc. When the disc is all cut down, the shoulder, the tie, and the nut, are brought back to their original position by lifting the nut, which is hinged on. The disc is fixed upon the shoulder by means ofshart points, and an upper washer. The shoulder and the washer have a very small diameter, in order that the knife may, in cutting down the disc, advance as near as possible to the centre. The rotatory movement of the disc and its shoulder, is given by an endless screw w, w, which governs a pinion p', provided with 10 teeth, and carried by the shaft A, upon which the shoulder is mounted. The arbor A' of this endless screw receives its motion from the first shaft A, by means of the wheels s and s' mounte.J upon these shafts, and of an intermediate wheel s". This wheel, of a diameter equal to that of the shaft A", is intendedl merely to allow this shaft to recede from the shaft A. The diameter of the wheel of this last shaft is to that of the two otheir- in the ratio of 10 to 8. Second machine for subdividing the ribands. Fig. 476.-The riband is engaged between the circular knives, c, c, which are mounted upon the rollers R, R; thin brass washers keep these knives apart at a distance which may be varied, and two extreme washers mounted with screws on each roller maintain the whole system. The axes of these rollers traverse two uprights M, M, furnished with brasses, and with adjusting screws to approximate them at pleasure. The axis of the lower roller carries a wheel 476 C t, which takes into another smaller wheel r' placed upon the same shaft as the pulley s, which is driven by a cord. The diameter of the wheel r is three times greater than the wheel r'. The pulley r is twice the size of the wheel r'; and its cord passes round a drum B, which drives the rest of the machine. The threads, when brought to this state of slenderness,,are put successively into tubs filled with cold water; they are next softened in hot water, and elongated as much as possible in the following manner:-They are wound upon a reel turned quickly, while the operative stretches the caoutchouc thread with his hand. In this way it is rendered 8 or 10 times longer. The reels when thus filled are placed during some days in a cold apartment, where the threads become firm, and seem to change their nature. This state of stiffness is essential for the success of the subsequent operations. The threads are commonly covered with a sheath of silk, cotton, or linen, by a braiding machine, and are then placed as warp in a loom, in order to form a narrow web for braces, garters, &c. If the gum were to exercise its elasticity during this operation, the different threads would be lengthened and shortened in an irregular manner, so as to form a puckered tissue. It is requisite therefore to weave the threads in their rigid and inextensible, or at least incontractile condition, and after the fabric is woven to restore to the threads of caoutchouc their appropriate elasticity. This restoration is easily effected by passing a hot smioothing iron over the tissue laid smoothly upon a table covered with blanket stuff. See BRAIDING MACHINE. ELECTIVE AFFINITY (Wahlverwamndtschaff, Germ.) denotes the order of preference, so to speak, in which the several chemical substances choose to combine; or really, the gradation of attractive force infused by Almighty Wisdom among the different objects of nature, which determines perfect uniformity an identity in their compounds ELECTRIC TELEGRAPHS. 623 amidst indefinite variety of combination. The discussion of this interesting sabjee4 beiongs to pure chemistry. See I)ECOMPOSITION. ELECTRO-TELEGRAPIIY. Ml[agnetic Needle Telegraphs.-After CErsted had discovered the mutual action of electric currents and magnetic needles, Ampere "proposed, in consequence of an idea suggested to him by the illustrious Laplace, to employ as many circuits as there were letters of the alphabet, and to make each of them act on a separate needle." Schweiger's invention of the galvanometer, followed more recently by Wheatstone's discovery of the velocity of electricity, gave renewed impulse to these inquiries. Professor Ritchie illustrated Ariiere's idea on a small scale, but rather with a view of pointing out the difficulties which enveloped it than to propose it for practical purposes. Alexander's telegraplh had thirty galvanomletric needles and thirty-one wires; each needle supported a screen, which it carried with it when deflected, and thus exposed a letter. Davy's filst telegraph was of the same character, only the letters were illuminated. Baron Schelliing and Feeliner proposed to limit this number by employing fewer needles and observing their combined miotions, a different character being indicated according to thle numllber of needles in motion. Mr. Bain has proposed to fix the magnet and deflect the coil. The arrangements peculiar to Mr. Wheatstone's needle telegraph are, that lie lhas one wire only for each needle; that two needles are ths always included in the circuit; that the combination of the two needles out of five, wlhich he generally used, will produce 20 signals, and that by a key-board, peculiarly Iiis contrivance, these several circuits can be readily formed. By combining three or four needles, 200 signals can be given. As the motion of these deflected needles was niot of itself sufficiently violent to ring a bell in order to call attention, arrangemenlt was made that one of tle needles by its deflection should complete the circuit of a distant battery, and this would then make an electromagnet, and liberate the detent of an alarm. Other modes of sounding an alarm were adopted on account of thle difficulties wlichl attended the early experiments on that form of telegraph which we sliall plesentlly describe. As it is not the intention to give here a history of telegraphs, tlle above illustrations of the chief applications of the galvanomneter to this purpose will suffice. "The instruments to be first described are the inventions of Messrs. W. Fothergill Cooke and Charles Wheatstone, F.R S. They are of two kinds: the one, in which a 477 A.,t- i IIItl{I 621 ELECTRIC TELEGRAPHS. single galvanometer;s employed; the other, in which there is a pair of galvanometers The former will serve our present purpose, as the mechanical adjustments of the latter are merely the double of this. I have removed the case from tile instrument in order to give a clear view of all the essential parts; and have engraved a back view of it (.fig. 477) with the battery E attached as if for use; and the circuit of the galvanometer A coimpleted by the wire w w. "Tlie instrument is possessed of a two-fold character; it is passive, or ready for receiving signals from another instrument; it is active, or ready for transmitting signals to another instrument. By describing first how it is fitted for receiving signals, and then how it is arranged for transmitting them, we shall be better able conveniently to analyze it, and to comprehend its general structure. The frame of tile coil B is of brass, or (which is in many respects better) of polished wood or of ivory; it is screwed upon the face of the -instrument, which face is a brass plate varnished on the inner side. Looking at the coil, a short wire from its right-hand end comes to a screw terminal, which latter, by a slip of brass neatly laid on the instrument case, is connected wiih another terminal u. The left-hand end of the coil comes also to a terminal, from which a slip of brass descends to a brass plate here, partly hidden; but its form may be gathered from a similar plate, visible on the left side. Tlese twin plates are in metallic connection by means of the two upright springs, plainly shown in the drawing. The springs are of stout steel, and press strongly on two points in a short insulated brass rod n, which is screwed in the wooden framework of the instrument. The left-hand plate is connected with the terminal D, also by a slip of brass. If now, the two terminals'u and D are connected by a wire ww, the circuit will be complete, as follows: from the terminal u into the coil at the right-hand side; out of the coil, at the left-side downwards to tihe right-hand plate; up the right-hand steel spring, across the brass rod n to the left-hand steel spring; downward by this spring to the left-hand p1,ate, thence by the slip of brass to the terminal D, and thence by the wire w w the terminal u, whence we started. If now the wire from u went up the line of railway, and the wire fiom D down the line, and the circuit were in some way kept complete on the large scale, as it has been here described on the small scale, any electric current passing along the wire from a distant station, would traverse this coil in its course, would deflect the needle, and so make a signal. I should here mention that for the sake of regularity, we adopt one unvaried order in attaching wires to the instrument; it is to put the up wire on the terminal, shown by u on the figure, thle coils being all uniformly wound. "So far for receiving a signal-now for sending one. Were we to go out on the open railway, taking with us a battery, and to cut any one of the wires, and place its two ends, thus obtained, upon the two terminal ends of the battery, a current would pass along the line, and the needles on that wire would be deflected; and if we changed hands so as to reverse the connections, the deflections of the needle would be reversed. The same would happen were we to cut a wire inside the office, or inside the telegraplh, and to treat it in a similar way. Now, in every apparatus contrived for transmitting signals, we have a place corresponding to such a cut wire; and near this place are the poles of the battery, mounted and moveable, so that they may be readily applied in the breach, one way or other as required. Tlie place here (fig. 477) is tile top of the springs. They are not joined to the brass rod n; but, as I said before, press hard upon it, and can readily be raised with the finger, or otherwise. It is obvious that, when either of them is raised, the circuit is broken. Now, near this place is a mechanical contrivance, by which the poles of the battery may make a breach in the circuit, and be applied in the breach in either direction. The drum B is of boxwood, the ends c and z being capped with brass, and insulated from each other by the wood, b, left between them. The drum is moveable by a handle, not in sight here, and is supported as shown in the present figure. A stout steel wire c' is screwed beneath into the c end of the drum; and a similar z' is screwed above into the z end. These two wires are the poles of the battery, z' being connected with the zinc end, and c' with the copper, thus:-from the copper end of the battery a wire is led to the terminal c; thence a slip of brass leads to a curved brass spring which presses closely on the drum at c; from the zinc end of the battery a wire goes to the terminal z, and thence a slip of brass leads to a similar curved spring, pressing on the continuation of the z end of the drum, as shown in the figure. It will be seen that, whenever the drum is moved, the steel wire z' will lift up one or other of the upright steel springs; it is now lifting up the right-hand one, and so breaks the circuit; but, by a little further motion of the drum, the wire c' will press upon the boss below, as shown in the figure, and thus there will be a battery pole on each side of the breach, and a signal will be made on this, and on all instruments. connected with it. And, from the peculiar arrangement with the drum, the motion can be changed as rapidly as the hand can move. I have shown the battery connections exactly as they occur in practice; and tile connections are such that, if the right-hand sprinlgs are moved off, the needle moves to t-b right, and, if the left, to tile left. The needle on the face of tlie instrument always ELECTRIC TELEGRAPHS. 625 h.s its north end upward, and the needle within the coil its north end downward, so bhat if we look at the face of anl instrumlrent, and see the top end of the needle move to I.iie right, we may be sure that inl tlre hal' of the coil nearest to us thle current is ascending." Thus the wires are the channels through which electric influences are conveyed to great distances with inconceivable velocity, and the niovealle nagnets, or galvanomreters, I;o which the wires are attached at the stations, are the parts of the apparatus by which signals are made. The mode of interpreting these signals is thus described by tle author:"DOUBLE-NEEDLE CODE.-Having described the apparatus and means employed for producing at pleasure the transmission of signals to distant places, it now remains tj us to explain the manner of interpreting these signals, so that each person shall understand the ideas the other would convey. "We have to describe how, out of only two needles, each of which has but iwo movements, the telegraph alphabet is formed. On tlle face of the instrument are the letters of the alphabet arranged, as it will be seen, seriatim in two lines, beginning at the left, and ending at the rigllt, as iL wwiting. The commencing series from A to P is above the top end of the needles; and the concluding series fiom R to Y below the bottom end. It will also be seen tliat some letters ail engraved once, some twice, and others three times. To make a letter engraved once, requnies one motion of the needle; to make one engraved twice, two motions of the needle; and to make one engraved three times, three motions. In respect to thle UPPER row, the needle nearest to tlhe letter is moved, and it is moved so as to point toward the letter. In respect to the LOWER roW, both needles are moved, and their lower end is made to point in the direction of the letter required. Six of the letters C, D, L, M, and U, V, require a twofold motion of the needle or needles, first to the rirght then to the left for C, L, anld U, and first to the left then to the right for D, M, and V. These six letters are engraved intermnediate, and with a double row between. The alphabet produced by this arrangement is of a simple character, and is very readily acquired. To the stranger it appeafrs confused; but when he has the key to it the difficulty disappears; it might at first sight appear that a dial instrument-a telegraph, that is, provided with alphabets engraved on a c;rcular dial, and an index made to revolve, and point to any required letter, is more simple; several such telegraphs exist; and among them are some very happily arranged; and there is something so simple in the fact of being able to point to any desired letter, lnat it is no wonder the public generally may, on a hasty glance, and before studying tlhe practical merits of the case, be ready to decide in their favor, and prefer them to any other plan, the A, B, C of which is less obvious. "But is it such a very serious matter to learn another alphabet? Every schoolboy, now-a-days, knows some half-dozen alphabets; there are ROMAN letters large, anod ROMAN letters small; MANUSCRIPTletters large, and manuscript letters small; (DDll.nlits) large, and Old English small; GREEK large, and Greek small, and so on, and all different, and not one of them in'wvhich the letters are represented by so few strokes of the pen as are the telegraph letters by beats of the needle. Take one of our plainest alphabets as an example; the ROMAN CAPITALS, for instance, and place a few of them in juxta-positicn with the corresponding telegraph signals:A \\ E / G /// B \\\ F // H \ "The simplicity of these symbols is obvious. Two diagonal and one horizontal line are required for the Roman A; two diagonal lines for the telegraph A; one vertical and three horizontal lines make the Roman E; one diagonal the telegraph E, and so on; the difference being that all the world have learned the Roman alphabet, and only a chosen few have studied the telegraphic symbols. That the latter really are simple and distinctive: that they are full of meaning and very legible; that they ire applicable to ordinary language, and good, ay, very good I no one will for a moment doubt, who has seen the rapidity and accuracy with wlich a telegraph officer receives a dispatch. "To one who sees a telegraph in operation for the first time, the effect borders on the marvellous; setting out of the question the fact that the needles are caused to move by an individual perhaps a hundred niles off; the motion of the needles hitler and thither; quicker than the untrained eye can follow; the want of all apparent order and rule in their movement; the ringing of the changes between one and the other, and both; the quiet manner in which the clerk points his needle to the letter F, in rapid intervals, implying that he understands the word; while, to the uninitiated looker-on, all is wonder and nystery, and confusion; and the ralre occurrence of the clerk pointing to *, implying he did not understasnd; and, finally, the quiet manner with which the clerk tells you, very coolly as the result of his operations, "That the very pretty girl, with bright blue eves and long curls, has sailed for IBoulognle in the Princess Clementine, now leaving Folkstone Itarbor; and that she is accompanied by 41 _ ~_v 626 ELECTRIC TELEGRAPHS. the tall, handsome man, with the dark moustache and military cloak.' As he tells yoo this, and says,'Message and answer, forty words two rates at 10s. 6d., one guinea, porterage a shilling-one pound two.' If you happen to be the papa of the pair of blue eyes, you are bewildered, and wish you were an electric current, and could be sent after them."-Fronm Electric Telegraph iManipulation, by C. V. Walker. An invention apparently very simple and comprehensive for electro-telegraphic correspondence, was made the subject of a patent in February, 1851, in Newton's Journal. It consists in the use of such parts or arrangements of apparatus as will allow two or more persons, by the agency of electricity, to send or receive signals or intelligence by one common wire of communication or main conductor, whilst the rapidity or closeness in the order of succession of the signals, consequent on the indefinite short time the main conductor is in actual use in conveying the electric current for transferring the signal shall be such, that all the persons so employed in these telegraphic operations can be continually and simultaneously occupied, in like manner as if each one of them had a distinct wire of communication all the time waiting for or appropriated to his particular use. By this invention the same practical telegraphic results are obtained, through agency of the one wire or main conductor, as, in the varieties of the electric telegraph before known or used, would require several distinct wires of communication. According to this improved plan of working, the wire of communication or electric conductor may he considered as a public word road, or an omnitelegraphic way; whereas, in contradistinction, the conductor, as heretofore used, may be considered a private word road, or a unitelegraphic way. In addition to the ability of allowing divers parties simultaneously to telegraph at will either all in the same or in contrary directions, over or along one wire of communication, this improvement enables each one of the operators, so employed, to have and to use as many distinct short wires or accessory conductors, all related to the main conductor, as the operators may desire to have separate signals; whereby the facility of making and receiving or recording signals or intelligence is greatly increased. Thus, for example,-suppose ten men at each end of the wire of communication are all using the same wire of communication which connects the distant places, their practical telegraphic facilities would be greater than could be had by the old system, if these twenty men had twenty different wires of communication in place of only one such wire; and would be as great as could be had by the old system, if each of those twenty men had as many such wires as they might desire to make or receive different signals. Thus, supposing twenty-five signals to be made and twenty-five to be received, for each of these twenty men, 1,000 separate wires or main conductors would be required, in order to accomplish wlat, by the new system, requires only one such main conductor, aided by 1,000 short wires or accessory conductors, or signal-making and signal-receiving wires, which need be of but a few inches in length severally, or so lono as to reach to, or be systematically put into, electric relation with the respective ends of the main conductor or wire of communication; or, otherwise by moti: n be successively brouglht into electric communication with, and so nmomentarily forming in succession, portions of the conductor, by which the electric current, circuit, or line of inductive action is established, maintained, or blroken, from time to time. It may be stated that this improvement rests upon takinr adlvantage of the circumstance that, practically speaking, no sensible portion of the time employed in working the telegraph is expended in the actual transmission of the electric influence, which is the medium or agent of the communication, but that is due to the operation of making or recording the signals. One wire, reclling between the distant places, is therefore eapible of being the instrument of transnlitting an indefinite number of different signals in a second of time, provided that suitable adaptations are made to enable so many different signals to be separately placed upon one end of tie main conductor, and received or recorded at the other end of the conductor, in an intelligible manner. Tlere are an indefinite number of methods of applying to practice this improvement, differing more or less in kinds of apparatus used, arnd in modifications of electrical actions applied. But all are substantially the same improvement; inasmuch as their action would be to set apart distinct and small and successive fractions of a second or olher period, and assign and apply such small fractions of time to different uses or for different persons; so that, although many persons should all simultaneously be employed in using one common wire of communication, yet all the signals so transmitted by it mn.y )e successive; the rapidity of the electric conduction admitting, by this invention, thle divers signals to be transmitted successively along the wire, and yet so quickly the one after the other, as to give a like practical result, as if they were simultaneously transmitted by separate wires or main conductors. A convenient mode of applying this improveme.pt to practice, and for illustrating the principle of tile invention, may be understood by referring to the diagram (fig. 478), wherein two pendulums, supposed to be actuated by clock work or other suitabje means, are indicated; such pendulums being made to vibrate as nearly as possible together in position and in time of vibration. At the chief station A, the ELECTRIC TELSGRAPHS. 627 standard pendulum is situate; and the dependent telegraph station is also provided with a pendulum, as at B. D, D are the pendululm rods. with these balls or wei(rhts E, the prolonged end of the pendulum rods, wlich shoulld be much longer in proportion than represented in the drawing; F, slight springs, united to the prolonged end of the C Z C A YY B I! i! I, D \ I "D\ 478 I I \ Di I \ P F! \ 1 I. I Ill G -. pendulum rods; and P, R, P, and P, s, p. are two grooves or pathways, so made that the spring F shall fall into the groove P, R, P, when the pendulum makes the vibration from left to right, and shall fall into the groove r, s, P, when making the vibration from right to left; c, c, is the main conductor or wire of comuniunication, connecting the two telegral)hic stations A and B together; x, x, are groun(d plates and ground wires. At station A, there are metallic points over which the spring F passes, touching the surface each vibration,-which points are connected with tlhe conductors L, x. The groove r, R, P, at station B, is of metal, and in electric communication with L and x. The spring F, in moving in. either of the grooves P, R, P, or in the p, s, P, of station A, is kept in its path by an insulated or non-conducting guide; z is a Leyden jar, prime conductor of an electrical machine, or galvanic pile, kept constantly charged, or capable of giving a great number of.visible sparks or electric pulsations per second, on making or breaking the electric circuit or line of inductive action. The wire c, c, c, has a metallic connection with the upper end of the pendulum rods, which are also metallic as well as their prolonged terminations. In this condition of things, whenever the spring F, at station A, passes over K, K, in its vibrations, there will be an electric conmmunication or circuit from z to K, through hi x, to the ground at station A; also from z to the metallic groove r, R, P, at station B, and to the ground there; provided the pendulum at station B is making its vibration from left to right, when the pendulum at station A carries its spring F over the conducting point K. At K on the left-hand side of the standard pendulum, there are two metallic faces near together; by this arrangement it can be known at station B when the pendulum at station A is is inotion, and the position of its vibrations exactly determined; so that the pendulum at B can be from time to timne set in motion, accelerated or retarded, in order to maintain that degree of synchronism in the action of the pendulums, and similarity of position, which are necessary for success of the telegraphic operations. When the pendulumii at B is correctly tiumted in its inotions, there will be visible two sparks on the left-hand side, and one spark on the right-hand side, of the conducting groove at K, K, at statioIn B, equal distance from the centre of vibration; but when this pendulum is not in its proper position or motion, these sparks can be seen at other places along the groove. n1 and l2, at both stations are sional-making wires; and o1, G2, at both stations, are signal-receiving wires. These signhal wires are to be supposed as numerous in each set as the number of different signals desired to be usedsay not less than the letters of the alphabet; a smaller nurnber is, however, shown in the drawing for distinctness' sake. All the signal-receiving wires reach into the groove or pathways P, s, P, in such a manner, that the spring F shall touch and slide over the flattened faces or ends of these wires in succession each time he pendulum moves from right to left. The signal-making wires on the contrary, 628 ELECTRO-GILDING. stand a little off, out of the groove or pathway, but are intended to be so mounted that each may be raised with the pressure of the finger, and brought into the line of the groove or pathway, to be touched by the spring F, when the pendulum swings from left to right. All these signal wires are united by one end to the conductor L, L, but are free and independent at the other end. The free end of the signal-receiving wires may have a width of half an inch, more or less, where F passes over them. The corresponding ends of the signal-making wires may be put on edge or line; so that the signal-making wires can be touched by F but for a moment, whilst tile signal-receiving wires will be touched for a sensible time by F, in passing over them. Under these circumstances, if any one of the signal-making wires iil, at station A, be touched and brought into contact with the end F, of the vibrating pendulum, a conducting circuit or electric current will be established for the moment, the corresponding pendulum at station B will be in front of the group of signal-receiving wires il of that station. Therefore, from the electric circuit existing for that moment of contact, there would be a spark visible upon the flattened end of that one of the signal-receiving wires which corresponds to that one of the signal-making wires at the other station, which may have been pressed upon and brought into the pathway of F; all these signal wires in each set being marked by and signifying the different letters of the alphabet, &c. It is obvious, that if the left-hand wire of each set be marked a, the next b, next c, &c., then, should a, b, or c, of a signal-making group ni, station A, be pressed upon and touched by F, this act will be known at station B, by the appearance of a spark on the end of that one of the signal-receiving wires a, b, or c, of group Hi station B, corresponding to that wire which mlay have been so touched at station A. Thus, at will, can any signal or letter be sent from station A to station B, and during the operation of signalmaking, by one person at station A, to another at station B. It will now be seen that another person, or the same person at station B, by the use of the wires ll, can telegraph in reply to station A, by making use of the set of wires nl of each station, in a manner similar to those in which the wires il, before described, were used. Suppose that the time of a double vibration of these pendulums is equal to the time necessary for conveniently making and observing a signal, then, by the use of the four sets of signal wires above naned, a person may send to or receive signals from or between stations A and B reciprocally; or four persons may be continually and simultaneously employed in making and receiving signals at each station. The use of these signal-wires referred to, as able to employ four persons in continual telegraphic intercourses, will in no way interfere with the simultaneous employment of two or four other operators using the other signal wires on the right-hand half of the vibrations marked n2 and G2; so also by lengthening out the ends of the pendulum rods, or increasing the angular motion of the pendulums, more space or places may be had for carrying out a larger number of telegraphic operations indefinitely. It has been said that the pendulum at station B may be kept adjusted to the motions of the regulating pendulum, by the appearance of sparks at K, K; but this synchronism may be more perfectly maintained by using any of the known forms of electro-magnets. In the above illustration the electric spark from an electrical machine has for simplicity bee.n chosen as the visible signal; but should it be desired to make signals by the hydro-electric current and the deflection of a needle, then each one of the signal-receiving wires, before uniting with the common conductor L, may be lengthened out sufficiently to form the coil of a galvanometer; and the current passing through any one of these wires can make itself known, or a signal be so given, by the deflection of the needle of the galvanometer belonging to that particular signal-receiving wire so signalized; or, in like manner, those prolonged signal-receiving wires may each one enclose a bar of iron, in place of a magnetic needle, so as to have an electro-magnet and keeper belonging to each one of these wires; then the passage of the current through any of the wires may give magnetism to the bar, or actuate the magnet or its keeper; and from this motion the signals may be perceived, or recorded and printed in any convenient form. From the above explanations, it will be obvious that divers stations and complex systems of telegraphic lines of communications can be established on the principle of this invention; and it will be also understood, that the invention is susceptible of an indefinite number of modifications or forms, as respects the apparatus employed in carrying it into use. The patentee claims, rendering available conducting power of electric telegraph wires, so that they may transmit one or more electric currents (in the same or opposite directions) during the time that must necessarily elapse between the transmission of succeeding signals which have reference to one and the same commnuni. tation.-Newton's Journal, xl. 36. ELECTRO-GILDING AND SILVERING. According to Le Docteur Philipp, the vessel required for this purpose should be made of the same material as that,*nmmonly employed for flower-pots: before being used it must be tested in the following manner: On being filled with water, if it becomes simply damp, without allowing the water to filter through it, it is fit for use, but not otherwise. This vessel is sur ELECTRO-METALLURGY. 62i rounded by a cylinder of zinc, and then introduced into another vessel (a wooden tub for instance) containing dilute sulphuric acid. The earthen vessel is intended to contain the solution of gold or silver, and is furnished with a web of copper wire, which is made to communicate with the zinc by means of one or more conducting wires. The objects to be gilt or silvered are placed upon the net-work. The earthen vessel containing a zinc cylinder, and some hydrochloric acid, is introduced into another vessel, containing the solution of gold or silver, placed in the centre of a wire web partition, which communicates with the zinc cylinder by means of a conducting wire. In the first case, the articles which are to receive the thickest coating are placed nearest the outer sides of the apparatus; in the second, nearest to the earthen vessel: in both cases it is advisable to shift their position occasionally. By combining these different arrangements, the deposit obtained is more abundant, and more equally distributed upon the surface to-be gilded or to be silvered. For this purpose all opening is made in the centre of the web in which the zinc cylinder is inserted, with connecting wires to the web. When the articles to be operated upon can be easily suspended from a given point, the web of the apparatus may be made with wider meshes, and the articles suspended vertically between them. Dr. Philipp prefers a single galvanic arrangement to a battery, as it affords more solid deposition. ELECTRO-METALLURGY. By this elegant art perfectly exact copies of any object can be made in copper, silver, gold, and some other metals, through the agency of voltaic electricity. The earliest application of this kind seems to have been practised about 16 years ago, by Mr. Bessemer, of Camden Town, London, who deposited a coating of copper on lead castings, so as to produce antique heads in relief, about 3 or 4 inches in size. IHe contented himself with formilg a few such ornaments for his mantelpiece; and though he made no secret of his purpose, he published nothing upon the subject. A letter of the 22d of May, 1839, written by Mr. J. C. Jordan, which appeared in the Miechanics' Maqg. for June 8, following, contains the first printed notice of the manipulation requisite for obtaining electro-metallic casts; and to this gentlemnan, therefore, the world is indebted for the first discovery of this new and important application of science to the uses of life. It appears that Mr. Jordan had made his experiments in the preceding summer, and having become otherwise busily occupied, did not think of publishing till he observed a vague statement in the Journals, that Professor Jacobi, of St. Petersburg, had done something of the same kind. Mr. Jordan's apparatus consisted of a glass tube closed at one extremity with a plug of plaster of Paris, and nearly filled with a solution of sulphate of copper. This tube, and its contents, were immersed in a solution of common salt. A plate of copper was plunged in the cupreous solution, and was connected by means of a wire and solder, with a zinc plate dipped in the brine. A slow electric action was thus established through the moist plaster, and copper was deposited on the metal in a thin plate, corresponding to the former in smoothness and polish; so that when he used an engraved metal matrix, he obtained an impression of it by this electric agency. " On detaching the precipitated metal," says he, " the most delicate and superficial markings, from the fine particles of powder used in polishing to the deeper touches of a needle or graver, exhibited their correspondent impressions in relief with great fidelity. It is, therefore, evident that this principle will admit of improvement, and that casts and moulds may be obtained fiom any form of copper. This rendered it probable that impressions might be obtained from those other metals having an electro-negative relation to the zinc plate of the battery. With this view a common printing type was substituted for the copper-plate, and treated in the same manner. This, also, was successful; the reduced copper coated that portion of the type immersed in the solution. This, when removed, was otund to be a perfect matrix, and might be employed for the purpose of casting, where time is not an object. Casts may probably be obtained from a plaster surface surrounding a plate of copper, &c." On the 12th of September following the above publication, Mr. Thomas Spencer read a paper " On Voltaic Electricity applied to the purpose of working in Metal,' before the Polytechnic Society of Liverpool; which he had intended to present to the British Association at Birmingham in the preceding August, but not being well received there, he exhibited merely some electro-metallic casts which he had prepared., The society published Mr. Spencer's paper, and thereby served to give rapid diffusion to the practice of electro-metallurgy. One of the most successful cultivators of this art. has been Mr. C. V. Walker, secretary to the London Electrical Society. He has published an -ingenious little work in two parts, entitled Electrotype Manipulation, where he presents, in a lucid manner, the theory and practice of working in metals, by precipitating them from their solutions through the agency of voltaic electricity. His first part is devoted to the explanation of principles, to the preparation of moulds, to the description of the voltaic apparatus to be used, to bronzing, to coating busts with copper, to the multiplication of engraved plato:, and to the deposition of other metals. 630 ELECTRO-METALLURGY. Fig. 479. represents a single-cell voltaic apparatus for electro-metallurgy. z h 479 a rod of anma1lgarated zinc, um is the mould on which the meta. VPIj is to be deposited; wt, is the wire jtoining them; c is a strong Zjl- solution of sulphate of copper in the large vessel; p, is a tube or cylinder of porous earthenware, standing in the other, and ]o I --- containing dilute sulphuric acid. The solution of blue vitriol is A ll jj > kept saturated, during the progress of its depositing copper, by \ piling crystals of the salt upon the shelf, shown by the dots under p. The mould to be coated should not be too small in reference to the surface of zinc under voltaic action. The time for the depoH? c si*on to be effected depends upon the temperature; and is less the t, iher this is within certain limits; and at a freezing temperature it ceases almost entirely. When a mould of fusible metal is used, it should not be placed in the v,,taic apparatus till everything is arranged, otherwise oxide will be deposited upon it, and spo'l the effect. When the circuit is completed the mould may be immersed, but not before. Wax moulds are rendered electric conductors, and thereby depositors as follows: After breathing on the wax, rub its surface with a soft brush dipped in plumbago; breathing and rubbing alternately till the surface be uniformly covered. Attach a clean wire to the back of the mould, connecting it by plumbaco with the blackened wax. Sealing-wax is coated in like manner. Casts of Paris plaster are first well im. bued with melted wax or tallow, and then black-leaded. Objects in Paris plaster should be thoroughly penetrated with hot water, but not wet on the surface, before wax casts are made from them. Moulds are best taken from medals in stearine (stearic acid). For plating and gilding by electro-chemical agency, the following simple plan of apparatus is used. Fig. 480, is a rectangular porcelain vessel, which contains in its centre a porous cell for containing the solution of oxide of silver or gold, by means of cyanide of potassium; and this porous cell is surrounded at a little distance by a similarly formed vessel of zinc. The connexion is formed between the zinc and the suspended object to be coated, either by a pinching screw, or by the pressure of its weight upon the wire. The dilute acid which excites the zinc should, in this case, be very weak, in reference to the strength of the cyanide solution, which should be recruited occasionally by the addition of oxide. It Las been found that with cyanide solutions of gold and stver in the electrochemical apparatus, the nascent cyanogen at the positive pole or plate, in a decomposition cell, will act upon and dissolve gold and silver. Two oi three of Daniell s evlndric cells, as shown at a in fig.481, of a pint size, for acti;g upon solutions of 481 KT 480 B-jn;? 1?~ I v=i — III I b *1i i a i, jI I~ i jI Ir j ) I i I I I -old or silver, wili in general suffice. The decomposition cell b is made of glass or porcelain. The zinc may be amalgamated, and excited with brine; the copper cell contains, as usual, a solution of blue vitriol. To the end of the wire attached to the copper cylinder of the battery, a plate of silver or gold is affixed; and to the end of the wire attached to the zinc cylinder is affixed the mould, or surface, to be plated or gilt. The plates of silver or gold and zinc should be placed face to face as shown in the figure in the decomposition cell; which is filled by the cyanide solution. A certain degree of heat favors the piocesses of electro-gilding and plating. The surface is dead as first obtained, but it may be easily polished with leather and plate-powder, and burnished in whole or i, parts with a steel or agate tool. ELECTRO-METALLURGY. 631 In March, 1840, Messrs. Elkington obtained a patent for the use of pr,,ssiate of potash, as a solvent for the oxides of gold and silver in the electro-chemical apparatus for plating and gilding metals. They also " sometimes employ a solution of protoxide (purple of Cassius) in the muriates of potash, &c." The chemical misnomers, in their specification, are very remarkable, and do great discredit to the person employed to draw it up. Prussiate of potash is the ordinary commercial name of a salt very different from the cyanide of potassium-the substance really meant by the patentees-and the purple of Cassius is very different from protoxide of gold. In plating or gilding great care must be bestowed in making the articles clean, bright, and perfl2tly free from the least film of grease. For this purpose, they should be boiled in a solution of caustic alkali, then scoured with sand and water, next dipped into a dilute acid, and finally rinsed with water. A solution of the nitrate or cyanide of mercury may also be used with advantage for cxaning surfaces. The following metals have been deposited by electro-chemistry:Gold, platinum, silver, copper, zinc, nickel, antimony, bi" —uth, cobalt, palladium, cadmium, lead, and tin; of these, the first five are the most important and valuable. The gilding solution may be prepared by placing slips or sheets of gold in a solution of cyanide of potassium, and attaching to the negative pole of a voltalc battery, a small plate of gold, but to the positive pole a much larger one; whereby the latter combines with the cyanogen, under the influence of positive electricity, and forms a solution. Or, oxide of gold, precipitated from the chloride by magnesia, may be dissolved, in the solution of the cyanide. For making copper medals, &c., a plate of amalgamated zinc is to be put into a vessel of unglazed earthenware, or of any other porous substance, filled with dilute sulphuric acid; which vessel is set into a trough of glass, glazed pottery, or pitched wood, containing blue vitriol in the state of solution, as well as in the state of crystals upon a perforated shelf, near the surface of the liquid. The moulds to be covered with copper are to be attached by a copper wire to the zinc plate. The surface of zinc excited by the acid should be equal to that of the moulds; with which view a piece of zinc, equivalent in size to the mould, should be suspended in front of it. For depositing copper upon iron, Messrs. Elkington use a solution of ferrocyanide of copper in cyanide of potassium in the decomposition trough, instead of sulphate of coppet, neutralized from time to time with a little caustic alkali, as in the common practice ot making medals, &c., of copper. I should imagine that the black oxide of clppe dissolved in solution of cyanide of potassium would answer better; as the iron in the ferrocyanide might be rather injurious. The iron to be coppered being previously well cleaned from rust, &c., with the aid of a dilute acid, is to be plunged into the cyanide solution heated to 120~ Fahrenheit, and connected by a wire with the negative pole of a voltaic battery, as formerly described. In from five to ten minutes, the iron will be completely coated. It is then to be scoured with sand, and plunged into solution of sulphate of copper; whereby it will show black spots wherever there are any defective places. In this case, it is to be cleaned and replaced under the cyanide solution, in the decomposition cell for a minute or two. Zinc may be deposited from a solution of its sulphate by a like arrangement. Metallic cloth may be made as follows:-On a plate of copper attach quite smoothly a stout linen, cotton, or woollen cloth, and connect the plate, with the negative pole of a voltaic battery; then immerse it in a solution of copper or other metal, connecting a piece of the same metal as that in the solution with the positive pole; decomposition takes place, and the separated metallic particles in their progress toward the metal plate or negative pole, insinuate themselves into the pores of the tissue, and form a complete sheet of flexible metal. Lace is metallized by coating it with plumbago, and then subjecting it to the electro-metallurgic process. The gilding solution should be used in the electric process at a temperature of 130~ F. The more intense the electric power, the denser and harder is the metallic:oat deposited. Metallic silver may be combined with cyanogen by subjecting it to the joint action of a solution of cyanide of potassium and positive electricity. Or cyanide of silver may be precipitated from the nitrate by a little cyanide of potassium, and afterward dissolved by means of an excess of cyanide of potassium. The quantity of electric power or surface-size of the battery should in all cases be proportioned to the surface of the articles to be placed or gilt, and the electric intensity or number ofsets of jars proportioned to the density of the solution. Plating is accomplished in from 4 to 6 hours. The articles Should be weighed before and after this operation, to ascertain how much silver they have taken on. Messrs. Elkington make their moulds with wax, combined with a little phosphorus, Which reduces upon their surfaces a thin film of gold or silv r, from solutions of these 332 ELECTRO-METALLURGY. metals, which films are better than the black-leaded surfaces for receiving the copper ]eposit. They also recommendt to add a little alkali to the solution of sulphate of copper, intended to afford a deposite of metal. The single cell, first described above, is best adapted for this purpose. M. Ruolz employs for gilding, a solution of sulphuret of gold in sulphuret of potassium, which he prepares by precipitating a solution of gold in aqua regia, by sulphuretted hydrogen, and redissolving the precipitate with sulphuret of potassium. By the use of this solution of gold, he obtains a very beautiful and solid gilding, and at less expense than with cyanide of potassium. Every metal which is a negative electrode to gold may be gilded. Platinizing is effected best by means of a solution of the potash-chloride of platinum in caustic potash. 1 milligramme (0'015 grain) covers completely a surface of 50 square centimeters (2 inches square); the finl of platinum is only one hundrWith of a milligramme thick. M. Bacttger has shown that we may easily tin copper and brass in the moist way by dissolving peroxide of tin (putty) in hydrate of potash (caustic potash ley), putting at the bottom of the vessel hol:ing that solution some turnings of tin, setting the piece of copper or brass upon the turnings, and making the liquor boil. An electric current is produced by the contact of the dissimilar metals; and as the tin is withdrawn by the copper or brass from the solution, it is restored to it by the turnings. Zinking may be done in the same way; by putting pieces of zinc into a concentrated solution of chlorine, by setting the piece of metal to be zinked in contact with these pieces, and applying heat to the vessel containing the whole. For certain new methods of constructing and arranging voltaic batteries for electrometallurgic operations, a patent was obtained by Dr. Leeson in June, 1842. Fig. 482, is a longitudinal section of the battery, and fig. 483, a plan view of the frame to which the metal plates are attached. a is a rectangular wooden trough, containing a wooden frame b, formed with vertical grooves in its sides, to receive a series of porous cells c, c, c. The plates of the battery are suspended in the fluid or fluids by brass torks d, d, fastened to a wooden frame e, e, which rests upon the trough a, and is con. nected to the other frame b, by two pinsf, when they are required to be raised together aut of the trough a, a. The battery may be charged as usual with one or two fluids; one of them in the latter case being contained in the porous cells c, c, c: and plates of copper and zinc, or any other suitable metals may be employed. The second improvement consists in cleaning copper and zinc plates after they have been used in a battery, by the employment of a voltaic battery; and also in amlalga483 -', i. _....?,,....? -' L.... T' m 482 X ^^1' ]sp[j ui rt~etvs^hEl^ Vj~i^Ei^B~j) ^^Thgjrl+Nir L \^ ___\ \\ \ e " W \ K 4 ELECTROTYPIE. 635 mating or coating with mercury the surfaces of zinc plates, by the same means to render them suitable for being used in the construction of the voltaic apparatus. The third improvement consists in exciting electricity by a combination of nitric, sullprhuric, or muriatic acid, with any of the following subistances; viz, impure ammoniaeal or lime liquor of the gas works, solutions of alkaline and earthy sulphurets, the alkalies and their carbonates, or lastly, the acidulous sulphate of iron generated from iron pyrites. Another of Dr. Leeson's manifold improvements for depositing metallic alloys consists in the employment of one battery, "with the alternating cathode," represented in fig. 484. It is composed of a beam, a, mounted on the shaft, b, which turns in bearings carried by standards, c; the beam cormunicates with the anode of the battery by the wire, d, and a vibrating motion is given to it by the rod, e, from the shaft, f, which is driven by an electro-magnetic engine, or any other suitable prime mover. g, g, are two vessels containing mercury, connected by wiret, h, h, with the cathode plates of the two metals composing the alloy (but if the alloy is to consist of more than two rmetals, tien more vessels, g, will be required, one for each cathode plate); these plates are immersed in a solution cormposed of similar salts of the different metals to be deposited, together with the anode, or surface to be deposited upon, whlich is connected by a wire with the cathode of the battery. A comlmunlication is established between the two cathode plates, or supply of metals, and the anode of the battery, by means of the rods, i, i, wllich are caused, by the vibration of tlhe bearm, a, to dip alternately into either the one or the other of the vessels, g; and thus each metal will be deposited on the articie to be coated, during tile time that the connection is established between it and the battery, by the immersion of its rod into the vessel of mercury. The relative proportions of tile two metals is adjusted by lengthening or shortening Ihe rods, i, i, as shown in tile figure, so that they may be immersed for a lonlger or shorter period in the mercury. Where the electrical current enters the electrolyte, is the anode; where it leads it, is the cathode. Tile patentee describes ten other improvements, which seem to be ingenious. See ewoton's Journal, xxii. 292. ELECTROTYPIE BY TrERrMO-ELECTRICITY. 1. For silverisng.-Dissolve I troy pound of silver in nitric acid, dilute with a gallon of water, precipitate the silver by solution of carbonate of soda (1 lit.) at 100~ Falr.; wash the precipitate on the filter with warm water. In another vessel dissolve 8 libs. of hyposulplite of soda in 2' gallons of water at 100~, add 1 lib. of carbonate of soda witlh the carbonate of silver, stirring until tle silver be dissolved. Filter the solution for use. It is advantageous to add 1 lib avoirdupois of hyposulphite, and one-third of a pound of carbonate of soda for every pound troy of silver that may be deposited. 2. Gold solution.-One ounce troy of fine gold is dissolved in nitro-muriatic acid, and tlie solution is evaporated till it assumes a deep red color, and crystallizes upon cooling. Dilute with a pint of pure water and filter. Heat this solution to about 200~ Fahr., and precipitate the gold by water of amnmonia. Wash the precipitate well on tlie filter with hot water. Dissolve this gold in 1 gallon of water containing 8 ounces of hyposulphite of soda, and boil together for an ihour. The solution when filtered is fit for use. In gilding, this solution may be warmed to about 130~ Fahr. A small anode of gold, of about one-tenth the size of the article to be gilded, and a current of two pairs of common galvanic plates, are used. 3. Copper solution.-Dissolve 1 pound of carbonate of copper in 8 pounds of hyposulplite of soda, and 1 pound of carbonate of soda dissolved in 2- gallons of distilled water at 1000 Fahr., or thereabouts, and filtered to obtain a clear solution. It is then fit for use, with currentrs of electricity at 100~ Fahr. Description of the thermo-electric battery.-100 pieces of German silver, containing from 20 to 25 per cent. of nickel, and 100 pieces of iron, each piece being 1 inch broad, 1 foot long, and one-eighth of an inch in thickness. These 200 pieces are soldered to each other, so that iron is always combined with German silver. To get a compact form, 10 rows must be first arranged (every one of 20 pieces or 10 pairs), and these rows must be so soldered to each other that they are parallel, and the whole take the form of a square; taking care that tie several pieces are soldered together in such a way that iron will always be in connection with German silver. When the whole is united, it is placed in a rim or frame of iron plate, 1 foot 2 inches high, but so that the netals do not touch each other, nor the iron rim or frame, and fill tile rim with plaster of Paris or clay, so that all soldered parts of the series of plates or bars are uncovered, that is, lhe under ends 1 inch, and the upper ends 3 inches. The clay is covered at the surface with a layer of pitch. The frame containing the series of bars or plates, is so placed that the lower end of the series (1 inch) dip into i sand bath which ii heated nearly to redness. The upper ends (3 inches) are to 634 ELEMENTS. be kept as cold as possible, and for this purpose a current of cold water is caused to flow from one vessel over this battery to another vessel. The upper end of the metali (3 inhies) may be covered with a lac or varnish. There is an anode wire leading from the Geriiman silver plate; and an artule wire leading from the iron plate. The thermo-electric apparatus is intended for the deposition of metals, from the above described solutions. ELEMENTS (Eng. and Fr.; Grundstofe, Germ.) The ancients considered fire, air, water, and earth, as simple substances, essential to the constitution of all terrestrial beings. This hypothesis, evidently incompatible with modern chemical discovery, may be supposed to correspond, however, to the four states in which matter seems to exist; namely, 1. the unconfinable powers or fluids,-caloric, light, electricity; 2. ponderable gases, or elastic fluids; 3. liquids; 4. solids. The three elements of the alche. mists, salt, earth, mercury, were, in their sense of the words, mere phantasmns. I. Eqivalents. II. Atomic Weights. II Equivalents (after a~ I. Eq~ivateats. 88~. Gerhaldt and Laurent). Denomination of the Substances. -_________ > 0=1I00. H==l. 0==100. H==l. 0==100. H=]. Aluminium - - Al. 17191900 1 694 17091 0 27-388 85-63 13-70 Antimony. Sb. 1612-903 129-269 8(06-452 129-239 403-25 64-50 Arsenicum - - As. 9388800 75'224 469-400 75-224 468 50 7500 Barium -. Ba. 85590 68533 85,5'290 137-C66 425-00 68 00 Bismuth -. Bi. 13310377 1.6-600 1380-377 213-200 1312-50 210[00 Boron - B. 186 204 10'914 16-2(,4 21-828 67'50 10680 Bronme.. Br. 999'620 80(i98 499810 80q098 500-00 80-00 Cadmium - Cd. 696-767 55-831 696-767 111-662 35(000 56-00 Calcium-. - Ca. 251-651 20'164 2500(;00 40-000 125'00 20-)0 Carbon - - C. 75'120 61119 75-120 12-038 75-00 1200 Cerium (Marignac) - Ce. 590-8(00 47261 591) 8(10 94-528 - - Chlorine- - - C1. 443 280 35'517 221-640 35-517 221-87 35-50 Chromium - Cr. 328-870 26-352 328-870 52-704 162-50 26 00 Cobalt - - Co. 368.650 29-539 368 650 596078 185'(10 2960 Copper - - Cu. 395-600 31-699 395 6(0 63-398 198.75 31180 Didymium (Marignac) D. 620-000 49-600 620-000 99200 - Fluorine.. 235-433 188865 117-717 18-865 116-85 1810 Gold - A. 2458:330 196982 1229-165 196-982 122500 196600 Glucinium - - 87-124 6-961 87'124 13-962 - - Hydrogen H. 12'480 16000 6-240 1'000 6-25 1600 Iodie - - I. 1585'992 127 082 792 996 127-082 787-50 126-00 Iridium - - Ir. 1232-080 98'724 1232080 197448 - - Iron - - - Fe. 350-527 68-087 35t0527 56-174 175-00 28,00 Lauthanium (Marignac) La. 5881 00 47'040 588 100/ 94'80 - Lead -. 129464.5 103'738 1294 643 207'476 650'00 10400 Lithium- -. Li. 81'660 6-543 81-660 13-086 40-16 6'40 Magnesium - - Mg. 158-140 12671 158'140 25342 75-00 12600 Manganese - Mn. 34-14.684 27-619 344'684 55-238 175-00 28-00 Mercury- H,. 1251290 100-026 12500'00 200(1110 625-00 100'00 Mtlybdenum - - Mn. 596O 1 O 17764 596-100 95-528 - - Nickel - Ni. 369-330 29-594 369'330 59-188 185-00 29-60 Niobium - N. - - N itlroenl. - N. 175-C60 14-027 87-530 14'027 87-50 14800 Noriium - No. - - - - - - Osimium - - Os. 1242624 99'569 1242624 199-138 - - Oxygen - - 0. 10 0100 8-000 101.0.10 16-000 100800 16600 Palladium - Pd. 655.477 53-323 665'477 106-646 - Pelopiumn Pe. - - - - - Phlosphorus -. 3 92041 31.414 196"021 31'414 200-00 32-00 Platinum. Pt. 1232-080 98'724 12321080 197-448 618-75 99600 Potassium - K. 4880856 39-171 488-856 78'342 24375 3900 Rhodium.i. -. 651'962 52'240 651-962 104-326 Ruthenium, according to Claus Lu. 651'1000 52-163 651-000 104-326 - - Selenium -. Se. 495'285 39 686 495-285 79-372 490-90 78-50 Silicium -. Si. 277'778 22-258 277-778 44'516 8750 14-00 Silver -. - Ag. 1349-660 108-146 1349-660 216-292 675600 108-00 Sodium.... Na. 289-729 23-215 289'729 46-430 143-75 2300 Sulphur - - - S. 2100750 16-086 200'750 32-171 20000 32600 Strontium - - Sr. 545929 43-744 545-929 87'488 275-00 44'00 Taritaliam - Ta. 1148-365 92'(16 1148365 184032 - Tellurium - - Te. 801-760 64-244 801-760 128-488 800-00 12800 Terbium - - - Tb. - - - Thorium - - Th. 743-860 59-604 743.860 119208 - Titanium- n - Ti. 301550 24158 301550 48316 - Tin - Sn. 735-294 58-918 735294 117-836 368-75 59-0 Tun-sten - W. 1188-360 95-220 188560 190-442 600-00 96-00 UraTnitima7 - U. 742-875 59-525 742'875 119-050 750'00 120-00 Vaadium... V. 856-892 68-661 856'892 137322 - - Yttrium...Y. - - - - - - Zilm.n' -. Zn. 4C6~591 32-579 406-591 65-158 206-25 3300 Zirconium - Zr.I 419-728 33632 419-728 67264 - In modern science, the term Element signifies merely a substance which has not yet )een resolved by analysis into any simpler form of matter; and it is therefore synonymous EMBALMING. 635 with undecompounded. This class comprehends 62 different bodies, of which no less than 52 are metallic. Five may be styled Archceal, from the intensity and universality of their affinities for the other bodies, which they penetrate, corrode, and apparently consume, with the phenomena of light and heat. These 5 are chlorine, oxygen, iodine, bromine, fuorine. Eight elements are eminently inflammable when acted upon by any of the preceding five, and are thereby converted into incombustible compounds. The simple non-metallic inflammables are hydrogen, azote, sulphur, phosphorus, selenium, carbon, boron silicon. The preceding table exhibits all the undecompounded bodies in alphabetical order, with their prime equivalent numbers, atomic weights, or reciprocal combining and saturating proportions, in reference to oxygen and hydrogen, reckoned 100,000, or 1'0. The numbers contained in columns I. and II. are deduced from those given by Berzelius, in the fifth edition of his Lehrbuch; and in column III. those atomic weights are added which Gerhardt and Laurent have quoted in the first number of the fifth volume of the Compte9 Rendus. Tlie following is a table of atomic weights corrected and fixed by various chemists in recent times:Equivalents. Atomic Weights. Denomination of the Substances. -; 0==100. H==l. 0,100. H== —l. Calcium (Erdmann and Marchand)- - Ca. 250-00 20-000 250-000 40-000 Carbon (ditto) - C. 75C00 6-000 75-000 12-000 Hydrogen - - - H. 12-000 1 000 6-250 1.000 Ironl ( Erdinann and Marchand) - Fe. 350-000 23-000 250-100 56-000 Mercury (ditto) - - H. 1250000 100-000 1250'000 200000 Phosphorus (Pelouze) - - - - P. 400-C00 32-024 200-150 32-024 Sodium (ditto) - Na. 287-170 22-973 287-170 45-046 Strontium (ditto) - Sr. 548-020 43-841 548-020 87-682 Sulphur (Erdmann and Marchand) - - S. 200-000 16 000 200-000 32-000 Within the last few years the following atomic weights have been revised:Barium - - - - - Ba. 856-770 Marignac. Calcium- - - - - C... 350.000 Erdm. and March. Chromium - - - - Cr. 833-500 Lefort. Chromium - - - - Cr. 835'091 Moberg. Fluorine - - - - Fl. 237 500 Louyet. Ma gnesium - - - - Mg. 152'550 Jacquelain. Me anesium - - - -. 154'490 Svanberg. Magenesium - - - - Mg. 150.000 March. and Scheer. Molybdenum - - - - Mo. 574'750 Berlin. Molybdenum - - - - Mo. 574-829 Svanb. and Struve. Tungsten - - - - W. 1150-780 Schneider. ELEMI is a resin which exudes from incisions made during dry weather through the bark of the amyris elemifera, a tree which grows in South America and Brazil. It comes to us in yellow, tender, transparent lumps, which readily soften by the heat of the hand. They have a strong aromatic odor, a hot spicy taste, and contain 12x per cent. of etherous oil. The crystalline resin of elemi has been called Elmine. It ia used in making lacquer, to give toughness to the varnish. ELUTRIATE. (Soutirer, Fr.; Schlemmen, Germ.) When an insoluble pulverulent matter, like whitening or ground flints, is diffused through a large body of water, and the mixture is allowed to settle for a little, the larger particles will subside. If the supernatant liquid be now carefully decanted, or run off, with a syphon, it will contain an impalpable powder, which on repose will collect at the bottom, and may be taken out to dry. This process is called elutriation. ELVAN. The name given by the Cornish m'iners to porphyry, as also to the heterogeneous rocky masses which occur in the granite or in the clay slate, deranging the direction of their metallic veins, or even the mineral strata; but elvan generally indicates a felspar porphyry. EMBALMING. (Embaument, Fr.; Einbalsamen, Germ.) Is an operation in which balsams (baumres, Fr.) were employed to preserve human corpses from putrefaction; whence the name. The ancient Egyptians had recourse to this process for preserving the bodies of nttmerous families, and even of the animals which they loved or worshipped. An excellent account of their methods is given in Mr. Pettigrew's work upon Mummies. Nlodern chemistry has made us acquainted with many means of counteracting putre 336 EMBOSSING CLOTH. faction more simple and efficacious than the Egyptian system of salting, srroki^, spicing, and bitumenizing. See PUTREFACTION. EMBOSSING CLOTH. Mr. Thomas Grei(, of Rose Banlk, near Bury, patented an invention, in November, 1835, which consists in an ingenious construction of ma. clinery for both embossing and printing silk, cotton, woollen cloth, paper, and othel fabrics, in one or more colors, at one operation. Figs. 4-85, 486 represent three distinct prinring cylinders of copper, or other suitable 485it0~ ~material, A, B, c, with 485 a H their necessary appenC dL _ -- K j Jdanges for printing three _II/- I-:'d Dv different colors upon o -t-^ the fabric as it'passes [ Fr\ (A ) / through the machine either of these cylinders ____ W 0490 491 492 493 494 1; 495 XEj (R^4. —--- construction of the furnace. It is square, and is shown in front elevation infig. 491. It consists of two pieces, the lower part A, or the body of the furnace, and the upper part B, or the capital, which is laid on the lower part, as is shown in fig. 492, where these two parts are separately represented. The furnace is made of good fire-clay, moderately baked, and resembles very closely the assay or cupellation furnace. Its inside dimensions are 9 inches in width; 13 inches in height in the body, and 9 in the capital. Its general thickness is 2 inches. The capital has an aperture or door c, fig. 491, which is closed by a fire-brick stopper m, when the fire is to be made active. By this door fuel is supplied. The body of the furnace has likewise a door D, which reaches down to the projecting shelf E, called the bib (mentonniere), whose prominence is seen at E, fig. 491. This shelf is supported and secured by the two brackets, F, F; the whole being earthenware. The height of the door D, is abridged by a peculiar fire-brick G, which not only covers the whole projection of the shelf E, but enters within the opening of the door D, filling its breadth, and advancing into the same plane with the inner surface of the furnace. This plate is called the hearth; its purpose will appear presently; it may be taken out and replaced at pleasure, by laying hold of the handle in its front. Below the shelf E, a square hole, H, is seen, which serves for admitting air, and for extracting the ashes. Similar holes are left upon each side of the surface, as is shown in the ground plan of the base, fig. 492, at H. On a level with the shelf, in the interior of the furnace, a thin fire-tile i rests, perforated with numerous small holes. This is the grate represented in a ground view in fig. 490. Figs. 493, 494,495, represent, under different aspects, the muffle. Fig. 492 shows the elevation of its further end; fig. 494, its sides; and fig. 495, its front part. At I, fig. 492, the muffle is seen in its place in the furnace, resting on two bars of iron, or, still better, on ledges of fire-clay, supported on brackets attached to the lateral sides of the furnace. The muffle is made of earthenware, and as thin as possible. The fuel consists of dry beech-wood, or oaken branches, about an inch in diameter, cut to the length of nine inches, in order to be laid in horizontal strata within the furnace, one row only being placed above the muffle. When the muffle has attained to a white red heat, the sheet iron tray, bearing its enamel plate, is to be introduced with a pair of pincers into the front of the muffle, and gradually advanced toward its further end. The mouth of the muffle is to be then closed with two pieces of charcoal only, between which the artist may see the progress of the operation. Whenever the enamel begins to flow, the tray must be turned round on its base to insure equality of temperature 650 ENAMELLING and as soon as the whole surface is melted, the tray must be withdrawn with its plat4 but slowly, lest the vitreous matter be cracked by sudden refrigeration. The enamel plate, when cold, is to be washed in very dilute nitric acid, and after. wards in cold water, and a second coat of granular enamel paste is to be applied, witkl the requisite precautions. This, being passed through the fire, is to be treated in the same way a third time, when the process will be found complete. Should any chinks happen to the enamel coat, they must be widened with a graver, and the space being filled with ground enamel, is to be repaired in the muffle. The plate, covered with a pure white enamel, requires always to be polished and smoothed with sandstone and water, particularly if the article have a plane surface; and it is then finally glazed at the fire. The painting operation now follows. The artist prepares his enamel colors by pound. ing them in an agate mortar, with a pestle of agate, and grinding them on an agate slab, with oil of lavender, rendered viscid by exposure to the sun in a shallow vessel, loosely covered with gauze or glass. The grinding of two drachms of enamel pigment into an impalpable powder, will occupy a laborer a whole day. The painter should have along. side of him a stove in which a moderate fire is kept up, for drying his work whenever the figures are finished. It is then passed through the muffle. Enamelling at the Lamp.-The art of the lamp enameller is one of the most agreeable and amusing that we know. There is hardly a subject in enamel which may no, be executed by the lamp-flame in very little time, and more or less perfectly, according to the dexterity of the artist, and his acquaintance with the principles of modelling. In working at the lamp, tubes and rods of glass and enamel must be provided, of all sizes and colors. The enamelling table is represented in fig. 488, round which several workmen, with their lamps, may be placed, while the large double bellows D below is set a-blowing by a treadle moved with the foot. The flame of the lamp, when thus impelled by a powerful jet of air, acquires surprising intensity. The bent nozzles or tubes, A A A A, are made oC glass, and are drawn to points modified to the purpose of the enameller. Fig. 489 shows, in perspective, the lamp A of the enameller standing in its cistern a; the blowpipe c is seen projecting its flame obliquely upwards. The blowpipe is adjust. able in an elastic cork D, which fills up exactly the hole of the table into which it enters. When only one person is to work at a table provided with several lamps, he sits down at the same side with the pedal of the bellows; he takes out the other blowpipes, and plugs the holes in the table with solid corks. The lamp is made of copper or tin-plate, the wick of cotton threads, and either tallow or oil may he tsed. Between the lamp and the workman a small board or sheet'of white iron a, called the screen, is interposed to protect his eyes from the glare of light. The screen is fastened to the table by a wooden stem, and it throws its shadow on his face. The enamelling workshop ought to admit little or no daylight, otherwise the artist, not perceiving his flame distinctly, would be apt to commit mistakes. It is impossible to describe all the manipulations of this ingenious art, over which taste and dexterity so entirely preside. But we may give an example. Suppose the enameller wishes to make a swan. He takes a tube of white enamel, seals one of its ends hermetically at his lamp, and while the matter is sufficiently hot, he blows on it a minikin flask, resembling the body of the bhird; he draws out, and gracefully bends the neck; he shapes the head, the beak, and the tail; then, with slender enamel rods of a proper color, he makes the eyes; he next opens up the beak with pointed scissors; he forms the wings and the legs; finally attaching the toes, the bird stands complete. The enameller also makes artificial eyes for human beings, imitating so perfectly the colors of the sound eye of any individual, as to render it difficult to discover that he has a blind and a seeing one. It is difficult to make large articles at the blowpipe; those which surpass 5 or 6 inches become nearly unmanageable by the most expert workmen. ENAMELLING OF CAST IRON AND OTHER HOLLOW WARE FOR SAUCEPANS, &c.-In De. cember, 1799, a patent was obtained for this process by Dr. Samuel Sandy Hickling. His specification is subdivided into two parts:1. The coating or lining of iron vessels, &c., by fusion with a vitrifiable mixture, composed of 6 parts of calcined flints, 2 parts of composition or Cornish stone, 9 parts of litharge, 6 parts of borax, 1 part of argillaceous earth, 1 part of nitre, 6 parts of calx of tin, and 1 part of purified potash. Or, Mdly, 8 parts of calcined flints, 8 red lead, 6 borax, 5 calx of tin, and 1 of nitre. Or, Sdly, 12 of potter's composition, 8 borax, 10 white lead, 2 nitre, 1 white marble calcined, 1 argillaceous earth, 2 purified potash, and 5 of calx of tin. Or, 4thly, 4 parts calcined flint, 1 potter's composition, 2 nitre, 8 borax, 1 white marble caL rined, J argillaceous earth, and 2 calx of tin. ENAMELLING. 651 Whichever of the above compositions is taken, must be finely powdered, mixed, fused;.he vitreous mass is to be ground when cold, sifted, and levigated with water. It is then made into a pap with water or gum-water. This pap is smeared or brushed ovel the interior of the vessel, dried, and fused with a proper heat in a muffle. Calcined bones are also proposed as an ingredient of the flux. The fusibility of the vitreous compounds is to vary according to the heat to be applied to the vessel, by using various proportions of the siliceous and fluxing materials. Colors may be given, and also gilding. The second part or process in his specification describes certain alloys of iron and nickel, which he casts into vessels, and lines or coats them with copper precipitated from its saline solutions. It also describes a mode of giving the precipitated copper a brassy surface by acting upon it with an amalgum of zinc with the aid of heat. A factory of such enamelled hollow wares was carried on for some time, but it was given up for want of due encouragement. A patent was granted to Thomas and Charles Clarke on the 25th of May, 1839, for a method of enamelling or coating the internal surfaces of iron pots and saucepans, in such a way as shall prevent the enamel from cracking or splitting off from the effects of fire. The specification prescribes the vessel to be first cleansed by exposing it to the action of dilute sulphuric acid (sensibly sour tothe taste) for three or four hours, then boiling the vessel in pure water for a short time, and next applying the composition. This consists of 100 lbs. of calcined ground flints; 50 lbs. of borax calcined, and finely ground with the above. That mixture is to be fused and gradually cooled. 40 lbs. weig';. of the above product is to be taken with 5 lbs. weight of potter's clay; to be ground together in water until the mixture forms a pasty-consistenced mass, which will leave or form a coat on the inner surface of the vessel about one sixth of an inch thick. When this coat is set, by placing the vessel in a warm room, the second composition is to be applied. This consists of 125 Ibs. of white glass (without lead), 25 lbs. of borax, 20 lbs. of soda (crystals), all pulverized together and vitrified by fusion, then ground, cooled in water, and dried. To 45 lbs. of that mixture, 1 lb. of soda is to be added, the whole mixed together in hot water, and when dry, pounded; then sifted finely and evenly over the internal surface of the vessel previously covered with the first coating or composition, while this is still moist. This is the glazing. The vessel thus prepared is to be put into a stove, and dried at the temperature of 212~ F. It is then heated in a kiln or muffle, like that used for glazing china. The kiln being brought to its full heat, the vessel is placed first at its mouth to heat it gradually, and then put into the interior of the fusion of the glaze. In practice it has been found ad. vantageous also to dust the glaze powder over the fused glaze, and apply a second fluxing heat in the oven. The enamel, by this double application, becomes much smoother and sounder. Messrs. Keurick of West Bromwich having produced in their factory and sent into the market some excellent specimens of enamelled saucepans of cast iron, were sued by Messrs. Clarke for an invasion of their patent rights; but after a long litigation in chancery, the patentees were nonsuited in the court of exchequer. The previous process of cleansing with dilute sulphuric acid appeared by the evidence on the trial to have been given up by the patentees, and it was also shown by their own principal scientific witness that a good enamelled iron saucepan could be made by Hickling's specification. In fact, the formulae by which a good enamel may be compounded are almost innumerable; so that a patent for such a purpose seems to be untenable, or at least most easily evaded. I have exposed the finely-enamelled saucepans of Messrs. Kenrick to very severe trials, having fused even chloride of calcium in them, and have found them to stand the fire very perfectly without chipping or cracking. I consider such a manufacture to be one of the greatest improvements recently introduced into domestic economy; such vessels, being remarkably clean, salubrious, and adapted ta the most delicate culinary operations of boiling, stewing, making of jellies, preserves, &c. They are also admirably fitted for preparing pharmaceutical decoctions, and ordinary extracts. The enamel of the said saucepans is quite free from lead, in consequence of the glass which enters into its composition being quite free from that metal. In several of the saucepans which were at first sent into the market by Messrs. Clarke, their enamel was found on analysis by several chemists to contain a notable proportion of oxide of lead. In consequence of the quantity of borax and soda in the glaze, this oxide was so readily acted upon by acids, that sugar of lead was formed by digesting vinegar in them with a gentle heat. The presence of this noxious metal formed, in my opinion, a legitimate ground for contesting the patent, being in direct violation of the terms of the specification. Messrs. Kenwick's wares have been always free from this deleterious metal. Messrs. Clarke, I understand, have for some time been careful tc reject from 6^52 ENAMELLING. their enamel-composition all glass which contains lead; and they now manufacture also wholesome enamelled ware. Thus the public have profited in a most important point by the aforesaid litigation. Enamelled iron saucepans had been many years ago imported from Germany, and sold in London. I had occasion to analyze their enamel, and found to my surprise tiat it contains abundance of litharge or oxide of lead. The Prussian government ias issued an edict prohibiting the use of lead in the enamelling of saucepans, which are so extensively manufactured in Peiz, Gleiwitz, &c. Probably the German ware sent to England was fabricated for exportation, with an enamel made to flux easily by a dose of litharge. The composition of the said enamel is nearly the same with that which I found upon some of the earlier saucepans of Messrs. Clarke. Had their patent been sustained, the important legal question would have arisen, whether it gave the patentees tne power of preventing dealers from continuing to sell what they had been habitually doing for a great many years. A suitable oven or muffle for lining or coating metals with enamel may have the following dimensions:The outside, 8 feet square, with 14-inch walls; the interior muffle, 4 feet square at bottom, rising 6 inches at the sides, and then arched over; the crown may be 18 inches high from the floor: the muffle should be built of fire-brick, 2- inches thick. Another arch is turned over the first one, which second arch is 7 inches wider at the bottom, and 4 inches higher at the top. A 9-inch wall under the bottom of the muffle at its centre divides the fireplaces into two, of 16 inches width each, and 3 feet 3 inches long. The flame of the fire plays between the two arches and up through a 3-inch flue in front, and issues from the top of the arch through three holes, about 4 inches square; these open into a flue, 10+ -9 inches, which runs into the chimney. The materials for the enamel body (ground flint, potter's clay, and borax) are first mixed together and then put into a reverberatory furnace, 6 feet 6 inches long, by 3 feet 4 wide, and 12 inches high. The flame from an 18-inch fireplace passes over the hearth. The materials are spread over the floor of the oven, about 6 inches thick, and ignited or fritted for four or five hours, until they begin to heave and work like yeast, when another coating is put on the top, also 6 inches thick, and fired again, and so on Ihe whole day. If it be fired too much, it becomes hard and too refractory to work in the muffles. The glaze is worked in an oven similar to the above. It may be composed of about one half borax and one half of Cornish stone in a yellowish powder procured'rom the potteries. This is fritted for 10 hours, and then fused into a glass which ii ENAMELLED CAST-IRON. Cast-iron vessels have been exceedingly well enamelled under two different patents within these few years; at first, by Mr. Clark, of Wolverhampton, and in November, 1846, by Messrs. Kenrick, of West Bromwich. Before the enamel is applied, the surface of the iron should be made quite clean and bright. The enamel consists of two coats; the one forming the body, and the other the glaze. The body is made by fusing 100 lbs. of ground flints, and 75 of borax, and grinding 40 lbs. of this frit with 5 lbs. of potter's clay in water till it is brought to the consistence of a pap. A coating of this pap being applied and dried, but not hard, the glaze powder is sifted over it. This consists of 100 parts of Cornish stone, in fine powder, 117 of borax, 35 of soda-ash, 35 of nitre, 35 of sifted slaked lime, 13 of white sand, and 50 of pounded white glass. These are all fused together; the frit obtained is pulverized. Of this powder 45 pounds are mixed with 1 pound of soda-ash, in hot water; and the mixture being dried in a stove is the glaze powder. When this powder has been very finely sifted over the body coat, the cast iron article is put into a stove, kept at a temperature of about 2120, to dry it hard; after which it is set in a muffle kiln to be fused into a glaze. The inside of pipes is enamelled (after being cleaned) by pouring the above body composition through them while the pipe is being turned about, to insure its being uniformly coated. After the body has become set, the glaze pap is poured in in a like manner. The pipe is finally fired in the kiln. ENAMELLED LEATHER. Instead of enamelling the grain surface as heretofore, Mr. Nossiter removes that surface by splitting or puffing, and then produces what is called "a finish" upon the surface thus formed, by means of a roller, or glass instrument. Or the flesh side may be thus prepared for enamelling; and it is less liable to crack, and the enamel to become cloudy, than the grain side. He also shaves hides and skins by knives set tangentially upon a rotary axis, with a certain degree of obliquity. He squeezes the grease out of the skins by hard pressure between rollers; and he uses a rotary brush to clear away all filth. ENAMELLING METALS. In February, 1847, Mr. Walton patented a method of ETCHING VARNISH. 653 enamelling copper and other vessels, by coating them (after their surfaces are scaled by heat and cleaned) with powders of a vitrifiable kind applied in a thin pasty state with a brush, then drying and firing them. His formula for the composition is as follows: 6 parts of flint glass, 3 of borax, 1 of red lead, and 1 of oxide of tin; mixed, fritted, ground into powder, made into a thin pas.te with water, applied, dried, and fused on by the heat of an enamel kiln (see POTTERY). A second and even a third coat is prescribed. Into the second he puts calcined bone in powder, with china clay and carbonate of potash. These materials are fritted, ground, and mixed with certain of the former vitrifiable materials. Being reduced to a creamy consistence with water in a porcelain mill, the mixture is painted on with a brush, or applied by dipping, dried, and fired. One of his formulae consists of 4 parts of ground felspar, 4 of white sand,, of carbonate of potash, 1 of arsenic, 6 of borax, 1 of oxide of tin, 1 of nitre, 1 of whiting-being in my opinion a most injudicious farrago, for which a much better and simpler combination of vitrifiable china-like materials might be substituted.-Newton's Journal, XXXL p. 183. EPSOM SALTS. Sulphate of Magnesia. EQUIVALENTS, CHEMICAL. (Stochiometrie, Germ.) This expression was first employed by Dr. Wollaston, i; denote the primary proportions in which the various chemical bodies reciprocally combine; the numbers representing these proportions being referred to one standard substance of general interest, such as oxygen or hydrogen reckoned unity, or 1,000. Dr. Dalton, who is the true author of the grand discovery of definite and multiple chemical ratios, calls these equivalent numbers atomic weights, when reduced to their lowest terms, either hydrogen or oxygen being the radix of the scale. Though it belongs to a chemical work to discuss the principles and develop the applications of the Atomic Theory, I shall be careful, upon all proper occasions, to point out the vast advantages which the chemical manufacturer may derive from it, and to show how much he may economize and improve his actual processes by its means. See ELEMENT. ESSENCES are either ethereous oils, in which all the fragrance of vegetable products reside; or the same combined and diluted with alcohol. See OILS, ETHEREOUS. ESSENCE D'ORIENT, the name of a pearly looking matter procured from the blay or bleak, a fish of the genus cyprinus. This substance, which is found principally at the base of the scales, is used in the manufacture of artificial pearls. A large quantity of the scales being scraped into water in a tub, are there rubbed between the hands to separate the shining stuff; which subsides on repose. The first water being decanted, more is added with agitation till the essence is thoroughly washed from all impurities; when the whole is thrown upon a sieve; the substance passes through, but the scales are retained. The water being decanted off, the essence is procured in a viscid site, of a bluish white color, and a pearly aspect. The intestines of the same fish are also covered with this beautiful glistening matter. Several other fish yield it, but in smaller proportion. When well prepared, it presents exactly the appearance and reflections of the real pearls, or the finest mother of pearl; properties which are probably owing to the interposition of some portions of this same substance, between the laminae of these shelly concretions. Its chemical nature has not been investigated; it putrefies readily when kept moist, an accident which may, however, be counteracted by water of ammonia. See PEARLS. ETCHING Varnish. (delzgrund-Deckfirniss, Germ.) Though the practice of this e3c.ant art does not come within the scope of our Dictionary, the preparation of the varnishes, and of the biting menstrua which it employs, legitimately does. The varnish of Mr. Lawrence, an English artist resident in Paris, is made as follows: Take of virgin wax and asphaltum, each two ounces, of black pitch and burgundy-pitch each half an ounce. Melt the wax and pitch in a new earthenware glazed pot, and add to them, by degrees, the asphaltum, finely powdered. Let the whole boil till such time as that, taking a drop upon a plate, it will break when it is cold, on bending it double two or three times betwixt the fingers. The varnish, being then enough boiled, must be taken off the fire, and after it cools a little, must be poured into warm water that it may work the more easily with the hands, so as to be formed into balls, which must be kneaded, and put into a piece of taffety for use. Care must be taken, first, that the fire be not too violent, for fear of burning the ingredients, a slight simmering being sufficient; secondly, that whilst the asphaltum is putting in, and even after it is mixed with the ingredients, they should be stirred continually with the spatula; and thirdly, that the water into which this composition is,hrown should be nearly of the same degree of warmth with it, in order to prevent a Kind of cracking that happens wlhen the water is too cold. The varnish ought always to be made harder in summer than in winter, and it will become so if it be suffered to boil longer, or if a greater proportion of the asphaltum or 554 ETHER. brown rosin be used. The experiment above mentioned, of the drop suffered to coo., will determine the degree of hardness or softness that may be suitable to the season when it is used. Preparation of the hard varnish used by Callot, commonly called the Florence Varaish:-Take four ounces of fat oil very clear, and made of good linseed- oil, like that used by painters; heat it in a clean pot of glazed earthenware, and afterwards put to it four ounces of mastick well powdered, and stir the mixture briskly till the whole be well melted, then pass the mass through a piece of fine linen into a glass bottle with a _ong neck, that can be stopped very securely; and keep it for the use that will be explained below. Method of applying the soft varnish to the plate, and of blackening it: —The plate being well polished and burnished, as also cleansed from all greasiness by chalk or Spanish white, fix a hand-vice on the edge of the plate where no work is intended to be, to serve as a handle for managing it when waim'; then put it upon a chafing dish, in which there is a moderate fire, and cover the whole plate equally with a thin coat of the varn;sh; and whilst the plate is warm, and the varnish upon it in a fluid state, beat every part of the varnish gently with a small ball or dauber made of cotton tied up in taffety, which operation smooths and distributes the varnish equally over the plate. When the plate is thus uniformly and thinly covered with the varnish, i must be blackened by a piece of flambeau, or of a large candle which affords a copious smoke; sometimes two or even four such candles are used together fur the sake of despatch, ioat the varnish may noc grow cold, which if it does during the operation, the plate must be heated again, that it may be in a melted state when that operation is performed; but great care must be taken not to burn it, which, when it happens, may be easily perceived by the varnish appearing burnt, and losing its gloss. The menstruum used and recommended by Turrell, an eminent London artist, for etching upon steel, was prepared as follows:Take Pyroligneous acid 4 parts by measure, Alcohol 1 part, mix, and add Nitric acid 1 part. This mixed liquor is to be applied from 16 to 15 minutes, according to the depth desired. The nitric acid was employed of the strength of 1'28-the double aquafortis of the shops. The eau forte or menstruum for copper, used by Callot, as also by Piranesi, with a slight modification, is prepared with 8 parts of strong French vinegar, 4 parts of verdigris, 4 ditto sea salt, 4 ditto sal ammoniac, 1 ditto alum, 16 ditto water. The solid substances are to be well ground, dissolved in the vinegar, and diluted with the water; the mixture is now to be boiled for a moment, and then set aside to cool. This menstruum is applied to the washed, dried, and varnished plate, after it has suffered the ordinary action of aquaf;rtis, in order to deepen and finish the delicate touches. It is at present called the eau forte a passer. ETHER is the name of a class of very light, volatile, inflammable, and fragrant spirituous liquids, obtained by distilling, in a glass retort, a mixture of alcohol with almost any strong acid. Every acid modifies the result, in a certain degree, whence several varieties of ether are produced. The only one of commercial importance is sulphuric ether, which was first made known under the name of sweet oil of vitriol, in 1540, by the receipt of Walterus Cordus. Froberus, 190 years after that date, directed the attention of chemists afresh to this substance, under the new denomination of ether. There are two methods of preparing it; by the first, the whole quantity of acid and alcohol are mixed at once, and directly subjected to distillation; by the second, the alcohol is admitted, in a slender streamlet, into a body of acid previously mixed with a little alcohol. and heated to 220~ Fahr. 1. Mix equal weights of alcohol at spec. grav. 0'830, and sulphuric acid at 1*842, by introducing the former into a large tubulated retort, giving it a whirling motion, so that the alcohol may revolve round a central conical cavity. Into this species of whirlpool the acid is to be slowly poured. The mixture, which becomes warm, is to be forthwith distilled by attac.hing a spacious receiver to the retort, and applying the heat of a sand-bath. The formation of ether takes place only at a certain temperature. If the contents of the retort be allowed to coo., and be then slowly heated in a water-bath, ilcohol alone will come over for some time without ether, till the mixture acquires the A i ETHER. 655 proper degree of heat. The first receiver should be a globe, with a tube proceeding from its bottom, into a second receiver, of a cylindric shape, surrounded with ice-cold water. The joints must be well secured by lutes, after the expanded air has been allowed to escape. The liquid in the retort should be kept in a steady state of ebullition. The ether, as long as it is produced, condenses in the balloon and neck of the receiver in striae; when these disappear the process is completed. The retort must now be removed from the sand; otherwise it would become filled with white fumes contain ing sulphurous acid, and denser striee would flow over, which would contaminate the light product with a liquid called sweet oil of wine. The tneory of etherification demonstrates that when strong sulphuric acid is mixed with alcohol, there is formed, on the one hand, a more aqueous sulphuric acid, and, on the other, sulphovinic acid. When this mixture is made to boil, the sulphovinic acid is decomposed, its dihydrate of carbon combines with the alcohol, and constitutes ether; while the proportion of sulphovinic acid progressively diminishes. Mr. Hennell, of the Apothecaries' Hall, first explained these phenomena, and he was confirmed in his views by the interesting researches of Serullas. The acid left in the retort is usually of a black color, and may be employed to convert into ether half as much alcohol again; an experiment which may be repeated several times in succession. The most profitable way of manufacturing ether has been pointed out by Boullay. It consists in letting the alcohol drop in a slender stream into the acid, previously heated to the etherifying temperature. If the acid in this case were concentrated to 1-846, the reaction would be too violent, and the ether would be transformed into bicarbureted hydrogen (dihydrate of carbon). It is therefore necessary to dilute the acid down to the density of 1*780; but this dilution may be preferably effected with Jcohol, instead of water, by mixing three parts of the strongest acid with 2 of alcohol, specific gravity 0'830, and distilling off a portion of the ether thereby generated; after'which the stream of alcohol is to be introduced into the tubulure of the retort through a small glass tube plunged into the mixture; this tube being the prolongation of a metallic syphon, whose shorter leg dips into a bottle filled with the alcohol. The longer leg is furnished with a stop-cock, for regulating at pleasure the alcoholic streamlet. The distilled vapors should be transmitted through a worm of pure tin, surrounded by cold water, and the condensed fluid received in a glass bottle. The quantity of alcohol which can be thus converted into ether by a given weight of sulphuric acid, has not hitherto been accurately determined; but it is at least double. In operating in this way, neither sulphurous acid nor sweet oil of wine is generated, while the residuary liquid in the retort continues limpid and of a merely brownish yellow color. No sulphovinic acid is formed, and according to the experiments of Geiger, the proportion of ether approaches to what theory shows to be the maximum amount. In fact, 57 parts of alcohol of 0'83 sp. grav. being equivalent to 46-8 parts of anhydrous alcohol, yield, according to Geiger, 331 parts of ether; and by calculation they should yield 37}. The ether of the first distillation is never pure, but always contains a certain quantity of alcohol. The density of that product is usually 0'78, and if prepared by the first of the above methods, contains, besides alcohol, pretty frequently sulphurous acid, and sweet oil of wine; impurities from which it must be freed. Being agitated with its bulk of milk of lime, both the acid and the alcohol are removed at the same time; and if it be then decanted and agitated, first with its bulk of water, next decanted into a retort containing chloride of calcium in coarse powder, and distilled, one third of perfectly pure ether may be drawn over. Gay Lussac recommends to agitate the ether, first with twice its volume of water, to mix it, and leave it in contact with powdered unslaked lime for 12 or 14 hours, and then to distil off one third of pure ether. The remaining two thirds consist of ether containing a little alcohol. If in preparing ether by Boullay's method, the alcohol be too rapidly introduced, much of this liquid will come over unchanged. If in this state the ether be shaken with water, a notable quantity of it will be absorbed, because weak alcohol dissolves it very copiously. The above product should therefore be re-distilled, and the first half that comes over may be considered as ether, and treated with water and lime. The other half must be exposed afresh to the action of sulphuric acid. Pure ether possesses the following properties. It is limpid, of spec. grav. 0'713, or 0-715 at 60~; has a peculiar penetrating strong smel; a taste at first acrid, burning, sweetish, and finally cooling. It has neither an acid nor alkaline reaction; is a nollconductor of electricity, and refracts light strongly. It is very volatile, boiling at 96~ or 97~ F.. and produces by its evaporation a great degree of cold. At the temperature of 62-4, the vapor of ether balances a column of mercury 15 inches high, or half the weight of the atmosphere. When ether is cooled to -24~ F. it begins to crystallize in Drilliant white plates, and at -47~ it becomes a white crystalline solid. When vapor of ether is made to traverse a red hot porcelain tube, it deposites within it one nIaif per cent. of charcoal, and there are condensed in the receii er one and two thirds __ \1 S56 EVAPORATION. pet cent. of a brown oil, partly in crystalline scales, and partly viscid. The crystalline portion is soluble in alcohol, but the viscid only in ether. The remainder of the decomposed ether consists of bi-carbureted hydrogen gas, tetrahydric carburet, carbonic oxyde gas, and one per cent. at most of gaseous carbonic acid. Ether takes fire readily, even at some distance from a flame, and it should not there. fore be poured from one vessel to another in the neighborhood of a lighted candle. It may be likewise set on fire by the electric spark. It burns all away with a bright fuliginous flame. When the vapor of ether is mixed with 10 times its volume of oxygen, it turns with a violent explosion, absorbs 6 times its bulk of oxygen, and produces 4 times iRs volume of carbonic acid gas. Ether alters gradually with contact of air; absorbing oxygen, and progressively changing into acetic acid and water. This conversion takes place very rapidly when the ether is boiled in an open vessel, while the acid enters into a new combination forming acetic elher. Ether should be preserved in bottles perfectly full and well corked, and kept in a cool place, otherwise it becomes sour, and is destroyed. In contains in this state 15 per cent. of its bulk of azote, but no oxygen gas, as this has combined with its elements. Ether is composed of oxygen 21'24; hydrogen 13'85; carbon 65'05. This composition may be represented by 1 prime equivalent of water, and 4 primes of bi-carburetted hydrogen gas; in other words, ether contains for 1 prime of water, once as much olefiant gas as alcohol, and its prime equivalent is therefore 468'15 to oxygen 100. By my analysis, as published in the Phil. Trans. for 1822, ether is composed of oxygen 27'10; hydrogen 13-3; and carbon 59'6 in 100 parts. The density of my ether was 0'700. One volume of vapor of ether consists of one volume of aqueous vapor and two volumes of olefiant gas (bi-carbureted hydrogen), while alcohol consists of two volumes of each. ETHER, ACETIC, is used to flavor silent corn spirits in making imitation brandy. It may be prepared by mixing 20 parts of acetate of lead, 10 parts of alcohol, and 11- of concentrated sulphuric acid; or 16 of the anhydrous acetate, 5 of the acid, and 4k of absolute alcohol; distilling the mixture in a glass retort into a very cold receiver, agitating along with weak potash ley the liquor which comes over, decanting the supernatant ether, and rectifying it by re-distillation over magnesia and ground charcoal. Acetic ether is a colorless liquid of a fragrant smell and pungent taste, of spec. grav. 0-866 at 45~ F., boiling at 166~ F., burning with a yellowish flame, and disengaging fumes of acetic acid. It is soluble in 8 parts of water. Acetic ether may be economically made with 3 parts of acetate of potash, 3 of very strong alcohol, and 2 of the strongest sulphuric acid, distilled together. The first product must be re-distilled along with one fifth of its weight of sulphuric acid; as much ether will be obtained as there was alcohol employed. ETHIOPS is the absurd name given by the alchemists to certain black metallic preparations. Martial ethiops was the black oxyde of iron; mineral ethiops, the black sulphuret of mercury; and ethiops per se, the black oxyde of mercury. EVAPORATION (Eng. and Fr.; Abdampfen; AIbdunsten, Germ.) is the process by which any substance is converted into, and carried off in, vapor. Though ice, camphor, and many other solids evaporate readily in dry air, I shall consider, at present, merely the vaporization of water by heat artificially applied. The vapor of water is an elastic fluid, whose tension and density depend upon the temperature of the water with which it is in contact. Thus the vapor rising from water heated to 165~ F. possesses an elastic force capable of supporting a column of mercury 10'8 high; and its density is such that 80 cubic feet of such vapor contain one pound weight of water; whereas 321 cubic feet of steam of the density corresponding to a temperature of 212~ and a pressure of 30 inches of mercury, weigh one pound. When the temperature of the water is given, the elasticity and specific gravity of the vapor emitted by it may be found. Since the vapor rises from the water only in virtue of the elasticity due to its gaseous nature, it is obvious that no more can be produced, unless what is already incumbent upon the liquid have its tension abated, or be withdrawn by some means. Suppose the temperature of the water to be midway between freezirg and boiling, viz., 122~ Fahr., as also that of the air in contact with it, to be the same but replete with moisture, so that its interstitial spaces are filled with vapor of corresponding elasticity and specific gravity with that given off by the water, it is certain that no fresh formation of vapor can ake place in these circumstances. But the moment a portion of vapor is allowed to es cape, or is drawn off by condensation to another vessel, an equivalent portion of vapor will be immediately exhaled from the water. The pressure of the air and of other vapors upon the surface of water in an open vessel, does not prevent evaporation of the liquid; it merely retards its progress. Experience shows that the space filled with an elastic fluid, as air or other gaseous body, is capable of receiving as much aqueous vapor as if it were vacuous, only the repletion of that EVAPORATION. 657 space with the vapor proceeds more slowly in the former predicament than in the latter, but in both cases it arrives eventually at the same pitch. Dr. Dalton has very in. geniously proved, that the particles of aeriform bodies present no permanent obstacle to the introduction of a gaseous atmosphere of another kind among them, but merely obstruct its diffusion momentarily, as if by a species of friction. Hence, exhalation at atmospheric temperatures is promoted by the mechanical diffusion of the vapors through the air with ventilating fans or chimney draughts; though under brisk ebullition, the force of the steam readily overcomes that mechanical obstruction. The quantities of water evaporated under different temperatures in like times, are proportional to the elasticities of the steam corresponding to these temperatures. A vessel of boiling water exposing a square foot of surface to the fire, evaporates 725 grains in the minute; the elasticity of the vapor is equivalent to 30 inches of mercury. To find the quantity that would be evaporated from the same surface per minute at a heat of 88~ F. At this temperature the steam incumbent upon water is capable of supporting 1'28 inch ofmercury; whence the rule of proportion is 30: 1'28:: 725: 30-93; showing that about 31 grains of water would be evaporated in the minute. If the air contains already some aqueous vapor, as it commonly does, then the quantity of evaporation will be proportional to the difference between "he elastic force of that vapor, and what rises from the water. Suppose the air to be in the hygrometric state denoted by 0*38 of an inch of mercury, then the above formula will become: 30: 1-28 - 0-38:: 725: 21-41; showing that not more than 21- grains would be evaporated per minute under these circumstances. The elastic tension of the atmospheric vapor is readily ascertained by the old experiment cf Le Roi, which consists in filling a glass cylinder (a narrow tumbler for example) with cool spring water, and noting its temperature at the instant it becomes so warm that dew ceases to be deposited upon it. This temperature is that which corresponds to the elastic tension of the atmospheric vapor. See VAPOR, Table of. Whenever the elasticity of the vapor, corresponding to the temperature of the water, is greater than the atmospheric pressure, the evaporation will take place not only from its surface, but from every point in its interior; the liquid particles throughout the mass assuming the gaseous form, as rapidly as they are actuated by the caloric, which subverts the hydrostatic equilibrium among them, to constitute the phenomena of ebullition. This turbulent vaporization takes place at any temperature, even down to the freezing point, provided the pneumatic pressure be removed from the liquid by the air pump, or any other means. Ebullition always accelerates evaporation, as it serves to carry off the aqueous particles not simply from the surface, but from the whole body of the water. The vapors exhaled from a liquid at any temperature, contain more heat than the fluid from which they spring; and they cease to form whenever the supply of heat into the liquid is stopped. Any volume of water requires for its conversion into vapor five and a half times as much heat as is sufficient to heat it from the freezing to the boiling temperature. The heat, in the former case, seems to be absorbed, being inappreciable by the thermometer; for steam is no hotter than the boiling water from which it rises. It has been therefore called latent heat; in contradistinction to that perceived by the touch and measured by the thermometer, which is called sensible heat. The quantity of heat absorbed by one volume of water in its conversion into steam, is about 1000~ Fahr.; it would be adequate to heat 1000 volumes of water, one degree of the same scale; or to rais-: one volume of boiling water, confined in a non-conducting vessel, to 1180~. Were the vessel charged with water so heated, opened, it would be instantaneously emptied by vaporization, since the whole caloric equivalent to its constitution as steam, is present. When, upon he other hand, steam is condensed by contact with cold substances, so much heat is set free as is capable of heating five and a half times its weight of water, from 320 to 212~ F. If the supply of heat to a copper be uniform, five hours and a half will be required to drive off its water in steam, provided one hour was taken in heating the water, from the freezing to the boiling pitch, under the atmospherical pressure. Equal weights of vapor of any temperature contain equal quantities of heat; for example, the vapor exhaled from one pound of water, at 77~ F., absorbs during its formation, and will give out in its condensation, as much heat as the steam produced by one pound of water, at 212~ F. The first portion of vapor with a tension=30 inches, occupies a space of 27'31 cubic feet; the second, with a tension of 0'92 inch, occupies a space of 890 cubic feet.* Suppose that these 890 volumes were to be compressed into 27*31 in a cylinder capable of confining the heat, the temperature of the vapor would rise from 77~ to 212', in virtue of the condensation, as air becomes so hot by comr * One pound avoirdupois of water contains 27-72 cubic inches; one cubic inch of water forms 1696 cubic inches of steam at 212~ F.: therefore one pound of water will form 27-31 cubic feet of such steam: and 0-92 O 2 7-31: 890 cubic feet. 43 558 EVAPORATION. pression in a syringe, as to ignite amadou. The latent heat of steam at 212~ F. is 1180~-180=1000; that of vapor, at 77~, is 1180-45=1135~; so that, in fact, the lower the temperature at which the vapor is exhaled, the greater is its latent heat, as Joseph Black and James Watt long ago proved by experiments upon distillation and the steam engine. From the preceding researches it follows, that evaporation may be effected upon two different plans:1. Under the ordinary pressure of the atmosphere; and that either, A, by external application of heat to boilers with a, an open fire; b, steam; c, hot liquid media. a, by evaporation with air; a, at the ordinal y temperature of the atmosphere; b, by currents of warm air. 2. Under progressively lower degrees of pressure than the atmospheric, down to evaporation in as perfect a vacuum as can be made. It is generally affirmed, that a thick metallic boiler obstructs the passage of the heat through it so much more than a thin one, as to make a considerable difference in their relative powers of evaporating liquids. Many years ago, I made a series of experiments upon this subject. Two cylindrical copper pans, of equal dimensions, were provided: but the metal of the one was twelve times thicker than that of the other. Each bein? charged with an equal volume of water, and placed either upon the same hot plate of iron, or immersed, to a certain depth, in a hot solution of muriate of lime, I found that the ebullition was greatly more vigorous in the thick than in the thin vessel, which I ascribed to the conducting substance up the sides, above the contact of the source of heat, being 12 times greater in the former case than in the latter. If the bottom of a pan, and the portions of the sides, immersed in a hot fluid medium, solution of caustic potash or muriate of lime, for example, be corrugated, so as to contain a double expanse of metallic surface, that pan will evaporate exactly double the quantity of water, in a given time, which a like pan, with smooth bottom and sides, will do immersed equally deep in the same bath. If the corrugations contain three times the quantity of metallic surface, the evaporation will be threefold in the above circums stances. But if the pan, with the same corrugated bottom and sides, be set over a fire, or in an oblong flue, so that the current of flame may sweep along the corrugations, it will evaporate no more water from its interior than a smooth pan of like shape and dimensions placed alongside in the same flue, or over the same fire. This curious fact I have verified upon models constructed with many modifications. Among others, I caused a cylindrical pan, 10 inches diameter, and 6 inches deep, to be made of tinplate, with a vertical plate soldered across its diameter; dividing it into two equal semi-cylindrical compartments. One of these was smooth at the bottom, the other corrugated; the former afforded as rapid an evaporation over the naked fire as the latter, but it was far outstripped by its neighbor when plunged into the heated liquid medium. If a shallow pan of extensive surface be heated by a subjacent fire, by a liquid medium or a series of steam pipes upon its bottom; it will give off less vapor in the same time when it is left open, than when partially covered. In the former case, the cool incumbent air precipitates by condensation a portion of the steam, and also opposes considerable mechanical resistance to the diffusion of the vaporous particles. In the latter case, as the steam issues with concentrated force and velocity from the contracted orifice, the air must offer less proportional resistance, upon the known hydrostatic principle of the pressure being as the areas of the respective bases, in communicating vessels. In evaporating by surfaces heated with ordinary steam, it must be borne in mind that a surface of 10 square feet will evaporate fully one pound of water per minute, or 725X 10 = 7250 gr., the same as over a naked fire; consequently the condensing surface must be equally extensive. Suppose 1tat the vessel is to receive of water 2500 lbs., which corresponds to a boiler 5 feet long, 4 broad, and 2 deep, being 40. cubic feet by measure, and let there be laid over the bottom of this vessel 8 connected tubes each 5 inches in diameter and 5 feet long, possessing therefore a surface of 5 feet square. If charged with steam, they will cause the evaporation of half a pound of water per minute. The boiler to supply the steam for this purpose must expose a surface of 5 square feet to the fire. It has been proved experimentally that 10 square feet surface of thin copper can condense 3 lbs. of steam per minute, with a difference of temperature of 90 degrees Fahr. In the above example, 10 square feet evaporate 1 lb. of water per minute; the temperature of the evaporating fluid being 2120 F., consequently 3:1:90: 0. During this evaporation the difference of the temperature is therefore 30~. Consequently the heat of the steam placed in connexion with the interior of the boiler, to produce the calculated evaporation, should be, 212+30 = 2420~ ccrresponding to an elastic force of 53-6 inches of mercury. Were the temperature of I_______ 1______ __ _____ i_______ -j EVAPORATION. 659 the steam only 224, the same boiler in the same time would produce a diminished quan. tity of steam, in the proportion of 12 to 30; or to produce the same quantity the boiler or tubular surface should be enlarged in the proportion of 30 to 12. In general, however, steam boilers employed for this mode of evaporation are of such capacity as to give an unfailing supply of steam. I shall now illustrate by some peculiar forms of apparatus, different systems of evaporation. Fig. 496 explains the principles of evaporating in vacuo. A B represents 496 | =.SG J a pan or kettle charged with the liquor to be evaporated. The somewhat wide orifice c, secured with a screw-plug, serves to admit the hand for the purpose of cleaning it thoroughly out when the operation is finished; h is the pipe of communication with the steam boiler; b is a tube prolonged and then bent down with its end plunged into the liquor to be evaporated, contained in the charging back, (not shown in the figure). H is a glass tube communicating with the vacuum pan at the top and bottom, to show by the height of the column the quantity of liquid within. The eduction evaporating pipe c is provided with a stop-cock to cut off the communication when required. i is a tube for the discharge of the air and the water from the steam-case or jacket; the refrigerator E is best formed of thin copper tubes about 1 inch in diameter, arranged zig-zag or spirally like the worm of a still in a cylinder. The small air-tight condenser F, connected with the efflux pipe f of the refrigerator, is furnished below with a discharge cock g, and surrounded by a cooling case, for the collection of the water co.densed by the refrigerator. In its upper part there is a tube k, also furnished with a cock, which communicates with the steam boiler, and through which the pan A B is heated. The operation of this apparatus is as follows: after opening the cocks c, f, g, and before admitting the cold water into the condenser E, the cock of fhe pipe k is opened, in order that by injecting steam it may expel the included air; after which the cocks k and g are to be shut. The water must now be introduced into the condenser, and the cock b opened, whereon the liquid to be evaporated rises from the charging back, through the tube b, and replenishes the vacuum pan to the proper height, as shown by the register glass tube H. Whenever the desired evaporation or concentration is effected, the cock c must be closed, the pipe k opened, so as to fill the pan with steam, and then the efflux cock a is opened to discharge the residuary liquor. By shutting the cocks a and k, and opening the cock b, the pan will charge itself afresh with liquor, and the operation will be begun anew, after b has been shut and c opened. The contents of the close water cistern r, may be drawn off during each operation For this purpose, the cock f must first be shut, the cold water is to be then run out of the condenser G, and k and g are to be opened. The steam entering by k makes the water flow, but whenever the steam itself issues from the cock g, this orifice must be immediately shut, the cock f opened, and the cold water again introduced, whereupon the condensed water that had meanwhile collected in the under part of the refrigerator, flows off into the condenser vessel r. Since some air always enters with the liquor bt0 EVAPORATION. sucked into the pal, it must be removed at the time of drawing off the water from the two condensers, by driving steam through the apparatus. This necessity will be less urgent if the liquor be made to boil before being introduced into the vacuum pan. Such an apparatus may be modified in size and arrangement to suit the peculiar object in view, when it will be perfectly adapted for the concentration of extracts of every kind, as well as saline solutions containing vegetable acids or alkalis. The interior vessel of A B should be made of tinned or plated copper. For an account of Howard's vacuum pan, made upon the same principle, see SUGAR. When a boiler is set over a fire, its bottom should not be placed too near the grate, lest it refrigerate the flame, and prevent that vivid combustion of the fuel essential to the maximum production of heat by its means. The evil influence of leaving too little room between the grate and the copper may be illustrated by a very simple experiment. If a small copper or porcelain capsule containing water be held over the flame of a candle a little way above its apex, the flame will suffer no abatement of brightness or size, but will continue to keep the water briskly boiling. If the capsule be now lowered into the middle of the flame, this will immediately lose its brightness, becoming dull and smoky, covering the bottom of the capsule with soot; and cwing to the imperfect combustion, though the water is now surrounded by the flame, its ebullition will cease. Fig. 497 is a section of two evaporating coppers en suite, so mounted as to favor the 497 lill[^B[~^lwNJl full combustion of the ftel. A is the hearth, in which wood or coal may be burned. For coal, the grate should be set higher and be somewhat smaller. a is the door for feeding the fire; d, an arch of fire-bricks over the hearth; c, a grate through which the ashes fall into the pit beneath, capable of being closed in front to any extent by a sliding door b. B and c are two coppers incased in brickwork; f the flue. At the end of the hearth near m, where the fire plays first upon the copper, the sole is made somewhat lower and wider, to promote the spreading of the flame under the vessel. The second copper, c, receives the benefit of the waste heat; it may be placed upon a higher level, so as to discharge its concentrated liquor by a stop-cock or syphon into the first. When coals are burned for heating such boilers, the grate should be constructed as shown in the figure of the brewing copper, page 151. Fig. 498 represents a pan for evaporating liquids, which are apt, during concentra-:^ f yi tion, to let fall crystals or other sediment. 498 These would be injured either by the fire play c...//.... ing upon the bottom of the pan, or, by adhesion._..::::...to it, they would allow the metal to get red hot, and in that state run every risk of being burnt or rent on the sudden intrusion of a little liquor I\5 >^, e\/'Mthrough the incrustation. When large coppers;|L~ 4 Na\/r~~~have their bottoms planted in loam, so that the d( 8Zll l^ K^ ^^ _ mflame circulates in flues round their sides, they are said to be cold-set. A is a pear-shaped pan, charged with the l 1^;a liquid to be evaporated; it is furnished with a dome cover, in which there is an opening with a flange f, for attaching a tube, to conduct the steam wherever it may be required. a is the fire-place; b the ash-pit. The conical part terA minates below in the tube g, furnished with a stop-cock at its nozzle hA. Through the tube c d c' furnished above and below with the stop. cocks c and c', the liquid is run from the EVAPORATION. 661 charging back or reservoir. During the operation, the upper ccck c is kept partially open, to replace the fluid as it evaporates; but the under cock c' is shut. The flame from the fire-place plays round the kettle in the space e, and the smoke escapes downwards through the flue i into the chimney. The lower cylindrical part g remains thus comparatively cool, and collects the crystalline or other solid matter. After some time? the under stop-cock c', upon the supply-pipe, is to be opened to admit some of the cold liquor into the cylindrical neck. That cock being again shut, the sediment settled, and the large stop-cock (a horizontal slide-valve would be preferable) h opened, the crystals are suffered to descend into the subjacent receiver; after which the stop-cock h is shut, and the operation is continued. A construction upon this principle is well adapted for heating dyeing coppers, in which the sediment should not be disturbed, or exposed to the action of the fire. The fire-place should be built as for the brewing copper. Fig. 499 represents an ||499 Hoblong evaporating pan, in which the flame, after kg^~~~~~~~~ Ji ___beating along its bottom, I IlllllillllllllllllllM[IIIIT I ~ n l l ll i tll``l g turns up at its further....__ ______L ____ ^end, plays back along its ______L~___ —'surface, and passes off in-' —-=i.^:-:.;7^ = q..^~ B yto the chimney. A is a rectangular vessel, from 10 to 15 feet long, 4 to 6 feet broad, and 1 or 1j feet deep. The fire-bricks, upon which the pan rests, are so arranged as to distribute the flame equably along its bottom. For the following scheme of generating, purifying, and condensing steam, Mr. Charles Clarke, merchant, London, obtained a patent in January, 1843. His apparatus for converting sea-water, &c., economically into good fresh water, is represented in figs. 500, 501, 502. A is the supply cistern, which communicates with a pipe a, with a self-regulating eduction apparatus B. C is a strong wrought iron cylinder, fitted at bottom into a flanged ring-place c, and covered with a conical top; it is about two thirds filled with the water to be operated upon. D is a cylindrical furnace concentric with the water cylinder c; d is an upward air and water-tight tube, which serves both as a feed-pipe, through which the fuel is supplied to the furnace, and as a passage for the escape of the smoke and other gaseous products of combustion; e is a hinged trap-door through which the fuel is passed into the tube d: h is a chimney into which the pipe d terminates: and i, a damper, by which the degree of activity given to the furnace can be regulated at pleasure; f is an open air-pipe, which leads from the outside, through the boiler, into the furnace, a little way above the fire-bars, and assists in securing a good draught through the furnace into the chimney. To the water cylinder c there are attached gauge-cocks, g g, for ascertaining from time to time the height of the water; 1 is a cock or tap for drawing off the brine, and other residual matters which collect at the bottom of the boiler; m is a screw-cap and hole, through which access may be had to the interior of the water cylinder c, when it needs to be cleaned; E is a short pipe fitted into the conical top of the water cylinder c, which conveys the steam generated in it into the steam-head or receiver F: G is a concave plate, resting upon the top of the pipe E, a little larger than that pipe, and kept steady by a weight, k, of one or more pounds, suspended from it by wires. This plate prevents, in a great measure, the escape-water escaping into the steam-head (an accident commonly called priming in steam engines); because, till the steam has acquired a pressure exceeding that of the counterweight k, it cannot raise the weight G, so as to escape freely into the steam-head F, since any particle of water must, during the rising of the cap a, strike against it, and drop back, either into the water cylinder c, through the pipe E, or into the space round that pipe at the bottom of the steamhead H; whence it may be withdrawn by the cock shown in the drawing. H is a pipe which conveys the steam from the steam-head F to the rectifier. This consists simply of a cylinder (about one third the size of the cylinder c) laid horizontally, in the lower part of which a body of water speedily collects, and serves to retain any particle of undecomposed matter, which may come over with the steam, as it continues to flow in from the boiler; whereby only its purer portions may pass off from the rectifier a, by the pipe N. n is a cock or tap, at the bottom of the cylinder R for drawing off its water occasionally; nR is a second steam-rectifier, like a, into which the steam passes from the pipe N, and is thereby still further purified; but when the proportion of saline matter is small, aR may be dispensed with, and for very foul water, two or three more such rectifiers may be added. The condenser for liquefying the purified steam, and aerating the resulting water, is shown at tl, t2, t3 It is composed of conical upright compartments communicating with each other; the chamber tl is surrounded by the water in the cistern A (slightly I. 662 EVAPORATION. heated by the steam in that chamber), while the chambers t2 and t3 are exposed freely to the air. The lowest of these, t3, terminates at bottom in a tube, u, containing at the mouth of the cone two or three plates of perforated zinc, for admission of the atme A\ 502 \:'500 sphere. An upright steam-tight tube of zinc, at about the middle of the lowesI chamber, t3, and is continued to the top of the uppermost chamber, t', having two lateral branches. This tube is closed at its lower end, but open at top, and at the ends of the two branches, to give a draught of cool air into the tube, and a rapid flow of heated air from the top of the tube. W, W, are pipes which pass externally from about the middle of the chamber t2, to near the bottom of the chamber 13. At their tops they are of large dimensions, as represented, but diminish gradually to small pipes at bottom, Of these pipes, there should be as many as can be conveniently applied, in order thai the process of condensation may be effectually promoted. From the second rectifier, RI, the steam is conveyed by a pipe, w, of gradually in. creasing dimensions, to near the top of the middle chamber, t, whence it diffuses itself through the three chambers, where it gets condensed. The hottest steam passes into ti, and is there most powerfully condensed. The main body of the water produced therefrom, either drops directly into the bottom of the chamber 13, or runs down the in. clined sides of the chambers 1', 12, t3, thence through the outer pipes W, W, and out at the bottom of the tube, getting partially aerated in its progress, by means of the air ascending constantly through the tube u. Z, Z, is an auxiliar steam-pipe from the rectifier RI, passing twice or thrice close round the water supplying the cistern, A, and terminating in a cylinder which communicates by pipes with the chambers, 12 and t3; whereby all the water thus condensed | C E L L- X _,~~~~~~~~t, 81UE —11~~~~~~~~~~~~~~~~~i 3 a= | H W~~~~rii= v 1 10 11 D4X~~~I ~ =t EM@ nicates by pipes with the chambers, t2 and t3; whereby all the water thlls condensed EVAPORATION. 663 may fall through the perforated zinc plates, into the general discharge tube, u. x id an outer casing of wood or metal, leaving a small space round the condenser, with draught-holes, x, x, for the admission of air. The refrigerator is made of protected metal "(tinned copper?)," and divided into three compartments, yl, y2, y3 In the top of yl, the end of the discharged tube u is inserted; and at a little distance from this tube there are air apertures, a, a, furnished with shutters in the inside, slanting from the top downward, to prevent as much as possible the escape outward of any vapor which may occasionally be carried down with the water from the condenser. The middle compartment, y2, is perforated, convex at top, and concave at bottom; so that the water that drops from the tube u, in the convex top of y2, falls off laterally through small pipes into the chamber y2, while its concave bottom turns the water into a central filtering-box, c, that projects a little into y3, set to receive it. For aerating this water, the bottom of y2 is covered about an inch deep with small pebbles. y3, which is the reservoir of the purified cool water, is perforated with small holes. ci, cl, are small pipes for promoting a continual upward flow of cold air. y3 is furnished with a tap to draw off its water, as required. For redistilling or rectifying spirituous liquids, the apparatus, fig. 501, is employed; in which the supply cistern A is much larger, and close at top; the upper condensing chambers, t1, t2, are also larger, but the lowest, t3, is narrowed. The second rectifier offig. 500, is removed. The feints collect in the bottom of the rectifier R, to be drawn off by a cock; while the rectified spirit passes off at top into the condenser. The refrigerator has only two compartments, and no pebbles. F is a funnel into which the spirits may be returned for redistillation. For extracting the soluble matter of vegetable infusions, the apparatus, shown in fig. 502,is used. The rectifier is vertical, has a screw-capped hand-hold, f, for admitting the vegetables. g is a steam-pipe; and h is a funnel for returning portions of the liquid extract. R is connected by a pipe, k, with the condenser, T, made in two por. tions, fitted water-tight together, but separable for the purpose of cleansing. The steam which passes from the boiler into the rectifier n disengages the soluble portion of the vegetable substances, and if they be volatile, carries them off to the condenser; if not, it combines and falls with them to the bottom of the vessel, whence this portion of the extract is drawn off by the cock, and a fresh charge may be introduced. The steam is shut off from the rectifier a by a cock on pipe g. When the steam is afterward admitted to assist the process of maceration, the supply of it is regulated by the stop-cocks in the pipes g and k.-Nwewton's Journal, xxiii. p. 247, C. S. In each experiment 1,840 lbs. weight were burnt, and the relative quantities of water evaporated show the relative economic effect. Two kinds of coal were used: Knowles's Clifton coal, a free burning kind which does not cake, and produces a considerable quantity of ashes; Barker and Evan's Oldham coal, a slow burning rich caking coal, yielding little ashes. The boiler was a 24-horse power, of Watt's waggon shape. Mr.. IH louldsworth's Economy of Evaporation. water evapoEffect per Minute. rted by Average ------- --- * — ---- Tempe- EcoWeight of Charge. Air. rature in nomie Coalt e aolbs. of oalf the first Effect. o eapo Ibs. of Coal. Flue urnt. rated. Coat. s Clifton coal: Lbs. Galls. Galls. Lbs. Degrees. a 460 lbs. - No air - - - 64 25 992 541 973 106 n 460 lbs. - 45 square inches constant / aperture - - - 4-63 321 1263 6-85 1165 135 230 lbs. - Air regulated partly by the |y eye, and partly by a scale, X varying in some degree with o the action of combustion - 443 3.09 1280 6'94 1122 136 B 230 lbs. - 45 square inches - - 4'65 3 05 1210 6-6 1220 129 >! 230 lbs. - No air - - - 4.43 2-3 942 512 995 100 460 Ibs. - Air through two pipes 6 in. a in diameter, each regulated a by light - - 4-65 3-13 1250 6'8 1160 134 Oldham coal: | 230 lbs. - No air - - - 367 2-65 1340 7-3 690 100 230 lbs. - 35 square inches constant e aperture - - 405 2-76 1260 5 1020 94 230 lbs. - 24 square inches constant' aperture.- - - S82 2-82 1360 7-4 1050 102 e 460 & 230 lbs, Air regulated by a scale - 384 2.94 1410 7.7 1070 106 230 lbs. - Air regulated so as to pro- i duce no smoke - - 3161 2-87 1530 8-3 1053 114 ~ Hald Oldham, half Clifton. - - - 4.05 2-9 1320 7-2 1060 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ________________________________ 664 EXPANSION. The average heat given in the first flue, as ascertained by a pyrometer and deduced from pyrometric diagrams. The air was admitted partly at the door and partly at the bridge; at the latter point through one of Mr. Williams's diffusion boxes, except in the last experiment with Clifton coal. They showed the effect of admitting air in greater or less quantity permanently or periodically by a uniform or varying aperture; and the general result arrived at is, that by the simple and inexpensive plan of admitting air into the furnaces at both the door and bridge by permanent apertures always open, varying in aggregate area from 1 to 3 square inches (according to the quality of the coals) for every square foot of area of grate, an important saving in fuel is effected, and 9. of the dense smoke prevented, without any special care of the fireman. Deductions from the experiments on Clifton Coal:Gain in evaporation by regulated admission of air - - 35 per cent. Do. by 45 square inches constant aperture - 34,, Do. by charges of 460 lbs. instead of 230 lbs. - 4 Steam produced in a given time:No air - - 230 lbs. charges - - 100 No air - -460 lbs. do. - - 109 53 square inches air - 230 lbs. do. - 132 Air regulated - - 230 lbs. do. - - 134 53 square inches - 460 lbs. do. - -140 showing that the admission of air increases the production of steam in a given time from 30 to 40 per cent. EUDIOMETER, is the name of any apparatus subservient to the chemical examination of the atmospheric air. It means a measure of purity, but it is employed merely to determine the proportion of oxygen which it may contain. The explosive eudiometer, in which about two measures of hydrogen are introduced into a graduated glass tube, containing five measures of atmospheric air, and an electric spark is passed across the mixture, is the best of all eudiometers; and of these the syphon form, proposed by me in a paper published by the Royal Society of Edinburgh in 1819, is probably the surest and most convenient. Volta's explosive eudiometer, as made in Paris, costs 3 guineas; mine may be had nicely graduated for 6 or 8 shillings. EXPANSION (Eng. and Fr.; d.usdehnung, Germ.) is the increase of bulk experienced by all bodies when heated, unless a change of chemical texture takes place, as in the case of clays in the potter's kiln. Table i. exhibits the linear expansion of several solids by an increase of temperature from 32~ to 212~ Fahr.; Table II. exhibits the expansion in bulk of certain liquids. TABLE I.-Linear Dilatation of Solids by Heat. Dimensions which a bar takes at 212~, whose length at 32~ is 1-000000. IDilatation Dilatation Substances Authority. in in Vulgar Decimals. Fractions. Glass tube - - - - Smeaton - - | 100083333 do. -. Roy - - - 100077615 do. - -Deluc's mean- - 1'00082800 T1 I do. - - Dulong and Petit 1-00086130 114 do, - - - - Lavoisier and Laplace 1-00081166 I 1 Plate glass - do. do. 1.000890890 _1. T-14 do. crown glass - - - do. do. 1-00087572 l1 do. do. -. do. do. 1-00089760 1 do. do. do. do. 1-00091751 1 9 do. rod - -. - Roy - - 1-00080787 Deal - - Roy, as glass - Platina - - Borda - - - 1 00085655 do. Dulong and Petit 1-00088420 T1 do. - - - Troughton - - 1-00099180 do. and glass - - Berthoud - - 1-00110000 Palladium -. Wollaston - - 100100000 Antimony -. Smeaton - - 100108300 Cast-iron prism - - - Roy -- - 1-00110940 Cast-iron.- - - Lavoisier,byDrYoung 10011111 \Steel.... Troughton - - 100118990 A _~~~~~~ EXPANSION. 665 Dilatation Dilatation Substances. Authority. in in Vulgar Decimals. Fractions. Steel rod - Roy - 1'00114470 Blistered Steel - - - Phil. Trans. 1795, 428 100112500 do. - - - Smeaton - - - 1'00115000 Steel not tempered - - -Lavoisier and Laplace 1-00107875 j do. do. - - do. do. 1-00107956 1 do. tempered yellow - - do. do. 100136900 do. do. do. - - do. do. 1-00138600 do. do. do. at a higher heat do. do. 100123956 Steel - Troughton - - 100118980 Hard Steel - - -Smeaton - - - 100122500 Annealed steel - - - Muschenbroek - 100122000 Tempered steel - - do. - - 100137000 Iron - - - - Borda - - - 1'00115600 do. - -Smeaton - - - 100125800 Soft iron, forged - - - Lavoisier and Laplace 1-00122045 Round iron, wire drawn - do. do. 1-00123504 Iron wire Troughton - - 100144010 Iron - - -Dulong and Petit 1-00118203 Bismuth - - - Smeaton- - 1-00139200 Annealed gold - - - Muschenbroek - 1'00146000 Gold -Ellicot, by comparison 1-00150000 do. procured by parting - Lavoisier and Laplace 1-00146606 jg2 do. Paris standard, unannealed do. do. 1-00155155 do. do. annealed - do. do. 100151361 Copper - Muschenbroek - 10019100 661 do. Lavoisier and Laplace 100172244 - do. - --- - do. do. 1-00171222,i do. Troughton - - 100191880 8 do. Dulong and Petit - 100171821 g 2 Brass - -Borda - - - 1-00178300 do. Lavoisier and Laplace 1-00186671 do. - -do. do. 1-00188971 Brass scale, supposed from Hamburg Roy - - - 100185540 Cast brass - - - Smeaton - - - 1-00187500 English plate-brass, in rod - Roy - - - 100189280 do. do. in a trough form do. - - 1'00189490 Brass -- - Troughton - - 1-00191880 Brass wire - - - - -Smeaton - - - 100193000 Brass - - - - Muschenbroek - 1-00216000 Copper 8, tin 1 - Smeaton - - - 100181700 Silver- - - - - Herbert - - - 100189000 do. - - -. Ellicot, by comparison 1-0021000 do, - - Muschenbroek - 1-00212000 do. of cupel - Lavoisier and Laplace 1-00190974 do. Paris standard - - do. do. 1P00190868 Silver - -Troughton - -10020826 524 Brass 16, tin 1 - - Smeaton - - - 100190800 Speculum metal - - do. - - - 100193300 Spelter solder; brass 2, zinc 1 - do. - - - 100205800 Malacca tin - Lavoisier and Laplace 1-00193765,T Tin from Falnouth - - do. do. 1-00217298 Fine pewter - - Smeaton - - - 100228300 Grain tin - - do. - - - 100248300 Tin --.Muschenbroek - 1-00284000 Soft solder; lead 2, tin 1 - Smeaton - -- 1-00250800 Zinc 8, tin 1, a little hammered do. - - -100269200 Lead - Lavoisier and Laplace 1-00284836 sT do.. - - Smeaton - - - 100286700 Zinc - - do. - - - 1-00294200 Zinc, hammered out - inch per foot do. - - 1- 00301100 1 Glass, from 32~ to 212~ - - Dulong and Petit - 100086130 T 61 do. from 212~ to 392~ - - do. do. - 100091827 Th9 do. from 392~ to 572~ - do. do. - 1-000101114 17 The last two measurements by an air thermometer. 666 EXPANSION. TABLE II. Expansion of certain Liquids by being Heated from 32~ to 212~. Expansion Expansion] Substances. Authority. in in Vulgar Decimals. Fractions. Mercury - Dulong and Petit - 0 01801800 G.to do. in glass - - - do. do. - 0'01543200 1 Water, from its maximum density Kirwan - 0-04332 Muriatic acid (sp. gr. 1-137) - Dalton - 0-0600 17 Nitric acid (sp. gr. 1-40) - - do. - - 01100 Sulphuric acid (sp. gr. 1-85) - do. - - 0-0600 I Alcohol (to its boiling point)? - do. - - 01100 Water - do. - - 00460 1 Water, saturated with common salt do. - - 0 0500 2 Sulphuric ether (to its boiling point)? do. - - 0'0' - Fixed oils - -do. - - 00800 2Oil of turpentine - - - do. - - 00700 -L If the density of water at 39~ be called - - - 1'00000, at 212~ it becomes - - - 0-9548, and its volume has increased to - - 104734; at 77~ it becomes - - - - 09973587, and its volume has increased to only - 1-00265, which, though one fourth of the whole range of temperature, is only -L of the to tal expansion. Water at 60~ F. has a specific gravity of - 0-9991953, and has increased in volume from 39~ to - 1'00008, which is only about -1- of the total expansion to 212~, with 1 of the total range of temperature. All gases expand the same quantity by the same increase of temperature, which from 32~ to 212' Fahr. -= i800 -= or 100 volumes become 1-375. For each degree cf Fahr. the expansion is 4-8o When dry air is saturated with moisture, its bulk increases, and its specific gravity diminishes, because aqueous vapor is less dense than air, at like temperatures. The following table gives the multipliers to be employed for converting one volume of moist gas at the several temperatures into a volume of dry gas. Temperature. Multiplier. Temperature. Mu!:iplier. 53~ F. 09870 64~ 0-9799 54 0-9864 65 0-9793 55 0-9858 66 0-9786 56 0-9852 67 0-9779 57 0-9846 68 0-9772 58 0-9839 69 0-9765 59 0-9833 70 0-9758 60 0-9827 71 0-9751 61 0-9820 72 0-9743 62 0'9813 73 0-9735 63 0-9806 Ex o of c i. Absolute Dilatation of a Expansion of certain Solids. Dilatation. Metre. Brass - - - 0-00187821 1-8782 Hammered iron - - - - 000122043 1'2204 Carrara marble - - - 000084867 0'8486 Marble of St. Beat - - - - 000041810 0-4181 Marble of Saht - - - - 000056849 0-5685 Stone of Vernon on Seine - - - 0'00043027 0-4303 Stone of St. Lew - - - - 0'00064890 0-6489 Stone of Veilvie (volcanic) - - - 000020390 0-2039 Alloy of D'Arcet - - 0'00169688 1-6968 Bismuth - - - - 000121034 1-2103 FAINTS. 667 EXTRACTS. (Extraits, Fr.; Extracten, Germ.) The older apothecaries used this term to designate the product of the evaporation of any vegetable juice, infusion, or decoction; whether the latter two were made with water, alcohol, or ether; whence arose the distinction of aqueous, alcoholic, and etherous extracts. Fourcroy made many researches upon these preparations, and supposed that they had all a common basis, which he called the extractive principle. But Chevreul and other chemists have since proved that this pretended principle is a heterogeneous and very variable compound. By the term extract therefore is now meant merely the whole of the soluble matters obtained from vegetables, reduced by careful evaporation to either a pasty or solid consistence. The watery extracts, which are those most commonly made, are as various as the vegetables which yield them; some containing chiefly sugar or gum in great abundance, and are therefore innocent or inert; while others contain very energetic impregnations. The conduct of the evaporating heat is the capital point in the preparation of extracts. They should be always prepared if possible from the juice of the fresh plant, by subjecting its leaves or other succulent part, to the action of a powerful screw or hydraulic press; and the evaporation should be effected by the warmth of a water bath, heated not beyond 100~ or 120~ F. Steam heat may perhaps be applied advantageously in some cases, where it is not likely to decompose any of the principles of the plant. But by far the best process for making extracts is in vacuo, upon the principles explained in the article EVAPORATION. It is much easier to fit up a proper apparatus of this kind, than most practical men imagine. The vacuum may either be made through the agency of steam, as there pointed out, or by means of an air-pump. One powerful air-pump may form and maintain a good vacuum under several receivers, placed upon the flat-ground flanges of'so many basins, each provided with a stop-cock at its side for exhaustion. The air-less basin containing the juice being set on the shelf of a water-bath, and exposed to a proper temperature, will furnish in a short time a large quantity of medicinal extract, possessing the properties of the plant unimpaired. For exceedingly delicate purposes, the concentration may be performed in the cold, by placing saucers filled with the expressed juice over a basin containing sulphuric acid, putting a glass receiver over them, and exhausting its air. These preparations of vegetables for medicinal use are made either by evaporating the infusions of the dried plant in water, or in alcohol, or the expressed juice of the fresh plant; and this evaporation may be effected by a naked fire, a sand bath, an air bath, a steam heat, or a liquid balneum of any nature, all of which may be carried on either in the open air, or in vacuo. Of late years, since the vacuum-pan has been so successfully employed in concentrating syrups in sugar-house3, the same system has been adopted for making pharmaceutical extracts. An elegant apparatus of this kind invented by Mr. Barry, of Plough Court, was made the subject of a patent about 85 years ago. The use of the air-pump for evaporating such chemical substances as are readily injured by heat, has been very common since Professor Leslie's discovery of the efficacy of the combined influence of rarified air and an absorbing surface of sulphuric acid in evaporating water at low temperatures. It has been supposed that the virtues of narcotic plants in particular might be better obtained and preserved by evaporation in vacuo than otherwise, as the decomposing agency of heat and atmospheric oxygen would be thereby excluded. There is no doubt that extracts thus made from the expressed juices of fresh vegetables possess, for some time at least, the green aspect and odor of the plants in far greater perfection than those usually made in'the air, with the aid of artificial heat. Dr. Meurer, in the Archiv. der Pharmacie for April, 1843, has endeavored to show that the color and odor are of no use in determining the value of extracts of narcotics, that the albumen left unchanged in the extracts made in vacuo tends to cause their spontaneous decomposition, and that the extracts made with the aid of alcohol, as is the practice in Germany, are more efficacious at first, and much less apt to be injured by keeping. M. Baldenius has, in the same number of the Archiv., detailed experiments to prove that the juices of recent plants mixed with alcohol, in the homceopathic fashion, are very liable to spontaneous decomposition. To the above expressed juice, the Germans add the alcoholic tincture of the residuary vegetable matter, and evaporating both together, with filtration, prepare very powerful extracts. F. FAHLERZ. Gray copper-ore, called also Panabase, from the many oxides it cENtains. FAINTS is the name of the impure spirit which comes over first and last in the 668 FAIRBAIRN'S TUBULAR BRIDGES. distillation of whiskey; the former being called the strong, and the latter, which is mucl more abundant, the weak faints. This crude spirit is much impregnated with foetid essential oil, is therefore very unwholesome, and must be purified by rectifications. FAIRBAIRN'S TUBULAR BRIDGES. Of the tubular bridge system, the Conway and Menai are the first, and will probably for ever remain the most remarkable specimens, to attest the scientific genius of Mr. W. Fairbairn, their inventor and constructor. His claims, indeed, are exclusive and palpable. Mr. Robert Stephenson, however, has fortunately for himself, claimed the entire merit of having not only first conceived the idea of constructing a tubular bridge of such huge dimensions as to allow the passage of locomotive engines and railway trains through the interior of it, and of such length as to span distances of from 400 to 600 feet, but of having assured himself by laborious investigation and calculation of "the perfect feasibility of the work," without consulting any one else on the subject; and he has assigned to Mr. Fairbairn, in a very slighting fashion the place of a mere after adviser, of one who, in common with two other gentlemen (Mr. Eaton Hodgkinson and Mr. Edwin Clarke), but not more than either of them, assisted him in working out the construction which he "first broached." Mr. Fairbairn maintains, on the contrary, that the idea of a tubular bridge, though it unquestionably originated with Mr. Stephenson, was in his hands nothing more than a crude conception, very hesitatingly entertained, until he (Mr. Fairbairn) was called in to work it out, and that it has been wholly owing to his determined perseverance in the execution of the task confided to him, and to his numerous and elaborate experiments, that " the true principle on which tubular bridges should be constructed has been established, and thereby Mr. Stephenson's vague idea. successfully carried into execution." "At the period of the consultation in April, 1845, there were no drawings illustrative of the original idea of the bridge, nor had any calculations been made as to the strength, form, or proportions of the tube. I was asked whether such a design was practicable, and whether I could accomplish it: it was ultimately arranged that the subject should be investigated experimentally, to determine not only the value of Mr. Stephenson's original conception, but that of any other tubular form of bridge which might present itself in the prosecution of my researches. The matter was placed unreservedly in my hands; the entire conduct of the investigation was intrusted to me; and, as an experimenter, I was t) be left free to exercise my own discretion in the investigation of whatever forms or conditions of the structure might appear to me best calculated to secure a safe passage across the Straits." ( W Fairbairn's Correspondence.) In commenting on the treatise of Mr. Fairbairn "on the Construction of the Britannia and Conway Bridges," the editor of the Mechanics' Magazine says, "We have read it carefully, and not without strong prepossessions in favor of the inculpated party, but we feel honestly bound, however, to say, that the perusal has left us convinced, in spite of all leanings, that Mr. Fairbairn has not received at Mr. Stephenson's hands that justice to which he was entitled, but, on the contrary, ha3 been treated most ungenerously and ungratefully. We will not say, that but for Mr. Fairbairn the tubular bridge idea would never have been carried out into practice, for that would be to assume that he engrossed in his single person all the practical skill of the country; but, looking into the facts of the case as they stand, and as we see them established in the volume before us beyond all possibility of dispute, we hesitate not to affirm, that it is more owing to Mr. Fairbairn, than to any one other individual whatever, not excepting Mr. Stephenson himself, that it is now the triumphant reality which it is. Another might possibly have done the part which fell to the lot of Mr. Fairbairn as well, but none could possibly have done it better. He conceived and directed all the preliminary experiments,-all at least with an exception or two, which were of any practical value, exhibiting therein a combination of philosophical painstaking with mechanical skill and ingenuity, such as is not often witnessed; he finally settled the form which it was best to give to the tube, and arranged the whole of the executive details; he personally superintended the construction of the Conway Bridge, which our readers are aware is but the Menai or Britannia Bridge on a smaller scale; and he only retired from further co-operation with Mr. Stephenson in the affair when nothing new was left to be discovered or achieved. The motives for his retirement are thus very fairly and temperately stated:"'I have now brought down this correspondence to the period when my official con nection with the Chester and Holyhead Railway Company as engineer, for the construction of the tubular bridges, may be said to have virtually ceased, and I should willingly have passed over in silence the remainder of the events which transpired, were it not that the completeness of the narrative, as well as the justification of my conduct, demanded some explanation, independently of the regret which I experienced in withdrawing from an undertaking to which I had devoted so much time and thought,-an FAIRBAIRN'S TUBULAR BRIDGES. 669 undertaking fraught with the greatest interest, and which had, as it were, grown up in all its magnificent proportions under my own directions. I can truly say that the dis. agreement which took place with Mr. Stephenson is on my part much deplored. But I trust that the reader of the foregoing pages will at least have arrived at the conclusion, that I had taken the most important part in developing, and giving a practical form to Mr. Stephenson's idea, and also in the superintending the construction and erection of the first Conway tube. The fact is, I labored almost incessantly in devising plans, or in watching over the practical details of the work, from the day in which Mr. Stephenson's suggestion was communicated to me until the close of my engagement; and I can sincerely say that I was always actuated by the principle of leaving nothing undone which could in any way contribute to the successful accomplishment of the undertaking. Regardless of the prognostications of failure with which the scheme was assailed, and in despite of the opposition of those whose assistance I had solicited, I uniformly advocated the peculiar principle on which the Conway Bridge has been constructed. "'Such being my position, and viewing the extent of services I had rendered, it will, I think, be generally allowed that it was very natural that I should desire to have my name publicly associated with Mr. Stephenson's as joint engineer for these bridges. Indeed, it may very fairly be said that I might have ventured to claim this distinction, since it had been conferred upon me by the Board of Directors on Mr. Stephenson's own recommendation. If, instead of success having crowned our efforts, failure had unfortunately ensued, would not my reputation have suffered as well as Mr. Stephenson's? The working plans having gone forth with my name alone attached to them, and from my being recognised as the acting engineer, might not the whole blame have been conveniently thrown on me in case of failure v "'It was not, however, on any of these grounds that I was induced to resign my appointment, for there had not then occurred any opportunity where I conceived it necessary to have my position publicly recognised; and I had always believed that, when the proper time came, Mr. Stephenson would be the first to establish that position, and acknowledge the services I had rendered. The recognition was, however, very shortly afterwards denied me. The first Conway tube having been completed, and the success of the principle established, I conceived that the construction of the remaining tubes simply required a close attention to the system of construction already adopted, and therefore might safely be entrusted to those gentlemen whose constant presence during the building of the first tube had rendered them thoroughly acquainted with the whole details of the work. By such an arrangement, moreover, the Company would save the amount which had hitherto been paid for my services, and I should be enabled to devote my time to other pursuits which I had neglected for this work, and which now urgently demanded my attention. This was one reason for my retirement; but what chiefly led me to this decision, was the position assumed by Mr. Stephenson, his public misrepresentation of the position I held under the Company, and his endeavor to recognise my services as the labors of an assistant under his control, and acting entirely under his direction. Had Mr. Stephenson in his public address done me the justice to state my independent claim to some of the most important principles observed in the construction of the tubes, I might, perhaps, have continued my services until the final completion of the whole undertaking; and, most assuredly, tfis work would never have come before the public. I now appeal to the preceding pages of this narrative, whether Mr. Stephenson's assertions are borne out by the simple statement of facts I have overstated nothing, concealed nothing; and the reader is left to draw his own conclusions from these facts, after having become acquainted with the course pursued by Mr. Stephenson, which I will in conclusion concisely relate.' (p. 171.) " Mr. Fairbairn proceeds then to give an account of a public dinner to celebrate the completion of the Conway Bridge, which took place on the 17th of May, 1848; on which occasion it was, Mr. Stephenson first openly assumed that position in regard to Mr. Fairbairn and the undertaking, which has made the present appeal to public justice necessary. Mr. Stephenson's speech was confessedly a studied affair-he had announced beforehand that he would avail himself of the opportunity of'setting the question at rest;' but for all that it does not take Mr. Fairbairn many words to demolish it utterly.'The inaccuracies, both as to facts and dates, in the statements of Mr. Stephenson, are very numerous. It simply requires a reference to the short description of the Ware Bridge, and to the drawings, to disprove the assertion, that it is a thin tubular bridge, although not precisely the same as the present, yet in principle precisely the same; and it can easily be shown too, that considering the Ware Bridge as a simple girder bridge, it is exceedingly defective in design. Is there anything new in this application of wrought-iron plate girders? As well might it be said that the comlination 670 FAIRBAIRN'S TUBULAR BRIDGES. of wrought-iron deck beams, so many years applied in iron ships for the support of the decks, is a " counterpart of the proposed cellular top for the Britannia tubes." I really cannot but regret that Mr. Stephenson, whose name will be always associated with the grandest bridge that has ever been constructed, should have committed himself in making such an erroneous assertion as that it was by reviving and extending his original conception of this imperfect structure at Ware, that he was led to originate the bridges creasing the Conway and Menai Straits. "'Mr. Stephenson's remarks further admit of the disingenuous construction that his scheme was matured before the Bill for the Chester and Holyhead Railway was passed by Parliament, and before I was consulted, and that he was at that early period acquainted with the present design of the bridge. He refers to the incredulous glances which were directed towards him when the description of the bridge was explained to the Committee; and intimates, " that it was not until the Bill had been obtained, and it became necessary to commence, that he requested my assistance." Now, my advice was asked by Mr. Stephenson before his evidence to the Parliamentary Committee was given, and he announced his idea to that Committee streL gthened by more than one opinion of its feasibility. Let the reader turn again to the earlier letters of the correspondence, and he will find of what a crude and dangerous scheme that idea consisted; how totally dissimilar in form and principle it was to the present tubular structures, and how slowly Mr. Stephenson was persuaded to give up his earliest conceptions. Again; Mr. Stephenson states that he called in the aid of Mr. Hodgkinson and myself at the same time; now it is essential to the proof of my claims that this assertion should be explicitly contradicted. It was I, and not Mr. Stephenson, who solicited Mr. Hodgkinson's co-operation, and this was not done until I had been actively engaged for several months in my experimental researches, and after I had discovered the principle of strength which was offered in the cellular top, and not only proved the impracticability of Mr. Stephenson's original conception, but had given the outline of that form of tube which was ultimately carried into execution. "'When Mr. Stephenson had made up his mind to claim in the manner he did the whole merit of the undertaking, it is not difficult to understand his reason for giving Mr. Clarke, his own assistant, so prominent a position. I willingly bear my testimony to the great value of the services rendered by Mr. Clarke, to his talents, and to the great energy which he displayed in working out his several duties, but these had no reference whatever to the designing of the structures.' (p. 178.) " There is one part of the case on which we think Mr. Fairbairn does not insist enough, though, in our judgment, it is of itself decisive of the inordinateness of Mr. Stephenson's pretensions. Mr. Stephenson and his friends, for obvious reasons, slur it over altogetler. We refer to Mr. Fairbairn's appointment to be joint engineer along with Mr. Stephenson to the Conway and Britannia Bridges. The evidence of this is a Minute of the Board of Directors of the Chester and Holyhead Railway, dated 13th May, 1846, which we here quote at length from the work before us. "'Resolved-lst. That Mr. Fairbairn be appointed to superintend the construction and erection of the Conway and Britannia Bridges, in conjunction with Mr. Stephenson. "'2d. That Mr. Fairbairn have, with Mr. Stephenson, the appointment of such persons as are necessary, subject to the powers of their dismissal by the Directors. "' 3d. That Mr. Fairbairn furnish a list of the persons he requires, with the salaries lie proposes for all foremen or others above the class of workmen. "'4th. That advances of money be made on Mr. Fairbairn's requisition and certificates, which, with the accounts, or vouchers, are to be furnished monthly. "'5th. That the Directors appoint a bookkeeper at each spot, the Conway and the Menai.' "To talk, after this, of Mr. Fairbairn's being only entitled to a secondary and subordinate place in the affair, is to outrage all truth and propriety. " We can but regard with profound pity the hallucination which has betrayed a man of Mr. Stephenson's genius and worth (this unfortunate episode notwithstanding) into so false a position. " We do not overlook that we have as yet Mr. Fairbairn's statement of the case only, and that we may expect to see, ere long, something of a very opposite complexion from Mr. Stephenson or some of his friends. We shall give all due consideration to any such counter-statement when it comes before us; but so well is all Mr. Fairbairn says borne out by written, and therefore unalterable proofs, that we do not, in the meanwhile, hesitate to avow our firm belief that nothing which can possibly be adduced in the way of either evidence or argument, can ever alter materially the conclusion at which we have already arrived."-Mechanic's Magazine.) FAIIRBAIRN'S TUBULAR GIRDER BRIDGES.-William Fairbairn, Esq., of Manchester F. R. S., and Member of the Institute of France, has been long recognised as the most accomplishel of our factory engineers and the most skilful of our millwrights, by his FAIRBAIRN'S TUBULAR BRIDGES. 671 admirable fire-proof buildings and his magnificent hydraulic machines. Having a few ears ago directed his constructive genius to the building of iron steam-ships, he became thereby well acquainted with the prodigious stiffness and strength of which hollow girders of thin sheet iron were susceptible. He was naturally pitched upon by Mr. Stephenson, the engineer of the Chester and Holyhead Railway, as the fittest person to execute the tubular bridge which was regarded by him as the only means of carrying ponderous railway trains over the tremendous sea-gulf of Menai's Straits or Conway's roaring flood. The tidal torrents of these two places being deep and rapid, required to be crossed by bridges of extraordinary span and strength. No centrings or other substructures usually resorted to for mounting such huge pontitectures could be erected. In such a dilemma, the most obvious resource of the engineer was a suspension bridge; but the failure of more than one attempt of that kind had proved the impossibility of running railway trains over such bridges with safety. Under Mr. Stephenson's direction, numerous other schemes had been devised. Both timber and cast-iron arches had been thought of; and a model of a very handsome bridge for crossing the Menai Straits on the latter principle had been constructed, and submitted to the consideration of a parliamentary committee. The possibility of throwing cast-iron arches over so great a span as 450 ft. was however questionable; and the security of such a bridge must have been endangered by the great changes which the material would have been subjected to from atmospheric influences, and from vibrations produced by the passage of heavy trains. But a more important objection even than these caused the withdrawal of this design. The Lords Commissioners of the Admiralty, as conservators of the navigation, opposed the erection of any structure which should offer a hindrance to the free passage of vessels under it, and insisted on a clear headway of 105 ft. from the level of high water. Mr. Stephenson then conceived the original idea of a huge tubular bridge, to be constructed of riveted plates, and supported by chains,* and of such dimensions as to allow of the passage of locomotive engines and railway trains through the interior of it. The illustrious Galileo, in demonstrating the strength of tubular structures, adverted to the quills of birds and the stalks of corn; but in our days we see that idea amplified into colossal dimensions. It was with reference to this expedient, after all others had been found inapplicable, that Mr. Fairbairn was consulted by him, and requested to give his opinion-first, as to the practicability of the scheme; and secondly, as to the means necessary for carrying it out. The consultation took place early in April, 1845. Mr. Stephenson conceived that the tube should be either of a circular or egg-shaped sectional form; and he was strongly impressed with the primary importance of the use of chains, placing his reliance in them as the principal support of the bridge. He never for a moment entertained the idea of making the tube self-supporting. The wrought-iron tube, according to his idea, was indeed entirely subservient to the chains, and intended to operate from its rigidity and weight as a stiffener, and to prevent, or at least to some extent counteract, the catenary principle of construction. "February 23d, 1846. "My dear Sir, "I have been considering the principle on which you purpose attaching the chain for the support of the tube; and with every deference to your judgment, I am almost inclined to differ with you upon that point. "It appears to me that the great and important consideration is to relieve the strain upon the tube. It is quite clear that a series of chains on each side of the plates, well fitted and tightly screwed up, would tend to stiffen the sides, and give greater rigidity to these parts. This is, however, not what is wanted. The rigidity is required on the top side; as in all the experiments the sides seldom get out of form unless distorted by the crushing of the top side. Under these circumstances the stiffening should in mny opinion be on the top platform of the tube."- William Fairbairn to Mir. Robert Stephenson.For many months afterwards, and even up to the time of the experiments on the model tube in December 1846, Mr. Stephenson insisted on the application of such chains. "I always felt," says Mr. Fairbairn, "that in a combination of two bodies, the one of a perfectly rigid, and the other of a flexible nature, there was a principle of weakness; for the vibrations to which the one would be subjected, would call into operation forces whose constant action upon the rivets and fastenings of the other could not but tend to loosen them, and thus, by a slow but sure agency, to break up the bridge." In consequence of the favorable opinion entertained by Mr. Stephenson on the cylin. * These chains, not only superfluous but dnngerous, would have cast 150,0001. t Conway and Menai Bridges, by W. Fairbairn, C. E., p. 48. 672 FAIRBAIRN'S TUBULAR BRIDGES. drical tubes, it was deemed expedient to commence experiments upon models of that kind, and to extend them subsequently to elliptical tubes. Experiments carefully made, demonstrated the weakness of these two forms, and the vastly greater strength of the rectangular tubes, which were accordingly adopted with cellular top and bottom. In Mr. Stephenson's examination before the Select Committee of Railways of the House of Commons, 5th and 6th of May, 1845, he says: "I am instituting a series of experiments in conjunction with Mr. Fairbairn of Manchester, who is already in possession of experiments on iron ships, which place the thing beyond all doubt. He has ascertained that a vessel of 250 ft. in length supported at the ends will not yield with all the machinery in the middle. "Have your calculations been submitted to any other engineers "I have made them, in conjunction with Mr. Fairbairn of Manchester, whose experience is greater than any other man's in England. There is an iron vessel now building by Mr. Fairbairn 220 ft. in length; and he says that he will engage, that, when it is finished, it shall be put down on the stocks at each end, and shall have 1000 tons of machinery in the middle of it, and it will not affect it. But that is not so strong as a tube, and therefore, any experiment that this would carry out, the tube would fully bear." Thefloating of thefirst Conway tube —" The transport of a huge mass of iron 412 ft. long, 25 ft. 6 in. high, 15 ft. wide, and weighing not less than 1300 tons, was a task of no ordinary difficulty. No former effort with which we are acquainted can, I think, be said to have equalled it, when the unwieldiness of its form, and the extraordinary natural difficulties to be encountered, are taket into consideration. Many of the works of the ancients are stupendous in conception and colossal in dimensions; and it has been a constant matter of inquiry, in what manner a people, ignorant of the mechanical appliances which we possess, could raise structures which have resisted all the inroads of time, and which are to the present generation objects of awe and admiration. In more recent times, the transport of the immense granite block which forms the base of the statue of Peter the Great at St. Petersburg, was looked upon as a most extraordinary achievement; but it cannot he said to have been so formidable an undertaking as the moving of the Conway tube. The granite block was a compact mass, being 42 ft. at the base, 21 ft. thick, and 17 ft. high, and capable of being moved on rollers, &c., to the raft which carried it down the Neva to the site of the city; but in the case of the Conway tube, after the most anxious consideration, and when numerous schemes and proposals had been weighed, examined, and rejected, that of floating the mass on pontoons or barges was decided upon as the most feasible and most secure, the centre of gravity being in this case, necessarily raised several feet. In addition to this disadvantage, the whole had to be handled and manceuvred in probably the most difficult tideway in Europe, where the current rushes through a narrow gorge of great depth to fill the broad expanse of the inland bay, at a rate of 6 or 7 miles an hour; and the utmost nicety had moreover to be observed in bringing the tube to its place, as there was only a clearance of 12 inches; that is, the distance between the opposite masses of masonry was only 12 inches greater than the length of the tube. All these obstacles may well be termed formidable; and I therefore conceive that the utmost praise is due to Mr. Stephenson for the admirable arrangements and contrivances which rendered the first attempt at so gigantic an operation perfectly successful." I have quoted these liberal remarks of Mr. Fairbairn in proof of his good feeling towards the engineer associated with him conformably to the Minute of the directors of the Chester and Holyhead Railway, of date May 13, 1846, already quoted. How defective, and even erroneous, Mr. Stephenson's conceptions were of the tubular girder construction so late as the 26th October, 1846, appears, from his stating in a letter of that date addressed to Mr. Fairbairn, "that this was not the first time he had the idea of employing wrought-iron tubular bridges; for three years ago, or thereabouts, I had erected at Ware, on the Northern and Eastern Railway, a cellular platform of wrought-iron. It was, in fact, I believe, a counterpart of the proposed top of the Britannia bridge." "As this statement," says Mr. Fairbairn, "has been frequently repeated since the letter was written, I feel myself called upon to show that Mr. Stephenson has no claim to originality in this bridge, and that it has no resemblance whatever, either in principle or construction, to the Conway or Britannia tubes. On the contrary, the bridge in question is constructed upon the principle of the common cast-iron girder bridge, each separate beam being formed of wrought-iron plates connected together by angle irons. This form of wrought-iron girder had been long in use before the erection of the Ware Bridge; and it is defective as well in principle as in construction; the great body of the material is not in the top flanches, as it ought to be, in order to attain the section of greatest strength. In Experiments 14, 15, and 16 (see Appendix and p. 10 in the Report), it is clearly shown that the top flanche of a wrought-iron girder, if made solid, FAIRBAIRN'S TUBULAR BRIDGES. 673 should be more than twice the area of the bottom flanche. Now it appears that the top flanche in the said bridge at Ware is to the bottom flanche as 4 to 15 nearly; an exceedingly defective structure. If this beam were turned upside down it would carry inore than double the weight. From the defective principle upon which the bridge is constructed, it is evident that Mr. Stephenson was not then acquainted with the proper form of wrought-iron girder bridges. Nor is this surprising, as no experimental facts were at that time in existence to show the difference between the two resisting forces of compression and extension of wrought-iron beams."-Conway and Britannia Bridges, by Mr. Fairbairn, pp. 113, 114. "It is impossible to trace any analogy between a combination of this form of beam and a tubular girder with a cellular top. The beams in the Ware Bridge do not offer a nnited resistance to strain in the manner which beams with a cellular structure do; on the contrary, each beam has its distinct part of the load to carry, and that imperfectly, for want of a due proportion in the top and bottom flanches." —Ibidem. A striking proof of the accuracy of Mr. Fairbairn is afforded by the fact, that it was not till the latter part of 1846, that Mr. Stephenson finally made up his mind to abandon the use of the chains, for in the engravings of both the Conway and Britannia Bridges, which were published in that year, there is attached to them the name of Robert Stephenson, Esq., engineer. These drawings represent, with tolerable accuracy, tlie proportions and forms of the tubes of blth bridges as they now exist,-viz., the long, low, rectangular galleries, which Mr. Fairbairl's experiments had shown to be much better adapted to the purpose than the elliptical tubes proposed by Mr. Stephenson. But mark, in both cases the chains are absolutely shown attached to the tubes. They are a prominent feature in the drawing, and therefore conclusive evidence that up to that time at least, and notwithstanding the discovery of the increased strength and security to be derived from the adoption of the tube with a rectangular section and the distribution of the material on the top side in the form of cells, Mr. Stephen son still thought the auxiliary support indispensable. From the moment that Mr. Fairbairn commenced this experimental investigation, the whole matter, as regarded the development of the best form of the tubes, was unreservedly in his own hands. iMr. Stephenson was not present at the experiments, he neither superintended nor directed them, but was simply made acquainted with results, and approved, when completed, what Mr. Fairbairn did. And now what did Mr. Fairbairn's experiments show? They first of all confirmed his own early opinion, that the security of the bridge, if built at all, must depend solely upon the self-contained strength of the tube, and that the application of any form of catenary would introduce into the structure an agency of a destructive tendency. They proved the weakness and total inadequacy of either of the sectional forms of tubes (cylindrical or elliptical), thought of by 1Mr. Stephenson. They led Mr. Fairbairn, after carefully observing all the signs and symptoms of weakness shown by the models when under strain, to recommend, as a stronger form of tube one having a rectangular section. They brought to light some curious and anomalous appearances exhibited by wrought-iron when subjected to a crushing force. They showed that tubes of a uniform distribution of material, when loaded with an increasing weight, first yielded on the upper side; and this fact, therefore, induced Mr. Fairbairn, first, to thicken the material in that part, and, subsequently, led him to suggest that distribution of the material in the form of hollow cells or tubes, wherein lies the secret of the strength of this system of tubular construction. Mr. Fairbairn therefore, reasoning fiom his experiments,-Ist, suggested the rectangular sections for the tubes; 2d, d'scovered that important and beautiful element of strength and lightness, the cellular ar sngement of the top; and 3d, was mainly instrumental in causing thie final abandonment of chains. Beyond this, after lie was appointed engineer with Mr. Stephenson for the structure, he worked out the detail of the tubes, had the whole of the working drawings for the tubes of both bridges made at his own office, and under his constant supervision, proportioned the different parts; and (again the result of reasoning from experiment) suggested that admirable system of chain riveting which is adopted in those parts of thle tubes liable to a tensile strain, and which adds in a material degree to the strength of the structure. A bridge with several spans of nearly 500 feet each was wanted, which should not only be unyielding with its own necessarily enormous weight, but which should possess within itself such an excess of strength as would satisfy an incredulous public that it would be abundantly safe when subjected to tile shocks and vibrations of a heavy locomotive engine with its accompanying train passing across it at a speed of forty miles an hour. The situations both at Conway and the Straits afford obstacles of extraordinary magnitude: at both places the estuaries were of great depth, defying the use of scaffold 44 L.z 674 FAIRBAIRN'S TUBULAR BRIDGES. ing to assist in the erection of the bridges, and the tides washed through with appalllng imrletuosity. Tile Menai or Britannlia Bridge was moreover to stretch from slhore ti shore at a giddy height of nmore tlan 100 feet from the level of high water, and, as if to render insuperable tile olstacles which Nature had raised to the progress of the engineer s work, an arbitrary but absolute order was issue(l from the controllers of the naviration that the whlole was to be accomplished without hindrance or obstruction to tile rights whicl they guarded. Thle manner in which all these necessities were complied with is well known. The Britannia and Conway Bridges exist, the pride of the country which possesses them, triumphs of the constructive arts, and immortal monuments to the men who were.associated in tleir contrivance and execution. It is to be deplored in every respect that jealousies and rivalries should have arisen under circumstances where so much renown and merit was to be divided. The grandeur and boldness of the conception was Robert Stephenson's, but the merits of tlhe existing structure, the ingenuity of the arrangement, alid proportions of tlle raterial,-the discovery, in fact, of 1lie tubular principles 4f construction,-are Williaml Fairbairn's. As an outgrowth of tile remarkable introductory experiments made in ccnnection with these wonders of Northl Wales, we must regard tile equally important, though less ilmposing tubular girder syster; the new and scientific discovery of great advantages to le derived from a peculiar combination of material, applied to the simple and generally used beamn or girder. A tubular girder, as tile namle implies, is a hollow beamn constructed of metal plates firmly riveted or fastened together. When subjected to a transverse strain or load tending to break it, the law, which is applicable to every body, be it solid or hollow, is observablle. The parts of tlhe girder above tlhe neutral axis have to arrange tlhemselves to a resistance of a coimpressive strain, wlile tlose below that line are violently subljected to a force tending to draw them asunder. Tile extreme difficulty of wiroughlrt-ironl and its greiat power to resist tension, were well known, and in the earlier stages of tlhe inquiry it was considered feasible, and frequenit eforts were made to arrange tire i)arts in such manner that these known properties,igllt be takern advantalge of in both tile upper and lower sides of tlhe girder, but every experilment )baffled tile ingenuity of tlhe contrivance, rand nature soon taught the construlctor that her unerri il laws were not to be disregarded. This point being established, viz., tlhat no distril)ltion of tile metal in a tullarllrr girder could change the charlacter of tle forces wliich would act upon it, MAr. Fairlairn's great merit lies in tlie ingenuity with which lie adapltedl iis new material to those strains. In the top or upper side of tire girder lie distri,buted it, in tlhat beautiful cellular form which illnmrts tlie real strength and security to tile structure, and in tile ibottor lie connected the parts Iy an ingenious system of fastening which assimilated tile strength of the joints wit hl that of tile solid plate. The description of one of tlhe best constructed tubular girders will give the most correct idea of their power and peculiarity. We select for illustration the beautiful 503 >_ ___ _ _ bridge erected across thle Trent at Gailnsoroullh. Fig. 503 represents a general eleva tion of the blrilde which clarries tlhe Lincolnshire railway across tile Trent. Its total lengtll is 332 feet, tile two inainl s)pia, s being 154 feet eachl. Tie width of roadway between the two main rgirders is 26 feet, griviln ample roomn for a double line of railway.. The width of the centre pier is 12 feet, and the tubularl girders have a bearing on each land abutlenlet of 6 feet. Fig 504 represents a cross section formi of the iaini girders, and to tlis we must dlirect especiarl attention in order to make tile peeuliarities of the system well understood. Tlhe height of each girlder fromn end to end is 12 feet; tlis parallelism is not the lbest form to give a maiximumrn resistance with a minimum almoutnt of matelrial; but frolr tlhe greater facilities of construetion is prefernlle to tihe paraibolic form, arnd practically tile prolortions of tie sterergth may be adjusted by varying thie thicknesses, inlsterd of the linear dimensions of tile parts.'The Bottom of the Girder.-Tlle bottonm is firllamle of doulnle thicknlesses of long rolled plates, connected together in tlre manner hereafter describted. Being subjected solely to a tensile strain, tile rmaterial is condense(d as muclh as possitle, so as to assimilate thatt part of tile structure to one unll)roken solid sheet, which, if practicable, would be the tbest distribuition of form. Each plate is 12 feet lonr Iby 18 inches wide, varying hi ticikniess according to its position from the centre line of each span, where the greatest _____ FAIRBAIRN'S TUBULAR BRIDGES. 67a, 1. t 1, 1 Ip I 1 t,504 i I'7"~~~~~~~', l | * e 8 I ~ 17.7 - I i._ I I f: _ _ 1 i )I I I II l[ i s,___ 67G FAIRBAIRN'S TUBULAR BRIDGES. The Sides of the Girder.-The side plates are 2 feet wide throughont,, and of unifotm thickness, exceptinig inl the immediate neiighborlhood of tile piers ard abutments, where they are strengtenlled and stiffened by pillars of strong T iroin, to offer a due resistance to the dead weilght of the girder itself. Tlhe joints tire madle with external covering plates 4} inches wide, and internal ribs of T iron, whicl suffice to keep tile side plate4 rigid, and enable them to accomplish their duty of separating tile top and bottom of the girder.'hie Top of the Girder.-In tllis part the principal novelty and ingenuity are observable. A single sheet of iron, like a slheet of paper is easily put out of shape by a compressive strain. It crumples up, and at once loses all power of resistance. A sheet of common writing paper, which when placed on edge will nearlly support itself, when rolled into a cylirder, say of 1 incl diameter, will carry a cornsiderable weight. In the same manner a given sectional area of plate, if placed irn that simple form in the top of the Trent girder, would crumple up with a comparatively small weight, but when distributed according to Mr. Fairbairn's tubular arranenellt it offers extraordi nary resistance to compression. 505,I 3.-... — 2.6.. —........................ —-------- The value of this arrangement will be understood when it is stated that notwithstanding the superior tenacity of wrought-iron, a well constructed tubular girder only requires an excess of sectional area in the top over the bottom of 12 In tihe Trent girder (see fig. 504), thle top compartment is 3 feet A inch wide, and 15 inches deep, divided by a vertical plate into two rectangular cells, and all firmly connected by rivets, and L iron. Those angle irons constitute important elements in its strlength. Since the construction of the Trent bridge, the cost of construction of tubular girders hIas been much diminished by a. different arrangemlent of the parts of the top compartment, as shown in the following, fig. 506. This form is equally powerful in its resistance. When the span of the bridge c.......... ---.-. -- —... i " —- i —-... ---— li- * /* —- *......... V renches 180 or 200 feet, the top compartment is arranged as shown in fig. 507, and wtnen it is under 60 feet as shown in fig. 508. It will be noticed that in every case the I1 FAIRBAIRN'S TUBULAR BRIDGE&l. 677 cells are proportioned, so as to admit of the entrance of a man for the plrposes of painting or repairs. 507 jj 1 --— 3 —----— 14" —*'"-^-1 ------ -l -------.......- 1_- I rI ^|i'"' r".', 5o9...508..< —-,4 —------ l 509 i * i ~~. v!ffi; 1 "I, ^ ___ _ ^ /. ^ ^ I il lll III! The Cross Beams or Supports of the Road?,ay.-Tlhese are generally, and ought to be universally, made of iron. In the Trent brihlre they are made hollow or box beams, as shown in the annexed figure, fig. 509. Tieir construction is now much simpler and equally good, thusfig. 510. 510 TThe Riveting. —Upon the judicious fas-. L _. _. /_ ~,,. tenings of the plates togetlier depends in a great measure the safety of a tubular,i;,i girder bri(ge. The system of riveting K, l ilffi0i ^! r followed in the several parts should have litt il ^ referenlce to t.le strains which occur in thlose parts. What are technically called 1"lap joints," where the ends of the plate glllll~ll illli 1overlap each other, andl are connected by a single row of rivets, (vide fig. 511,) r l 4 a sioulld be avoided in every part of the llillll lillllll structure, as they have been proved to! lijlll[lllll/l.j~ ai';li! i;^! E be we.ak and insufficient. Mr. Fairbairn W^ ^^^ iliiili (Phil. Trans. part ii. 1852) gives the value |_ "l|t/, of single and double riveted joints, as'70 i|i|t ^*ES^S and 56 respectively, the solid plate being assumed to be 100. "Butt joints" and covering plates are used throughout the girder, the lernth and substance of these covering plates and the number of rivets varying according to situation. In the top compartment the ends of the plates having been carefully fitted to each other, so as to take their portion of the strain the morlent tle load is applied, are covered by strips of sufficient width to receive a double row of rivets, one on each side of the joint, thus, as shown in fig. 512. This arrangement effectually prevents some such effect as indicated in fig. 513, which would occur were tlw lap joint used, and the load very great. In the tops the rivets are generally spaced 3 inches apart from centre to centre. 678 FAIRBAIRN'S TUBULAR BRIDGES. As before mentioned, instead of simple strips covering the vertical joints of the sidt plates, inside T iron bars are used to afford stiffness, and prevent the approach of the M7 top and bottom (vide fig. 514.) Thus, the rivets N.,~... ~~.being spaced 3 inclhes, the strips give to the ex-- --- - ^..ternal elevation of the girder the appearance of a series of panels. ^g 1__ 513 In the bottom an exceedingly ingenious and.....-...'...... ~ beautiful arrangement of riveting has been introduced by Mr. Fairbairn. It is evident that to join two plates together (these two plates.51^2^\ having to resist a force tending constantly to il*- ".........separate them) a certain number of rivets or pins _514 p, are require(], and according to the old system of W:777 _.%)~.~y7,,.7. ~ 5 jointing, these rivtts were placed in single rows T 5: \ ~z~ alolg the edge of the plates, being in fact either single lap joints, or silngle butt joints. Suppose thle plates in fig. 515 to be each 2 feet wide, and - incli thick, and that to connect them there were wanted 16 rivets, each 1 inch diameter. It is evident the resisting powers of the plates are weakened exactly by the amount of material punched out, in this case one-third, the section of resistance being through the line a b, and not through the line c d. But if these 16 rivets, instead of being placed all parallel with the joint, are arranged as shown id fig. 516 and covered with long "covering plates"'nstead 515 @1 516 IT, I of "strips," it is equally evident that they are in this position equally fitted to their duty of joining the 1lates, and that tIhe punching has weakened the resting powers of the plates only 1- instead of'. These proportions will readily.explain the saving in material and weight which Mr. Fairbairn's "chain riveting" has effected, and the following figure of the "bottom" of the Trent bridge will shlow how it is practically applied (fig. 517.) The joints of the angle irons in the bottom are also jointed by,t':;517, _' *,,, iooooo oooo ) 000C 00o 00oo o 0ooo 00000 <~ —-.0- 0..0. 0 000 O 0 0 0 0 000 < _ —- --- - 5 6- -- -— 2.. -—.- -> - o,; co o o. C Cool 1oo o o o o oo 0 0 o o o o O O o o o,' > o o b oo o ooQ,.L2o2 -------- O C/ C10 O0o C 0 o O o ~.. —-- -.. —..;, long corner pieces, as may be noticed at a, in fig. 518, which is a view of a short length of the bottom of the main Trent girder. Having thus described the tubular girder bridge in its best and most generally adopted form, a glance at the following figures (figs. 519, 520) will indicate modifications of the system which have gained favor in some quarters. FAIRBAIRN'S TUBULAR BRIDGES. 675 518 \ oO: O:C o0 0 o.. _, li o1o....t \. I -o -f o ooi o olo TI h Pr: ~~''0' 0 0 0t 10 Oi 0 0 1o Q00 oro 1n t1 l to ~ ~ one a lll ofQO; \, o o o t o j 01~ i oip o l I to fi.oh rl-tiv sooH __ o o jofteol a______ 0o of llllIo f. —- 30. u t —O= —,.....,,, -0 0 519 520 The Proportions and Strength of Tubular Girders.-The limits of this article w 11 not admit of a lengthened exalmination of these interesting topics. A well proportioned beam or girder should have such a sectional distribution of its material, that when subjected to a transverse strain, the top should yield to compression and the bottom to extension at one and the same time; and as nearly all materials offer unequal resistances to the two forces, direct experiment can alone determine the exact relative proportions of the two parts. Thus, the resisting power of cast-iron to compression is nearly six times greater tlian that which it offers to extension; but Mr. Fairbaim n's ingenious distribution of the wrought-iron plates in the "cellular top" has enalled him to fix the relative sectional areas of the tops and bottoms of tubular beanm in the ratio of 12 to 11. The tables of the following page show the proportions for tubular girder bridgea of spans from 30 up to 300 feet. Mr. Fairbairn's formula for calculating the strengthl of tubular girder bridges has been much disputed, but at tle sare time it has had many able defenders, and may be followed with perfect reliance and safety. If it errs, it errs on the right side-that of understating the real strength; it i3 adc where w=the centre brealdng weight in tons irrespective of the weight of the girder a - sectional area of bottom in inches d==depth of beam in inches c==.a constant derived from experiment for the particular form of girder, and ==length of girder between the supports in inches. The formula always assumes a well made and well proportioned girder, having the relative areas of 12 to 11 in the top and bottom and the chain riveting. The constant c for the tubular girders we have described was ascertained to be 80. Get us now find by this formula the strength of one of the spans of the Trent bridge 680 FAIRBAIRN'S TUBULAR BRIDGES. TABLE showing the Proportions of Tubular Girder Bridges, from 30 to 150 Feet Span. I Centre Breaking Sec. Area of Sec. Area of Depth at the Span Weight of Bottom of one Top of one Girder in the Bridge. Girder. Girder. Middle. Feet. In. Tons. Inches. Inches. Feet. In. 30 0 180 14-63 17-06 2 4 35 0 210 17-06 19-91 2 8 40 0 240 19-50 22-75 3 1 45 0 270 21'94 25-59 3 6 50 0 300 24-38 28-44 3 10 55 0 330 26-81 31-28 4 3 60 0 360 2uY25 34-13 4 7 65 0 390 31'69 36-97 5 0 70 0 42() 34-13 39-81 5 5 75 0 450 36-56 42-67 5 9 80 0 480 39(-00 45-50 6 2 85 0 510 41'44 48-34 6 7 90 0 540 43-88 51-19 6 11 95 0 570 46-31 54-03 7 4 100 0 600 48-75 56-88 7 8 110 0 660 53-63 62-56 8 6 120 0 720 58'50 68'25 9 3 130 0 780 63-38 73-:94 10 0 140 0 840 68-25 79-63 10 9 150 0 900 73-13 85-31 11 6 TABLE showing the Proportions of Tubular Girder Bridges, from 160 to 300 Feet Span. Centre Breaking Sec. Area of Sec. Area of Depth at the Span. Weight of Bottom of one Top of one Girder in the Bridge. Girder. Girder. Middle. Feet. In. Tons. Inches. Inches. Feet. In. 160 0 960 9'-(00 10o5)00 10 8 170 0 1020 95'63 111-56 11 4 180 0 1080 101'25 118-13 12 0 190 0 1140 1()688 124-69 12 8 200 0 1200 112'50 131-25 13 4 210 0 1260 118'13 137 81 14 0 220 0 1320 123-75 144-38 14 8 230 0 1380 129-38 150(94 15 4 240 0 1440 135 00 157'50 16 0 250 0 15)0 14(063 164'06 16 8 260 0 1560 146-25 170'63 17 4 270 0 1620 151-88 177'19 18 0 280 0 1680 157 50 183-75 18 8 290 0 1740 163-13 190'31 19 4 300 0 1800 168-75 196.88 20 0 which we have described. By reference to fig. 504, it will be observed that here a=58-5, d-144, and 1/1848. a dc 58 X144X80 w. —. 3==364-6 tons I 1848 as the weight which a tubular girder 154 feet between the supports will carry suspended from one point in the centre before fracture. Now the actual weight of this girder itself is under 70 tons, and it may safely be asserted that no other form of construction would give so favorable a result. The centre breaking weight of one girder bieing 364j tons, it would carry 729 tons equally distributed along its entire length, and there being two main girders to tlhe bridge, the ultimate strength of the structure is in round nulmbers, 1,500 tons. It would be possible, by both lines of railway being covered with FAIRBAIRN'S TUBULAR BRIDGES. 681 heavy goods train, to have a load on the bridge of about 250 tons at one and the same time, and we thus see there is a margin of strength of six times the greatest possible load. Engineers differ in opinion as to the excess of strength which it is desirable that railway structures should possess; some are satisfied with even as low an ultimate breaking strength as three times the load; but with a comparatively untried material, and one moreover liable to deterioration from atmospheric influences, the larger excess is the better. On the discovery of Mr. Fairbairn's cellular arrangement for the top compartment of the Conway and Britannia Bridges, several able mathematicians advocated the introduction of iron cylindrical instead of rectangular cells, as being a better distribution of the material to resist the compressive strain. Mr. Fairbairn's original views were in the same direction, but were abandoned on account of the complexity of construction and the difficulties of manufacture, and it is curios- to notice now that subsequent scientific investigations have confirmed the practical engineers views, and shown that the rectangular cells are superior in strength. M'. Tate especially thus ingeniously artues:-" The cells in a transverse strain undergo a different kind of strain to what they are subjected to in a simple crushing force equally distributed over the section of the tube. In this case all the parts of the section are equally compressed, and it is reasonable to conclude that the best form of cell will be that in which the material is equally distant fiom the axis of pressure; but the case of transverse strain is very different, the upper edge undergoes the greatest strain, and of the other parts that which is nearest the natural axis of the beam undergoes the least; in this case therefore the material in the square cells is symmetrically distributed with respect to the axis of pressure, the neutral axis of the beam." The Durability of Tubular Girders -On this head there is as yet but a very limited experience as a basis for positive assertion. There can be no doubt that if neglected the effects of oxidation upon the wrought-iron plates and rivets would speedily be productive of very disastrous results. On the other hand, there are many existing ex. aml>les of wrought-iron structures, such as iron ships and other vessels, suspension bridgles, &c., which with proper care and attention have withstood the wear and tear of constant exposure and use without any serious impairment of their powers of resistance, for periods of upward of thirty years. It will ble noticed too that tubular bridges have been designed with an especial view to the easiest access to every part for the purposes of painting and repairs, and it is not therefore improbable that with attention those structures will prove to be more' durable than either cast-iron, timber, or other structures similarly situated. Their Cost.-In estimating the cost of a tubular girder bridge, one of their most important recommendations must not be overlooked, viz., the saving which they afford in the construction of the masonry, abutments, and piers. For example, in the formation of a bridge of 150 feet span, if cast iron or stone be the material employed, vast sulms of money would have to be expended in the formation of ponderous and solid./lbutmnents to receive the thrust of the arch and its load, whereas with the girder bridge two simple well-constructed walls giving a bearing of five or six feet to the ends of the girders is all that is necessary, the girders themselves receiving and maintaining tile strain due to the load. The m.ere iron superstructure mray thus in some cases appear costly, but when the whole of the adjuncts of a bridge are taken into consideration there is perhaps no other form of pontitecture which can compete with the wroughtiron girder when the clear space exceeds 70 feet. In estimating the cost of the iron superstructure it may be assumed, when the value of manufactured iron is at an average rate, at 201. per ton weight fixed and erected. General Advantages.-The more prominent advantages of these ingenious structures, viz. lightness, strength, security, and economy, have been referred to in the foregoing remarks. In addition they are a ready resource to the engineer in localities where he is limited for space. Thus, in crossing at a low level a road, river, or canal, a height of 15 inches from the bottom of the tridge to the level of the roadway will suffice for a width of bridge which will admit of a double line of railway or ordinary turnpike road. Again, the structures are inexpensively fixed. The Trent girders, for example, were constructed on the railway embankment close to the west abutment of the bridge, and drawn across to their permanent places without the expense of scaffolding, &c. in the river. The main girders themselves, in addition to forming the main strength of the bridge, form parapets and protection to the traffic. In conclusion, it may be stated that, although devoid of the massive but imposing elegance of the stone arch or the fairy lightness of the suspension roadway, the beauty of a tubular girder bridge consists in its usefulness and its evident fitness for the work it has to perform. THE BIIDGE OVER TIE RIIINE BT COLOGNE.-" During tlle course of autumn, 1849, 682 FAIRBAIRN'S TUBULAR BRIDGES. Mr. Fairha;rn of Manchester, was induced by representations made to him through a high official functionary, to propose to the Prussian Government a plan for an!ron bridge across the Rhine at Cologne on the tubular prinecille. This plan met with the entire approbation of the scientific world at Berlin, was sanctioned by the King, and was all but adopted by the Prussian Cabinet. It happened, however, that simllltaneously with the proposal of Mr. Fairbairn. one Oberbaurat.h Lentze had become convinced tlat a suspension bridge was the true means of conmunlication across the Rhine. Ht had arrived at this conclusion after years of patient investigation, and so far worthy ol all praise, though it somewhat unfortunately chanced that his discovery was some thirty years too late, so that his labors, which would have been at the height of science in 1820, have only served to illustrate a job in 1850. Here, in England, we have some little notion of the nature of jobs, but we question whether any more colossal in this kind has ever neen perpetrated in our palmiest days of corruption tlhan the attempt of our worthy friend Herr Van der Heydt, in whose paper, if we are not mnistaken, the celebrated figment of the payment of 6,)001. to the editors of the'Times',y the Danish Government first appeared, to bolster iup the scheme of AM. Lentze, and to throw cold water upon tlat of Mr. Fairbairn. What mattered it that Baron HIumboldt, tlhe Nestor of physical science, sided with Mr. Fairbairn, or that the King of Prussia, in one of his haplpy nmoments, lhad graciously extended his royal protection to the English engineer? Was not M. Van der Heydt, and the whole army'of the Prussian bureaucracy, whose nanme is Legion, arrayed on the other side I Still the English schemle nmust be burked officially; it was to be smothered in due form with thie cushion of bureaucracy; so a commission was appointed to inquire into tile English tubular bridges; and of whom do our readers suppose that it consisted? Wily of Herr Oberbaurath Lentz himself and another person, wlo, after due deliberation, set off for England on their scientific mission. Whiy lneed we detail'at length the wanderings of tlhese duumviri of bureaucracy? how they landed in England-how they were received with narked courtesy by Mr. Fairbairn-how they saw tile Conway Bridge, the Britarnnia Bridge, and otlier structures of minor dimensions in Lancashirel? Suffice it to say tlat they were quite blind to the merits of tubular bridges, and made their report dead against tubular bridges and strongly in favor of suspension bridges-a report which was adopted by tlhe government, that is to say, by Herr Van der Heydt, who forthwith issued his famous notice, calling upon the engineers of the whole world to comrlete for the honor of contributing to the glorification of Herr Oberbaurath Lentze, wlhose plans have been long since in the bureau of M. Van der Heydt, and in all probability will be ultimately carried out.'" —iles. IT. Fairbairn, Esq., to Baron Humboldt. "My dear Baron Humboldt,-I gather, fiom an article which has recently appeared in the'Times' newspaper, and frolm a communication which his Excellency M. Van der Heydt has honored me with, that a most unfortunate decision has been colme to by the authorities at Berlin, with reference to the important structure by which it is intended to connect tile opposite banks of the Rhine at Cologne. It having been my good fortune to hiave been consulted, many nmonths ago, on tlhe subject of this important bridge, and to have visited Berlin for the purpose of submitting my proposals, 1 irold( it due to tlre warm recommendation wlich emanated from our excellent friend in London, thle Chevalier Bunsen-to the lively interest you manifested in favor of the olject of ny jolurney, and also to the gracious approval expressed by His Majesty the King of Prussia in person-to make known as widely as possible tlhe insuperable oljections which, in rmy opinion, attach to tile limited programme which has recently been issued from the burreau of the Minister of Public Works. "So far as words can be allowed to convey an intimation of a genuine conviction, M. Van der Heydt acknowledged at tlhe palace, on the 1st of November last, that no structure should ever be allowed to cross the Rhine which was not calculated to meet, with perfect security, the utmost requirements of the most extended traffic, and the possilile contingencies of great military olerations. Your own enlarged conceptions at once prompted you to acknowledge tliat tile design (which at that time had received the sanction of the authorities) was totally unfit for these purposes, and to admit that a siuspension bridge, owing its strength to a flexible catenary, was inadequate to tlhe tranlslort of heavy weights. But when I sulinitted the results which had been accomplisled in this country by the judicious apllication of a naterial until recently untried in sucl structures-when I announced tile successful realization of one of the boldest con ceptions of modern tinmes-whe-n I stated that tidal streams, such as the rivet Conway and the Menai Straits, had been crossed by solid and unyielding bridges of enormous span, which were crpablle nevertheless of sustailing ten timres the greatest possilble strain that the heaviest railwav traffic could, in practice, subject therm towhen I had shown that this new principle of construction was peculiarly adapted FAIRBAIRN'S T.UBUL. R BRIDGES. i8~ to strmount the numerous difficulties which the passage of the Rhine offers, by requiring very few and coilparatively small piers in the stream, and thus allowing of Ilie passage of l' gre tilmber rafts in the sumnler, and offering the least possible resistance in times of floods and breaking up of ice in tire winter; and, above ali, when I had proved that a structure so Miuch superior could be erected and fixed at an outlay considerably below tlat which had beel demanded for a very imperfeet onle-I confess I was not prepared to find tle Minister of an enlightened and powerful people asking for the assistance of the world at large to perpetuate a schemle unlworthy of Prussia, unworthy of the practical scientific knowledge of the age, anld in opposition to the deliberate and carefully-weighed opinion of Science's greatest ornament. "Pardon me for tlie warmth with which I address to you this remonstrance; but, feel that your unwelaried exertions, and the friendship which you unreservedly testified to me, call upon rme to urge, as forcibly as I can, the retracing of tile unfortunate steps already taken- We live in times of progress. A scientific discovery, or a liractical improvement. of any kind, cannot be confined to a particular locality or to one country, it becowr-s at once the Iroperty of all. The community of Knowl edge-the most powerful destroyer of national prejudices and antipathies, as it is the surest foundation for general and permanent peace and good will-must ride over and bear down individual ignorance and petty bureaucratic objections. Punctuality and rapidity in our inter-communications lhave become almost essentials of our existellce; and in this manlner all Europe may be said to be interested in tile completion of that railway systemn which will traverse the Prussian dominions from one extremity to the otlher. "And now let me point out tlie lamentable imperfections which characterise tlhe Ministel's programme, and tlhe limitations and requirements which will effectually trammrnel tlie efforts of men of genius, and deter those of experience and reputation from entering at all upon the conmpetition. "It is an express condition of the scheme that the railway communication is not to be continuous, and the public will therefore continue to suffer the annoyance and inconvenience of considerable delays; for it may be safely said that the proposal of disinltegrating a train at one terminus and drawing it across to the other by men or horses, bit by bit, and hour by hour, will offer equal, if not greater, obstacles to a rapid journey than the existing system does. How much better would it be that the br;ldge should embody within itself such elements of strength and durability as would afford at all times and in all seasons a safe transit to those neans of locomiotion which constitute the wonder and glory of the age? Instead of sich a permanent and substantial structure, will the Prussian Government sanction the erection of one, the feeble and rickety constitution of which would shudder at the very sight of a locomotive? Surely not! Public opinion must step in and forbid it. What is wanted is a bridge to connect the existing railways, not one that will permanently separate them. "But again; it is stated that the tifference between the levels of the existing railways and that required for the roadway of the intended bridlge is too great to be overcome by tlhe locomotive within a short distance of length. The objection is purely imaginary; for I can state from personal examination, that the necessary gradient would not be so heavy as several which are worked witl great ease in this country Besides, on the left bank of the Rhine the terminus of the Aix-la-Chapelle line is at the right level; and that on the side of Deutz may without difficulty be reached by arny easy gradient of less than 1 in 100. "Without meaning the slightest disrespect to the author of tire design for the chain bridge, I must repeat my firmi and deliberate conviction, that it would prove an incomplete and unsatisfactory structure. A. permanent, inflexible, durable, and handsome bridge, of enormous strength (the breaking weiglit of the bridge I proposed, with tlie splan of 310 feet. was equal to 6,000 tons or 120,000 cwt., equally distributed over cach span., giving as tire ultimate strength of tlie bridge, with four spans, 24,000 tons, or 480,000 cwts.), adapted, by arrangements which I have now in progress of execution for similar purposes in this country, to give every possible facility to the navigation ot tlie river-calculated to carry across the heaviest railway train at any speed, and which you might cover with the most powerful ordnance from end to end, may be erected at Cologne within the sum which has been demanded for the chain bridge. These statements are not the imaginings of a sanguine mind; but their accuracy may be corroborated by numerous examples of a similar character which have been erected in this country. "If, therefore, the determination of the Minister of Public Works to erect a chain bridge cannot be shaken, I confidently anticipate that such an event will not be allowed to pass by without a strong protest on the part of thos. who sre in advance of the 684 FAIRBAIRN'S TUBULAR BRIDGES. knowledge and judgment displayed by the authors of the invitation which has been issued to the engineering world. "My letter has attained a much greater length than I at first anticipated. My anx iety to forward your own forcibly expressed views on the subject of a fixed bridge must be Iny apology for it. " With an expression of my profound esteem, and with best wishes for your continued good health, Believe me to remain, my dear Baron Humboldt, your very faithful and very obedient servant, " WILLIAM FAIRBAIRN."' Manchester, April 15." FAIRBATRN'S W'ROUGHT-IRON GIRDER BRIDGE. Report on the Strength, Elasticity, and.t'7.er Properties of Wrrought-Iron Girder Bridges as applicable to Railways and other Structures. By W. Fairbairn, Esq., C. E. (From the Appendix to Report of the Comnlissioners appointed to inquire iiito the application of Iron to Railway Structures.) -"The idea of crossing tle River Conway and the Meinai Straits on the line of the Chester and Holyhead Railway (two of the most formidable barriers ever presented to the engineer), properly belongs to Mr. R. Stephenson. "To carry this into practice, required the united skill of the mechanical as well as tlie civil engireer; and it is highly gratifying to find that the successful completion of tile first of the Conway tubes has not only attained that olject, but it has establishred a nlew era in the history of bridges, by the development of the properties of a hitherto traleied material, and enables the engineer of the present day to conquer obstacles wliich, at no very distant date, were considered insurmountable. " An undertaking of such importance to the scienltific world, to the publlic, and to tliose rmore immediately interested, involving heavy resplonsibilities on tlie engilneer; before ranything definite could be accomplished, it became absolutely necessary to inslitlute a series of experimellts to determine the practicability of such a structure, inclrdliing other inquiries into the proportions and other proprerties of the tube. At the request of Mr. Stephenson, [ had the honor of being selected to conduct tlis inquiry. Experiments on circular, elliptical, and rectangular tubes were accordingly undertaken; but it soon became evident fiom the results obtained that those of a rectangular forml were best calculated for the purpose. It was not, however, until I lhd adoplted tlie tube with the corrugated top, that the real value of the tubular form becarre apparent, arld, in fact, absolutely requisite in that part to offer sufficient resistance to tihe criusiiilg force. " I will not trouble the Commissioners with the details of the experiments, but simply state that it evidently became necessary to adopt some other shape than those of 1lie circular and elliptical kind, and so to proportion the top and bottom sides of tlhe tiube as to effect a balance of tlhe resisting forces of extension and compression, and thrus to enslre tlie maximum force of resistance in every part. These proportions were clearly indicated by tlhe rectangular form; and the forniation of cells on thie top side give more effective powers of resistance to the crushing force than had been heretofore accomplishled by the single plate. "This discovery of the cellular top, and the greatly increased value which a tube thus constructed gave to the experiments, at once stggested a modified fornm of tubular girder ardapted to shorter spans. This description of bridge is now becoming general; and from its superior powers of resistance, grenter security, and its adaptation to alrrost every description of span, we may reasonably infer that wroughlt iron is cheaper and safer, if not equally durable with any other description of materials. It nay, anid I have no do-ubt it will be urged, that wrought-iron is much more subject to oxidatior and decay than cast-iron or stone; a circumstance which cannot b, disputed; but that can only arise from gross negligence on the part of thoose lhving charge of tle structurie, as two coats of good oil paint every three years will effectually protect it. and render it duratlle for almost any length of time. Besides, the girders, as now constructed, are accessible in every part, and, iy careful attention, I can see no reason why they should not last 500 instead of 50 or 100 years. Another obljection brought against this de scription of bridge is, the risk of the rivets becoming loose; and from tlhe nunlber of joints, the whole is considered by some as dangerous and insecure. Now, as regards this objection, no real weight can be attached to it; as the parties raising it cannot be acquainted with the nature and solidity of the work. It is next to impossible for a singile rivet to get loose (unless the work is improperly executed); and in the whole of my experience, I am not acquainted with any description of jointing so certainly secure, and so well adapted to resist any description of strain, as that of riveted plates. I speak practically and unhesitatingly on this subject; and I have only to instance steaml boilers, iron ships, and other vessels subjected to severe strain, as examples ol FA.IRBAIRN'S TUBULAR BRIDGES. 685 the strength and tenacity of riveted plates; in fact, rivets seldom or never got loose, but retain their position under every species of strain, and become, as it were, integral parts of the structure in common with the plates themselves. "In submitting these remarks to the consideration of the Commissioners, and in order to bear them out, it may uot be uninteresting briefly to notice a few of the results of tlhe exleriments illustrative of this subject, and to show, with a greater degree of exactitude, the nature and value of this description of structure. For these objects, I beg to insert a few of the earlier experiments on different descriptions of tubes, as recorded in a report addressed to Mr. Stephenson and the directors of the Chester and Holyhead Railway, the partiiculars of which have already been before the public." (Here follow the details of the experiments referred to.) Tile experiments, of which the ablove is a brief notice, have led to other improvements of great utility in practical science, and probably of equal value with those for which they were originally undertaken. "I have already stated that the difficulty which the weakness Jf the material to resist a crushing force occasioned, was overcome by tie adoption of the cellilar form of top; but another, and, to tmy mind, very serious difficulty presented itself, in the reduction in tile strength of tie plates at tie joints by the ordinary method of riveting, in tie bottom and those parts where the tensile strain came into operation. Tils led to a new system of riveting, which, without weakening the body of the plate to so great an extent as formerly, gives a joint of almost equal strength with tile plate itself, and thus adds in a most material miarlner to the security of tile structure. "Consequent upon the experimlenlts and the results obtained therefrom, numerous advantages presented themselves in the construction of wrought-iron girders. Tile strength, ductility, and comparative lightness of the material are the important elements of these girders; and their elasticity, retention of form, and other properties, render them infinitely more secure than those composed of cast-iron, which, from the brittle nature of the material and irmperfections in the castings, are liable to break without notice, and to whlich the wrought-iron girder is not subject. This is, however, probally of less importance, as the wrought-iron girder will be found not only cheaper, but (when well constructed, and upon the right principle) upwards of three times the strerngthi of cast-iron. I have elsewhere stated to the Commissioners that the experinments attlracted the notice generally of railway engineers, and, amongst others, that of Mr. Vignoles, who immedirtely gave an order for two wrought-iron girder bridges for tie Blackbturn and Bolton Rallway Cornpany:-one to cross the Liverpobl and Leeds Canal, land the other over the turnpike road, both in the vicinity of Blackburn. These bridges were constructed simultaneously with another of similar form (with a cast-iron top) executed by Mr. Dockrlay, under the direction of Mr. Robert Stephenson, for carrying tlie turnpike road over the London and North-Western Railway at Camden Town. Those for the Blackburn and Bolton Railway were, however, the first adapted for railway traffic; and alth-iogh they are probably not so well proportioned as others since constructed, they nevertheless exhibit extraordinary powers of resistance; and conceiving that a description of these bridges, with the tests to which they were subjected, might be useful, I have great pleasure in submitting the same, with the necessary drawings, to the consideration of the Commissioners. Explanation of the Engravings, descriptive of the Hollow Girder Bridge over the Turtnpik Road near Blackburn. "Fig. 521 is an elevation or side view of the girder, each 66 ft. long, and bedded on cast-iron lbase plates. " Fig. 522 is a transverse section of the bridge, showing thle sides of the cross-beams, and the cross sections of the outside and niddle girders. "Fig. 523 is an enlarged transverse section of the outside girder, showing the attachment of the cross-beams, which are riveted to the bottom of the girder, exclusive of two bolts A A, which extend through the bottom plates and angle iron of the girder, and the top and bottom plates of tie cross-beam. "Fig. 524 is an enlarged view of a part of the side of the large girder, exhibiting a transverse section of the cross beam, at B, which is made of wrought-iron, with the top and bottom plates so proportioned as to equalise its powers of resistance to the force of compression on the top, and that of tension on the bottom. It also exhibits the mode of riveting up the joints of the side plates with the covering strip c c c, and the additional strength as obtained by the attachment of T iron in the interior of the tube. "Fig. 525 is a plan of the bridge, showing on one side the platform and the rails, and on tile other the cross-beams, which in this bridge are placed 6 ft. asunder; but in those more recently constructed, I have placed them at distances of only 4 ft., and considec this arrangement preferable. 6S6 FAIRBAIRN'S TUBULAR BRIDGES. 521 e 6'1S N 622 523 m 524 f~1Il ______t__ L __ C -tl! _ gd_ st7te., s t - 1 n 11 11 11 11 1'1 11 11 11 1 11 ii F F11 1 r I I il i 1, il I - 1 every species of strain, the middle girder is nuade nearlydouble the strength of those on rdob strute le. Wn th ee itui g irders r studiport a gioad eqrs aly distrong ross-ributed of 76every tonhres; and fee it, oder to renter it sto fe under evel y species of strais, the middle girder is made tonearly double the strength of those on the outside. Thiis s essentil, as two t trains e passings, as te bridfftsge at the samin the strumoment; in hi cmse the miappdle girder wotheld bridge subjected to a pressure equal to double the load on i te otsie girdere, I wils. w dire the construction s othef lager span, I geners to teally prefer only two largckbure longitudinal girders with strong cross-beanis every three feet,, of sufficient length to admit two lines of rails, and sufficient room for two trains to pass at the same time. This mode of constrnction is preferable to die three girders, as it effects greater simplicity in the structure, and, from every appearance, renders tlhe bridge equally effective and secure. "Having thus described tlie advantages lpeculliar to this description of bridge, I will now direct the attention of the Colmlnissioners to the tests to which the Blackburn Bridge was subjected, previolus to its openilig for public traffic. The experiments were madel in the presence of Captain Coddington, the Government Inspector of Railways, and Mr. Flanagan, engineer of the line, as follows:"Three locomotive engines, weighing, 60 tons, were coupled together, and( passed over the bridge at velocities varying from 5 to 15, and 25 miles an hour. This load (60 tons) produced a deflection of'025 of a foot, or about W6ths of an inch, and that without any perceptible increase in the deflection arising from the different rates of speed. In fact the deflection was found to be the same at all velocities. "After these tests were made, two wedges or inclined plates were fitted to the rails, fig. 526, at the middle of the b-idge, and the engines run over them at the rate of 1 to 52o _ - - RAIL L 10 miles an hour. The shock of the engines, as they respectively fell upon the girders, from a height of one inch, the thickness of the wedge at D, gave an increased deflection from -025 to'035 of a foot, and another set of wedges, 1 feet in height, gave a further increase of deflection (at the same velocity) of'035 to.045 of a foot. "From the above experiments it appears evident that wrought-iron girders ore well FATS. 68 A calculated to resist not only a heavy dead weight, but the force of impact administered with an unsparing hand; for, in fact, the girders were not injured by the blows inlflicted by eng'ines falling a heilght of 11 inrches upon them, but restored themselves to their original position froml which thev were deflected by the shock. ")On the whole we may, therefore, reasonably conclude that the present structure is not only the strongest, Ibut the best calculated to resist strain when applied to large spans, and particularly in situations where bridges, with a perfectly horizontal soffit, are alone admissible. (Signed) "WILLIAM FAIBAIRN." Manchester, April 26th, 1848." FAN (Eventail, Fr.; Ficher, Germ.) is usually a semi-circular piece of silk or paper, pasted doule, enclosing slender slips of wood, ivory, tortoise-shell, whale-bone, &c., arranged like the tail of a peacock, in a radiating form, and susceptible of being folded together, and expanded at pleasure. This well-known hand ornament is used by ladies to cool their faces by agitating the air. Fans made of feathers, like the win, of a bird, have been employed from time immemorial by the natives of tropical countries. I'Fa is also the name of the apparatus for winnowing corn. For an account of the powerful blowirn and ventilating fan machine, see FOUNDRY and VENTILATOR. FARINA (1'arine, Fr.; lehl, Germ.) is the flour of any species of corn, or starchy root, such as potato, arrow root, &c. See BREAD and STAtACH. FA r (Graisses, Fr.; Fette, Germ.) occur in a great number of the animal tissues, being abundant under the skin in what is called the cellular membrane, round the kidneys, in the folds of the omentum, at the base of the heart, in the mediastinum, the mesenteric webb, as well as upon the surface of the intestines, and amoni many ol the muscles. They vary in consistence, color, and smell, according to the animals from which they are obtained; thus, they are gen.rally fluid in the cetaceous tribes, soft and rank-flavored in the carnivorous, solid and nearly scentless in the ruminants, usually white and copious in well-fed young animals; yellowish and more scanty in the old. Their consistence varies also according to the organ of their produciion; being firner under the skin, and in the neighborhood of the kidneys, than among the moveable viscera. Fat forms about one twentieth of the weicht of a healthy animal. But as taken out by the butcher it is not pure, for being of a vesicular structure, it is always encloser/ in membranes, mixed with blood, blood-vessels, lymphatics, &c. These foreign matters must first be separated in some measure mechanically, after the fat is minced small, and then more completely by meliing it along with hot water, passing it through a sieve, and letting the whole cool very slowly. By this means a cake of cleansed fat will be obtained. Many plans of purifying fats have been proposed; one of the best is to mix two per cent. of strong sulphuric acid with a quantity of water, in which the tallow is heated for some time with much stirring; to allow the materials to cool, to take ofl the supernatant fat, and re-melt it with abundance of hot water. More tallow will thus be obtained, and that considerably whiter and harder than is usually procured by the melters. I have found that chlorine and chloride of lime do not improve, but rather deteriorate, the appearance of oils and other fatty bodies. According to Appert, minced suet subjected to the action of high-pressure steam in a digester, at 250~ or 260~ F., becomes so hard as to be sonorous when struck, whiter, and capable, when made into candles, of giving a superior lighit A convenient mode of rentdering minced tallow, or melting it, is to put it in a tub, and drive steam through it from numerous orifices in raimifying pipes placed near the bottom. Mr. Watt assures me that his plan of purifying fats, patented in March, 1836, has been quite successful. He employs dilute sulphuric acid, to which he adds a little nitric acid, with a very small quantity of bichromate of potash, " to sup. ply oxygen;" ani some oxalic acid. These are mixed with the fat in the steaming tub. When the lumps of it are nearly dissolved, lie takes for every ton of fat, one pound of strong nitric acid, diluted with one quart of water; to which lie adds two ouctees of alcohol, naplhtha, sulphiuric ether, or spirits of turpentine; and after introduci!ng this mixture, he continues the boiling for half an hour. The fat is finally waslhed. As I do not codlprehend the modes operandi of these ingredients, I shall abstain from any comment ulpon the recipe. Others have proposed to use vegetable or animal charcoal first, especially for rancid oils, then to heat them with a solution of sulphate of copper and common salt, which is supposed to precilpitate the fetid albuminous matter. Mlilk of lime has been also prescribed: but it is, I believe, always detrimental. Davidson treats whale oil with infusion of tan, in older to separate the gelatine ann allbuine in flocks; next with water and chloride of lime, to destroy the smell; and lastly, with dilute sultphuric acid, to precil:itate all the lime in the state of a sulphate. This is certainly one of the cheapest and most effective methods of purifying that su bstauce. 088 FATS. Braconnot and Raspail have shown that solid animal fats are composed of very small, microscopic, partly polygonal, partly reniform particles, which are connected togelher by very thin membranes. These may be ruptured by mechanical means, then separated by triturating the fresh fats with cold water, and passing the unctuous matter througl a sieve. The particles float in the water, but eventually collect in a white granulal crystalline appearance, like starch. Each of them consists of a vesicular integument, of the nature of stearine, and an interior fluid like elaine, which afterwards exudes. The granulrs float in the water, but subside in spirits of wine. When digested in strong alcohol, the liquid part dissolves, but the solid remains. These particles differ in shape and size, as obtained from different animals; those of the calf, ox, sheep, are polygonal, from o1 to I l of an inch in diameter; those of the sow are kidney-shaped, and from -l to 1; those of man are polygonal, and from -1 to 6-t; those of insects are spherical, and at most -1 of an ncen. Fats all melt at a temperature much under 212~ F. When strongly heated with contact of air, they diffuse white pungent fiimes, then blacken, and take fire. When sub. jected to distillation, they afford a changed fluid oil, carbureted hydrooen, and the other products of oily bodies. Exposed for a certain time to the atmosphere, they become rancid, and generate the same fat acids as they do by saponification. In their fresh state they are all composed principally of stearine, margarine, and oleine, with a little coloring and odorous matter; and in some species, hircine, from the goat; phocenine, from the dolphin; and butyrine. fiom butter. By subjecting them to a great degree ol cold, and compressing them between folds of blotting paper, a residuum is obtained, consisting chiefly of stearine and margarine; the latter of which may be dissolved but by oil of turpentine. Beef and Multon Suet.-When fresh, this is an insipid, nearly inodorous fat, of a firm consistence, almost insoluble in alcohol, entirely so if taken from the kidneys and mesenteric web of' the ox, the sheep, the goat, and the stag. It varies in its whiteness, consistence, and combustibility, with the species and health of the animals. That of the sheep is very white and very solid. Tley may all be purified in the manner above described. Strong sulphuric acid developes readily the acid fats by stirring it through melted suet. Alkalis, by saponification, rive rise at once to the three acids,-the stearic, margaric, and oleic. Beef suet consists of stearine, margarine, and oleine; mutton and goat suet contain a little hircine. The specific gravity of the tallow of which common candlles are made is, by my experiments, 0-936. The melting point of suet is from 98~ to 104~ F. The proportion of solid and fluid fat in it is somrewhat variable, but the forier is in much larger proportion. Multon suet is soluble in 44 parts of boiling alchol, of 0-820; beef suet in 44 parts. Marrow fat consists of 76 of stearine, and 24 of oleine; it melts at 115~ F. Hog's-lard is soft, fusible at 81~ F., convertible, by an alkaline solution, into a stearate, margarate, oleate, and glycerine. Its sp. grav. is 0-938, at 50~ F. It consists of 62 of oleine, and 38 of stearine, in 100 parts. Goose-Jft consists of 68 oleine and 32 stearine. Butter, in summer, consists of 60 of oleine and 40 of stearine; in winter, of 35 of cleine, and 65 of stearine; the former substance heing yellow, and the latter whito It differs, howexver, as produced from the milk of different cows, and also according to their pasture. The eltimate constituents of stearine, according to Chevreul, are 79 carbon, 11-7 hydrogen, and 9-3 oxygen, in 100 parts. 1,294,009 cwts. of the tallow imported in 1837 were retained for internal consumption. See MARGARINE, O.FINE., SOAP. STFARTINE. The following statement is given on the authority of Braconnot:Oleine. Stearine. Fresh.Butter in summer - - - 6 40 - -- in winter - - - 37 63 Hog's Lard - - - 62 38 Ox Marrow - - - - - 24 76 Goose Fat - - - 68 32 D)uck Fat - - - - 72 28 Ox Tallow - - - - 25 75 Mutton Suet - - 26 74 bM. Dumas says that butter contains no stearine. The purification and decoloration of fats have been the object of many patents. Under CANDLE, Hempel's process for refining palm-oil and extracting its mllargarine is described. About 30 years ago, palinmoil was deprived of color to a certain degree by mixing with the melted oil, previously freed from its impurities by filtration, some dilute nitric FATS. 689 acid, wooden vessels being used, and the oil being in a melted state. This process was both expensive and imperfect. More lately wlitening has been prescribed by means of chromic acid, which, in the act of decomposition into chromic oxide, gives out oxygen, and thereby destroys vegetable colors. One pound of lichromnate of potash in solution is to be mixed with two poundls of strong sulphnric acid, diluted beforehaiuil with about two gallons of water; and this mixture is to be incorporated by Jdliigent stirring with 2 cwt. of the filtered palmn-oil, at a telmperature of about 100 F., contained in a wooden vessel. The palm-oil is afterward to be washed in warm lime-water, to which some solution of chloride of lime may be advantngeoasit adled. By this process, well managed, a fat may be obtaine' from palm-oil fit litb j m king white soap. Tallow may be also blanched to a considelaole degree by a like operation. instead of sulphuric acid, the muriatic may be used to convert the chromic acid into chromic oxide in the above process, and thereby to liberate the blanching oxygen. The resulting solution of green muriate of chrome bein, freed from some adhering oil, is to be mixed with so much milk of lime as just to neutralize the excess of acid that may be present. The clear green muriate is then to be decomposed in a separate vessel, by the addition of well-slaked and sifted lime, in some excess. The green mixture of lime and chrome-oxide is now to be dried, and gtrntly ignited, whereby it is converted into yellow chromate of lime, with some unsaturated lime. This compound beinm decomposed by dilute sulphuric acid, affords chromic acid, to be applied again in the decoloring of palm-oil, on the principles above explained. Mr. Prynne obtained a patent in March, 1840, for purifying tallow for the candlemaker, by heating it along with a solution of carbonate of potash or soda for 8 hours, letting the whole cool, removing the tallow to another vessel, heating it by means of Eteam up to 206~ F., along with dry carbonate of potash (pearlash): letting this mixture cool very slowly; and finally removing the tallow to a vessel enclosed in steam, so as to expel any subsidiary moisture.-Newton's Journal, xxi. 258. A patent for a like purpose was obtained in June, 1842, by Mr. H. H. Watson. He avails himself of the blanching power of oxygen, as evolved from manganate of potash (chameleon mineral), in the act of its decomposition by acids, while in contact with the melted fat. He prescribes a leaden vessel (a well-joined wooden tub will also serve) for operating upon the melted tallow, with one twentieth of its weight of the manganate, dissolved in water, and acidulated to the taste. The whole are to be well mixed, and gradually heated from 150 up to 2123 F., and maintained at that temperature for an hour. On account of the tendency of the dissolved manganate to spontaneous decomposition, it should be added to the dilute acid, mixed with the fat previously melted at the lowest temperature consistent with its fluidity. Palm-oil may be well blanched in the course of 12 hours by heat alone; if it be exposed in a layer of one or two inches to the air and sunshine, upon the surface of water kept up at nearly the boiling point by a coil of steam-pipes laid in the bottom of a square cistern of lead or wood, well jointed. Mr. Wilson, of Vauxhall, has applied centrifugal action to the separation of the nmore liquid from the more solid parts of fatty matters, using in preference the hydro-extractor, used by Seyrig and Co., for drying textile fabrics. Mr. Wilson employs a stout cotton twill in addition to the wire grating; and in order to avoid the necessity of digging the concrete parts, and to prevent them from clogging the interstices for the discharge of tile oily matter, he places the whole in a bag 8 inches in diameter, and of such length that when laid on the rotating machine against the grating the two ends will meet. The speed of the machine must be kept below that at which stearic acid or stearine would pass; which is known by the limpidity of the expressed fluid. To take advantage of the liquefying influence of heat, he keeps the temperature of his room about 2~ F. above that of the substances under treatment. The improved fat and candle factory, called Price's, of which Mr. Wilson, of Belmont, Vauxhall, seems to be the main conductor and schemer, is mounted upon a colossal scale. It has five separate works near London, great plantations of cocoa-nut trees in Ceylon, with a capital of about half a million sterling, an annual division of profits to the amount of 50,0001., and it employs about 800 work-people, whose physical and moral well-being is well looked after by the benevolent manager of the whole concern. See CANDLES. Tallow imported for home consumption in 1850, 1,219,101 cwt.; in 1851, 1,085,660 cwt. Gross amount of duty received, 78,2701. and 68,0351. respectively; the duty being ld. per cwt. from British possessions, and Is. 6d. per cwt. from foreign countries. F T BLEACIIiNG. By transmitting streams of atmospheric air through heated palmoil and other colored and odorous fatty matters, they are deprived so far of their eolor and siiell as to be capable of forming white soaps. Mr A Dunn obtained e patent for this object in 1843. 45 590 FEATHERS. FAULTS (Failles, Fr.), in mining, are disturbances of the strata which interrupt the miner's operations, and put him at Jault, to discover where the vein of ore or bed of coal has been thrown by the convulsions of nature. Many examples of faults ate exhib, ited under PITCOAL. FEATHERS (Plumes, Fr.; Federn, Germ.) constitute the subject of the manufacture of the Plumassier, a name given by the French (and also the English) to the artisan whn prepares the feathers of certain birds forornaments to the toilet of ladies and for militar men, and to him also who combines the feathers in various forms. We shall content ourselves with describing the method of preparing ostrich leathers, as most other? are prepared in the same way. Several qualities are distinguished in the feathers of the ostrich; those of the male, in particular, are whiter and more beautiful. Those upon the back and above the win-s ale preferred; next, those of the wings, and lastly, -" the tall. The down is merely the feathers of the other parts of the body, which vary irl ength from 4 to 14 inches. This down is black in the males, and gray in the females. The inest white feathers of the female have always their ends a little grayish, which lessens their lustre, and lowers their price. These feathers are imported from Algiers, Tunis, Alexandria, Madagascar, and Senegal; this being the order of their value. The scouring process is thus performed:-4 ounces of white soap, cut small, are dissolved in 4 pounds of water, moderately hot, in a large basin; and the solution is made into a lather by beating with rods. Two bundles of the feathers, tied with packthread, are then introduced, and are rubbed well with the hands for five or six minutes. After this soaping they are washed in clear water, as hot as the hand can bear. The whitening or bleaching is performed by three successive operations. 1. They are immersed in hot water mixed with Spanish white, and well agitated in it; after which Hey are washed in three waters in succession. 2. The feathers are azul ed in cold water containing a little indigo tied up in a fine cloth. They should be passed quickly through this bath. 3. They are sulphured in the same way as straw hats are (See SULPHURING); they are then dried by hanging upon cords, when they must be well shaken from time to time to open the fibres. The ribs are scraped with a bit of glass cut circularly, in order to render them very pliant. By drawing the edge of a blunt knife over the filaments they assume the curly form so much admired. The hairs of a dingy color are dyed black. For 20 pounds of feathers, a strong decoction is made of 25 pounds of logwood in a proper quantity of water. After boiling it for 6 hours, the wood is taken out, 3 pounds of copperas are thrown in; and, after continuing the ebullition for 15 or 20 minutes, the copper is taken from the fire. The feathers are then immersed by handfuls, thoroughly soaked, and worked about; and left in for two or three days. They are next cleansed in a very weak alkaline ley, and soaped three several times. When they feel very soft to the touch, they Inust be rinsed in cold water, and afterwards dried. White feathers are very difficult to dye a beautiful black. The acetate of iron is said to answer better than the sulphate, as a mordant. For dying other colors, the feathers should be previously well bleached by the action of the sun and the dew; the end of the tube being cut sharp like a toothpick, and the feathers being planted singly in the grass. After fifteen days' exposure, they are cleared wi lh soap as above described. Rose color or pink, is given with safflower and lemon juice. Deep red, by a boiling hot bath of Brazil wood, after aluming. Crimson. The above deep red feathers are passed through a bath of cudbear. Prune de Monsieur. The deep red is passed through an alkaline bath. Blues of every shade, are dyed with the indigo vat. Yellow; after alurning, with a bath of turmeric or weld. Other tints may be obtained by a mixture of the above dyes. Feathers have some more useful employments than the decoration of the heads of women and soldiers. In one case, they supply us with a soft elastic down on which we can repose our wearied frames, and enjoy sweet slumbers.' Such are called bed feathers. Others are employed for writing. and these are called quills. Goose feathers are most esteemed for beds, and they are best when plucked from She living bird, which is done thrice a year, in spring, midsummer, ard the beginning of harvest. The qualities sought for in bed feathers, are softness, elasticity, lightness, and warmth. Their only preparation when cleanly gathered is a slight beating to clear away the loose matter, but for this purpose they must be firstwell dried either by the sun or a stove. Bleaching with lime water is a bad thing, as they never can be freed from white dust afterwards. The feathers of the eider duck, anas mollissima, called eider down, possess in a supe. rior degree all the good qualities of goose down. It is used or'v as a covering to beds, and never should be slept upon, as it thereby loses its elasticity FELTED CLOTH. 691 Quills for wuiting. These consist usually of the feathers plucked out of the wings of geese. Dutch quills have been highly esteemed, as the Dutch were the first who hit upon the art of preparing tiem well, by clearing themn both inside and outside from a falt) humor with which they are naturally impregnated, and which prevents the ink fron flowing fieely along the pens made with them. Ihe Lutch lot a long time employed hot cinders or ashes to attain this end; and their secret was preserved very carefully, but it at lenoth transpired, and the process was then improved. A bath of very fine sand must be kept constantly at a suitable temperature, which is about 140~ F.; into this, the quill end of the feather must be plunged, and lelt in it a few instants. On taking them out they must be strongly rubbed with a piece of flannel, after which they are found to be white and transparent. Both catlbonate of potash in solution and dilute sulphuric acid have been tried to effect the same end, but without success. The yellow tint which gives iuills the air of age, is produced by dipling them for a little in dilute inuiiatic acid, and then making them perfectly dry. But this process must be pleceded by the sand-bath )peration. The above is the French process. Quills are dresstd by the London dealels in two ways; by the one, they remain of U.eir ratural color; by tlie other, they acquire a yellow tint. The former is called the Dutch nethod, and the principal workman is called a Dutcher. He siis befote a slmall slove fire, anto which he thrusts the barrel of the quill for about a second, thin lays its loot quickly below his blunt-edged knife called a hook, and, pressing this firmly with the left hand, traws tlse quill briskly through with his righlt. The bed on which the quill is laid to re.eive this pressure is called the plate. It is a rectangular smooth lump of il on, aboutt " nches long, 1I broad, and 2- thick, which is heated on his stove to about the 350th deVree Fahr. The hook is a ruler of about 15 inches in length, somewhat like the pattennaker's knife, its fulcrum being formed at the one end by a hook and staple, and the power of pressure beirn applied by the hiand at the other end.'1 he quill, rendered soft ind elastic by the heat, endures the strong scraping action of the tool, and thus gets stripped of its opaque outer membrane, without hazard of being split. A skilful worknan can pass 2000 quills throught his hanrds in a day of 10 hours. They are next cleaned by being scrubbed by a woman witl a piece of rough dog-fish;kin, and finally tied utp by a man in one quarter of a hundred bundles. In another mode of dressing quills, they are steeped a nighlt in decoction of turmeric, to stain them yellow; taken out and dried in warm sand contained in a pot, then scraped by the Dutcher as above described. The first are reckoned to make the best pens, though;he second may appear more beautiful. Crow quills for draunhtsmen, as well as swan quills, are prepared in the same way. The quills plucked from well-fed living birds have most elasticity, and are least subject to be moth-eaten. The best are those plucked, or which are spontaneously cast in the month of May or June, because they are then fully ripe. In the goose's wing the five exterior feathers only are valuable for writing. The first.is the hardest and roundest of all, but the shortest. The next two are the best of the five. They are sorted into those of the right and the left wing, which are differently bent. The heaviest quills are, generally speaking, the best. Lately, steaming for four hours has been proposed as a good preparation. FECULA (Fecule, Fr.; S/drke7rehl, Germ.) sometimes signifies corn flour, sometimes starch fiom whatever source obtained. FELDSPAR (Orihose, Fr.; Feldspalh, Germ.) is a mineral crystallizing in oblique rhomboidal prisms, susceptible of two clivages; lustre more pearly than vitreous; spec. grav. 2.39 to 2.58; scratches glass; yields no water when calcined; fusible at the blowpipe into a white enalnel; not aflected by acids. The liquid left from its analytical treatment with nitrate of baryta, nitric acid, and carbonate of ammonia, affords on evaporation an alkaline residuum which precipitates platina fiom its chloride, and appears fiom this, as well as other tests, to be potash. Feldspar consists of-silica, 66-75; alumina, 17-50; potash, 12; lime, 1-25; oxyde of iron, 0-75. Rose. This mineral is a leading constituent of granite; and in its decotn posed state furnishes the petuntse or Cornish stone, so much used in the porcelain and best pottery manufactures. FELTED CLOTH. This woollen fabric, made without spinning and weaving, was made the subject of a patent by M:'. T. R. Williams in February, 1850. A copious description of the process is given in Newton's Journal, xxii. 1. Varnished or Japanned Felt is made by imbuing the stuff of coarse hat bodies with drying oil, prepared by boiling 50 lbs. of linseed oil with white lead, litharge, and umber, of each one pound. The felt is to be dried in a stove, and then polished by pumrice-stone. Five or six coats of oil are required. The surface is at last varnished. Whlen the object is intended to be stiff, like visors, the fabric is to be impregnated first 692 FERMENT. of all with flour-paste, then stove-dried, cut into the desired shape, next imbued with the drying-oil, and punmiced repeatedly; lastly placed, to the number of 20, in a hot iron mould, and exposed to strong pressure. Japanned hats, made in this way, are sold in France at Is. 3d. a piece; and they will stand several years' wear. FELTING. (Feutrage, Fr.; Filzen, Germ.) is the process by which loose flocks of wool, and hairs of-various animals, as the beaver, rabbit, hare, &c., are mutually interlaced into a compact textile fabric. The first step toward making felt is to niix, it the proper proportions, the different kinds of fibres intended to form the stuff; and then, by the vibratory strokes of the bowstring, to toss them up in the air, and to cause then; to fall as irregularly as possible, upon the table, opened, spread, and scattered. The workman covers this layer of loose flocks with a piece of thick blanket stuff slightly moistened; he presses it with his hands, moving the hairs backward and forward in all directions. Thus the different fibres get interlaced, by their ends pursuing ever tortuous paths; their vermicular motion being always, however, root foremost. As the matting gels denser, the hand pressure should be increased in order to overcome the in creasing resistance to the decussalion. A first thin sheet of soft spongy felt being now formed, a second is condensed upon It in like manner, and then a third, till the requisite strength and thickness be obtained. These dilferent pieces are successively brought together disposed n a way suitable to the wished-for article, and united by continued dexterous pressure. The stuff must be next subjected to the fulling-mill. See HAT MANUFACTURE. FERMENT (Eng. and Fr.; Hele, Germ.) is the substance which, when added in a small quantity to vegetable or animal fluids, tends to excite those intestine motions and changes which accompany fermentation. It seems to be the result of an alteration which ve(etable albumen and gluten undergo with contact of air amidst a fermenting mass. The precipitate or lees which fall down when fermentation is finished consist of a mixture of the fermenting principle with the insoluble matters contained in the ferz;ented liquor, some of which, like hordeine, existed in the worts, and others are probably generated at the time. To prepare a pure ferment, or at least a compound rich in that principle, the precipitate separated during the fermentation of a clear infusion of malt, commonly called yeast or barin, is made use of. This pasty matter must be washed in cold distilled water, drained and squeezed between the folds of blotting paper.. By this treatment it becomes a pulverulent mass, composed of sinall transparent grains, yellowish gray when viewed in the compound microscope. It contains much water, and is therefore soft, like moist gluten and albumen. When dried, it becomes like these bodies, translucid, yellowish brown, horny, hard, and brittle. In the soft humid state it is insipid, inodorous, insoluble in water and alcohol. If, in this state, the fkernelt be left to itself at a temperature of fiom 60~ to 70' F., but not in too dry a situation, it putrefies with the same phenomena as vegetable gluten and albumen, and leaves, like them, a residuum resembling old cheese. At the beginning of this change, particularly if the ferment be enclosed in a limited portion of air, there is an absorption of oxygen gas with a fivefold disengagement of carbonic acid gas; while acetic acid makes its appearance in the substance. When distilled by itself it affords the same products as gluten. Dilute acids dissolve it very readily; and so does potash with the production of ammonia, a peculiar circumstance, for in dissolving gluten the alkali causes no such evolution. The property possessed by yeast of determining the fermentation of a properly diluted solution of sugar is very fleeting, and is lost by very trifling alterations. It is destroyed by complete desiccation, and cannot be restored by moistening it again. The attempts made in London to squeeze out the liquid part of yeast in bags placed in a powerful press, an l to obtain a solid cake, in order to transport ferment to India, have had but a very partial success; for its virtue is so impaired that it will rarely excite a perfect fermentation in the best prepared worts. The same method is adopted in Germany, to send yeast to only moderate distances; and therefore with more advantage. If yeast be boiled for ten minutes, it loses the greater part of its fermenting rower, and by longer boiling it becomes inert. When alcohol is poured upon yeast, it immediately destroys its fermenting faculties, though, on filtering it off, it seems to carry no remarkable principle with it. One thousandth part of sulphuric acid equally deprives yeast of its peculiar property, apd so does a little strong acetic acid. All the acids and the salts, especially those which part readily with their oxygen, produce the same effect. A very small quantity of sulphurous acid, or sulphites, mustard powder, particularly the volatile oil of mustard, and in general the volatile oils that contain sulphur, as well as the vegetables which yield them, such as horse-radish and garlic, all kill the fermenting agent. Lastly, fermentation is completely stopped by a moderate depression of temperature. FERMENTATION. 693 During fermentation the yeast undergoes a change; it loses the property of causing another wort to ferment. This change probably depends upon the chemical reaction between the ferment and the sugar that is decomposed; for a certain quantity of yeast can effect the fermentation of only a certain quantity of sugar, and all the sugal exceeding this quantity remains unaltered in the liquor. It has been concluded fiom some rather loose experiments, that one part and a half of yeast (supposed to be in the dry state), is adequate to the fermentation of a solution of 100 parts of pure sugar. When such a solution is fermented by the precise proportion of yeast, the fermenting principle is exhausted, for no new yeast is formed in it. There is a deposit indeed to about half the weight of the yeast employed, of a white matter insoluble in water. which affords no ammonia by dry distillation, and is incapable of acting as a ferment upon a fresh saccharine solution. Of all the bodies convertible into yeast during fermentation, vegetable gluten and albumen possess the most rapid and energetic powers. But ordinary glue, isinglass, animal fibrine, curd or caseun, albumine, urine, and other azotized substances, all enjoy the property of causing a solution of sugar to ferment; with this difference, that whilst yeast can establish a complete fermentation in less than an hour, at a temperature of about 680, the above substances require several days, with a heat of from 07~ to 87~ F., for becoming ferments, and for occasioning fermentation. Substances devoid of nitrogen do not produce a ferment. FERMENTATION. (Eng. and Fr.; Gahrung, Germ.) When organic substances, under the influence of water, air, and warmth, are abandoned to the reciprocal operation of their proximate principles (sugar, starch, gluten, &c.), they are entirely changed and decomposed, so that their ultimate principles (oxygen, hydrogen, carbon, and in some cases azote) combine in new proportions, and thus give birth to various new compounds. To this process, the general name of fermentation has been given. These operations.nd their products differ according to the differences of the substances, and of the circumstanzes in which they are placed. The following may be enumerated as sufficiently distinct species of fermentation. 1. The saccharine fermentation, in which starch and gum are changed into sugar. 2. The vinous fermentation. in which sugar is converted into alcohol. 3. The mucilaginous fermentation, in which sugar is converted into slime, instead of alcohol. 4. The acetous fermentation, in which alcohol and other substances are converted into vinegar. 5. The putrid fermentation oi putrefaction, which characterizes particularly the decomposition of azotized organic substances. 1. The saccharine fermentation. When a paste made by boiling one part of starch with twelve parts of water is left entirely to itself, water merely being stirred in as it eval-orates, at the end of a month or two in summer weather it is changed into sugar, equal in weight to from one third to one half of the starch, and into gum, equal to from one fifth to one tenth, with a residuum of starch paste somewhat altered. This saccharifying process advances much quicker through the co-operation of vegetable albumine or gluten, acting as a ferment. If we boil two parts of potato starch into a paste with twenty parts of water, mix this paste with one part of the gluten of wheat flour, and set the mixture for 8 hours in a temperature of from 122* to 1670 F., the mixture soon loses its pasty character, and becomes by degrees limpid, transparent, and sweet, passing at the same time first into gum, and then into sugar. The remainderconsists of the unchanged starch with the altered gluten, which has become sour, and has lost the faculty of acting upon fiesh portions of starch. It is probable, however, that the sugar formation in the first case, when the starch undergoes a spontaneous change, may be due to the action of a small portion of gluten and albumine left in the starch, since a putrefactive smell is eventually evolved indicative of that azotized matter. The gum into which during this process the starch is first converted, and which becomes afterwards sugar, is of the same nature as British gum, formed by the roasting of starch. This production of sugar takes pla e in the germination and kiln-drying of malt; and the mashing of the brewer as well as the sweetening of bread in baking, rests upon the same principles. In many cases the vinous fermentation precedes the saccharification, or accompanies it; the starchy parts of the fermenting mass changing into sugar, while the previously formed sugar becomes wine or beer. In the sweetening of fruits by keeping, a similar process occurs; the gummy and starchy fibres become sugar from the action of the glutinous ferment which they contain; as happens also to the juices of many fruits which sweeten for a little while after they have been expressed.' he nature of this sugar formation through the influence of gluten upon starch, is undoubtedly the same as the conversion of starch into sugar, by boiling it with sulphuric acid; though the whole theory of this change is not entirely developed. The most energetic substance for the conversion of starch into sugar, is the malt of sarley. According to the researches of Payen and Persoz, the gum which by this f~~~~~~~~~~~~~~~~~~~~~~~~~ 694 FERMENTATION. process is first formed, may be prevented from going into sugar, by merely exposing it to a boiling heat, and hence we have it in our power either to make sugar or gum at pleasure. Of finely ground malt fromn 10 to 25 parts must be taken for 100 parts of starch. Into a pan placed in a water bath, 400) parts of water being warmed to from 77~ to 86'- F., the ground malt must be slirred in, and the temperature must be raised to 140~. The 100 parts of starch must now be added, and well mixed. The heat is then to be increased to 158~ F.; and be so regulated that it shall not fall below 1490, nor rise above 167c. In the course of 20 or 30 minutes the originally milky and pasty liquid will become gradually more attenuated, and eventually it will turn as fluid nearly as water. This is the point of time in which the starch has passed into glum, or into the substance lately denominated dexlrine by the chemists. Should this mucilaginous matter, which appears to be a mixture of guri and a little starlchy sLuar, be wished for in that state, tlie temperature of tire liquid must be suddenly raised to tlhe boiling point, whereby the fuirlther action of the nallt lul)on it is stopledtl. IlBut on the other lLaid, if sular be desired, then thle temperature must be steadily maintained at from 158~ to 167~ or three quarters of an hour, in wlich time the greater Dart of the starch will have becore sugar, and from the evaporation f tlre fluid a starchy syrup will be obtained, entirely similar to that procurable by tne action of very dilute sulphuric acid upon Btar'Ch. The substance which operates this saccharine change, or the appropriate yeast of the sugar fermentation, which had been previously imagined to be a residuum of gluten or vegetable albumen in the germinated grain, has been traced by Payen and Persoz to a peculiar proximate vegetable principle called by them diastase. This substance is generated durin.r the.ernination of barley, oats, and wleat, and may be obtained separately by infuising the ground malt in a small quantity of cold water, straining off the liquor, tlhen filtering it, and heating the clear solution in a water-bath to the temperature of 158~ F. T'Ie greater part of the vegetable albumen is thus coagulated, and must be separated by a fresh filtration; the liquid is afterwards treated with alcohol as long as the flocculent precipitate of diastase falls. In order to purify it still more comrlr.etly Iroml tie azotized matter, it may be once more dissolved in water, and again precipitated by alcohol. When dried at a low temperature, it appears as a while solid, which contains no azote, is insoluble in strong alcohol, but dissolves in weak alcohol and water. Its solution is neutral and tasteless; and if left to itself, it changes spontaneously, sooner or later, according to the degree of warmth, and becomes sour. At the temperature of from 149~ tc 168~, it has the property of converting starch into gurm or dextrine, and sugar; and, when sufficiently pure, it does this with such energy, that one part of it is capable of saccharifying 2000 parts of dry starch. It acts the more rapidly the larger its prolortion. Whenever the solution of diastase with starch or dextrine has beez heated to the boiling point, it loses the property of transforming these substances. One hundred parts of well malted barley appear to contain about one part of this new body. 2. The Vinoul Fermentation.-In this fermentation the sugar existing in watery solution is, by tile operation of the ferment or yeast, converted into alcohol, with disengagement of carbonic acid gas. If we dissolve one part of pure sugar in ten parts of water, and leave the solution in a temperature of from 68~ to 77~ F., which is that most favorable to fermentation, it will remain unaltered. But if we stir into that solution some beer yeast, the phenomena of fermentation soon appear in the above cirrlumstances; for carbonic acid gas is evolved, with intestine movements of the liquid, ant an increase of its temperature. A body of yeast rises to the surface, and exhibits a continual formation and rupture of air bubbles. At length the sugar being in a great measure decomposed, the motions cease, the liquor becomes clear, and instead of being a sirup, it is now a dilute alcohol. The yeast has by this time fallen to the bottom in a somewhat compact form, and of a whitisl color, deprived of the property of exciting fermentation in fresh sirup, provided no undue excess of it was added at first, for that alone would remain effective. Experience shows that for the conversion of a determinate quantity of sugar by fermentation, a determinate quantity of yeast is necessary, which has been estimated at abou: 1- per cent. in the dry state. When the yeast has been decomposed by fermenting its definite proportion of sugar, it loses its termentable property, and leaves the excess of sugar unaffected, formnirig a sweet vinous solution. The same thing happens if the yeast be separated from the wort by a filter in the progress of the fermentation, for then all intestine motion speedily stops, although much saccharine matter remains. In the juices of sweet fruits, of grapes, for example, the ferment is intimately associated with the sugar. It is at first soluble and inactive, till it absorbs oxygen from the atmosphere, whereby it becomes an operative ferment, but, at the same time, insoluble, so as to precipitate at the end of the process. When the expressed juice of the grape, ar miLst, is enclosed in a vessel out of contact of air, and there subjected to the heat of FERMENTATION. 695 )otiing water, the small portion of oxygen present is rendered inactive. and the liquor ex periences no fermentative change. If the grapes be squeezed in an atmlosphere deprived of oxygen, and confined in the same, the juice will also remain unaltered. Recently ex. pressed grape juice is limpid, and manifests the commencement of fermentation by the sep)aration of the yeasty substance, which can take place only with access of air. The sclution becomes turbid after a certain time, gas begins to be evolved, and the separated ferment decomposes the sugar. At the end of the process the yeast collects at the bottorn of the vessel, usually in larger quantity than was sufficient to complete the fermentation; and hence a considerable portion of it possesses still the fermentative faculty. The fermentation itself, when once begun, that is, whenever the yeasty particles are er olved and fl.at in the liquid, for which evolution a very minute quantity of oxygen is sufficient, L thenceforth independent of the contact of air, and goes on as well in close as in open vessels; so that the production of alcohol and carbonic acid depends solely upon the mutual reaction of the ferment and the sugar. Tie yeast, which may be obtained tolerably pure from a fine inft.ion of malt in a state of fermentation, after being washed with cold water to separate the soluble, gummy, and saccharine matter, and after being pressed between f Ids of blottiL.n paper, constitutes a pulverulent, grayish yellow, granular substance, destitute of both taste and smell, insoluble both in water and alcohol. Cold water dissolves, indeed, only J-, and boiling water very little more. The essentially operative constituent of yeast is a peculiar azotized;.atter, which ir the wine vat is mixed with some tartar and other salts, and in the beer tun with gum, starch, &c. This animalized substance may be obtained in a separate state, according to Braconnot, by acting upon the washed yeast powder with a weak ley of carbonate of potash, and by decomposing the solution with vinegar, whereby the matter is thrown down in a gelatinous form. The substance thus obtained is insoluble in cold water and alc(ohol, but dissolves readily in very dilute alkaline leys, and even in lime water. When diffused through water, it assumes a homogeneous aspect, as if it were really dissolved; but wlen this mixture is heated, the animalized matter coagulates, and separates in thick flocks. In this state it has lost its former properties, being no longer solurble in alkaline leys, even when concentrated. Acids exercise no solvent power over this peculiar matter; they precipitate it from its solutions, as do also the earthy and metallic salts, which, moreover, combine with it. This is also the case with tannin. The combination of the ferment stuff with acids increases the stability of its constitution, and counteracts its tendency to influence solutions of sugar. These properties of the operative principle of yeast explain many of the phenomena of fermentation, as we shall presently see. The animalized matter of yeast resembles gluten, albumen, caseum, and other azotized substances; if any one of these be put into a saccharine solution ready for fermentation, it will begin to operate a change, when aided by warmth and time, if it be previously decomposed in some measure to facilitate its influence; or if these substances be brought into a slightly putrescent state beforehand, they will cause more speedy fermentation. Thus white of egg, when added to saccharine liquors, requires a period of three weeks, with a temperature of 96~ F., before it will excite fermentation; afterwards the excess of the albumen forms a precipitate which may be used instead of yeast upon other sweet worts. The rapidity with which such azotized substances are capable of being converted into ferments of more or less purity and power is very variable; vegetable gluten and albrumen being best fitted for this purpose. This conversion is accelerated when the sweet liquor in which the substance is diffused or dissolved has already begun to ferment; whence it appears that the presence of carbonic acid gas, combined with the liquor, is here of singular influence. Upon it, in fact, the formation and elimination of the yeast in fermenting liquors depend. A solution of pure sugar, which has been made to ferment by the addition of yeast, filrnishes no new yeast; but there remains after the process a portion of the yeast originally mixed, in an altered inoperative condition, should its quantity have been exactly adequare to the decomposition of the sugar, or in an operative state, should the quantity have been originally excessive. But if the fermentable liquor contains vegetable albumen and gluten, as.is commonly the case with the sweet juices of fruits and beer woris, these substances become changed into ferments in the course of the fermentation induced by the yeast, and, being superfluous, so to speak, for tlat particular process, they remain entire at the end, and may be eoletcted for use in other operations. Upon this principle is founded the increased production of yeast, and the manufacture of what has been called urtificial barmr, in which the fermentation is conducted chiefly with a view to the formation of yeast. To the fermenting mass, those kinds of meal are added, which abound in albumen and gluten, as barley, beans, or wheat, for instance;... B96 FERMENTATION. and the process is similar to the production of a great lump of leaven, from the action of a small piece of it upon dough. The following prescription will illustrate this subject. Take three ounces of bean flour, add to it five quarts of boiling water, and boil the mixture for half an hour. Pour the decoction into a vessel, and stir into it. while hot, 56 ounces of wheaten flour. After the mixture cools to the temperature of 54~ F., add to it about two quarls of beer barm, stirring the whole well together. About 24 hours after the commencement of the fermentation, incorporate with the mixture 112 ounces or barley or bean flour, till it becomes a uniform dough, which must be thoroxlghly kneaded, rolled out into cakes about an inch thick, and cut into pieces of the size of a dollar, These cakelets must be dried upon laths in the sun in favorable weather, and then puti up in a dry situation. For use, one of these discs is to be broken into pieces, laid in warm water, and set in a warm place during 12 hours. The soft mass will then serve the purpose of beer yeast. Or we may mix equal parts of barley malt, wheat malt, and crushed rye, pour water at the temperature of 122~ F. over them into a tub till it stand a span above their surface; then stir well toseliher, and allow the whole to remain at rest for a few hours, till it cools to about 65~ F. We must now add for each pound o' the mingled meals, a quarter of an ounce of beer barm. The tub must be thee covered, and preserved at a temperature of 63~ F. The husks, as they bein to rise to the surface, in consequence of the fermentation, must be taken off and squeezed through a cloth over the vessei. When the meal comes afterwards to subside to the bottom. the whole must be strained through a canvass bag, and freed from the superfluous moisture by squeezin, The bag witli its dou!hy mass must next be surrounded with dry ashes, to remove the remaining humidity, and to arrest any further fermentation. This consistent ferment.na.- be used instead of beer yeast. It is difficult to prepare an artificial yeast without barm. The best process for this purpose is the followinz. Take five parts of honey, one part of powdered tartar, and sixteen parts of wheat or barley malt, stir the whole in water of the temperature of 122~ F., and place in a fermenting heat; when the yeast will, as usual, be eliminated. The change which gluten or vegetable albumen undergoes in the different kinds of meal, when it becomes a ferment, consists apparently in an oxydation, since analysis shows that this ferment contains more oxygen than gluten does. It has been alrea;ly stated that yeast in its liluid condition readily putrefies, and becomes altogether useless for the process of fermentation. In order to preserve it for some time, it must be dried to such a degree as to resist spontaneous decomposition without losing its fermentative faculty; but completely dried yeast loses that properly, and does not recover it by being again moistened. Beer barm may be dried alter being washed several times with cold water, till the last quantity comes off clear; but the insoluble portion mast be allowxed to settle fully before the water is poured away from it. The residuum being freed as much as possible from water, by drainage and pressure between flannel cloths, is to be dried in the shade by a current of warm air as quickly as possible, with the aid of frequent turning over. It must be afterwards kept in dry earthen vessels. Yeast may also be preserved a short time in activity by being kneaded with as much barley or wheat flour as it can take up without losing the doughy consistence. Dried yeast has, however, always an impaired activity. The easiest and most certain method of preserving yeast in its primitive power, is by mixing it, after pressure in flannel, with as much pulverized sugar as will render it dry, and putting up the mixture in air-tight vessels. The fermentative power of yeast is destroyed by the following means: 1. as already stated, by making it completely dry either by the evaporation of the water, or its abstraction by alcohol; 2. by boiling, which if continued for ten minutes renders yeast quite inoperative; 3. by the action of such substances as dissolve out its essential constituents; by alkalis, for instance, since the particles of yeast seem to be operative only in their insoluble granular state; 4. by such substances as form combinations with it, and thereby either alter its nature, or at least increase the cohesion of its constituent parts, so that they can no lonrcer operate upon sweet liquors by the decomposing affinity of its ultimate particles. Such bodies are the acids, especially the mineral ones, tannin and most salts, particularly the metallic, which unite with the yeast into new compounds. The volatile oils which contain sulphuir exercise the same paralyzing influence upon yeast. The circumstances which promote, and are necessary to, the vinous fermentation are, conformably to the above views, the following:-1. The presence of the proper quantity of active yeast, and its proper distribution through the worts. If in the course of a slack fermentaion the yeast subsides to the bottom, the intestine motions cease entirely, but they may be excited anew by stirring up the ingredients, or rousing tile tun, as the brewers say.. A certain degree'of warmth, which should never be less than 51~ F., nor more than 86~; the temperature of from 68~ to 77~ being the most propitious for the FERMENTATION. 697 commencement and progress of fermentation. When other circumstances are the same, the rapidity of the fermentation is proportional to the temperature within certain limits, so that, by lowering it, the action may tbe nroderated at pleasure. 3. The fermentation proceeds the better and more equably the greater the mass of fermenting liquor, probably on account of the uniformly high templerature, as well as the uniform distribution of the active particles of the yeast by the greater energy of the intestine movements. 4. The saccharine solution must be sfficiently diluted with water; when too much concentrated it will not f-rment. Hence very sweet musts furnish wines containing much undecomposed sugar. i'or a complete fermentative action, one part of sugar shlould be dissolved in ten parts or wa;ter. Fermentation may be tempered or stopped: 1. by those means which render the yeast inoperative, particularly by the oils that contain sulphur, as oil of mustard; as also by the sulphurous and sullphuric acids. The opleration of the sulphurous acid in obstructingr the fermentation of must consists partly, no doubt, in its absorbing oxygen, whereby the elimination of the yeasty parti- es is prevented. The sulphurous acid, moreover, acts more powerfully upon fermenting liquors that contain tartar, as grape juice, than sullphuric acid. This acid decomposes the ta:.aric salts, and combining with their bases, sets the vegetable acid free, which does not interfere with the fermentationl; but the sulphurous acid operates directly upon tlie yeast: 2, by the separation of tile yeast, either with the filter or by subsidence; 3, by lowering the temperature to 45~ F. If tie fermenting mass become c;l r at this temperature, and be drawn off fiom the subsided yeast, it will not ferment again, though it should be heated to the proper pitch. The products of vinous fermentation are carbonic acid gas, and alcohol; of which the former escapes during the process, except in the case of the sparkling wines, like cham. paign, that are partially fermented in close vessels. The alcohol remains in the fermented liquor. 100 parts of sugar afford by complete decomposition nearly 50 parts of alcohol. According to Thenard, 100 parts of sugar are converted into 46'8 parts of carbonic acid, and 49-38 of alcohol; besides 3-82 parts of carbon otherwise employed, which the sugar contained, above what is present in the foimer two products. This chemist found in the fermented liquor 4 per cent. of an extractive matter, soluble in water, and having an acidulous reaction, to whose formation, probably, that excess of carbon may be necessary. In what way the action of the yeasty particles upon the saccharine substance is carried on in the vinous fermentation, or what may be the interior working of this process, is not accurately understood. The quantitative relation of the carbonic acid and alcohol to the sugar is pretty well made out; but the determination of the ultimate principles of the ferment itself, before and after the virious change, and of the residuum dissolved in the fermented liquor, has not been well ascertained. It is probable that the yeast undergoes in the proce-s a similar decomposition to that of the putrefactive, and that its elementary constituents enter into new combinations, and abstract so much carbon and hydrogen from the sugar, that the remainder, amounting to 96 per cent. of the whole, may constitute one atom of alcohol and one of carbonic acid. 3. The slimy or glutinous fermentation.-This process takes place in weak solutions of sugar, at ordinary fermenting temperatures, where, from defect of good yeast, the vinous fermentation cannot proceed. In such circumstances, from one part of sugar, one third part of gum is formed. According to Desfosses, however, 100 parts of sugar aflbrd 109-48 of cum or slime. This is formed when one part of sugar is dissolved in twenty parts of water, which had been previously boiled with washed barm or gluten, and then filtered. The process proceeds slowly and quietly, equally well in close vessels, as with contact of air, and continues at ordinary temperatures about 12 days; but it goes on more rapidly and completely at the heat of from 77~ to 86~ F. A small quantity of hydrogen and carbonic acid gas is disengaged, in the proportion of two to one by volume. The fermented liquor becomes turbid, and assumes a tough thready appearance, like a decoction of linseed. A small addition of sulphuric or sulphurous acid, of muriatic acid and alum, or of tannin, impedes this species of fermentation; because these substances combine, as in the vinous fermentation, with the ferment into an insoluble precipitate, unsusceptible of further chanze. In many wines, especially when bottled, this slimy fermentation occurs, and occasions their ropiness, which may be best remedied or prevented by the addition of as much tannin as will precipitate the dissolved mucous matter. This species of fermentation attacks very rapidly the rinsing waters of the sugar refiner, which always contain some fermentative gluten. A little alum is the best preventive in this case, because it precilpiates the dissolved ferment. 4. The acelous or sour fermen/ation.-In this process, alcohol, more or less dilute, is resolved into water and vinegar in consequence of the operation of the ferment; cxy 698 FERMENTATION. dizement of the alcohol being effected by the oxygen of the atmospherical air. The requisites of this process have been already detailed under the article ACETIC ACTD. They are,the presence of atmospherical air; alcohol diluted to a certain degree with water ferment or yeast, and a temperature above 66~ F. The most active ferinen s are such substances as have already passed into the acetous state; hence vinegar, especially when it contains some yeasty particles, or is combined with porous and spongy bodies, so as to multiply its points of contact with the vinous liquor, is particularly powerful. Commron yeast may also be employed for vinegar ferments, if it be imbued with a little vinecar, with leaven, crusts of bread soaked in vinegar, the stalks and husks of grapes, savwdust and shavings of beech or oak impregnated with vinegar, or the slimy sedimena of vinetar casks called rolther; all of which operate as ferments chiefly in consequence of the vinegar which they contain. The inside shavings of the staves of vinegar tuns act on the same principle. The acetous fermentation may, r oreover, go on along with the vinous in the same liquor, when this contains sugar as well as alcohol. Whilst the acidification of the alcohol is effected by the absorption of oxvyen from the atmosphere, th.e sugar becomes alcohol with disengagement of carbonic acid, and then passes into vinegar. Since most liquors intended;,r making vinegar, such as wine, juices of fruits, ales, &c., contain still a little sugar, they disengage always a little caibonic acid. Besides spirits, some other substances, such as gurm, the mucilage of plants, and starch paste, direcily ferment into vinegar. Sugar also seems to be convertible into vinegar without any vinous clianse. The albuminous matter of potato juice, precipilated by vinegar, serves as a proper ferment for that purpose, when added in its moist state to weak sirup. 5. See PUTREFACTION. Mr. William Black, in his treatise on Brewing, has, with much ingenuity and apparent truth, endeavored to show that the process of fermentation is strongly influenced by electricity, not only that of the atrosphere, as has been lonl klnown fiom the circuurrstace of beer and wine becoming speedily sour after thunderstorms, but the voltaic, produced by electric combinations of metals in the fermenting tuns. He therefore recoin. mends these tuns to be made with as little metallic work as possible, and to be insulated from the floor of the brewhouse. For the propriety of this advice he adduces some strikino' examples. Wort which had become stationary in. its fermentation, on being putnped out of square gyles imbedded in the floor, into casks placed upon wooden stillions, benan immediately to work very well, and gained about 6 degrees of attenuation wlkile throwing off its yeast. From the stagnation of the process in the gyles, he had in the morning predicted an approaching thunderstorm, which accordingly supervened in the course of the evening. In further support of his views lie instances the fact, that, in dairies where the milk is put into porcelain vessels, and placed upon wooden shelves, it is seldom injured by lightning; but when contained in wooden or leaden vessels, and placed upon the ground, it almost invariably turns sour in thundery weather. His general conclusion is, "that the preservation or destruction of beer depends upon electricity; and the most certain mode of preservation is to insulate as much as possible, both the squares and all other utensils or vessels connected with the brewing or storing of beer." Mr. Black further considers that unsoundness of worts is often the result of electricity excited between the mash tun and the copper. Why is beer liable to get spoiled in thunder-storms, though apparently well insulated in glass bottles? I shall conclude this article with Mr. Black's description of the phenomena of beer fermentation. In every regular process there are five distinct stages. In the first we see a substance like cream forming all round the edges of the gyle tun; which extends towards the centre until the whole is creamed over, constituting the first change. Next a fine curl appears like cauliflower, which also spreads over the square surface, and according to the strength and appearance of this curl, the quality of the fermentation may be predicated. This he calls the second stage. What is technically called tile stomach or vinous vapor now begins to be smelt, and continues to gain strength till the process is concluded. From the vinous energy of this odor, and the progressive attenuation of the wort, the vigor of the fermentation may be inferred. The experienced brewer is much guided in his operations by the peculiarity of this effluvium. The third chanse is when the cauliflower or curling top rises to a fine rocky or light yeasty head; and when this falls down, the fourth stage has arrived. Finally the head should rise to what is called close yeastv, having the appearance of yeast all over. About this period the gas becomes so powerful as to puff up occasionally in little bells or bladders about the size of a walnut, which immediately break. The bells should appear bright and clear. If they be opaque or whey colored, there is some unsoundness in the wort. The greal FERMENTATION. 599 point is to add just so much yeast as to carry the fermentation completely through these five changes at the regular periods. Tile term fermentation has bteen of late extended to several operations besides those formerly included under it. Tile phenomena wlic(h it ex'hibits under these different phases and the changes which it effects among the various sutjects of its operations, are no less striking and mysterious in their priiciple than important in their application to tile arts of life. Fermentations are now arranged into twelve classes-1, the alcoholic; 2, the glucosic or saccharine; 3, the viscous or mucous; 4, the lactic; 5, the ascetic; 6, the gallic: 7, the pectic; 8, the benzoilic; 9, te aic; 1 the immonaial; 10, the putrid; and 12, the fatty. Fermentation. in the most general sense, may be defined to be a spontaneous reaction, a chemical metamorplosis, excited in a mass of organic matter by tile mere presence of another substance, which neither extracts from, nor gives to, the matter which it decomposes any tilrin wlatever. This process requires the following conditions:-1. A temperature fromn 450 to 900 F.; 2. Water; 3. The contact of air; 4. The presence of a neutral organic azotize( matter, in a very small quantity, and of a crystalliza;ble non-azotized substance, in considerable quantity. The former is the fermentt, the latter undergoes fermeentation. In ordinary chemical actions we perceive one body unite to another to form a new compound; or one body turn another out of a combination, and take its place, in virtue of a superior affinity. These effects are foreseen and explained by the interveltion of that molecular force which governs all chemical operations, that attractive power which un'*es the particles of dissimilar bodies. Thus, also, in the ordinary phenomena of decomposition, we perceive the agency of heat at one time, at another of light, or of electricity; forces of which, though we are not acquainted with the essence, yet we know the exact effect under determinate circumstances. But fermentation, on the contrary, can be explained neither by the known laws of chemical affinity nor by the intervention of the powers of light, electricity, or heat. Fermentation reduces complex organic substances to simpler compounds, thereby reducing them nearer to the constitution of mineral nature. It is an operation analogous, in some respects, to that effected by animals upon their vegetable food. With a good microscope, any person:nay convince himself that ferment or yeast is an organized matter, formed entirely of globules, or of corpuscles slightly ovoid, from the three to the four thousandth part of an inch in diameter. Sometimes their surface seems to have a little tail, which has been regarded as a bud or germ attached to the mother cell. Whenever the fermentation begins, the yeast does not remain an instant idle. These small round bodies become agitated in all directions, and if the substance undergoina fermentation is mixed with an azotized matter, as in beer-worts, the corpuscles become larger, the small tails get developed, and on acquiring a certain size they separate from the parent globule, to live by themselves and give birth to new corpuscles.* In the fermentation of beer from malt, this series of multiplications produces a quantity of yeast seven times greater than what was added at the commencement. Were the above ingenious speculations demonstrated with certainty; we should be led to admit, in all these phenomena, actions truly vital, and a reproduction like that of buds in the vegetable kingdom. The existence of a vital force seems to be rendered probable by the fact that in incomplete fermentation, such as that of fine syrup with too little yeast, the ferment loses its properties and powers. If, however, we add to the solution of pure sugar an albuminous substance, a caseous or fleshy matter, the development of yeast becomes manifest, and an additional quantity of it is found at the end of the operation. Thus with nourishment, ferment engenders ferment. It is for this reason that a little fermenting must, added to a body of fresh grape-juice, excites fermentation in the whole mass. These effects are not confined to alcoholic fermentation. The smallest portions of sour milk, of sour dough, or sour juice of beet-root, of putrefied flesh or blood, occasion like alterations in fresh milk, dough, juice of beet-roots, flesh, and blood. But further, and which is a very curious circumstance, if we put into a liquid containing any fermenting substance, another in a sound state, the latter would suffer decomposition under the influence of the former. If we place urea in presence of beer- yeast, it experiences no change; while if we add to it sugar-water in a fermenting state, the urea is converted into carbonate of ammonia. We thus possess two modes of decomposition, the one direct, the other indirect. Although yeast has all the appearances of an organized substance, it is merely by analogy that its multiplication by growth is assumed, for this is a phenomenon very difficult of experimental demonstration. When blood, cerebral substance, gall, pus, and such like substances, in a putrid state, are laid upon fresh wounds in animals, von iting, de* M. Turpin, AM. Cagniard Latour, M. Quevenne, and Professor Mitscherlich. 700 FERMENTATION. debility, and death soon supervene. The scratches from bones in putrid bodies have been often the causes of disease and death to anatomists. The poison in bad sausages is of the same class of ferments. In Wurtemberg, where sausages are prepared from very miscellaneous matters, as blood, livers, brains, and offal of many other kinds, with bread, meal, salt, and spices, fatal results fromn eating them are not uncommon. Death in these cases is preceded by the gradual wasting of the muscular fibre, and of all the like constituents of the human body; so that the patient becomes emaciated, dries into a complete mummy, and soon expires. The cadaver is stiff as if frozen, and is not subject to putrefaction. During the progress of tie sausage disease, the saliva becomes viscid, and emits an offensive smell. No peculiar poison can be detected by analysis in the sausa(ges; but they are rendered wholesome foou for animals by the action of alcohol, or by that of boiling water, which destroy the noxiousfomes without acquiring it tlhemrselves; and thus decompose the putrefactive ferment of the sausages. When this, however, passes unillhanged through the stomach into the circulating system, it imparts its peculiar action to the constituents of the blood, operating upon it as yeast does upon wort. Poisois of a like kind are pioJluced by the body itself in some diseases. In plague, small-pox, measles, &c., substances of a peculiar fermertative nature are generated from the blood, which are capable of inducing in the blood of a healthy person a deconilposition like that of hichll themselves are the subjects. The morbid virus reproduces itself, and multiplies indefinitely, just as the particles of yeast do in the fermentation of beer. The temperature of boiling water, and alcohol applied to matters imbued with such poisonous secretions, renders their poison inert. Many acids, chlorine, iodine, bromine, empyreumatic oils, smoke, Creosote, strong decoctloa of coffee, have the same salutary effect. All these agents are known to counteract fer. mentation, putrefaction, and that dry wasting of organic matter called eremacausis, or sloW combustion. It is most deserving of remark that the poisons chemically neutral or alkaline, such as those of small-pox in man, and of typhus ruminantinum in cows, lose their baneful power when subjected to the action of the stomach; whereas that of bad sausages, which is acid, resists the modifying power of the digestive organs. Alcoholic fermentation has been copiously discussed in the Dictionary. I may here add that ammonia, being a product of that change in solution of pure sugar, proves the presence of azote in the yeast; and that sulphuretted hydrogen, being made manifest in the disengaged gaseous products, by their blackening paper imbued with acetate of lead, proves the presence of sulphur. The acid liquor accompanying yeast may be washed away, without impairing materially its fermenting power, while the acid so removed has of itself no such virtue. Yeast, freed from all soluble matters by water, alcohol, and ether, contains, independently of ashes-carbon, 50-6; hydrogen, 73; azote, 15; oxygen, sulphur, and phosphorous, 27'1, in 100 parts. Viewed atomically, yeast bears a close analogy to albumen. Like albuminous matter, yeast takes a violet tint with muriatic acid, and it may be replaced as ferment by gluten. Caseum (the curd of milk) and flesh operate the same effect. All these fermentative powers have the same globular appearance in the microscope with yeast. When the activity of yeast has been destroyed by heat, &c., it can be restored by the positive energy of the voltaic battery, which causes its combina. tion with oxygen. The best proportion of sugar and water, for exhibiting the phenomena of fermentation, is 1 of the former to 3 or 4 of the latter, and 5 parts of sugar to 1 of fresh yeast may be added; though in the course of fermentation, 100 parts of sugar do not consume 2 parts of yeast, estimated in the dry state. The quickest fermenting temperature is from 68D to 86~. A very little oil of turpentine or creosote, or of the mineral acids, prevents or stops fermentation completely; oxalic and prussic acids have the same effect, as also corrosive sublimate and verdigris. It has been known from time immemorial in Burgundy, that a little red precipitate of mercury, when added to the must-tun, stopped the fermentation. All alkalies counteract fermentation, but when they are saturated it recommences. The first person who described the microscopic globules of yeast with precision was Desmazieres, who arranged them among the mycodermes (fungus-skinned), under the name of mycoderma cerevisice. They have not the flattened form of the globules of blood, but are rather egg-shaped. One small black point may be seen on their surface, which, after some days, is associated with 3, 4, or 5 others. Their average diameter is from 5~ to -1b- of an inch. Sometimes more minute globules cluster round one of ordinary size, and whirl about with it, when the liquor in which the globules float is agitated. Fresh yeast loses, by drying, 68 parts in the 100, and becomes solid, horny-looking, and semitransparent, breaking readily into gray or reddish fragments. With water, it resumes immediately its pristine appearance. When fresh yeast is triturated with its own weight of white sugar, it forms a liquid possessing the fluidity of oil of l almonds and a yellow color. The globules continue unchanged, except perhaps becoming FERMETJ' ATIOIN. 70( somewhat smaller. Yeast in the dry state retains its fermentative virtue for a long time. Saccharine Fermentation is that by which starch and dextrine are converted into sugar, as shown remarkably in the action of diastase upon these bodies. If we mix 2 parts of starch paste with 1 part of dry gluten, and keep the mixture at a temperature of from 122~ to 140~ Fahr., we obtain a good deal of sugar and dextrine. Some lactic acid is also formed. Flour paste, long kept, spontaneously produces sugar by a like reaction. See FERMENTATION 11n he Dictionary. Lactic Fermentation.-Almost all azotized organic matters, after being modified by the contv ct of air, become capable of giving rise to this fermentation. Oxygen does not come into play, except as the means of transforming the animal substances into a ferment. Diastase and caseum are well adapted to exhibit this change. The body that is to furnish the lactic acid may be any one of the neutral vegetable matters, possessing a like composition with lactic acid, such as cane-sugar, grape or potato sugar, lextrine, and sugar of milk. All the agents which stop the alcoholic, stop also the lactic fermentation; while diastase and caseum are its two best exciters. For producing abundance of lactic acid, we have merely to moisten malt, to expose it to the air for a few days, then to triturate it with a quantity of water, and leave the emulsion for some days more in the air, at a temperature between 670 and 860 F. We then saturate the liquor with chalk, after having filtered it, and thereby obtain the lactate of lime which may be crystallized in alcohol, to deprive it of the dextrine and earthy phosphates; and then decomposed by sulphuric acid. Lactic./cid, formed from curd (caseum), exhibits more remarkable phenomena. Tihus whfn mil;k is left alone for some time it becomes sour, and coagulates. The doaaulum rs formed of caseum and butter; while the whey of it contains sugar of milk and some salts. The coagulation of the caseum has been occasioned by the lactic acid, which was generated in consequence of an action which the caseum itself exercised upon the sugar of milk. Thus with the concourse of air, the caseum becomes a ferment, and excites the conversion of the sugar of milk into lactic acid. The lactic acid in its turn coagulates the caseum, which in the consolidation of its particles attracts the butter The caseum then ceases to act upon the sugar of milk, and consequently produces no more lactic acid. But now, if the lactic acid already formed be saturated, the caseum will redissolve. and the phenomena will recommence in the same order. This is easily done by adding a due dose of bicarbonate of soda to the soured milk. In the course of 30 hours a fresh portion of lactic acid will be generated, and will have coagulated the4nilk again. We may also add some sugar of milk to the liquid, and to a certain extent convert it into lactic acid. Milk boiled, and kept from contact of air, will not coagulate, and remains fresh for many months. Animal membranes, modified by exposure to moist air for some time, form a true ferment for the lactic fermentation, and acidify solutions of sugar, dextrine, and gum, but the membranes must not be putrescent. Cane-sugar, starch-sugar, and sugar of milk, by assuming or losing a little water, acquire the constitution of lactic acid. Viscous or Mucous Fermentation.-Every one is acquainted with this spontaneous modification of white wine and ale, which gives them a stringy or oily aspect, and is called in French graisse, or fat of wines, and in English the ropiness of beer. The viscous fermentation may be excited by boiling yeast with water, and dissolving sugar in the decoction, after it has been filtered. The syrup should have a specific gravity from 1-040 to 1'055, and be kept in a warm place. It soon assumes the consistence and aspect of a thick mucilage, like linseed tea, with the disengagement of a little carbonic acid and hydrogen, in the proportion of 2 or 3 of the former gas to 1 of the latter. A ferment of globular texture like that of yeast is formed, which is capable of producing viscous fermentation in any saccharine solution to which it is added, provided the temperature be suitable. The viscid matter being evaporated to dryness forms transparent plates, of a sub-nauseous taste, and soluble in water, but less easily than gum arabic. Its mucilage is, however, thicker than that of gum, and yields with nitric acid, oxalic acid, but no mucic acid. Four parts of sugar, treated as above described, furnish 2'84 of unchanged sugar, and 1'27 of the mucilage; from which it appears that water becomes fixed in the transformation. Muriatic, sulphuric, sulphurous acids, and alum, prevent the production of the viscous fermentation, by precipitating its ferment. It is pro'bly the soluble portion of gluten which is the cause of this species of fermentation. It has been found, accordingly, that tannin, which precipitates the said glutinous ferment, completely stops the viscous fermentation, or graisse, of wines. It is owing to the tannin which the red wines derive from the grape-stalks, with which.hey are long in contact during fermentation, that they are preserved from this malady Af the white wines. The gluten of must is of two kinds the one soluble in virtue of _______Ii________________________ 702 FERMENTATION. the alcohol and tartaric acid, and producing the viscous, the other inssluble, and producing the alcoholic fermentation. The art of the wine maker consists in precipitating the injurious ferment, without impeding the action of the beneficial one; an art of considerable delicacy with regard to sparkling wines. Acid Fermentation has been fully discussed under acetic acid. It requires the pres. ence of ready formed alcohol and air. The lactic fermentation, on the contrary, may take place with starchy or saccharine substances, without the intervention of alcohol o0 constant exposure to the atmosphere; and when once begun, it can go on without air. Acetification has a striking analogy with nitrification, as is shown by the necessity of a high temperature, and the utility of porous bodies for exposing the liquid on a great surface to the air. BeUzoic Fermentation is that which transforms the azotised neutral crystalline matter,. existing in bitter almonds, which has no action upon the animal economy, into new and remarkable products, among others the hydrure of benzoile and hydrocyanic (prus ic) acid, which together constitute the liquid, called oil, or essence, of bitter almonds, a compound possessed of volatility and poisonous qualities. The attentive study of this fermentation has revealed a great fact in vegetable physiology, the spontaneous production, by means of certain artifices, of certain volatile oils, not pre-existing in the plants, yet capable of being generated in the products of their decomposition. The volatile oil of bitter almonds constitutes in this respect a starting point, frorm which have proceeded the oil of mustard, the oil of spirea, and which will likely lead to other discoveries of the same kind. See ALMOND and AMYGDALINE. Sinapic Fermentation is that by which the oil of mustard is formed, and which takes place by the contact of water, under certain conditions, of too refined and scientific a natire for this practical work. Pectic Fermentation.-Pectic acid may be obtained from the expressed juice of cat rots. and it seems to be formed in the process of extraction by the reaction of albuminc in the carrots upon a substance called pectine; a transformation analogous therefore with that which takes place in the formation of the essence of bitter almonds. Gallic Fermentation.-Gallic acid does not exist ready formed in nut-galls, but Is generated from their tannin when they are ground, made pasty with water, and exposed to the air. This conversion may be counteracted by the red oxide of mercury, alcohol, sulphuric, muriatic, and nitric acids, bromine, essence of turpentine, creos(te, oxalic, acetic, and prussic acids. The tannin disappears in the sequel of the above metamorphosis. Fatty Fermentation.-All fats are transformed by the action of an alkaline or other base into certain acids, the stearic, margaric, the oleic, ethalic, &c. When these acids are once formed, they can not by any means, hitherto known, be reconverted into the primitive fat. By the fixation of water in the acid and the base (called glycerine), a change is effected which can not be undone, because the glyceric base is incapable by itself to displace the water, once combined in the hydrated fat acid. The circumstances necessary to the fatty fermentation, are like those of other fermentations; namely, the cooperation of an albuminoid matter, along with water, and a temperature of from 60~ to 86~ F.; under these conditions, the matter becomes warm, and assumes speedily the charar ter of rancidity; acid is generated, and the carbonate of soda can then form salts, while the fatty acid is liberated; a circumstance impossible when the fat was acted upon in the neutral state. This altered fat, treated with water, gives up to it glyric alcohol. Digestive Fermentation.-Digestion of food may be considered in its essential features as a peculiar fermentative process. The gastric juice is a genuine ferment. Tiedmann, Gmelin, and Prout, have shown that the gastric juice contains muriatic acid; and Eberli has made interesting experiments on the digestion of food out of the body, with water containing a few drops of the same acid. He observed that when this liquid con tained none of the mucous secretion of the stomach, it did not dissolve the aliments put into it; but with a little of that mucus it acquired that property in an eminent degree. Even the mucus of the bladder had a like effect. Schwann and Vogel have produced this digestive principle in a pure state, called by them pepsine, as obtained most abundantly from the stomachs of swine. The glandular part of that viscus being separated from the serous, is cut into small pieces, and washed with cold distilled water. After digestion for 24 hours, that water is poured off, and fresh water is poured on. This operation is repeated for several days, till a putrid odor begins to be felt. The watery infusion thus obtained is precipitated by acetate of lead. This white flaky precipitate contains the pepsine, accompanied with much albumen. It is then washed, mixed with water, and subjected to a stream of sulphuretted hydrogen. The whole being nov hi own on a filter, the coagulated albumen remains on the paper, along with the sul FERMENTATION. 703 phuret of lead, while the pepsine liquor passes, associated with some acetic acid. If to this liquor a very small quantity of muriatic acid be added, it becomes capable of carry-.ig on artificial digestion. Dry pepsine may be obtained by evaporating the above filtered liquor on a water bath, to a syrupy consistence, then adding to it absolute alcohol, which causes a bulky whitish precipitate. This dried in the air constitutes pepsine. It contains a minute quantity of acetic acid, which may be removed completely, by heating it some hours on the water bath. The white powder then obtained is soluble in water, and betrays the presence of no acid whatever. According to Vogel, this substance is composed of, carbon, 57*72; hydrogen, 5-67; azote, 21'09; oxygen, &c., 15.52 =100. Vogel has proved the analogy between the action of pepsine and diastase by the following experiment:He dissolved two grains of pepsine in very weak muriatic acid, and put into this liauor heated to 81~ F., small bits of boiled beef. In the course of a few hours the pieces became transparent on their edges, and not long after they were completely dissolved. He now added fresh morsels in succession, till those last put in remained unchanged. He found by analysis, that 1-98 grains of the pepsine were left, showing how minute a portion of this ferment was necessary to establish and eflect digestion. In fact, we may infer that pepsine, like yeast, serves to accomplish digestion without any waste of its own substance whatever, or probably with its multiplication. Rennet, with which milk is coagulated in making cheese, is somewvhak, f the same nature as pepsine. It has been called chymosine. But the simplest digesting liquor is the following:If 10,000 parts of water by weight be mixed with 6 parts of ordinary muriatic acid and a little rennet, a liquor is obtained capable of dissolving hard boiled white of egg, beef, gluten, &c., into a transparent jelly in a few hours. ~.mmoniacal Fermentalion.-Under this title may be described the conversion of urea into carbonate of ammonia under the influence of water, a ferment, and a favorable temperature. Urea is composed in atoms; reckoned In volumes, Carbon 4; hydrogen 8; azote 4; oxygen 2; which by fixing 4; - 2; give 4; 12; 4; 4: which is 4 vol. of carbonic acid, and 8 of ammonia; equivalent to ordinary carbonate of ammonia. The fermentation of urea plays an important part in the reciprocal offices of vegetable and animal existence. By its conversion into carbonate of ammonia, urea becomes a food fit for plants; and by the intervention of the mucous ferment which urine contains. hat conversion is effected. Thus the urea constitutes a neutral and innocuous substance while it remains in the bladder, but is changed into a volatile, alkaline, and acrid substance, when it is acted upon by the air. Yeast added to pure urea mixed with water, exercises no action on it in the course of several days; but when added to urine, it soon causes decomposition, with the formation of carbonate of ammonia, and disengagement of carbonic acid. The deposite on chamberpots ill-cleaned acts as a very powerful ferment on urine, causing the complete decomposition of fresh urine in one fifth of the time that would otherwise be requisite. Nitrous Fermentation, as exhibited in the formation of nitric acid from the atmosphere, and consequent production of nitrates in certain soils, has been with much probability traced to the action of ammonia on oxygen, as the interr-edium or ferment. Caseous and putrid Fermentations.-Curd is convertea into cheese, when after being coagrulated by rennet, it is left to itself under certain conditions; and this constitutes the true distinctive character of caseum. In the. production of cheese there is evidently the intervention of a peculiar ferment which is gradually formed, and the decomposition of the curd intonew products. For animal and vegetable matters to run into putrefaction, they must be in contact with air and water, at a certain temperature; viz., between the freezing and boiling points of water. The contact of a putrid substance acts as a ferment to fresh animal and vegetable matters. The reagents which counteract fermentation in general stop also putrefaction. In this process, myriads of microscopic animalcules make their appearance, and contribute to the destruction of the substances. A dispute having taken place between some distillers in Ireland and officers of Excise, concerning the formation of alcohol in the vats or tuns by spontaneous fermen. tation, without the presence of yeast, the Commissioners of Excise thought fit to cause a series of experiments to be made upon the subject, and they were placed under my general superintendence. An experiment was made on the 6th of October, with the following mixture of corn: 704 FERMENTATION. 2 Bushels of Barley, weighing - - - 100llbs. 5 oz. 2 Bushel of Malt, - - - - - 21 7 Bushel of Oats - - - - - 20 12 Total, 3 Bushels, weighing - - -142 8 The bruised corn was wetted with 26 gallons of water at the temperature of 160~ F., and, after proper stirring, had 8 gallons more of water added to it at the average tem. perature of 194~. The mash was again well stirred, and at the end of 45 minutes the whole was covered up, havinr at that time a temperature of 138~ F. Three hours afterward, 16 gallons of wash only were drawn off; being considerably less than should have been obtained, had the apparatus been constructed somewhat differently, as shall be presently pointed out. The gravity of that wash was 1'060, or, in the lan. guage of the distiller, 60P. After a delay of two hours more, twenty addit'inal gallons of water at the temperature of 20() were introduced, when the mash was well stirred, and then covered up for two hours, at which period 23 gallons of fine worts of specific gravity 1-042 were drawn off. An hour afterward 12 gallons of water at 200- were added to the residual grains, and in an hour and a half 11 gallons of wort of the density 1'033 were obtained. Nxt morning the several worts were collected in a new mash tun. They consisted of 48 gallons at the temperature 80~, and of a specific gravity 2*0465 when reduced to 603. Being set at 80~, fermentation soon commenced; in two days the specific gravity had fallen to 1-0317, in three days to 1-018, in four days to 1-013, and in five days to 1.012, the temperature having at last fallen to 780 F. The total attenuation was therefore 34~O, indicating the production Df 3-31 gallons of proof spirit, while the produce by distillation in low wines was 3-22; and by rectification in spirits and feints it was 3'05. The next experiment was commenced on the 12th of October, upon a similar mixture of corn to the preceding. 48 gallons of worts of 1'043 specific nravity were set at 820 in the tun, which next day was attenuated to 1-0418, in two days to 1-0202, in three days to 1-0125, and in five days to 1'0105, constituting in the whole an attenuation of 32:~, which indicates the piuduction of 3'12 gallons of proof spirits; while the produce of the first distll; tion was 2-93 in low wines, and that of the second in feints and spirits was 2*66. In these experiments the wash, when fermenting most actively, seemed to simmer and boil on the surface, with the emission of a hissing noise, and the copious evolution of carbonic acid gas. They prove beyond all doubt that much alcohol may be generated in grain worts without the addition of yeast, and that, also, at an early period; but the fermentation is never so active as with yeast, nor does it continue so long, or proceed to nearly the same degree of attenuation. I was never satisfied with the construction of the mash tun used in these experiments, and had accordingly suggested another form, by which the mash mixture could be maintained at the proper temperature during the mashing period. It is known to chemists that the diastase of malt is the true saccharifying ferment which converts the fecula, or starch of barley and other corn, into sugar; but it acts beneficially only between the temperatures of 1453 and 168~ F. When the temperature falls below the former number, saccharification langu.shes; and when it rises much above the latter, it is entirely checked. The new mash tun was made of sheet zinc, somewhat wider at bottom than top; it was placed in a wooden tun, so much larger as to leave an interstitial space between the two of a couple of inches at the sides and bottom. Through this space a current of water at 1603 was made to circulate slowly during the mashing period. Three bushels of malt, weighing 125 lbs. 3 oz., were wetted with 30 gallons of water at 1670, and the mixture being well agitated, the mash was left covered up at a temperature of 1403 during three hours, when 19 gallons of fine worts were drawn off at the specific gravity of 1-0902 or 90*2J. Twenty gallons more water at 167~ were then added to the residuum, which afforded after two hours 28 gallons of wort at the gravity 1*036; 12 gallons of water at 1670 were now poured on, which yielded after other two hours 15 gallons at the gravity 1-0185. Forty gallons of fine worts at 1-058 gravity and 68~ temperature were collected in the evening of the same day, and let into the tun with 5 per cent. of yeast. The attenuation amounted in six days to 54~. The third wort of this brewing, amounting to 15 gallons, being very feeble, was mixed with 7 gallons of the first and second worts, put into a copper, and concentrated by boiling to 11 gallons, which had a gravity 1-058 at 603 F. They were separately fermented with 5 per cent. of yeast, and suffered an attenuation of 484~. The produce of spirit from both indicated by the attenuation was 5-36 gallons; the produce in low wines was actually 5'52, and that in spirits and feints was 5'33, being a perfect accord, ance with the Excise tables. The next experiments were made with a view of determining at what elevation of temperature the activity or efficiency of yeast would be paralysed, and how far the FERMENTATION. 705 attenuation of worts could be pushed within six hours, which is the time limited by law for worts to be collected into the tun, from the time of beginning to run from the coolers. When worts of the gravity 1'0898 were set at 96~ Fahr., with 5 per cent. of yeast, they attenuated 26.9~, in 6 hours; worts of 1'0535 gravity set at 110 with 5 per cent. of yeast, attenuated 16~ in about 5 hours; but when worts of 1P0533 were set, as above, at 120~, they neither fermented then, nor when allowed to cool; showing that the activity of the yeast was destroyed. When fresh yeast was now added to the last portion of worts, the attenuation became 5-8 in 2 hours, and 28'43 in 3 days; showing that the saccharine matter of the worts still retained its fermentative faculty. Malt worts, being brewed as above specified, were set in the tun, one portion at a tenmperature of 70~, with a gravity of 1-0939, and 5 per cent. of yeast, which attenuated 66~ in 3 days; other two portions of the same gravity were set at 120~ with about 10 per cent. of yeast, which underwent no fermentative change or attenuation in 6 hours, all the yeast having fallen to the bottom of the tuns. When these two samples of worts were allowed, however, to cool to from 74~ to 720, fermentation commenced, and produced in two days an attenuation of about 79~. It would appear, from these last two experiments, that yeast to the amount of 5 per cent. is so powerfully affected by strong worts heated to 1200 as to have its fermentative energy destroyed; but that when yeast is added to the amount of 10 per cent., the 5 parts of excess are not permanently decomposed, but have their activity merely suspended till the saccharine liquid falls to a temperature compatible with fermentation. Yeast, according to my observations, when viewed in a good acromatic microscope, consists altogether of translucent spherical and spheroidal particles, each of about the 6000th part of an inch in diameter. When the beer in which they float is washed away with a little water, they are seen to be colorless; their yellowish tint, when they are examined directly from the fermenting square or round of a porter brewery, being due to the infusion of the brown malt. The yeast of a square newly set seems to consist of particles smaller than those of older yeast, but the difference of size is not considerable. The researches of Schulze, Cagniard de la Tour, and Schwann, appear to show, that the vinous fermentation, and the putrefaction of animal matters, processes which have been hitherto considered as belonging entirely to the domain of chemical affinity-are essentially the results of an organic development of living beings. This position seems to be established by the following experiments: 1. A matrass or flask containing a few bits of flesh, being filled up to one third of its capacity with water, was closed with a cork, into which two slender glass tubes were cemented air-tight. Both of these tubes were passed externally through a metallic bath, kept constantly melted, at a temperature approaching to that of boiling mercury. The end of one of the tubes, on emerging from the bath, was placed in communication with a gasometer. The contents of the matrass were now made to boil briskly, so that the air contained in it and the glass tubes was expelled. The matrass being then allowed to cool, a current of atmospherical air was made constantly to pass through it from the gasometer, while the metallic bath was kept constantly hot enough to decompose the living partic -s in the air. In these experiments. which were many times repeated, no infusoria or fungi appeared, no putrefaction took place, the flesh underwent no change, and the liquor remained as clear as it was immediately after being boiled. As it was found very troublesome to maintain the metallic bath at the melting pitch, the fol-lowing modificationa of the apparatus was adopted in the subsequent researches: A flask of three ounces ca'acity, being one fourth filled with water and flesh, was closed with a tight cork, secured in its place by wire. Two glass tubes were passed through the cork; the one of them was bent down, and dipped at its end into a small capsule containing quicksilver, covered with a layer of oil; the other was bent on leaving the cork, first into a horizontal direction, and downward for an inch and a half, afterward into a pair of spiral turns, then upward, lastly horizontal, whence it was drawn out to r point. The pores of the cork having been filled with caoutchouc varnish, the contents of the flask were boiled till steam issued copiously through both of the glass tubes, and the quicksilver and oil became as hot as boiling water. In order that no living partides could be generated in the water condensed beneath the oil, a few fragments of corrosive sublimate were laid upon the quicksilver. During the boiling, the flame of a spirit lamp was drawn up over the spiral part of the second glass tube, by means of a glass chimney placed over it, so as to soften the glass, while the further part of the tube was heated by another spirit lamp, to prevent its getting cracked by the condensation of the steam. After the ebullition had been kept up a quarter of an hour, the flask was allowed to cool, and get filled with air through the hot spiral of the second tube. When the contents were quite cold, the end of this tube was hermetically sealed, the part of it between the point and the spiral was heated strongly with the flames, and the lamps were then withdrawn. The matrass contained now nothing but 46 706 FERRIC ACID. boiled flesh and gently ignited air. The air was renewed occasionally through the second tube, its spiral part being first strongly heated, its point then broken off, and connected with a gasometer, which caused the air to pass onward slowly, and escape at the end of the first tube immersed in the quicksilver. The end of the second tube was again hermetically closed, while the part interjacent between it and the spiral was exposed to the spirit flame. By means of these precautions, decoctions of flesh were preserved, during a period of six weeks, in a temperature of from 143 to 203 R. (63-~ to 77~ F.), without any appearance of putrefaction, infusoria, or mouldiness: on opening the vessel, however, the contents fermented in a few days, as if the- had been boiled in the ordinary manner. In conducting such researches, the greatest pains must be taken to render the cork and junctions of the glass tubes perfectly air-tight. The following more convenient modification of the experiment, but one equally successful and demonstrative, was arranged by F. Schulze. The glass tubes connected with the flask were furnished each with a bulb at a little distance from the cork; into one of which globes caustic alkaline ley being put, and into the other strong sulphuric acid, air was slowly sucked through the extremity of the one tube, while it entered at the other, so as to renew the atmosphere over thp decoction of flesh in the flask. In another set of experiments, four flasks being fillb I with a solution of canesugar containing some beer-yeast, were corked and plunged in boiling water till they acquired its temperature. They weie then taken out, inverted in a mercurial bath, uncorked, and allowed to cool in that position. From one third to one fourth of their volume of atmospherical air was now introduced into each of the flasks; into two of them through slender glass tubes kept red hot at a certain point, into the other twG through glass tubes not heated. By analysis it was found thi the air thus heated contained only 19*4 per cent. of oxygen, instead of 20-8; but, to compensate for this deficiency, a little more air was admitted into the two flasks connected with the heated tubes than into the two others. The flasks were now corked and placed in an inverted position, in a temperature of from 10' to 143 R. (54.' to 63k' F.). After a period of from four to six weeks, it was found that fermentation had taken place in both of the flasks which contained the non-ignited air —for, in loosening the corks, some of the contents were proiected with force —but, in the other two flasks, there -was no appeai ince of fermentation, either then, or in double the time. As the extract of nux vomica is known to be a poison to infusoria (animalcules), but not to vegetating mould, while arsenic is a poison to both, by these tests it was proved that the living particles instrumental to fermentation belonged to the order of plants of the confervoid family. Beer yeast, according to Schwann, consists entirely of microscopic fungi, in the shape of small oval grains of a yellowish white color, arranged in rows oblique to each other. Fresh grapes must contain none of them; but after being exposed l J the air at 20~ R., for 36 hours, similar grains become visible in the microscope, ai. may be observed to grow larger in the course of an hour, or even in half that time. A few hours after these plants are first perceived, gas begins to be disengaged. They multiply greatly in the course of fermentation, and at its conclusion subside to the bottom of the beer in the shape of a yellow white powder. FERRIC ACID. This new compound having been prescribes as a source of supplying oxygen to persons confined in diving-bells and in mines, by M. Payerne, in a patent recently granted to him, merits notice in a practical work. M. Fremy is the discoverer of this new acid, which he obtains in the state of ferrate of potash, by projecting 10 parts of dry nitre in powder upon 5 parts of iron filings, ignited in a crucible; when a reddish mass, containing much ferrate, of potash, is formed. The preparation succeeds bht when a large crucible, capable of holding about a pint of water, is heated so strong.y that the bottom and a couple of inches above it, appear faintly, but distinctly red, in which state the heat is just adequate to effect due deflagration without decomposition. An intimate mixture of about 200 grains of dried nitre with about one half its weight of the finest iron filings, is to be thrown at once upon the side of the crucible. The mixture will soon swell and deflagrate. The crucible being taken from the fire, and fhe ignited mass being cooled, is to be taken DUt with an iron spoon. pounded, immediately put into a bottle, and secluded from the air, in which it would speedily attract moisture, and be decomposed. It is resolved by the action of water, especially with heat, into oxygen gas, peroxide, and nitrate Df iron.. Mr. J. D. Smith prepares the ferrate of potash by exposing to a full red heat a mixhlre of finely powdered peroxide of iron with four times its weight of dry nitre. It has an amethyst hue, but so deep as to appear black, except at the edges. Oxygen is rapidly evolved by the action of the sulphuric or nitric acid upon its solution. He conEiders the atom of iron to exist in this compound, associated with 3 atoms of oxygen, or double the proportion of that in the red oxide. Hence 52 grains of pure ferric actl FIBRE, VEGETABLE. 707 should give off 12 grains of oxygen, equal to about 85 cubic inches; but how much of the ferrate of potash may be requisite to produce a like quantity of oxygen cannot be stated, from the uncertainty of the operation by which it is produced. FERRIC-CYANIDE OF POTASSIUM, or Red Prussiale of Potash. This beautiful and useful salt, discovered by L. Gmelin, is prepared by passing chlorine gas through a weak solution of the prussiate of potash (ferro-cyanide of potassium) till it ceases to affect solution of red sulphate of iron, taking care to agitate the liquid all the while, and not to add an excess of chlc-;ne. On looking through the weak solution to the flame of a candle, one may see tht period of change from the greenish to the red hue, which indicates the completion of the process. The liquor being filtered and evaporated in a dish with upright sides, will eventually afford crystalline needles, possessed of an almost metallic lustre, and a yellow color, inclining to red. These being dissolved and recrystallized, will become extremely beautiful. This salt is composed of 33'68 parts of potassium, 16-48 of iron, and 47'84 of cyanogen. It is therefore a dry salt. It dissolves in 38 parts of cold water, and as it forms then the most delicate test of the protoxide of iron, is very useful in Clorometry.-See ALKALIMETRY. *The solution of this salt affords the following colored precipitates with the solutions )f the respective metals:Titanium - - - - Brownish yellow. Uranium - - - - Reddish brown. Manganese - - - - Brownish gray. Cobalt - - - - Deep reddish brown. Nickel - -. Yellowish brown. Copper - - - - Dirty yellowish brown. Silver - - - Orange yellow. Mercury - - - - Yellow, with both the protoxide and peroxide salts. Tin - - - - White. Zinc - - - Orange Yellow. Bismuth - - - Yellowish brown. Lead - - - No precip. Iron protoxide - - - - Blue. - peroxide - - No precip. The ferric-cyanide of potassium has been introduced into dyeing and calico-printing. In case an excess of chlorine has been used in preparing the above salt, Posselt r-ortmnends to add to its solution, when near the crystalline point, a few drops of pouash lye, in order to decomnpose a green substance that is present, which takes place w;th the precipitation of a little peroxide of iron. FERROCYANATE, or, more correctly, FERROCYANIDE. (Ferrocyanure, Fr.; Eisencyanid, Germ.' Several compounds of cyanogen and metals possess the property of uniting together into double cyanides; of which there are none so remarkable in this respect, as the protocyanide of iron. This appears to be capable of combining with several simple cyanides, such as that of potassium, sodium, barium, sltontium, calcium, and ammonium. The only one of these double cyanides of any importance in manurfactlres is the first, which' is described under its commercial name, PRUSSIATE OF POT ASH. FERROPRUSSIATES; another name for Ferrocyanides. FIBRE, VEGETABLE, called also LIGNINE (Ligneux, Fr.; Pflanzen-faserstoff, Germ.), is the most abundant and general ingredient of planIs, existing in all their parts, the root, the leaves, the stem, the flowers, and the fruit; amounting in the compact wood to 97 or 98 per cent. It is obtained in a pure state by treating saw-dust successively with hot alcohol, water, dilute muriatic acid, and weak potash ley, which dissolve, first, the resinous; second, the extractive and saline matters; third, the carbonate and phosphate if lime; and, lastly, any residuary substances. Ligneorls fibres, such as saw-dust, powdered barks, straw, hemp, flax, linen, and cotton cloth, are convertible by the action of strong sulphuric acid into a gummy substance analogous to dexirine, and a sugar resembling that of the grape. If we put into a Riass mortar 24 parts, by weight, of dry old cordage, chopped small, and sprinkle over it 34 parts of sulphuric acid, by degrees, so as to avoid heating the mixture, while we constantly stir it; and if, in a quarter of an hour, we triturate the mass with a glass pestle, the fibres will disappear without the disengagement of gas. A tenacious mucilage will be produced, almost entirely soluble in water. The gum being thus formed, may be separated from the acid by dilution with water, and addition of the requisite quantity of chalk; then straining the saturated liquid through linen cloth, concentrating it by evaporation, throwing down any remaining lime by oxalic 708 FIBRINE. acid, filtering anew, and mixing the mucilage with alcohol in great excess, which wil take up the free acid, and throw down the gum. From 24 parts of hemp fibres thls treated, fully 24 parts of a gummy mass may be obtained, containing, however, probably some water. When, instead of saturating the diluted acid paste with chalk, we boil it for 10 hours, the gummy matter disappears, and is replaced by sugar, which may be purified without any difficulty, by saturation with chalk, filtration, and evaporation to the consistence of sirup. In 24 hours crystallization begins, and, in 2 or 3 days, a concrete mass of grape sugar is formed; which needs merely to be pressed strongly between old linen cloths doubled, and then crystallized a second time. If this sirup be treated with hone black, a brilliant white sugar will be procured. 20 parts of linen rags yield 23 of good sugar. Braconiot. Guerin got 87~ of dry sugar from 100 parts of rags, treated with 250 of sulphuric acid. See WOOD. FIBRINE (Eng. and Fr.; Thierischer Faserstoff, Germ.) constitutes the principal part of animal muscle; it exists in the chyle, the blood, and may be regarded as the most abundant constituent of animal bodies. It may be obtained in a pure state by agitating or beating new drawn blood with a bundle of twigs, when it will attach itself to them in long reddish filaments, which may be deprived of color by working them with the hands under a streamlet of cold water, and afterwards freed from any adhering grease by digestion in alcohol or ether. Fibrine, thus obtained, is solid, white, flexible, slightly elastic, insipid, inodorous, denser than water, but containing four fifths of its weight of it, and without action on litmus. When dried, it becomes semi-transparent, yellowish, stiff, and brittle: water restores its softness and flexibility. 100 parts of fibrine consist of 53-36 carbon, 19-68 oxygen, 7-02 hydrogen, and 19'31 azote. As the basis of flesh, it is a very nutritious substance, and is essential to the sustenance of carnivorous aninals. FILE (Lime, Fr.; Feile, Germ.) is a well knowi steel instrument, having teeth upox the surface for cutting and abrading metal, ivory, wood, &c. When the teeth of these instruments are formed by a straight sharp-edged chisel, extending across the surface, they are properly called files; but when by a sharp-pointed tool, in the form of a triangular pyramid, they are termed rasps. The former are used for all the metals, as well as ivory, bone, horn, and wood; the latter for wood and horn. Files are divided into two varieties, from the form of their teeth. When the teeth are a series of sharp edges, raised by the flat chisel, appearing like parallel furrows, either at right angles to the length of the file, or in an oblique direction, they are termed single cut. But when these teeth are crossed by a second series of similar teeth, they are said to be double cut. The first are fitted for brass and copper, and are found to answer better when the teeth run in an oblique direction. The latter are suited for the harder metals, such as cast and wrought iron and steel. Such teeth present sharp angles to the substance, which penetrate it, while single cut files would slip over the surface of these metals. The double cut file is less fit for filing brass and copper, because its teeth would be very liable to become clogged with the filings. Files are also called by different names according to their various degrees of fineness. Those of extreme roughness are called rough; the next to this is the bastard cut; the third is the second cut; the fourth, the smooth; and the finest of all, the dead smooth. The very heavy square files used for heavy smith-work, are sometimes a little coarser than the rough; they are known by the name of rubbers. Files are also distinguished from their shape, as flat, half-round, three-square, foursquare, and round. The first are sometimes of uniform breadth and thickness throughout, and sometimes tapering. The cross section is a parallelogram. The half-round is generally tapering, one side being flat, and the other rounded. The cross section is a segment of a circle, varying a little for different purposes, but seldom equal to a semi-circle. The three-square generally consists of three equal sides, being equilateral prisms, mostly tapering; those which are not tapering are used for sharpening the teeth of saws. The bur-square has four equal sides, the section being a square. These files are generally hiickest in the middle, as is the case with the smith's rubber. In the round file, the section is a circle, and the file generally conical. The heavier and coarser kinds of files are made from the inferior marks of blistered steel. Those made from the Russian iron, known by the name of old sable, called from its mark CCND, are excellent. The steel made from the best Swedish iron, called hoop L or Dannemora, makes the finest Lancashire files, for watch and clock makers; a manufacture for which the house of Stubbs in Warrington is celebrated. The steel intended for files is more highly converted than for other purposes, to give them proper hardness. It should however be recollected, that if the hardness be no, accompanied with a certain degree of tenacity, the teeth of the file break, and do but little service. Small files are mostly made of cast steel, which would be the best for all others, if FILE. 709 It were not for its higher price. It is much harder than the blistered steel, and from having been in the fluid state, is entirely free from those seams and loose parts so common to blistered steel, which is no sounder than as it comes from the iron forge before conversion. The smith's rubbers are generally forged in the common smith's forge, from the converted bars, which are, for convenience, made square in the iron before they come into this country. The files of lesser size are made from bars or rods, drawn down fiom the blistered bars, and the cast ingots, and known by the name of tilted steel. The file-maker's forge consists of large bellows, with coke as fuel. The anvil-block, particularly at Sheffield, is one large mass of mill stone girt. The anvil is of considerable size, set into and wedged fast into the stone; and has a projection at one end, with a hole to contain a sharp-edged tool for cutting the files from the rods. It alsc contains a deep groove for containing dies or bosses, for giving particular forms to the files. The flat and square files are formed entirely by the hammer. One man holds the hot bar, and strikes with a small hammer. Another stands before the anvil with a two-handed hammer. 1he latter is generally very heavy, with a broad face for the large files. They both strike with such truth as to make the surface smooth and flat, without what is called hand-hammering. This arises from their great experience in the same klnd of work. The expedition arising from the same cause is not less remarkable. The half round files are made in a boss fastened into the groove above mentioned. The steel being drawn out, is laid upon the rounded recess, and hammered till it fills the die. The three-sided files are formed similarly in a boss, the recess of which consists of two sides, with the angle downwards. The steel is first drawn out square, and then placed in a boss with an angle downwards, so that the hammer forms one side, and the boss two. The round files are formed by swage similar to those used by common smiths, but a little conical. The file-cutter requires an anvil of a size greater or less, proportioned to the size of his files, with a face as even and flat as possible. The hammers weigh from one to five or six pounds. The chisels are a little broader than the file, sharpened to an angle of about 20 degrees. The length is just sufficient for them to be held fast between the finger and thumb, and so strong as not to bend with the strokes of the hammer, the intensity of which may be best conceived by the depth of the impression. The anvil is placed in the face of a strong wooden post, to which a wooden seat is attached, at a small distance below the level of the anvil's face. The file is first laid upon the bare anvil, one end projecting over the front, and the other over the back edge of the same. A leather strap now goes over each end of the file, and passes down upon each side of the block to the workman's feet, which, being put into the strap on each side, like a stirrup, holds the file firmly upon the anvil as it is cut. While the point of the file is cutting, the strap passes over one part of the file only, the point resting upon the anvil, and the tang upon a prop on the other side of the strap. When one side of the file is single cut, a fine file is run slightly over the teeth, to take away the roughness; when they are to be double cut, another set of teeth is cut, crossing the former nearly at right angles. The file is now finished upon one side, ani it is evident that the cut side cannot be laid upon the bare anvil to cut the other. A flat piece of an alloy of lead and tin is interposed between the toothed surface and the artIl, while the other side is cut, which completely preserves the side already formed. Similar pieces of lead and tin, with angular and rounded grooves, are used for cutting triangular and half- rund files. Rasps are cut precisely in the same way, by using a triangular punch instead of a flat chisel. The great art in cutting a rasp is to place every new tooth as much as possible opnosite to a vacancy. iMany abortive attempts have been made to cut the teeth of files by machinery. The following plan. for which a patent was obtained by Mr. William Shilton, of Birmingham, in April, 1833, is replete with ingenious mechanical resources, and deserves to succeed. The blanks of steel for making the files and rasps, are held in a pair of clamps in connexion with a slide, and are moved forward at intervals under the head of the tilt hammer which carries the tool; the distance which the blank is to be advanced at every movement being dependant upon the required fineness or coarseness of the cut of the file,'which move-nent is effected and regulated by a rack and pinion, actuated by a pall and ratchet wheel, or the movement may be produced by any other convenient means. When the machine is employed for cutting or indenting the teeth of rasps, the cutting tool being pointed and only producing one tooth at a blow, the tilt hammer carrying the tool mast be made to traverse at intervals across the width of the blank piece of steel 710 FIr,. from one edge to the other and back again; the blank being advanced in iength on)l when the hammer has produced the last cut or tooth toward either edge of the rasp. In order to render this invention better understood, two views of the apparatus for pro. ducing the cross-cut or teeth of the files are given. Fig. 527 is an elevation of the <^~>~~ 528 "upper part of the file-cutting machine, a-j ^"T ——') g as seen on one side; fig. 528 is a _\ _ ) pplan or horizontal view, as the machine appears on the top. a, is the head of the tilt hammer pi\'.'~ X^ lo,^1 -placed in the end of the lever b, _ _ l _, which is mounted on an axle c, real' Ir \ _^ j17 OF a turning in proper bearings in the in i111=~ 5 7''t > _ _ ow 2 $1 fiame work of the machine; d, is the f4 Xel~t~^ Hi.-. T Kl tilt wheel mounted on another axle s,.^} s::^i ^n^ = ~ ~ Dalso turning in bearings on the frame Em0 l]. o work of the machine, and having any required number of projections or, ^ — g"" p. G ~ ~ ~tappets upon it for depressing the tail or shorter end of the hammer or tilt lever b. il, 5~ 5~)y7 ~ The tilt wj eel d, receives its rota527< M j tory motion from the toothed wheel //tg ( ciTW. f, mounted upon the same axle, and q4^ ^^r,,^ G it takes into gear with a pinion g, upon the main shaft h, which is ac. tuated by a band passed from any first' mover to the rigger on its end, or in any other convenient manner. h >~ - ^^J^^^ ^Tt ^The bed upon which the blank piece m <@, O FFof steel bears is marked i. This bed is firmly supported upon masonry placed upon proper sleepers; j, is one of the blank pieces of steel under operation, and is shown secured in v the pair of jaws or holding clamps k, mounted on centre pins in the slide 1, fig. 528; which slide is held down by a spring and slide beneath, and is moved backwards and forwards in the machine upon the (v) edges m, m, of the frame, by means of the rack n, and its pinion; the latter being mounted upon the axle of the ratchet wheel p, and which ratchet wheel is made to turn at intervals by means of the pall q, upon the end of the lever r, fig. 528. This lever is depressed, after every cut has been effected upon the blank by means of the teeth or tappets of the wheel s, coming in contact with the inclined plane t, upon the lever r. The tappet wheel s, is mounted upon the end of the axle e, of the tilt wheel, and consequently revolves with it, and by depressing the lever r, every time that a tooth passes the inclined plane t, the click q, is made to drive the ratchet wheel p, and thereby the advancing movement of the blank is effected after each blow of the tilt hammer. There is a strong spring u, attached to the upper side of the tilt hammer, its end being confined under an adjustable inclined plane v, mounted in the frame w, which inclined plane can be raised or lowered by its adjusting screws as required, to produce more or less tension of the spring. A similar spring is placed on the under side of the tilt hammer, to raise and sustain the cutter or tool clear of the bed after every blow, and in conjunction with safety holders or catchers, to counteract any vibration or tendency the spring u may have to cause the hammer to reiterate the blow. The end of the lower spring acts on an inclined plane, mounted in the frame w, which has an adjusting screw similar to v, to regulate the tension of the spring. In case the under spring should raise, that is, return the hammer, with sufficient force or velocity to cause the top spring u, to reiterate the blow, the ends of the safety holders or catchers are made to move under and catch the tail of the lever b, immediately on its being raised by the under springs, whic'h is effected by the following means:-The hold. ers are mounted upon a plate or carriage 1, fig. 527, which turns upon a small pin or axle mounted in the ears of a cross bar; the upper ends of the holders are kept inclined towards the tail of the tilt hammer by means of a spring fixed to the cress bar, and which Iats upon one end of the plate or carriage 1. FILE. 711 In order that the holders may be removed out cf the way of the tail of the hammer b, when the tilt wheel is about to effect a blow, the tooth of the tilt wheel which last acted upon the hammer comes in contact with an inclined plane fixed on the plate or carriage I, and by depressing that end of the plate, causes the upper enus of the holders to be withdrawn from under the tail of the hammer b. The tilt wheel continuing to revolve, the next tooth advances, and depresses the tail of the hammer, but before it leaves the tail of the hammer, the tooth last in operation will have quitted the inclined plane and allowed the spring to return the holders into their former position. After the tooth has escaped from the tail of b, the hammer will immediately descend and effect the blow or cut on the blank, and as the tail of the hammer rises, it will come in contact with the inclined planes at the upper ends of the holders, and force them backwards; and as soon as the tail of the hammer has passed the top of the holders, the spring will immediately force the holders forward under the tail of the hammer, and' prevent the hammer rising again until the next tooth of the tilt wheel is about to depress the end of the hammer, when the same movements of the parts will be repeated, and the machine will continue in operation until a sufficient length of the blank of steel (progressively advanced under the hammer) has been operated upon, when it will be thrown out of gear by the following means:Upon the sliding bar 6 there is placed an adjustable stop, against which the foremost end of the slide 1, fig. 528, comes in contact as it is moved forward by the rack n, and its pinion. The sliding bar 6 is connected at its left end to the bent lever 8, the other end of this lever being formed into a forked arm, which embracet a clutch upon the main shaft, and as the slide 1 continues to advance, it will come in contact with a stop; and when it has brought a sufficient length of the blank pieces of steel under the operation of the cutting tool, the slide 1, in its progress, will have moved that stop and the bar 6 forward, and that bar, by means of the bent lever 8, will withdraw the clutch on the main shaft, from locking into the boss of the fly-wheel, and consequently stop the further progress of the machine; the rigger and fly-wheel turning loosely upon the main shaft. The cut file can now be removed from out of the clamps, and reversed to cut the other side, or another blank piece put in its place; and after throwing back the pall q of the ratchet wheel p, the slide 1, and with it the fresh blank may be moved back into the machine by turning the winch handle, on the axle of the ratchet wheel p, the reverse way, which will turn the pinion backwards, and draw back the rack n, without affecting any other parts of the machine; and on moving back the bar 6, by the handle 11, placed on the stop, the clutches will be thrown into gear again, and the machine proceed to cut the next blank. When the blanks have been thus cut on one side, and are reversed in the machine to form the teeth upon the other side, there should be a piece of lead placed between the hlank and the bed to protect the fresh cut teeth. It will be seen that the position of the stop upon the bar 6 will determine the length or extent of the blank piece of steel which shall be cut or operated upon; and in order that the progressive movement of the blanks under the cutting tool may be made to suit diffe?nt degrees of fineness or coarseness of the teeth (that is, the distance between the cuts), Mere is an adjusting screw upon the lever r, the head of which screw stops against the under side of an ear projecting from the frame-work, and thereby determines the extent of the motion of the lever r, when depressed by the tappets of the wheel s, acting upon the inclined plane t, consequently determining the number of teeth the ratchet wheel p shall be moved round by the pall q; and hence the extent of motion communicated by the rack and pinion to the slide I, and the blank j, which regulates the distance that the teeth of the filt- Are apart, and the lever r is forced upwards by a spring pressing against its under side. It will be perceived that the velocity of the descent of the hammer, and consequently the force of the blow, may be regulated by raising or lowering the inclined plane v of the spring u; and in order to accommodate the bed upon which the blanks rest to the different inclinations they may be placed at, that part of the bed is formed of a semi-globular piece of hardened steel, which fits loosely into a similar concavity in the bed r, and is therefore capable of adjusting itself so that the blanks shall be properly presented to the cutting'tool, and receive the blow or cut in an equal and even manner; or the piece of steel may be of a conical shape, and fit loosely in a similar shaped concavity. There are guides, 16, placed on th( top of the bed i, for the purpose of keeping the blanks in their proper position toward, the cutting tool, and these can be regulated to suit blanks of any width, by turning the right and left handed screw 17. There is also another adjustable stop on the jaws or clamps k, which serves as a guide when placing 2he blanks within the jaws; and 19 is a handle or lever for raising the clamps when required, which has a weight suspended fiom it for the purpose of keeping down the blanks with sufficient pressure upon the bed. The cutting tool in the face of the hammer, can be placed at any required angle or 712 FILE. inclination with the blank, it being secured in the head of the hammer by clamps and screws. In cutting fine files a screw is employed in preference to the rack and pinion, for advancing the slide 1, and the blank piece of steel in the machine. Hardening offiles.-This is the last and most important part of file making. What. ever may be the quality of the steel, or however excellent the workmanship, if it is no' well hardened all the labor is lost. Three things are strictly to be observed in hardening; first, to prepare the file on the surface, so as to prevent it from being oxydated by the atmosphere when the file is red hot, which effect would not only take off the sharpness of the tooth, but render the whole surface so rough that the file would, in a little time, become clogged with the substance it had to work. Secondly, the heat ought to be very uniformly red throughout, and the water in which it is quenched, fresh and cold, for the purpose of giving it the proper decree of hardness. Lastly, the manner of immersion is of great importance, to prevent the files from warping, which in long thin files is very difficult. The first object is accomplishi- by laying a substance upon the file, which, when it fises, forms, as it were, a varnish upon the surface, defending the metal from the action of the oxygen of the air. Formerly the process consisted in first coating the surface of the file with ale grounds, and then covering it over with pulverized common salt (muriate of soda). After this coaling became dry, the files were heated red hot, and hardened; after this, the surface was lightly brushed over with the dust of cokes, when it appeared white and metallic, as if it had not been heated. This process has lately been improved, at least so far as relates to the economy of the salt, which, from the quantity used, and the increased thickness, had become a serious object. Those who use the improved method are now consuming about one fourth the quantity of salt used in the old method. The process consists in dissolving the salt in water to saturation, which is about three pounds to the gallon, and stiffening it with ale grounds, or with the cheapest kind of flour, such as that of beans, to about the consistence of thick cream. The files require to be dipped only into this substance, and immediately heated and hardened. The grounds or the flour are of no other use than to give the mass consistence, and by that means to allow a larger quantity of salt to be laid upon the surface. In this method the salt forms immediately a firm coating. As soon as the water is evaporated, the whole of it becomes fused upon the file. In the old method the dry salt was so loosely attached to the file, that the greatest part of it was rubbed off into the fire, and was sublimed up the chimney, without producing any effect. The carbonaceous matter of the ale grounds is supposed to have some effect in giving hardness to the file, by combining with the steel, and rendering it more highly carbonated. It will be found, however, upon experiment, that vegetable carbon does not cornbine with iron, with sufficient facility to produce any effect, in the short space of time a file is healing for the purpose of hardening. Some file makers are in the habit of using the coal of burnt leather, which doubtless produces some effect; but the carbon is generally so ill prepared for the purpose, and the time of its operation so short, as to render the result inconsiderable. Animal carbon, when properly prepared and mixed with the above hardening composition, is capable of giving hardness to the surface even of an iron file. This carbonaceous matter may be readily obtained from any of the soft parts of animals, or from blood. For this purpose, however, the refuse of shoemakers and curriers is the most convenient. After the volatile parts have been distilled over, from an iron still, a bright shining coal is left behind, which, when reduced to powder, is fit to mix with the salt. Let about equal arts, by bulk, of this powder, and muriate of soda be ground together, qnd brought t. the consistence of cream, by the addition of water, Or mix the powdeied carbon with a saturated solution of the salt, till it become of the above consistence. Files which are intended to be very hard should be covered with this composition previous to hardening. All files intended to file iron or steel, particularly saw files, should be hardened with the aid of this mixture, in preference to that with the flour or grounds. Indeed, it is probable that the carbonaceous powder might be used by itself, in point of economy, since the ammonia or hartshorn, Obtained by distillation, would be of such value as to render the coal of no expense. By lmeans of this method the files made of iron, which, in itself, is unsusceptible of hardening, acquire a superficial hardness sufficient for any file whatever. Such files may, at the same time, be bent into any form; and, in consequence, are particularly useful for sc'lp. tors and die-sinkers.'The next point to be considered is the best method of heating the file for hardening. For this purpose a fire, similar to the common smith's fire, is generally employed. The file is held in a pair of tongs by the tang, and introduced into the fire, consisting of very small cokes, pushing it more or less into the fire for the purpose of heating it regularly. It must fiequently be withdrawn with the view of observing that it is not too hot in any part. When it is uniformly heated, from the tang to tie point, of a FILTRATION. 713 cherry red color, it is fit to quench in the water. At present an oven formed of firebricks is used for the larger files, into which the blast of the bellows is directed, being open at one end, for the purpose of introducing the files and the fuel. Near to the top of the oven are placed two cross bars, on which a few files are placed, to be partially heating. In the hardening of heavy files this contrivance affords a considerable saving, in point of time, while it permits them also to be more uniformly and thoroughly heated. After the file is properly heated for the purpose of hardening, in order to produce the greatest possible hardness, it should be cooled as soon as possible. The most common method of effecting this is by quenching it in the coldest water. Some file-makers have been in the habit of putting different substances in their water, with a view to increase its hardening property. The addition of sulphuric acid to the water was long held a great secret in the hardening of saw files. After all, however, it will be found that clear spring water, free from animal and vegetable miatter, and as cold as possible, is the best calculated for hardening files of every description. In quenching the files in water, some caution mnust be observed. All files, except the half-round, should be immersed perpendicularly, as quickly as possible, so that the upper part shall not cool. This management prevents the file from warping. The half-round file must be quenched in the same steady manner; but, at the same time that it is kept perpendicular to the surface of the water, it must be moved a little horizontally, in the direction of the round side, otherwise it will become crooked backwards. After the files are hardened, they are brushed over with water and powdered cokes, when the surface becomes perfectly clean and metallic. They ought also to be washed well in two or three clean waters, for the purpose of carrying off all the salt, which, if allowed to remain, will be liable to rust the file. They should moreover be dipped into lime-water, and rapidly dried before the fire, after being oiled with olive oil, containing a little oil of turpentine, while still warm. They are then finished. FILLIGREE (Filigrane, Fr.; Filigran, or Feine Drahtgeflecht, Germ.) is, as the last term justly expresses it, intertwisted fine wire, used for ornamenting gold and silver trinkets. The wire is seldom drawn round, but aenerally flat or angular, and soldered by gold or silver solder with borax and the blowpipe. The Italian word, fiiligrana, is comp!)unded of filbtn and granum, or granular net-work; because the Italians, who first introduced this style of work, placed small beals upon it. FILTRATION (Eng. and Fr.; Filtriren, Germ ) is a process, purely mechanical, for separating a liquid from the undissolved particles floating in it, which liquid may be either the useful part, as in vegetable infusions, or of no use, as the washings of mineral precipitates. The filtering substance may consist of any porous matter In a solid, foliated, or pulverulent form; as porous earthenware, unsized paper, cloth of many kinds, or sand. The white blotting paper sold by the stationers, answers extremely well for filters in chemical experiments, provided it be previously washed with dilute muriatic acid, to remove some lime and iron that are generally present in it. Filter papers are first cut square, and then folded twice diagonally into the shape of a cornet, having the angular parts rounded off. Or the piece of paper being cut into a circle, may be folded fan-like from the centre, with the folds placed exteriorly, and turned out sharp by the pressure of the finger ar.d thumb, to keep intervals between the paper and the funnel into which it is fitted, to;avor the percolation. The diameter of tile funnel should be about three fourths of ilt height, measured from the neck to the edge. If it be more divergent, the slope will be too small for the ready efflux of the fluid. A filter covered with the sediment is most conveniently washed by spouting water upon it with a little syringe. A small camel's-hair paint brush is much employed fur collecting and turning over the contents in their soft state. Agitation or vibration is of singular efficacy in quickening percolation, as it displaces the particles of the moistened powders, and opens up the pores which had become closed. Instead of a funnel, a cylindrical vessel may be employed, having its perforated bottom covered with a disc of filtering powder folded up at the edges, and made tight there by a wire ring. Linen or calico is used for weak alkaline liquors; and flannels, twilled woollen cloth, or felt-stuff, for weak acid ones. These filter bags are often made conical like a fool's cap, and have their mouths supported by a wooden or metallic hoop. Cotton wool put loose into the neck of a funnel answers well for filtering oils upon the small scale. In the larae way, oil is filtered in conical woollen bags, or in a cask with many conical tubes in its bottom, filled with tow or cotton wool. Stronger acid and alkaline liquors must be filtered through a layer of pounded glass, quartz, clean sand, or bruised charcoal. The alcarrhazas are a porous biscuit of stone ware made in Spain, which are convenient f r filtering water, as also the porous filtering stone of Teneriffe, largely imported into En-land at one time, but now superseded in a great measur eby the artificial filters patented under many forms, consisting essentially of strata of gravel, sand, and charcoal powder. It is convenient to render the filter self-acting, by accommodating the supply of liquid 1J 714 FILTRATION. to the rate of percolation, so that the pressure upon the porous surface may be always equally great. Upon the small scale, the lamp-fountain or bird's-glass form, so generally used for lamps, will be found to answer. Fig. 529 represents a glass bottle, A, partly filled with the fluid to be filtered, supportea in the ring of a chemical stand, and having its mouth inverted into the same liquor in the filler funnel. It is obvious that whenever this liquor by filtration falls below the lip of the bottle, air will enter into it. let down a fresh supply to feed the filter, and keep the funnel regularly charged. If larger quantities are to be operated upon, the u-529 1 / a following apparatus may 529 E x' be employed. Fig. 530,'530 A B, is a metallic vessel which may be made air-.~ ~A ~\ / ~t tight; c is the under pipe, provided with a stopcock, -_____/ A \ R, for letting down the ___.. _~^- \_|~ _ / \ liquor into the filter a b. -=/~ ^ —-. —- The upper pipe t, through ~~~\i|H~~~~~~ T which the fluid is poured by means of the funnel E, g It has also a stopcock which opens or shuts, at the sa me time, the small side tube u t, through vwhich, durin the entrance of the fluid, the air is let off from -\ B /I* the receiver. A glass tube, g, shows the level of the liquor in the body _ I! _-n~m ='7 ab R of the apparatus. In using it, the cock R must be first ____ ___-' ____ _' _ - - _ _ _ _d closed, and the cock s must be opened to fill ihe receiver. Then the filter is set a going, by re-opening the cock R, so as to keep the fluid in the filter upon a level with the opening of the tube c. Both these pieces of apparatus are essentially the same. In many manufactures, self-acting filters are fed by the plumber's common con533 531 ~ 1 C. B \ } - A j C t _I C | O D PP D rivance of a ball-cock, in which the sinking and rising of the ball, within certain limits, serves to open or 532 r — __ 1 t |i shut off the supply of JJ A liquor, as it mnay be required or not. Dumont 6t b Jl~ lll i | has adopted this expedient rt1 _jc = i-_:11 l ~T ~[ *i ~ for his system of filtering...... ^ 1 * - - L sirup through a straturn of _~/A ~_ 1- t granularly ground animal I // charcoal or bone-black. Ct r 7 - IB >< \ \~ Fig. 531 is' a front view IT h I(. l | // 1. llof this apparatus with 4 S^B^,t | __ nfilters, c; and fig. 532 is a cross section. The fiameNV/ work B supports the cismern A, in which the sirup is contained. From it the liquor flows through the stopcocl FILTRATION. 71T b, and the connexion-tube a, into the common pipe c, which communicates, by the short branch tubes e, with each of the four filters. The end of the branch tube, which is inside of the filter tub, is provided with a stop-cock d f, whose opening, and thereby the efflux of tue liiluor from the cistern through the tube a, is regulaied by means of the float- ball g. Upon the brickwork D the filter tub stands, furnished at h with a false bottom of zinc or copper pierced with fine holes; besides which, higher up at i there is another sciek plate of metal furnished with a strong handle k, by which it may be removed, when the bone black needs to be changed. In the intervening space 1, the granular coal is placed. o is the cover of the filter tub, with a handle also for lifting it. One portion of it may be raised by a hinge, when it is desired to inspect the progress of the filtration within. Am mn is a slender vertical tube, forming a communication between the bottom part h, and the upper portion of the filter, to admit of the easy escape of the air from that space, and from among the bone black as the sirup descends; otherwise the filtration could not go on. p is the stopcock through which the fluid collected in the space under h, is let off trom time to time into the common pipe q,fig. 531. r is a trickling channel or groove lying parallel to the tube q, and in which, by means of a tube s, inserted at pleasure, the sirup is drawn off in case of' its flowing in a turbid state, when it must be returned over the surface of the charcoal. The celerity with which any fluid passes through the filter depends, 1. upon the porosi. ty of the filtering substance; 2. upon the pressure exercised upon it; and 3. upon the extent of the filtering surface. Fine powders in a liquor somewhat glutinous, or closely complacted, admit of much slower filtration than those which are coarse and free; and the former ought, therefore, to be spread in a thinner stratum and over a more extensive surface than the latter, for equal etieci; a principle well exemplified in the working of Damont's apparatus, just described. In many cases filtration may be accelerated by the increase of hydrostatic or pneumatic pressure. This happens when we close the top of a filtering cylinder, and connect it by a pipe with a cistern of fluid placed upon a higher level. The pressure of the air may be rendered operative also either by withdrawing it partially from a close vessel, into which the bottom of the filter enters, or by increasing its density over the top of the liquor to be filtered. Either the air pump or steam may be employed to create a partial void in the receiver beneath the filter. In like manner, a forcing pump or steam may be employed to exert pressure upon the surface of the filtering liquor. A common syphon may, on the same principle, be made a good pressure filter, by making its upper leg trumpet-shaped, covering the orifice with filter paper or cloth, and filing the whole with liquor, the lower leg being of such length so as to create considerable pressure by the difference of hydrostatic level. This apparatus is very convenient either on the smalL or great scale, for filtering off a clear fluid from a light muddy sediment. The pressure of the atmosphere may be elegantly applied to common filters, by the apparatus represented infig. 533, which is merely a funnel enclosed within a gasometer. The case A; bears an annular hollow vessel a b, filled with water, in which receiver the cylindrical gasometer d, e, f, i, is immersed. The filter funnel is secured at its upper edge to the inner surface of the annular vessel a b. In consequence of the pressure of the gasometer regulated by the weight g, upon the air enclosed within it, the liquid is equally pressed, and the water in the annular space rises to a corresponding height on the outer surfa.re of the gasometer, as shown in the figure. Were the apparatus miade of.heet iron, the annular Space might be charged with mercury. In general, relatively to the application of pressure to filters, it may be remarked, that it cannot be pushed very far, without the chance of deranging the apparatus, or rendering the filtered liquor muddy. The enlargement of the surface is, generally speaking, the safest and most efficacious plan of increasing the rapidity of filtration, especially for liquids of a gletinous nature. This expedient is well illustrated in the creased bag filter now in use in mob. of the sugar refineries of London. See SUGAR. In many cases it is convenient so to construct the filtering apparatus, as that the liquid shall not descend, but mount by hydrostatic pressure. This method has two advantages: 1. that without much expensive apparatus, any desired degree of hydrostatic pressure may be given, as also that the liquid may be forced up through several filtering surfaces placed alongside of each other; 2. that the object of filtering, which is to separate the particles floating in the fluid without disturbing the sediment, may be perfectly attained, and thus very foul. liquids be cleared without greatly soiling the filtering surface. Such a construction is peculiarly applicable to the purification of water, either alone, or combined with the downwards plan of filtration. Of the former variety an example s shown in fig. 534. The wooden or zinc conical vessel is provided with two per. forated bottoms or sieves e e, betwixt which the filtering substance is packed. Over this, for the formation of the space h h, there is a third shelf, with a hole in its middle, through which the tube d b is passed, so as to be water tight. This places the upper 716 FILTRATION..pen part of the apparatus in communication with the lowest space a. From the com. partment hI h a small air tube I runs upwards. The filtering substance consists at bottom of pebbles, in the middle o' gravel, and at the top of fine sand, which may be mixed with coarsely ground bone black, or covered with a layer of the same. The water to be filtered being poured into the cistern at top, fills through the tube b d the inferior compartment a, from which the hydrostatic pressure forces the water upward through the perforated shellf and the filtering materials. The pure water collects in the space h h, while the air escapes by the small tube 1, as the liquid enters. The stopcock i serves to draw off the filtered water. As the motion of the fluid in the filter is slow, the particles suspended in it have time to subside by their own gravity; hence there collects over the upper shejf at d, as well as over the under one at a, a precipitate or deposite which may be washed out of the latter cavity by means of the stopcock 7n. As an example of an upwards and downwards filter,fig. 535 may be exhibited. A B CD 535 is a wooden or metallic cistern fur. A D nished with the perforated shelf 4 c d near its under part, upon which a vertical partition is fixed through | F E \\l l the axis of the vessel. A semid j circular perforated shelf is place..I i i \ at a, and a second similar one at r b,,^ —r^ *c A, ^ th f b. These horizontal shelves rest e upon brackets in the sides of the ~~If H |1r~~ C l~ ncisterns, so that they may be readily lifted out. The space G iD filled with coarse sand, J with mod mL b a C." * X i a 3 - D erately fine, and H with very fine d, ~1 ^ *?'^i% C vE- \ The foul water is poured into tht | J | chamber E, and presses through |r t, *f~ |~ ~G J H and into the space F; whence ~~3B l['' ~-,cfi*< C it may be drawn by the stopcock f. Fig. 536 represents in section a filtering apparatus consisting of two concentric chamrbers; the interior being destined for downwards filtration, and the exterior for upwards. Within the larger cistern A, a smaller one B is placed concentrically, with its 536 _ F under part, and is lelt open from y, ~ __===*__ _ _ j di-tance to distance, to make a I I }lI m l m I T 1 I communication between the in\f-l a __ tI1tei ior cavity and the exterior annular space. These cavities _e ____l i = fl flj-j-l-l-l are filled to the marked height with sand and gravel. The _ 1= l llll inner cylindrical space has fine ___ _ _ _ - lllsand below, then sharper sand al _ ___ IiE- - 0with granular charcoal, next = coarse sand, and lastly gravel. |b^'^.-M ^| ~The annular space has in like manner fine sand below. The 1_-_ ___ ___ _ — _ r foul water is introduced by the pipe E, the orifice at whose end is acted upon by a ball-cock with its lever a; whereby the water is kept always at the same level in the inner vessel. The water sinks through the sand strata of the middle vessel, passes outwards at its bottom into the annular space, thence up through the sand in it, and collecting above it, is let off by the stopcock on the pipe b. When a muddy deposite forms after some time, it may be easily cleared out. The cord e, running over the pulleys f f, being drawn tiaht, the ball lever will shut up the valve. The stopcock d made fast to the conducting tube E must then be opened, so that the water now overflows into the annular space at A; the tube r, in communication with the inner space B, being opened by taking out the stopper h. The water thereby percolates through the sand strata in the reverse direction of it 3 usual course, so as to clear away the impurities in the space B, and to discharoe them by the pipe c h. An apparatus of this kind of moderate size is capable of filtering a great body of water. It should be constructed for that purpose of masonry; but upon a small scale it may be made of stone-ware. A convenient apparatus for filtering oil upwards is represented infig. 537. g is an oil cask, in which the impure parts of the oil have accumulated over the bottom. Immediatelv above this, a pipe a is let in, which communicates with an elevated water cistern FIRE ARMS. 717 a. f is the filter (placed on the lid of the cask), furnished with two perforated shelves, one at e and another at d; which divide the interior of the filter into three com537 partments. Into the lower space immediately over the shelf e, the tube b, furnished with a stopcok, enters, to establish a... z_~ communication with the cask; the middle cavity e is filled with ---'L coarsely ground charcoal or other fillering materials: and the, upper one has an eduction pipe, 1. When the stopcocks of the tubes a anl b are opened, the water passes from the cistern into thle oil cask, occupies from its density always the lowest place, and presses the oil upwards, without mixing the two liquids; whereby first the upper and purer portion of the oil is forced through the tube b into the filter, and thence out through the a pipe 1. When the fouler oil follows, it deposites its impurities in the space under the partition c, which may from time to time be drawn off through the stopcock k, while the purer oil is pressed upwards through the filter. In this way the different strata of oil in the cask may be filtered off in succession, and kept separate, if found necessary, for sale or use, without running any risk of mixing up the muddy matter with what is clear. According to the height of the water cistern n, will be the pressure, and, of course, the filtering force. When the filter gets choked with dirt, it may be easily recharged with fresh materials. In filtering caustic alkaline leys through linen or quartz, it is proper to exclude the free contact of air; which is done by enclosing the upper vessel, and attaching a pipe of communication between its cover and the shoulder of the lower vessel or recipient of the leys. In proportion as these flow down, they will displace their bulk of air, and drive it into the top of the upper vessel above the foul leys. Many modifications of the above described apparatus are now on sale in this country; but certainly the neatest, most economical, and effective means of transforming the water of a stagnant muddy pool into that of a crystalline fountain, is afforded by the Royal Patent Filters of George Robins. FIRE ARMS, MANUFACTURE OF. This art is divided into two branches, that of the metallic and of the wooden work. The first includes the barrel, the lock, and the mounting, as also the bayonet and ramrod, with military arms. The second comprises the stock, and in fowling pieces, likewise the ramrod. 1. The Barrel. Its interior is called the bore; its diameter, the calibre; the back enr, the breech; the front end, the muzzle; and the closing of the back end, the breech pin or plug. The barrel is generally made of iron. Most military muskets and lowpriced guns are fashioned out of a long slip of sheet-iron, folded together edgewise round a skewer into a cylinder, are then lapped over at the seam, and welded at a white heat. The most ductile and tenacious soft iron, free from all blemishes, must be selected for this slip. It is frequently welded at the common forge, but a proper airfurnace answers better, not being so apt to burn it. It should be covered with ashes or cinders. The shape of the bore is given by hammering the cylinder upon a steel mandril, in a groove of the anvil. Six inches of the barrel at either end are left open for forming the breeclr and the muzzle by a subsequent welding operation; the extremity put into the fire bemng stopped with clay, to prevent the introduction of cinders. For every length of two inches there are from two to three welding operations, divided into alternating high and low heats; the latter being intended to correct the defects ot the former. The breech and muzzle are not welded upon the mandril, but upon the horn of the anvil; the breech being thicker in the metal, is more highly heated, and is made somewhat wider to save labor to the borer. The barrel is finally hammered in the groove of the anvil without the mandril, during which process it receives a heat every two minutes. In welding, the barrel extends about one third in length; and for muskets, is eventually left from 3 to 3 feet long; but for cavalry pistols, only 9 inches. The best iron plates for gun-barrels are those made of stub iron, that is, of old horse-shoe nails welded together, and forged into thin bars, or rather narrow ribands. At one time damascus barrels were much in vogue; they were fashioned either as above described, from plates made of bars of iron and steel laid parallel, and welded together, or from ribands of the sauie damascus stuff coiled into a cylinder at a red heat, and then welded together at the seams. The best modern barrels for fowling pieces are constructed of stub-nail iron in this manner. The slip or fillet is only half an inch broad, or sometimes less, and is left thicker at the end which is to form the breech, and thinner at the end which is to form the muzzle, than in the intermediate portion. This fillet being moderately heated to increase its pliancy, is then lapped round the mandril in a spiral direction till a proper length of cylinder is formed; the edges being made to overlap a little in order to give them a better hold in the welding process. The coil 718 FIRE ARMS. being taken ofl the mandril and again heated, is struck down vertically with its muzzle end upon the anvil, whereby the spiral junctions are made closer and more uniform. i is now welded at several successive heats, hammered by horizontal strokes, called jumpinsg, and brought into proper shape on tie mandril. The finer barrels are made of still narrower stub-iron slips, whence they get the name of wire twist. On the Continent, barrels are made of steel wire, welded together lengthwise, then coiled spirally into a cylinder. Barrels that are to be rifled require to be made of thicker iron, and that of the very best quality, for they would be spoiled by the least portion of scale upon their inside. Soldiers' muskets are thickened a little at the muzzle, to give a stout holding to the bayonet. The barrels thus made are annealed with a gentle heat in a proper furnace, and slowly cooled. They are now ready for the borer, which is an oblong square bit of steel, pressed in its rotation against the barrel, by a slip of wood applied to one of its flat sides, and held in its place by a ring of metal. The boring bench works horizontaiiy, and has a very shaky appearance, in respect at least of the bit. In some cases, however, it has been attempted to work the barrels and bits at an inclination to the horizon of 30~, in order to facilitate the discharge of the borings. The barrel is held in a slot by only one point, to allow it to humor the movements of the borer, which 538 would otherwise be infallibly -- === broken. The bit, as reprosented in fig. 538, has merely its square head inserted into a 539.....l....... 539d, fi *- - - clamp-chuck of the lathe, and plays freely through the rest a I"1 -of its length. _________c ______ wFig. 539 represents in plan the boring bench for musket barrels; ff is the sledge or carriage frame in which the barrel is supported; a is the revolving chuck of the lathe, into which the square end of the bit,fig. 538, is inserted; b is the barrel, clamped at its middle to the carriage, and capable of being pressed onwards against the tapering bit of the borer, by the bent lever c, worked by the left hand of the operative against fulcrum knobs at d, which stand about two inches asunder. Whenever the barrel has been thereby advanced a certain space to the right, the bent end of the lever is shifted against another knob or pin. The borer appears to a stranger to be a very awlkward and unsteady mechanism, but its perpetual vibrations do not affect the accuracy of the bore. The opening broach may be of a square or pentagonal form, and either gradually tapered from its thickest part, or of uniform diameter till within two inches of the end, whence it is suddenly tapered to a point. A series of bits may be used for boring a barrel, beginning with the smallest and ending with the largest. But this multiplication of tools becomes unnecessary, by laying against the cutting part of the hit slips of wood, called spales, of gradually increasing thickness, so that the edge is pressed by them progressively further from the axis. The bore is next polished. This is done by a bit with a very smootth edge, which is mounted as above, with a w-dge of wood besmeared with a mixture of oil and emery. The inside is finished by working a cylindrical steel file quickly backwards and forwards within it, while it is revolving slowly. In boring, the bit must be well oiled or greased, and the barrel must be kept cool by letting water trickle on it; for the bit, revolving at the rate of 120 or 140 times a minute, gener:es a rreat deal of heat. If a flaw be detected in the barrel during the boring, that part is hammered in, and then the bit is employed to turn it out. Many sportsmen are of opinion that a barrel with a bore somewhat narrowed towards the muzzle serves to keep shot better together; and that roughening its inside with pounded glass has a good effect, wilh the same view. For this purpose, also, fine spiral lines, have been made in their interior surface. The justness of its calibre is tried by means of a truly turned cylinder of steel, 3 or 4 inches long, which ought to move without friction, but with uniform contact from end to end of the barrel. Whatever irregularities appear must be immediately removed. Thfe outer surface of the barrel is commonly polished upon a dry grindstone, but it is better finished, and less dangerouslv to the workman, at a turning lathe with a slide rest. If a stone be used, it should be made to revolve at the mouth of a tunnel of some kind, into which there is a good draught to carry off the ferruginous particles, A piece of moist cloth or leather should be suspended before the orifice. Rifle barrels have parallel orooves of a square or angular form cut within them, each groove being drawn in succession. These grooves run spirally, and form each an aliquot part of a revolution from the chamber to the muzzle. Rifles should not be too deeply indented; only so much as to prevent the ball turning round within the barrel FIRE ARMS. 719 and the spires should be truly parallel, that the ball inay glide along w;th a regular pace. See infra. The Parisian gun-makers, who are reckoned very expert, draw out the iron for the barrels at hand forges, in fillets only one ninth of an inch thick, one inch and a half broad, and four feet lona. Twenty-five of these ribands are laid upon each other, between two similar ones of double thickness, and the bundle, weighing 60 pounds, bound with wire at two places, serves to make two barrels. The thicker plates are intended to protect the thinner from the violence of the fire in the numerous successive heats necessary to complete the welding, and to form the bundle into a bar two thirds of an inch broad, by half an inch thick; the direction of the individual plates relatively to the breadth being preserved. This bar, folded flat upon itself, is again wrought at the forge, till it is only half an inch broad, and a quarter of an inch thick, while the plates of the primitive ribands are now set perpendicular to the breadth of the narrow fillet; the length of which must be 15 or 16 feet French (16 or 17 English), to form a fowling piece from 28 to 30 inches long. This fillet, heated to a cherry red in successive portions, is coiled into as close a spiral as possible, upon a mandril about two fifths of an inch in diameter. The mandril has at one end a stout head for drawing out, by means of the hammer and the grooves of the anvil, previous to every heating. The welding is performed upon a mandril introduced after each heat; the middle of the barrel being first worked, while the fillets are forced back against each other, along the surface of the mandril, to secure their perfect union. The original plates having in the formation of the ultimate long riband become very thin, appear upon the surtace of the barrel like threads of a fine screw, with blackish tints to mark the junctions. In making a doluble-barrelled gun, the two are formed from the same bundle of slips, the coils of the one finished fillet being turned to the right hand, and those of the other to the left. The Damascus barrels forged as above described, from a bundle of steel and iron plates laid alternately together, are twisted at the forge several times, then coiled and welled as usual. Fifteen Parisian workmen concur in one operation: six at the forge; two at the boring mill; seven at filing, turning, and adjusting; yet all together make only six pairs of barrels per week, which are sold at from 100 to 300 francs the pair, ready for putting into the stock. The breeching is of three kinds: the common; the chamber, plug, or mortar, fig. 540; 541 and the patent, fig. 541. The common was formerly used for soldiers' muskets 540 and inferior pieces. The second is a trifling improvement upon it. In the 7w[ m ^~ -g /g*~ patent breeching, the screws do not interfere with the touch-hole, and the ignition is quicker in the main chamber. The only locks which it is worth while to describe are those upon the percussion =|l l = F^'"^'asB I~~)principle, as flint locks will certainly soon 7 ^ ~ o q mcease to be employed even in military muskets. Forsyth's lock (fig. 542) was an ingeniolls contrivance. It has a maga= zine a, for containing the detonating powder, which revolves round a roller b, whose end is screwed into the breech of the barrel. The priming powder passes through.....1 a small hole in the roller, which leads to a channel in communication with the chamber of the gun. The pan for holding the primngr is placed immediately over the litt.e hole in the roller. There is a steel punch c, in the magazine, whose under end stands above the pan, ready 00 O o~~~~ 720 FIRE ARMS. to ignite the priming when struck upon the top by the cock d, whenever the trigger is drawn. The punch immediately after being driven down into the pan is raised by the action of a spiral spring. For each explosion, the magazine must be turned so far round as to let fall a portion of the percussion piowder into the pan; after which it is turned back, and the steel punch recovers its proper position for striking another blow into the pan. The invention of the copper percussion cap was another great improvement upon the detonating plan. Fig. 543 represents the ordinary percussion lock, which is happily divested of three awkward projections upon the lint lock, namely, the hammer, hammer spring, and the pan. Nothing now appears upon the plate of the lock, but the cock or striking hammer, which inflicts the proper blow upon the percussion cap. It is concave, with a small metallic ring or border, called a shield or fence, for the purpose of enclosing the cap, as it were, and preventing its splinters doing injury to the sportsman, as also protecting against the line of flame which may issue from the touch-hole in the cap nipple. This is screwed-into the patent breech, and'perforated with a small hcle. 543 The safety lock of Dr. Somerville is a truly humane invention. Its essential feature is a slide stop or catch, placed under the trizger A, fig. 544. It is pulled forward into ~a notch in the trigger, by means of a spring B, upon the front of the guard, which is worked by a key c, pressing upon the spr ing when the piece is discharged. In another safety plan there is a small moveable curved piece of iron, A, which rises through an opening B, in the lock-plate c, and prevents tile cock from reaching the nipple, as represented in the figure, until it is drawn back within the plate of the lock when the piece is fired. 544 lo fire this gun, two different points must be pressed at the same time. Ift ry accident the key which works the safety he touched, nothing happens, because the trigger is not drawn; and the trigger touched alone can produce no effect, because it is locked. The pressure must be applied to the trigger and the key at the same instant, otherwise the lock will not work. The French musket is longer than the British, in the proportion of 44-72 inches to 42 but the French bayonet is 15 inches, whereas the British is 17. FIRE ARMS. 721 Eng. Dimensions. Fr. Dimensions. Diameter of the bore - - - 0.75 in. 069 in. Diameter of the ball - - - - 0676 0'65 Weight of the ball in oz. - - 1-06 0-958 Weight of the firelock and bayonet in lbs. - 12-25 10-980 Length of the barrel and bayonet - - 59 00 59-72 Within these few years a great many contrivances have been brought forward, and several have been patented for fire arms. The first I shall notice is that of Charles Random, Baron de Berenger. Fig. 545 shows the lock and breech of a fowling piece, with a sliding protector on one of the improved plans; a is the hammer, b the nipple of the touch-hole, c a bent lever, turning upon a pin, fixed into the lock-plate at d. The upper end of this bent lever stands partly undtr the nose of the hammer, and while in that situation stops it fiom striking the nipple. A. slider g f h, connected with the under part of the gun-stock, is attached to the tail of the bent lever at i; and when the piece is brought to the shoulder for firing, the hand of the sportsman pressing against the bent part of the slider at g, forces this back, and thereby moves the end of the lever c forward 545 from under the nose of the cock or hammer, as shown by the dotted lines. The trigger being now drawn, the piece will be discharged; and on removing the hand from thie end g, of the slider f, the spring at h acting against the guard, will force the slider forward, and the lever into the position first described. Mr. Redford, gun-maker of Birminghan, proposes a modification of the lock for small fire-arms, in which the application of pressure to the sear spring for discharging the piece is made by means of a plug, depressed by the thumb, instead of the force of -the finger exerted against the trigger. Fig. 546 represents a fowling piece partly in 546 section. The sear spring is shown at a. It is not here connected with the;rigger as in other locks; but is attached by a double-jointed piece to a lever b, which turns upon a fulcrum pin in its centre. At the reverse end of this lever an arm extends forwards, like tiat of an ordinary sear spring, upon which arm the lower end of the plug c is intended to bear; and when this plug is depressed by the thumb bearing upon it, that end of the lever b will be forced downwards, and the reverse end will be raised, so as to draw up the end of the sear spring, and set off the piece. For the sake of protection, the head of the plug c is covered by a moveable cap d, forming part of a slider e, which moves to and fro in a groove in the stock, behind the breech end of the barrel; this slider e is acted upon by the trigger through levers, which might be attached to the other side of the lock-plate; but are not shown in this figure, to avoid confusion. When the piece is brought to the shoulder for firing, the fore-finger must be applied as usual to the trigger, but merely for the purpose of drawing back the slider e, and uncovering the head of the plug; when this is done, the thumb is to be pressed upon the head of the plug, and will thus discharge the piece. A spring bearing against the lever of the slider e, will, when the finger is withdrawn from the trigger, send the slider forward again, and cover the head of the plug, as shown. It is with pleasure I azain advert to the humane ingenuity of the Rev. John Somerville, of Currie. In April, 1835, he obtained a patent for a firther invention to prevent the accidental discharge of fire arms. It consists in hindering the hammer from reaching the nipple of a percussion lock, or the flint reaching the steel of an ordinary one, by the interposition of moveable safety studs or pins, which protrude fiom under the false breech before the hammers of the locks, and prevent them from descending to strike. 47 722 FIRE ARMS. These safety studs or pins are moved out of the way by the pressure of the right hand of the person using the gun only when in the act of firing, that is, when the force of the right hand and arm is exerted to press the butt end of the stock of the gun against the shoulder while the aim is taken and the trigger pulled. In carrying the gun at rest, the proper parts of the thumb or hand do not come over Mr. Somerville's moveable buttons or studs. Fig. 547 is a side view of part of a double percussion gun; and fig. 548 is a top or plan view, which will serve to explain these improvements, and show one, out of many, methods of carrying them into effect. A is the stock of the gun; B the barrels; c the breech; D the nipples; E the false breech, on the under side of which the levers which work the safety studs or pins are placed; F is the shield of the false breech;, G, triggers; H the lock-plate; and i the hammers: all of which are constructed as usual: a a are the safety studs or pins, which protrude before the shield F, and work through guide pieces on the under side of the false breech. The button piece is placed in the position for the thumb of the right hand to act upon it; but when the pressure of the ball of the right thumb is to produce the movement of the safety studs, it must be placed 547 in or near the position K; and when the heel of the right hand is to effect the move ments of the safety studs, the button piece must be placed at L. or nearly so. 548 D 549 a In these last two positions, the lever (which is acted upon by the button piece to work the safety studs through a slide) would require to be of a different shape and differ. ently mounted. When the hammers are down upon the nipples after discharging the gun, the ends of the safety pins press against the inner sides of the hammers. When this invention is adapted to single-barrelled guns, only one pin, a, one lever and button piece will be required. Mr. Richards, gun maker, Birmingham, patented, in March, 1836, a modification of the copper dap for holding the percussion powder, as represented fig. 549; in which the powder is removed from the top of the cap, and brought nearer the mouth; a being the top, b the sides, and c the position of the priming. The dotted lines showthe direction of the explosion, whereby it is seen that the metal case is opened or distended only in a small degree, and not likely to burst to pieces, as in the cornmon caps, the space between a and c being occupied by a piece of any kind of hard metal d, soldered or otherwise fastened in the cap. George Lovell, Esq., director of the Royal Manufactory of Arms at Enfield, has re. cently made a great improvement upon the priming chamber. He forms it into a vertical double cone, joined in the middle by the common apex; the base of the upper cone being in contact with the percussion cap, presents the most extensive surface to the fulminate upon the one hand, while the base (f the under one being in a line with the inierior sat face of the barrel, presents the largest surface to the gunpowder charge, upon the other. In the old nipple the apex of the cone being at its top, afforded very injudiciously the minimum surface to the exploding force. Guns, Rifling of the Barrels. - The outside of rifle barrels is, in general, octagonal, After the barrel is bored, and rendered truly cylindrical, it is fixed upon the rifling machine. This instrument is formed upon a square plank of wood 7 feet long, to which is fitted a tube about an inch in diameter, with spiral grooves deeply cut internally through its whole length; and to this a circular plate is attached, about 5 inches diameter, accurately divided in concentric circles, into fiom 5 to 16 equal parts, and spI)ported by two rings made fast to the plank, in which rings it revolves. An arm w:nnected with the dividing graduated plate, and pierced with holes, through which a FIRE ARMS. 723 pin is passed, regulates the change of the tube in giving the desired number of grooves to the barrel. An iron rod, with a moveable handle at the one end, and a steel cutter in the other, passes through the above rifling tube. This rod is covered with a core of lead one foot long. The barrel is firmly fixed by two rings on the plank, standing in a straight line on the tube. The rod is now drawn repeatedly through the ban el, fiom end to end, until the cutter has formed one groove of the proper depth. The pin is then shifted to another hole in the divi(ing plate, and the operation of arooving is repeated till the whole nulber of riflings is completed. The barrel is next taken out of' the machine, and finisned. This is done by casting upon the end of a small iron rod a core of lead, which, when besmeared with a mixture of fine emery and oil, is drawn, fbr a considerable time, by the workmen, from the one end of the barrel to the other, till the inner surface has become finely polished. The best decree of spirality is found to be fromn a quarter to half a revolution in a length of three feet. Military Rifles.-An essential improvement in this destrL.tive arm has lately been introduced into the British service at the suggestion of Mr. Lovel. The intention in all rifles is to impart to the ball a rotatory or spinning motion round its axis, as it passes out through the barrel. This object was altaiied, to a certain degree, in the rifles of the old pattern, by cutting seven spiral grooves into the inside of;he barrel, in the manner shown by fig. 550, the spherical ball, fig. 551, being a little 553 552 550 551 larger than the bore, was driven down with a mallet, by which the projecting ribs were forced into the surface of the ball, so as to keep it in contact with their curvatures, during its expulsion. Instead of this laborious and insecure process, the barrel being now cut with only two opposite grooves, fig. 552, and the ball being formed with a projecting belt, or zone, round its equator, of the same form as the two grooves, fig. 553, it enters so readily into these hollows, that little or no force is required to press it down upon the powder. So much more hold of the barrel is at the same time obtained, that instead of one quarter of a turn, which was the utmost that could be safely given in the old way, without danger of stripping the ball, a whole turn round the barrel, in its length, can be given to the two grooved rifles; whereby a far more certain and complete rotatory motion is imparted to the ball. The grand practical result is, that better practice has been performed by several companies of the Rifle Corps, at 300 yards, than could be produced with the best old military rifles at 150 yards; the soldier being meanwhile enabled to load with much greater ease and despatch. The belt is bevelled to its middle line, and not so flat as shown in the figure. This mode of rifling is not, however, new in England. In faict, it is one of the oldest upon record; and appears to have fallen into disuse from faults in the execution. The id, was revived within the last few years in Brunswick, and it was tried ia 554 \Mr. Lovell's Lock. Hanover also, but with a lens-shaped (Linsenformig) ball. The judicious modifications and improvements it has finally received in Mr. Lovell's hands, have brought out all its 724 FIRE ARMS. advantages, and rendered it, when skilfully used, a weapon of unerring aim, even at the prodigious distance of 700 yards. The locks, also, for the military service generally, are now receiving an important irprovement by means of his labors, having been simplified in a remarkable manner. The action of the main spring is reversed, as shown byfig. 554; thus rendering the whole mechanism more solid, compact, and convenient; while the ignition of the charge'being effected by percussion powders in a copper cap, the fire of the British line will, in future, be more murderous than ever, as a miss-fire is hardly ever experienced with the fire-arms made at the Royal manufactury, under Mr. Lovell's skilful superintendence. Barrel-welding by lMachinery.-The barrels of musquets, birding-guns, &c., or what are called plain, to distinguish them from those denominated stub or twisted barrels, have of late years been formed by means of rolls, a process in which the welding is first effected on a short slab of thick iron, and then the barrel is brought down to its destined length, and form, by repeatedly passing it between a pair of rolls, that have been previously grooved to the exact shape of the barrel intended to be made. This method has entirely superseded the skelp-welding by hand described in the Dic. of Man., p. 717, and is conducted as follows:The iron being thoroughly refined, and reduced into flat bars by the process described at length at p. 1079, is cut by the shears into slabs or lengths of 10 to 12 inches, and 10 to 10I lbs. weight, or less, according to the description of gun-barrel that is intended to be made. These slabs are then heated, and bent in their whole length, bh means of conveniently grooved bending rolls, until they assume the form of rough tubes, 555 of the kind of section shown by A, fig. 555. They are then placed c,. the hearth of the reverberatory furnace (Dic. p. 1081), and brought to a full welding heat, and as soon as the edges of a tube come to a semi-fluid state, it is taken out and passed between rolls having grooves somewhat smallel in diameter than the exterior of the tube, by which means the tube is perfectly welded from end to end; and if care be taken in the management of the heat, and the juncture be kept clear of dirt and cinders, the iron will be found perfectly homogeneous in every part, and there, will be no appearance whatever of the seam where the edges came together. These tubes are repeatedly heated, and passed between the barrel rolls, which are of sufficient diameter to admit of gradually decreasing grooves, the whole length of the intended barrel being indented on their surfaces. To preserve the tubular form, and insure regularity in the size of the bore during the welding process, they are taken out of the furnace, by thrusting into them a tool called a mandril B, which consists of a long rod of iron, having a short steel treblett on its end, of the diameter that the bore of the barrel is meant to bore. This rod is so adjusted by means of a strong iron plate c, near its handle, which is of wood, and long, that when passed with the heated tube on it between two tranverse holding bars, the short steel treblett D, shall be found exactly between the point of impact of the barrelrolls, E E. 0(/4~~~\) ~556 T a s. 1 The adhesion of the hot iron to the surface of the rolls is strong enough to draw the tube off the mandril, which thus keeps the bore open from end to end, and by repeating the process through the whole series of grooves in the rolls, the barrel is gradually elongated, and brought (town to the exact form required: any superfluous length at the tuzzle is then cut off. The breach end is then adjusted by the hammer-a tripple-seat welded on by hand iF it be intended for a percussion lock, and then the barrel is ready to go forward to the mill to be bored, turned, and finished. Gun-barrels formed by this mechanical method are found to stand proof better than those worked by hand, because the heat is more equalized; and any imperfections in the original mass of iron are more dispersed over the whole extent of the tube. Mr. Wells Ingram, of Bradford street, Birmingham, has lately perfected a very complete lathe for turning the exterior of gun-barrels of all descriptions, a process which is FIRE ARMS. 725 fast superseding the use of the grindstone, for equalising the barrels of all kinds of fire. arms. I am indebtedfor this article to K2ir. Lovell, Director of the Royal Arms fManufactory. See MUSQUET. Since the first edition of the Dictionary large strides have been made towards increasing the efficacy of military fire artns; the French had found in their skirmishes with Abd-el-Kader in Africa, that the long matchlocks of the Arabs told at fearful odds against their men at distances where the ordinary French musquet was powerless of offence. After a while it was found that this increased range was due solely to the greater elevation taken by the natives in aiming, and their expertness in judging their distances, taught by long practice and experience; for the Arab arms and ammunition taken at Constantine were found of the rudest construction. These observations led the French officers of artillery to'institute all sorts of experiments to render their small arms more effective; by the adoption of wall-pieces of wider bore; by introducing a more general use of rifled barrels, but at the same time avoiding the tedious method of loading by means of mallets formerly observed with such kind of arms. The first attempt towards such object was that proposed by M. Delvigne, an officer of the royal ex-guard, (fig, 557), in which the upper orifice of the chamber that 557 contained the powder took the form of a cup, wherein the ball (somewhat wider in diameter) was received, and by two or three smart blows of a heavy-leaded rammer (also cupped out for the purpose) became expanded latterly, and thus the rotary motion was imparted to it by the spiral grooves of the barrel in passing out. Colonel Poncharra suggested the addition of a wood bottom or sabot under the ball and a greased woollen patch; and Colonel Thouvesino proposed (fig. 558) a steel stem or pillar about 2 inches 558 long inserted into the face of the breech-pin; round this pin, the charge of powder was received, and the diameter of the ball, when resting on the top of the pin was enlarged by the blows of the heavy-headed rammer, as suggested by Delvigne. This system took the name of' Carabine a Tige," and has been very generally intro. duced for the service of fusilier battalions in continental armies; very grave objections, however, have been found against it in use, from the impossibility of keeping the chamber (or post round the pin) clear; and from the severe labor to the soldier in ramming down and enlarging the diameter of the ball sufficiently to ensure the rotary motion desired. But if the ultimate results thus attained with spherical balls turned out not entirely satisfactory, it was made clearly manifest, in the course of the experiments carried on, that no insuperable difficulty stands in the way of rendering the fire of infantry very much more accurate and powerful, by the use of rifled barrels throughout the army, and thus leading to a verification of the prediction made by Robins above one hundred years ago, that "whatever state shall thoroughly comprehend the nature and advantages of rifled barrel pieces, and having facilitated and completed their construction, shall introduce into their armies their general use, with dexterity in the management of them, will by this means acquire a superiority which will almost equal any thing that has been done at any time." But besides smoothing the way to such an essential improvement, it has been elicited of late years, that when the accuracy of flight is secured by the rotary motion derived from the rifling, the bullet, instead of being limited to the form of a sphere as hereto fore, may, up to certain limits, be elongated with considerable increase of destructive ef feet; and with an augmentation of range very much beyond anything that has hitherto been considered to lie within the reach of small arms-placing them, in fact, with reference to artillery and cavalry, in the first place instead of the last. An immensely extended field has thus been opened to experimenters. Ist. Mons. Didon proposed a true oval (fig. 559) as the best form of bullet, so that when shortened by the blows of the heavy ranmmer and widened in its diameter it might be brought nearer to the spherical shape before leaving the barrel. 726 FIRE ARMS. 2,]. Mons. Delvigne took a patent for a bullet (fig. 560) under the deesgnation of "Cylindro Ogivale;" it had a conical opeJning behind, in which lie imagined that the force of the powder would exert itself with sufficient energy to expand tie lead permanently, and so make the hall take the rotary movement derived from the rifling, without any fatigue to the soldier in loading; with this projectile, indeed, the operation it but slightly more difficult than with the ordinary cartridge and smooth barrels. 559 560 561 562 563 The bullet (fig. 561) of the "Carabine a Tige" was called "Cylindro Coniqc e," and was said to possess this advantage over the preceding, that, being brought more to a point in front, it bored its way through the air with greater ease, and thus retained greater velocity, and of course more extended range; and with this bullet it was that Mons. Tamisier introduced three sharp-edged channels round it, which he stated were necessary to keep its flight steady, by offering a resistance to the action of the air. Finally Mons. Mnii6, an officer of the French line, suggested (fig. 662) the addition of a denoyau or culot to the hollow ball of Delvigne. This, in the form ot a little cup made of sheet iron, is placed in the orifice of the conical hollow -of the ball behind, and by the energy of the powder is driven into the ball, enlarging its diameter permanletly, and thus giving all the accuracy of the rifle, with nearly the same facility of loading as with the plain barrel. The principle of the invention, as thus developed, has, we learn, been adopted by our government for the general use of the army, seeing tlhat it offers so great advantages over the system of plain barrels, but the bullet (fig. 563), as modified by the Inspector of Small Arms, has on its exterior no channels, they being found not only useless as to steadying the flight of the projectile, but absolutely injurious in lowering its velocity. The bullet in its improved form, too, being more truly balanced in its proportions, and made by mechanical means instead of by casting, has no tendency to the gyrations which appear to have so puzzled French artillerists, and for which they have invented the word "derivation," and wasted much learned disquisition. Though well satisfied with the results of their course of experiments, our neighbors, however, do not appear to have come to any final decision as yet; indeed, the fact of being able to. make use of an elongated projectile with a rifle lias let loose such a crowd of inventors, that they seem to be entirely bewildered. In Switzerland every Canton has its pecuilar form of bullet, each one, of course, being tlhe best, and fiomn the length and size of a small caterpillar upwards, every man seems to have his own maggot, which lie vaunts before the world. But even if it were ever to happen, which is not likely, that these various projectors could be brought to agree as to the best form of projectile, they will then find out, that although by the general introduction of rifled and elongated bullets an immense advantage has been realised over plain barrels, their plans, based as they all are upon a system of loading at the muzzle, are at best but one step in advance; and that a good sound military fire-arm loading at the breech will, after all, remain the great desideraturn-an arml that, without any less accuracy or power to reach masses of artillery or cavalry at a thousand yards' distance, will enable the soldier to triple the quantity of his fire at any moment that lie may be called upon to repel a charge of cavalry or at tack or defend a breach at close quarters; of such simple construction, and so easily handled in every position of tle body, that the soldier can pour every shot of his most murderous fire upon the enemy with unerring precision, whilst he himself may lay coolly behind a stone or in a ditch in entire security. These are no longer wild imaginings, although so many hundreds of attempts towards the same object, from the earliest period to the present day, have been one a'ter another seen invariably to fail. The Gerilans have been long and steadily pursuirug the great object, until at length Herr Dreysa, of S6rtmerda in Tlhuringia, has succeeded, after more than twenty years of continued labor, in establishing a musquet, under the name i ------ -- --- FIRE-WORKS. 727 of "Ziindnadelgewehr," which if not quite perfect, has been found to work so well in the hands of the men, that the Prussian government has already 80,000 in possession, and they are going on to arm the whole of their line regiments and Landwehr with them. Even-with the assistance of a diagram, it is hardly possible to convey a clear notion of the construction of this musquet, because the several parts work one within the other, and their combination, which is without pin or screw, is hard to comprehend by a mere description. There is a strong socket, fig. 564), a, open on the upper side, screwed on to the barrel, 564 ri --- ---. - A -_ 6, which is rifled in the usual manner; within this socket is a slider c, which in fact constitutes the lock, as it contains the spiral spring and mechanismL;hat produces ignition by percussion; it has a stout hebel or handle, by which it., moved backwards and forwards freely. The cartridge (fig. 565) consists of the ball a, the sabot b, or bottom of hard paper, and holding the priming matter, and lastly the charge of powder, c, the whole 6 being made up in paper pasted together. In use, the slider being drawn back, the soldier puts the cartridge with the point of the ball in fiont'nto the open breech of the barrel, pushes the slider forward, and secures its close \ junction by a turn to the right against an inclined edge of the open sceket. \ he spiral spring is then brought into action (or the gun is cocked) by pressing the spring case forward with the thumb................ n pulling the trigger, the interior needle, from which the musquet takes its name, is darted forward through the charge of powder into the percussion primer in the sabbt, and thus effects the ignition inside the barrel. The principle of loading at the breech carries with it so many other.Ij... Iadvantages beyond that by the muzzle, that many ingenious men are occupying themselves with its imnprovement; Lefaucheur and, Robert in France; Montigny in Belgium; Kufahl Schultz and Friedrix in Prussia; c Sears and Needham in England, have lately brought forward various plans; and now that the idea is taken up upon a right base, there can be little doubt that eventually a system will be hit upon, that shall secure all the requisites for military service, and avoid all objections. But it is clear, from the recent publications on gunnery and the observations of ancient warriors, that the advocates'for heavy battalion movements, for drawing up their infantry in long lines and compact bodies for destruction by artillery, will be with difficulty brought to look with patience upon the scrambling and desultory sort of warfare which the general introduction of these improved rifles must bring about. Time, however, daily goes on to work wonders upon prejudice, and the day will come when it will be found that cross-belts and blank-cartridges may be abolished without utter ruin to the army; and that men behind trees, with effective weapons in their hands, may be more dangerous enemies, at long ranges, than when strapped up and paraded out in masses, and carrying arms that at any distance over 300 are powerless of offence. FIRE-DAMP; the explosive carburetted hydrogen of coal mines. See PITCOAL FIRE-WORKS. (Feux d'artifice, Fr.; Feuerwerke, Germ.) The composition of luminous devices with explosive combustibles, is a modern art resulting from the discovery of gunpowder. The finest inventions of this kind are due to the celebrated Ruggieri, father and son, who executed in Rome and Paris, and the principal capitals of Europe, the most brilliant and beautiful fire-works that were ever seen. The following description of their processes will probably prove interesting to many of my readers. The three prime materials of this art are, nitre, sulphur, and charcoal, along with filings of iron, steel, copper, zinc, and resin, camphor, lycopodium, &c. Gunpowder is used either in grain, half crushed, or finely ground, for different purposes. The longer the iron filings, the brighter red and white sparks they give; those being preferred which are made with a very coarse file, and quite free fromn rust. Steel filings and cast-iron borings contain carbon, and afford a more brilliant fire, with wavy radiations. Copper filings give a greenish tint to flame; those of zinc a fine blue color; the sulphuret of antimony gives a less greenish blue than zinc, but with much smoke; amber affords a yellow fire, as well as colophony, and common salt; but the last must be very dry. Lampblack produces a very red color with gunpowder, and a pink with nitre in excess 728 FIRE-WORKS. It serves for making golden showers. The yellow sand or g istening mica, communicatel to fire-works golden radiations. Verdicris imparts a pale green; sulphate of copper and sal-ammoniac, a palm-tree green. Camphor yields a very white flame and aromatic fumes, which mask the bad smell of other substances. Benzoin and storax are used also on account of their agreeable odor. Lycopodium burns with a rose color and a magnificent flame; but it is principally employed in theatres to represent lightning, or to charge the torch of a fury. Fire-works are divided into three classes: 1. those to be set off upon the ground; 2. those which are shot up into the air; and 3. those which act upon or under water. Composition for jets offire; the common preparation for rockets not more than 3 of an inch in diameter, is; gunpowder, 16 parts; charcoal, 3 par s. For those of larger diam. eter; gunpowder, 16; steel filings, 4. Brilliant revolving wheel; for a tube less than I of an inch; gunpowder, 16; steel filings, 3. When more than 4: gunpowder, 16; filings, 4. Chinese or Jasmine fire; when less than 3 of an inch: gunpowder, 16; nitre, 8; charcoal (fine), 3; sulphur, 3; pounded cast-iron borings (small), 10. When wider than -: gunpowder, 16; nitre, 12; charcoal, 3; sulphur, 3; coarse borings, 12. ~d fixed brilliant; less than 4 in diameter: gunpowder, 16; steel filings, 4; or, gunpowder, 16; and finely pounded borings, 6. Fixed suns are composed of a certain number of jets of fire distributed circularly, 7ke the spokes of a wheel. All the fisees take fire at once through channels charged with quick matches. Glories are large suns with several rows of fusees. Fans are portions of a sun, being sectors of a circle. The Patte d'oie is a fan with only three jets. The mosaic represents a surface covered with diamond shaped compartments, formed by two series of parallel lines crossing each other. This effect is produced by placing at each point of intersection, four jets of fire, which run into the adjoining ones. The in. tervals between the jets must be associated with the discharge of others, so as to keep up a succession of fires in the spaces Palm trees. Ru-gieri contrived a new kind of fire, adapted to represent all sorts of trees, and especially the palm. The following is the conposition of this magnificent green fire-work: crystallized verdigris, 4 parts; sulphate of copper, 2; sal-ammoniac, 1. These ingredients are to be ground and moistened with alcohol. An artificial tree of aly kind being erected, coarse cotton rovin.s about 2 inches in diameter, impregnated with that composition, are to be festooned round the trunk, branches, and among the leaves; and immediately kindled before the spirits have had time to evaporate. Cascades imitate sheets or jets of water. The Chinese fire is best adapted to such decorations. Fixed stars. The bottom of a rocket is to be stuffed with clay, and one diameter in height of the first preparation being introduced, the vacant space is to be filled with the following composition, and the mouth tied up. The pasteboard must be pierced into the preparation, with live holes, for the escape ol the luminous rays, which represent a star. Composition of fixed stars:Ordinary. Brighter. Colored. Nitre - - - 16 12 0 Sulphur - - 4 6 6 Gunpowder meal - 4 12 16 Antimony - - 2 1 2 Lances are long rockets of small diameter, made with cartridge paper. Those which burn quickest should be the longest. They are charged by hand without any mould, with rods of different lengths, and are not strangled at the mouth, but merely stuffed with a quick match of tow. These lances form the figures of great decorations; they are fixed with sprigs upon large wooden frame works, representing temples, palaces, pagodas, &c. The whole are placed in communication by conduits, or small paper cartridges like the lances, but somewhat conical, that they may fit endwise into one another to any extent that may be desired. Each is furnished with a match thread fully 1 inches long, at its two ends. Composition for the white lances: nitre, 16; sulphur, 8; gunpowder, 4 or 3. For a bluish-white: nitre, 16; sulphur, 8; antimony, 4. For blue lances: nitre, 16; antimony, 8. For yellow: nitre, 16; gunpowder, 16; sulphur, 8; amber, 8. For yellower ones: nitre, 16; gunpowder, 16; sulphur, 4; colophony, 3; amber, 4. For greenish ones: nitre, 16; sulphur, 6; antimony, 6; verdigris, 6. For pink lances: nitre, 16; gunpowder, 3; lampblack, 1. Others less vivid are made with nitre, 16; colophony, 3; ariber, 3; lycopodium, 3. Cordage is represented in fire-works, by imbuing soft ropes with a mixture cf nitre, 2 sulphur, 16; antimony, 1; resin of juniper, 1..______________________________________________________~~~__ FIRE-WORKS. 723 The Bengal flames rival the light of day. They consist of, nitre, 7; sulphur, 2; an. tirony, 1. This mixture is pressed strongly into earthen porrirgers, with some bits of quick match strewed over the surface. These flames have a fine theatrical effect for conflagrations. Revolving suns, are wheels upon whose circumference rockets of different styles are fixed, and which communicates by conduits, so that one is lighted up in succession after another. The composition of their common fire is, for sizes below 2 of an inch: gunpowder meal, 16; charcoal, not too fine, 3. For larger sizes: gunpowder, 20; charcoal, not too fine. 4. ForJfiery radiations: gunpowder, 16; yellow micaceous sand, 2 or 3. For mixed radiations: gunpowder, 16: pitcoal, 1; yellow sand, 1 or 2. The waving or double C;ltherine wheels, are two suns turning about the same axis in opposite directions. The fusees are fixed obliquely and not tangentially to their peripheries. The wheel spokes are charged with a great number of fusees; two of the four wings revolve in the one direction, and the other two in the opposite; but always in a vertical plane. Tile girandoles, caprices, spirals, and some others have on the contrary a horizontal rotation. The fire-worker may diversify their effects greatly by the arrangement and color of the jets of flame. Let us take for an example the gloce of i' ht. Imagine a large sphere turning freely upon its axis, along with a hollow hemisphere, which revolves also upon a vertical axis passing through its under pole. If the two pieces be covered with colored lances or cordage, a fixed luminous globe will be formed, but if horizontal fusees be added upon the hemisphere, and vertical fusees upon the sphere, the first will have a relative horizontal movement, the second a vertical movement, which being combined/with the first, will cause it to describe a species of curve, whose effect will be an agreeable contrast with the regular movement of the hemisphere. Upon the surface of a revolving sun, smaller suns might be placed, to revolve like satellites round the primaries. Rnggieri exhibited a luminous serpent pursuing with a rapid, winding pace a butterfly which flew continually before it. This extraordinary effect was produced in the following way. Upon the summits of an octagon he fixed eight equal wheels turning freely upon their axles, in the vertical plane of the octagon. An endless chain passed round their circumference, going from the interior to the exterior, covering the outside semi-circumference of the first, the inside of the second, and so in succession; whence arose the appearance of a great festooned circular line. The chain like that of a watch, carried upon a portion of its length a sort of scales pierced with holes for receiving colored lances, in order to represent a fiery serpent. At a little distance there was a butterfly constructed with white lances. The piece was kindled commonly by other fire-works, which seemed to end their play, by projecting the serpent from the bosom of the flames. The motion was communicated to the chain by one of the wheels, which received it like a clock from the action of a weight. This remarkably curious mechanism was called by tle artists a salamander. The rockets which rise into the air with a prodigious velocity, are among the most common, but not least interesting fire-works. When employed profusely they form those rich volleys of fire which are the crowning ornaments of a public fete. The cartridge is similar to that of the other jets, except in regard to its length, and the necessity of pasting it strongly, and planing it well; but it is charged in a different manner. As the sky-rockets must fly off with rapidity, their composition should be such as to kindle instantly throughout their length, and extricate a vast volume of elastic fluids. To effect this purpose, a small cylindric space is left vacant round the axis; that, is, the central line is tubular. The fire-workers call this space the soul of the rocket (ame de la fuse). On account of its somewhat conical form, hollow rods, adjustable to different sizes of broaches or skewers, are required in packing the charge; which must be done while the cartridge is sustained by its outside mould, or copper cylinder. The composition of sky-rockets is as follows (see next page). The cartridge being charged as above described, the pot must be adjusted to it, with the garniture; that is, the serpents, the crackers, the stars, the showers of fire, &c. The pot is a tub of pasteboard wider than the body of the rocket, and about one-third of its length. After being strangled at the bottom like the mouth of a phial, it is attached to the end of a fusee by means of twine and paste. These are afterward covered with paper. The garniture is introduced by the neck, and a paper plug is laid over it. The whole is enclosed within a tube of pasteboard terminating in a cone, which is firmly pasted to the pot. The quick-match is now finally inserted into the soul of the rocket. The rod attached to the end of the sky-rockets to direct their flight, is made of willow or any other light wood. M. Ruggieri replaced the rod by conical wings containing explosive materials, and thereby made them fly further and straighter. The garnitures of the sky-rocket pots are the following:1. Stars are small, round, or cubic solids, made with one of the following compoI r30 FISH-HOOKS. When the bore is A of an inch; 1 to 174; l; Nitre - - - 16 16 16 Charcoal - - 7 8 9 Sulphur - - 4 4 4 Brilliant Fire. Nitre - - - 16 16 16 Charcoal - - 6 7 8 Sulphur - - 4 4 4 Fine steel filings - 3 4 5 Chinese Fire. Nitre - - - 16 16 16 Charcoal - - 4 5 6 Sulphur - -3 3 4 Fine borings of cast-iron 3 coarser 4 mixed 5 sitions, and soaked in spirits. WlVite stars, nitre, 16; sulphur, 8; gunpowder, 3. Others more vivid consist of nitre, 16; sulphur, 7; gunpowder t. Stars for golden showers, nitre, 16; sulphur, 10; charcoal, 4; gunpowder, 16; lamp. black, 2. Others yellower are made with nitre, 16; sulphur, 8; charcoal, 2; lampblack, 2; iunpowder, 8. The serpents are small fusees made with one or two playing cards; their bore being less than half an inch. The lardons are a little larger, and have three cards; the vet tilles are smaller. Their composition is, nitre, 16; charcoal, not too fine, 2; gunpowder, 4; sulphur, 4; fine steelfilings, 6. The petards are cartridges filled with gunpowder and strangled. The saxrons are cartridges clayed at each end, charged with the brilliant turning fire, and perforated with one or two holes at the extremity of the same diameter. The cracker is a round or square box of pasteboard, filled with granulated gunpowder, and hooped all round with twine. Rom(an candles are fusees which throw out very bright stars in succession. With the composition (as under) imbued with spirits and gum-water, small cylindric masses are made, pie-rced with a hole in their centre. These bodies, when kindled and projected into the air, form the stars. There is first put into the cartridge a charge of fine gun. powder of the size of the star; above this charge a star is placed; then a charge of composition for the Roman candles. The stars, when less than o of an inch, consist of nitre, 16; sulphur, 7; gunpowder, o. When larger, of nitre, 16; sulphur, 8; gunpowder, 8. Roman candles, nitre, 16; charcoal, 6; sulphur, 3. When above I of an inch, nitre, 16; charcoal, 8; sulphur, 6. The girandes, or bouquets, are those beautiful pieces which usually conclude a fire. work exhibition; when a multitude of jets seem to emblazon the sky in every direction,.nd then fall in golden showers. This effect is produced by distributing a number of cases open at top, each containing 140 sky-rockets, communicating with one another by quick-match strings planted among them. The several cases communicate with each other by conduits, whereby they take fire simultaneously, and produce a volcanic display. The water fire-works are prepared like the rest; but they must be floated either by woode i bowls, or by discs and hollow cartridges fitted to them. Blue fire for lances may be made with nitre, 16; antilmony, 8; very fine zinc filings, 4. Chinese paste for the stars of Roman candles, bombs, &c.:-Sulphur, 16; nitre, 4; gunpowder meal, 12; camphor, 1; linseed oil, 1; the mixture being moistened with spirits. The feu gregois of Ruggieri, the son: —Nitre, 4; sulphur, 2; naptha, 1. See PYROTECHNY and ROCKETS. The red fire composition is made by mixing 40 parts of nitrate of strontia, 13 of flowers of sulphur, 5 of chlorate of potash, and 4 of sulphuret of antimony. White fire is produced by igniting a mixture of 48 parts nitre; 13- sulphur; 71 sulphuret of antimony; or, 24 nitre, 7 sulphur, 2 realgar; or, 75 nitre, 24 sulphur, 1 c.arcoal; or, finally, 100 of gunpowder meal, and 25 of cast-iron fine borings. The blue fire composition is 4 parts of gunpowder meal; 2 of nitre; sulphur and zinc, each 3 parts. FISH-HOOKS (Hamecons, Fr.; Fishangeln, Germ.) are constructed with simple tools, but require great manual dexterity in the workmen. The iron wire of which they FLANNEL. 731 they are made should be of the best quality, smooth and sound. A bundle of such wire is cut in lengths, either by shears or by laying it down upon an angular wedge of bard steel fixed horizontally in a block or anvil, and striking off the proper lengths by the,lows of a hammer. In falshliorning the barbs of the hooks, the straight'piece of wire is laid down in the groove of an iron block made on purpose, and is dexterously struck by the chisel in a slanting direction, across so much of tile wire as may be deemed necessary. A sharp-pointed little wedge is thus formed, whose base graduates into Lne sulstance of the metal. The end of the wire where the line is to be attached is now flattened or screw-tapped; the other end is sharp pointed, and the proper twisted curvature is given. The soft iron hooks are next case-hardened, to give them the steely stiffness and elasticity, by imbedding them in animal charcoal contained in an earthen or iron box; see CASE-HARDENING; after which they are brightened by heating and agitating them with bran, and finally tempered by exposure to a regulated temperature upon a hot iron plate. Hooks for salt-water fishing are frequently tinned, to prevent then wearing rapidly away in rust. See TIN PLATE. FLAKE WHITE is the name sometimes given to pure white-lead. FLAME (Flamme, Fr. and Germ.) is the combustion of an explosive mixture of an inflammable gas or vapor with air. That it is not, as many suppose, combustion merely at the exterior surface, is proved by pluneing a fragment of burning phosphorus or sulphur into the centre of a large flame of alcohol. Either of these bodies will continue to burn there with its peculiar light; thus proving that oxygen is mixed with the whole of the burning vapor. If we mix good coal gas with as much atmospheric air as can convert all its carbon into carbonic acid, the mixture will explode with a feeble blue light; out if we mix the same gas with a small quantity of air, it will burn with a rich white flame. In the latter case the carbonaceous particles are precipitated, as Sir H. Davy first showed, in the interior of the flame, become incandescent, and constitute white lilht: for from the ignition of solid matrer alone can the prismatic rays be emitted in that concentrated union. Towards the interior of the flame of a candle, a lamp, or a gas jet, where the air is scanty, there is a deposition of solid charcoal, which first by its ignition, and afterwards by its combustion, increases in a high degree the intensity of the light. If we hold a piece of fine wire gauze over a jet of coal ras close to the orifice, and if we then kindle the gas, it will burn above the wire with its natural brilliancy; but if we elevate the gauze progressively higher, so as to mix more and more air with it belbre it reaches the burning point, its flame will become fainter and less white. At a certain distance it becomes blue, like that of the above explosive mixture. Since the combustion of all the constituents is in this case direct and complete, the heat becomes greatest in proportion nearly as the light is diminished. If a few platina wires be held in that dim flame they will grow instantly white hot, and illuminate the apartment. On reversing the order of this experiment, by lowering progressively a flat piece of wire gauze from the summit towards the base of a gas flame. we shall find no charcoal deposited at its top, because plenty of air has been introduced there to convert all the carbon of the gas into carbonic acid, and therefore the apex is blue; but as we descend, more and more charcoal will appear upon the meshes. At the very bottom, indeed, where the atmospheric air impinges upon the gauze, the flame is again blue, and no charcoal can therefore be deposited. The fact of the increase of the brilliancy and whiteness of flame by the developmen and ignition of solid matter in its bosom illustrates many curious phenomena. We can thus explain why olefiant gas affords the most vivid illumination of all the gases; because. being surcharged with charcoal, its hydrogen lets it go in the middle of the flame, as it does in an ignited porcelain tube, whereby its solid particles first get ignited to whiteness, and then burn away. When phosphorus is inflamed it always yields a pure white light, from the ignition of the solid particles of the snowy acid thus produced. In the blowpipe the inner blue flame has the greatest heat, because there the combustion of the whole fatty vapor is complete. The feeble light of burning hydrogen, carbonic oxyde, and sulphur, may, upon the principles now expounded, be increased by simply placing in them a few particles of oxyde of zinc, slender filamants of amianthus, or fine platina wire. Upwa-ts of twenty years ago I demonstrated, in my public lectures in Glasgow, that by narrowing the top of a long glass chimney over an argand flame either from oil or coal eas, the light could be doubled at the same cost of material. The very tall chimneys used by the Parisian lampists are very wasteful. I find that with a narrow chimney of half the length of theirs, I can have as good a light, and save 30 per cent. of the oil. Thus the light of a flame may be increased by diminishing its heat, or the intensity of its combustion; and conversely the heat of a flame may be increased by diminishing its light. FLANNEL; a plain woollen stuff, of a rather open and slight fabric... - 732 FLAX. FLAX. The general appellation of the fibrous produce used in the manufacture of linen threads, &c, of the plant Linum usitatissi2mum, which is cultivated, not for this produce only, but for that of its seed, employed in agriculture for feeding and fattening cattle, as well as in commerce for making the oil so well known as'linseed oil." This plant grows to the height of 2 or 3 feet, having a round and hollow stem, which divides into several branches, bearing blue flowers; these become the seed-pods of 10 cells, each of which contains one seed. As varieties, we distinguish the " spring" flax with short knotty stems, whose seed capsules at the period of maturity open with a perceptible sound; and the "close" flax, with longer, smoother stems, whose capsules give out the seed only when thrashed; the latter variety is the one most generally cultivated. Owing to the many improvements recently made in the various processes of the flax manufacture, all the operations for converting the raw plant to its ultimate useful and ornamental state have been greatly simplified and facilitated, and much attention has been paid to improving its cultivation, which has necessarily produced many cnanges in the formerly established modes of husbandry. Flax may be grown upon a great variety of soils: the best is a sound, dry, deep loam, with a clay subsoil; this should be properly drained, as too much underground or surface water is alike injurious. It is necessary that the land should be brought to an exceedingly fine state by frequent ploughings and harrowings, commenced in the autumn previous to the sowing, which should take place toward the end of March, or beginning of April. From 2 to 21 bushels of seed are required for one acre: the seed selected should be of a bright brown color, heavy, shining, and of an oily feel, avoiding such as have hard ends. Riga is the best for the greatest variety of soils, though Dutch is frequently used with great success. American does not generally suit, as it is apt to produce a coarse, branchy stem. The manner of sowing should be varied according to the purpose for which the crop is intended. When grain is the object of the grower, the sowing should be thin, as the plants then put out more branches, and thus yield more seed, but the fibrous produce becomes soft and meagre; the contrary is the case when the sowing is thick. Being one of the most tender plants of field cultivation, it requires very peculiar care in weeding, so as not to be injured by either the neglect or excess of this work, which should be done when the plants are about 3 inches high, that is, about a month after sowing. Guano and bone dust are suitable manures if farm dung is scarce. The following artificial manure, it has been said, will replace chemically the constituents of the plants produced from an acre of land, viz:Muriate of potash - 30 lbs. Common salt - - - - - 28 lbs. Burned gypsum, powdered - - - 34 lbs. Bone dust - - - - - 54 lbs. Sulphate magnesia - - - - 56 lbs. The average produce of seed is 12 bushels to the acre. In regard to flax being considered a wasting crop for the land there are some observations to be made that may controvert that idea and establish one more sound in its place. Assuming that the ashes of plants left after they are consumed by fire form a criterion of the quantity of nutritive matter they have extracted from the soil, there may at first sight appear much truth in the prevailing opinion as to the exhausting nature of the flax crop, since the ashes of this plant are 5~Q of the whole, which is a large proportion. But as no ashes result from burning the pure fibre, which is solely the part that may not be reconsumed upon the land, it proves that the fertility of the soil is not injured by that production. The nutrition withdrawn by the other parts can be as easily replaced by this plant as by any other, _9-ths by the water alone in which the steeping is to be afterward carried on, and. which should therefore be kept and enmployed as a liquid manure, to which must be added that more solid resulting from feeding cattle on the seed or oil cake, and from the ashes of the chaff, and thus a far greater part of the constituent of this plant is returned than of almost any other. Though the color of the flax is rather improved by letting the water run in a small stream through the steeping-pond during the operation, yet perhaps it may be a greater object to retain it for manure than to waste it for that purpose. Whenever the flax is ripe, which is shown by the bottom of the stalk becoming yellow, and the leaves beginning to drop off, it must be immediately reaped by pulling it up by the roots. The seeds are still immature, fit merely for the oil press, and not for sowing. When the seed crop is the object, the plant must be suffered to acquire its full maturity; in whicli case the fibres are less fine and soft. The flax is carried off the field in bundles to be rippled, or stripped of its seeds, which fLAX. 733 is done by drawing it by handfuls, through an iron comb with teeth eight inches long, fixed upright in a horizontal beam. When the seeds are more fully ripened, they may be separated by the thrashing mill. The operations next performed upon the flax will be understood by attending to the structure of the stem. In it two principal parts are to be distinguished; the woody heart or boon, and the harl (covered outwardly with a fine cuticle), which encloses the former like a tube, consisting of parallel lines. In the natural state, the fibres of the harl are attached firmly, not only to the boon, but to each other, by means of a green or yellowish substance. The rough stems of the flax, after being stripped of their seeds, lose in Inoisture, by drying in warm air, from 55 to 65 per cent. of their weight; but somewhat less when they are quite ripe and woody. In this dry state they consist in 100 parts of fiom 20 to 23 per cent. of harl, and from 80 to 77 per cent. of boon. The latter is composed upon the average of 69 per cent. of a peculiar woody substance, 12 per cent. of a matter siuble in water, and 19 per:ent. of a body not soluble in water, but in alkaline leys. The harl contains at a mean 58 per cent. of pure flaxen fibres, 25 parts soluble in water (apparently extractive and albumen), and 17 parts insoluble in water, being chiefly gluten. By treating the harl with either cold or hot water, the latter substance is dyed brown by the soluble matter, while the fibres retain their coherence to one another Alkaline leys, and also, though less readily, soap water, dissolve the gluten, which seems to be the cement of the textile fibres, and thus set them free. The cohesion of the fibres in the rough harl is so consideratb.e that by mechanical means, as by beatine, rubbing, &c., a complete separation of them cannot be effected, unless with great loss of time and rupture of the filaments. This circumstance shows the necessity of having recourse to some chemical method of decomposing the gluten. The process employed with this view is a species of fermentation, to which the flax stalks are exposed; it is called retting, a corruption of rotting, since a certain degree sf putrefaction takes place. The German term is rusting. This is the first important step in the preparation of flax. After the retting is completed, the boon of the stalks must be removed by the second operation called breaking, and other subordinate processes. The harl freed from the woody parts contains still a multitude of fibres, more or less coherent, or entangled, and of variable lengths, so as to be ill adapted for spinning. These are removed by the heckle, which separates the connected fibres into their finest filaments, removes those that are too short, and disentangles the longer ones. I. Of retting.-The fermentation of this process may be either rendered rapid by steep. ing the flax in water, or slow by using merely the ordinary influence of the atmospheric damp, dews, and rain. Hence the distinction of water-retting and dew-retting. Both may also be combined. Prior to being retted, the flax should be sorted according to the length and thickness of its stalks, and its state of maturity: the riper the plant, the longer must the retting last. The due length of the process is a point too little studied. Water-retting.-When flax stalks are macerated in water, at a temperature not too low, fermentation soon begins, evinced in the dingy infusion, by disengagement of carbonic acid gas, and the production of vinegar. If the flax be taken out at the end of a few days, dried, and rubbed, the textile filaments are found to be easily separable from each other. By longer continuance of the steep, the water ceases to be acid, it becomes to a certain degree alkaline, from the production of ammonia, diffuses a fetid odor, from the disengagement of sulphureted hydrogen gas, along with the carbonic acid; the acetous fermentation being in fact now changed into the putrid. The filaments become yellowish brown, afterwards dark brown, and lose much of their tenacity, if the process be carried further. When the operation is conducted with discernment, the water-retting may be completed by the acetous fermentation alone, as the putrefaction should never be suffered to proceed to any length; because when over-retted, flax is partially rotten, gets a bad color, and yields a large proportion of tow. For water-retting, the flax must be bound up in sheaves, placed in layers over each other in the water, or sometimes upright, with the roots undermost. Straw may be put below to keep it from touching the ground, and boards may be laid upon the top, with weights to hold it immersed about i foot beneath the surface, especially when the fermentative gases make it buoyant. As soon as it sinks at the end of the fermentation, it must be inspected at least twice a day, and samples must be taken out to see that no over-retting ensues. A single day too long often injures the flax not a little. We may judge that the retting is sufficient when the harl separates easily from the boon by the fingers, when the boon breaks across without bending, and when several stalks knitted together sink to the bottom upon being thrown into the water. For this completion. a 734 FLAX. shorter or longer time is required according to the quality of the flax, the temperature, &c., so that the term may vary from five to fourteen days. It may be done either in ruariri g or in stagnant water. For the latter purpose, tan ks five feet deep are dug in the ground. In stagnant water, the process is sooner finished, but it is more hazardous and gives a deeper stain to the fibres, than in a stream, which carries off much of the color. Tie best place for steeping flax is a pond with springs of water at its bottom; or a tanlk into which a rivulet of water can be occasionally admitted, while the foul water is let off. For every fiesh quantity of flax, the pond should be emptied, and supplied with clear water. Water impregnated with iron stains flax a permanent color, and shotild therefore never be used. After retting, the flax should be taken out without delay, rinsed in clean water, and exposed in an airy situation to dry by the sun. Rough rippled flax stalks, well seasoned before being retted, and dried afterward, show a loss of weight, amounting to 20 or 30 per cent., affecting both the boon and the harl. This loss is greater the finer the stems, and the longer the retting. The harl contains, besides the textile filaments, a certain portion of a glutinous cement; but nothing soluble in water. Tile destruction of the giuten can not be pushed to the last point by steeping, without doing an essential injury to the filaments. Duw-retting.-The fetid and noxious exhalations which the water-retting diffuses over an extensive district of country, and the danger of over-retting in that way, especially with stagnant water, are far from recommending that process to general adoptiorn. Dew-retting accomplishes the same purpose, by the agency of the air, dews, and rain, in a much more convenient, though far slower manner. The flax, with this view, sliould be spread out thin upon meadow or grass lands, but never upon the bare ground, and turned over, from tine to time, till the stems, on being rubbed between the fingers, show that the harl and tie boon are ready to part. Tile duration of dew-retting is, of course, very various, from two to six or eight weeks, as it depends upon the state of tile weather; a moist air being favorable, and dry sunshine the reverse. Tle loss of weight by dew-retting is somewhat less than by water-retting; and the textile fibres are of a brighter color, softer and more delicate to the touch. Mixed retting.-This iray be fairly regarded as the preferable plan, the retting being begun in the water and finished in the air. The flax should be taken out of the steep whtinever the acetous fermentation is complete, before the putrid begins, and exposed, for two or three weeks, on the grass. Witlin the last two years, the hazardous and tedious process above described has been attempted to be superseded by steeping the flax plant in vats of water artificially heated to 70~ Fahr., whereby the effects are produced in sixty or seventy hours. Drying by fire in kilns is pernicious alike to tile seed or fibrous produce; as in the former it dries up too soon tile nutritious particles that would be absorbed by the seed fronm its pod or outer covering, and in tlhe latter impairs the rich and oily property of the flax. Tile following is a description of an establishment for tile prosecution of Mr. Schenck's process, situated at Newplort river, county Mayo. Tile tenements containing the vats arnd drying shelves are siimple wooden sheds of cheap construction. In one end of the bllilding are four vats set parallel to each other the length of the house; they are made of inlch deal in the form of a parallelogram, fifty feet long, six broad, and four deep. There are false bottomns perforated with hioles; underneath these are introduced tile ste;lm-pipes, crossing the vlts, and having stop-cocks at their entrance, by which the steaml can be let on from the main pipe as required. The steam is generated in a small boiler, which also serves to turn two hydro-extractors, a patent apparatus used to drive off a portion of tie water with which the flax is satturated, on being taken fiom the vwlts. Tihe flax is packed into the empty vats, on the butt ends, in a half sloping position, precisely as in the case of a steep pool, only one layer being the depth. Tile water is then let in, and a frame fastened over the top of tile flax, answering the end of stories and straw or soda in the steeping pools, for prevention of the rising of the flax in course of fermentation. This process is now renolunced. Tire steam is then let into the pipes by turning the stop-cocks, and the water is some eillhteen or-twenty hours in becoming heated to the required point, 85~ or 90~ The fermentation then commences, and no further steam is required, the action going on until tire flax is thorolirhly rotted, which is in forty hours afterward, being sixty from the tirme of the admission of the water. At the end of the sixty hours, the flax is taken out the water allowed to run off, and the vat permitted to cool. The same process is then repeated with fresh water and fresh flax. When taken from the water, the flax is packed in the hydro-extractor, which is a round vessel of iron made to revolve by steam power with great velocity, the water being driven out of the flax on tile principle of the centrifugal force. Thirty beets or small handfuls are placed in this machine at a time, and about 20 lbs. of water are extracted in from three to five minutes. A few hours suffice for the contents of a vat, each vat containing 2 tons of flax straw. The hydro-extractor only separates a portion of the water; the flax now remains to be FLAX. 735 thoroughly dried. In summer, or indeed, for six months in the year, this can be accomplished, as usual, by spreading upon grass land in the open air. ])uring winter, however, it is necessary to procure other means of drying. A shed has therefore been erected, communicating by doors with the vat house, filled with ranges of shelves, composed simply of railings of lathwood in five or six tiers. The flax is spread lightly along these shelves by women, and the house is heated by steam-pipes. This house is capable of drying the full of one vat per diem. The flax, when dried, is made up in beets or handfuls, of a size suited for feeding into the breaking rollers of the mill. 2. The breaking is performed by an instrument called a brake. In order to give the wood or boon such a degree of brittleness as to make it part readily fiom the harl, whereby the execution of this process is rendered easy, the flax should be well dried in the sun, OF what is more suitable to the late period of the year, in a stove. Such is often attached to the bakers'ovens in Germany, and otherflax-growing countries. The drying temperature should never exceed 120~ F., for a higher heat makes it brittle, easy to tear, and apt to run into tow. Before subjecting the flax to the brake, the stems should be equalized and laid parallel by the hand, and the entangled portions should be straightened with a coarse heckle. The brake has one general construction, and consists of two principal parts, the frame or case, and the sword or beater. In the simplest brakes, the frame e, fig. 566, is a piece of wood cleft lengthwise in the middle, suplported by the legs a and c. The sword f, also of hard wood, is formed with an edge beneath, and turns round the centre of motion at q, when seized by the handle h, and noved up and down. As it descends, the sword enters the cleft of the frame, and breaks the flax stalks laid transversely upon it, scattering the boon in fragments, 573.... _ ^l'567 d' But those hand brakes are more convenient which are provided with a double cleft, or triple row of oblong teeth, with a double sword. This construction will be Inder. stood by inspecting figs. 566, 561, 568. Fig. 566 is the section of that side at which the operative sits; fig. 567 is a section in the line A B, of fig. 566; and fig. 568, the ground plan. The whole machine is made of hard wood, commonly red beech. Two planks, a and c, form the legs of the implement. a is mortised in a heavy block, to give the brake a solid bearing; two stretchers d bind a and c firmly together. The frame e consists of three thin boards, which are placed edgewise, and have their ends secured in a and c. The sword f is a piece of wood, so chamlfered from i to k, that it appears forklike, and embraces the middle piece of the frame; its centre of motion is the wooden pin q; in front is the handle h, which the operative seizes with the right hand. Both tlhe latlies of the frame and those of the sword are sharpened, from I to the front end, as is best shown in fig. 567; but the edges must not be too sharp, for fear of injuring the flax; and, for the same reason, the sword should not sink too far between the lathes of the frame. Such hand-brakes are laborious in use, and often tear the harl into tow. The operative, usually a female, in working the brake, seizes with her left hand a bundle of flax, lays it transverely across the frame, and strikes it smartly with repeated blows of th( sword, pushing forward continually new portions of the flax into the machine. She begins with the roots, turns next round the tips, then goes on through the length of the stalks. Flax is frequently exposed twice to the brake, with a stove-drying between the two applications. Tile brake machines afford a far preferable means of cleaning flax than the above hand tools. The essential part of such a nmachine consists in several deeply fluted rollers of wood or iron, whose teeth work into each other, and while they stretch out the flaxen stalks between them, they break the wood or boon, without doing that violelnc 736 FLAX. to the harl which hand mechanisms are apt to ao. The following may be regarded as one of the best constructions hitherto contrived for breaking flax. Fig. 569 is a view of the right side of this machine. Fig. 570, the view from behind, where the broken 570 569 -E dr p iis~~"i walls a, a, which are mortised into the bottom b, b; ad are firmly fixed to it by of these a lateral arm e, is mortised in an oblique direction; a cross bar Jf unites both arms. Fig. 571 shows the inside of a71 rthe left sidle of the frame, with the m57 o r lsubsidiary parts. The three rollers, I1_! ~ ~ 9 i, I, k, may be made of red beech, hev\S J^with iron gudgeons, and fluted in rol. their lengtL, each of the flutes being Nte re e2ths of an inch broad, and _4_ths deep. \2 E \ t] The large roller g, bears upon the s righlt side, a handle h, which on being 0o m B turned, sets the whole train in motion. 9 The side partitions a, a, are furnished with brasses in whose round holes, 1, g fig. 571, the gudgeons g work. For the extremities of the two smaller a rollers, there are at a and e slots in brasses as may be see n in fig. of te569. Within the partition a, there 57 t'are movable brasses 1, for the pivots of i and k, shown in fig. 571. Each / brass slides in a. groove, between \ two ledges. A strong cord made cast at in to the partition a, runs /over the brass of i, next over that 0// \^^. of k, then descends perpendicularly, and passes over the cross bar n, E I I1 EC l Af}.A ight. 569 and 570. This construction being repeated at both ends of the rollers, the rod In binds both cords. Against the cross bar d' of the frame, a lever o is sustained, which lies upon the rod Xn, and carries a weight p. The farther or nearer this weight hangs toward the end of the lever, it stretches the cord more or less, and presses by means of the brasses 1, the rollers i, k, toward the main roller g. A table q, serves for spreading out the flax to be broken, and a second one r, for the reception of the stalks at their issuing from between the rollers. Both tablea FLAX. 737 hang by means of iron hooks to rings of the frame s, t, figs. 569 and 571, and are supported by the movable legs u, u, u, figs. 569 and 570. In using the machine the operative lays an evenly spread handful of flax upon the table q, introduces their root ends with his left hand between the rollers g and i, and turns round the handle h, with the right. The stems are first broken betwixt g and i, then between g and k, and come out upon the table r. The handle is moved alternately forward and backward, in order that the flax may be rolled alternately in the same directions, and be more perfectly broken. The boon falls down in very small pieces, and the harl remains expanded in parallel bands. This should be drawn over the points of a heckle, then laid for a couple of days in a cellar to absorb some moisture, and afterward worked once more through the machine, whereby the flax acquires a peculiar softness. The advantages of this brake machine are chiefly the following:It takes up little room, and from its simplicity is easily and cheaply constructed; it requires no more power to work, than the ordinary hand-brake; it tears none of the filaments, and grinds nothing except the boon, in consequence of the flutings of the rollers going much less deep into each other, than the sword of the hand-brake; it prevents all entanglements of the flax, whence in the subsequent heckling the quantity of short fibres or tow is diminished; and it accomplishes the cleaning of even the shortest flax, which cannot be well done by hand machines. The comminution of the boon of the stems, which is the object of the ireaking process, can however be performed by thrashing or beating, although in this way the separation of the woody matter from the textile fibres is much less completely effected. It is the practice in Great Britain, instead of breaking, to employ a water-driven wooden.5s-72 mallet, between which and a smooth stone the flax is laid. In that part of Belgium where the preparation of flax has been studied, the brake is not used, but beating by means of the Bott-hammer, to the great improvement, it is said, of the flax. The Bott-hammer, fig. 572, is a wooden block, having on its under face channels or flutings, 5 or 6 lines deep, and it is fixed to a long bent helve or handle. In using it, a bundle of the dried flax stalks is spread evenly upon the floor, then powerfully beaten with the ~r^ A! ~hammer, first at the roots, next at the points, and lastly in the middle. When the upper surface has been well beat in this way, it is turned over, that the under surface may get its turn. The flax is then removed, and well shaken to free it from the boon. By the brake or the hammer the whole wood is never separated from the textile fibres, but a certain quantity of chaffy stuff adheres to them, which is removed by another operation. This consists either in rubbing or shaking. The rubbing is much practised in Westphalia, and the neighboring districts. In this process, the operative lays the rubbing apron on a piece of dressed leather, one foot square, upon her knee; then seizes a bundle of flax in the middle with her left hand, and scrapes it strongly with the Ribbeknife held in her right, fig. 573. This tool, which consists of a wooden handle s, and a thin iron blade r, with a blunt and somewhat bent edge, acts admirably in cleaning and also in parting the filaments, without causing needless waste in flax previously well broken. The winnowing, which has the very same object as the rubbing, is, however, much more generally adopted than the latter. Two distinct pieces of apparatus belong to it, namely, the swing-stock and the swing-knife. The first consists of an upright board with a groove in its side, into which a handful of flax is so placed that it hangs down over half the surface of the board. While the left hand holds the flax fast above, the right carries the swing-knife, a sabre-shaped piece of wood from 1 to 2 feet long, planed to an edge on the convex side, and provided with a handle. With this knife the flax is struck parallel to the board, with perpendicular blows, so as to scrape off its woody asperities. The breadth of the swing-knife is an important circumstance; when too narrow it easily causes the flax to twist round it, and thereby tears away a portion of the fibres. When 8 or 10 inches broad, it is found to act best. Knives made of iron will not answer, for they injure the filaments. Figs. 574, 575 show the best construction of the swing-stock. The board a has for its base a heavy block of wood b, upon which two upright pins e e, are fixed. The band f, which is stretched between the pins, serves to guide the swing-knife in its movements, and prevent the operative from wounding his feet. The under edge of the groove c, upon which the flax comes to be laid, is cut obliquely and rounded off (see d 48 738 FLAX. In fig. 574); thus we perceive that the swing-knife can never strike against that edge, s as to injure the flax. Fig. 576 exhibits the form of a very convenient implement which is employed in 575 Belgium instead of the swing-knife. It is a sort of _ 576 ) wooden hatchet, which is not above two lines thick, /k / and at the edge g h is reduced to the thickness of the 1a c / back of a knife. The fly k gives force to the blow, a. I / and preserves the tool in an upright position. The I_.' g \ short flat-pressed helve i is glued to that side of the L "( (y^ —- ~ leaf which in working is turned from the swing-stcck; l _ a h r and is, moreover, fastened with a wooden pin. 74Dy === = oThe rubbing and swinging throw off the coarsest 574 sort of tow, by separating and shaking out the shortest fibres and those that happen to get torn. That tow is used for the inferior qualities of sacking, being mixed with many woody fibres. We may in general estimate that 100 pounds of -b _ the stalks of retted flax, taken in the dry state, afford { -- ~I.' from 45 to 48 pounds of broken flax, of which, in the swinging or scutching, about 24 pounds of flax, with 9 or 10 pounds of scutch tow are obtained. The rest is boon-waste. The breaking of 100 pound& of stalks requires, in the ordinary ront ne of a double process by hand, about 20 hours; and with the above described machine, from 17 to 18 hours. To scutch 100 pounds of broken flax clean, 130 hours of labor are required by the German swinging method. Mr. Bundy obtained a patent in 1819, for certain machinery for breaking and preparing flax, which merits description here. Fig. 577, A A A A, is the frame, made either of 577 A' o wood or metal, which supports the two conical rollers B and c. These revolve independently of each other in proper brass bearings. A third conical roller D is similarly supported under the top piece E of the machine. All these rollers are frusta of cones, made of cast iron. Whatever form of tocth be adopted, they must be so shaped and disposed with regard to each other as to have considerable play between them, in order to admit the quantity of flax stem which is intended to be broken and prepared. The upper piece E of the machine which carries the upper conical roller D, is fixed or attached to the main frame A A A A by strong hinges or any other moveable joint at G, and rods of iron or other sufficiently strong material; H H is attached at its upper end by a joint to the top piece E, through a hole near I, and is fixed at its lower end by another joint K to the treadle or lever K L, which turns upon the joint or hinges M. A spring or weight (but the former is preferable for many reasons) is applied to the machine in such manner, that its action will always keep the upper piece E, and consequently the upper roller D, in an elevated or raised position above the rollers B and c, when the machine is not in action; and of course the end L of the treadle will also be raised, which admits of the flax to be worked being, introduced between the rollers, viz., over the two lower rollers B, c, and under the upper roller D; such a spring may be applied in a variety of ways, as between the top piece E, and the top or platform of the machine at N; or it FLAX. 739 rollers B, c, and under the upper roller D; such a spring may be tpplied in a variety of ways, as between the top piece E, and the top or platform of the machine at N; or it may be a strong spiral wire spring, having its upper end fastened to the platform while its lower extremity is fixed to the rod H H, round which it coils as shown at o, or it may be placed under the end L of the treadle; but in every case its strength must be no more than will be just sufficient to raise the upper roller D about two inches from the lower rollers, otherwise it will occasion unnecessary fatigue to the person working the machine. The manner of using it is as follows: the upper and lower rollers being separated as aforesaid, a small handful of dried flax or hemp stems is to be introduced between them, and held extended by the two hands, while the rollers are brought together by the pressure of the foot upon the treadle L. This pressure being continued, the flax or hemp is to be drawn backwards and forwards by the hands between the rollers, in a direction at right angles to their axes, and eventually withdrawn by pulling with one hand only. The foot is now to be removed until the flax or hemp is again replaced, and each end is this way to be drawn several times through the machine, until such ends are respectively finished. By a succession of these operations, using the pressure of the foot upon L, each time that the flax or hemp is introduced between the rollers, and regulating such pressure according to the progress of the work, the flax or hemp will soon be sufficiently worked and the fibre brought into a clean and divided state fit for bleaching; or if it be required to spin it in the yellow state, it may be made sufficiently fine by a longer continuation of the same process, particularly if worked between tbe smaller ends of the rollers. Indeed, the operation may be commenced and continued for some time, with the larger part of the rollers, and finished with their smaller ends; and, in this point of view, the invention of conical rollers will be found both convenient and useful; for as the flutes, grooves, or teeth vary in their distance from each other at all points between the large and small ends, so it becomes almost impossible for the workman to draw the flax or hemp through such rollers in the same track; and thus the breaking of the boon must be much more irregular, and the fibre will be much more effectually cleansed than it can be by the flutes, grooves, or teeth of cylinders, or other such contrivances formerly employed; because they would probably fall frequently upon the same points of the fibres. If it is intended that the flax shall be bleached before it is spun, then the second part of Mr. Bundy's invention may be had recourse to, which consists in moving certain trays or cradles in the water, or other fluid used for bleaching the flax or hemp in the manner following, viz.: The flax or hemp,'after having been broken and worked in the machine, should be divided into smaller quantities of about one ounce each, and these should be tied loosely in the middle with a string, and in this state laid in the trays or cradles, and then be soaked in cold soft water for a day or two, when each parcel should be worked separately, while wet, through a machine, precisely similar to that already described, except only that the rollers should be cylindrical, and made entirely of wood with metal axles, and the teeth, which will be parallel, should be similar in form to those shown i: section at Q, fig. 578. Such operation will loosen the gluten and colouring matter, for the rinsing and wringing which must follow. The flax must then be again disposed in a flat and smooth manner, in such trays or cradles, and once more set to soak in sufficient soft water to cover it, in which a small quantity of soap, in the proportion of about seven pounds of soap to each hundred weight of flax, has been previously dissolved, and in this state it should remain for two or three days longer, and then be finally worked through the machine, rinsed with clear water, and wrung: which will render it sufficiently white for most purposes. Can flax be prepared without retting?-The waste of time and labour in the steeping of flax; the dyeing of the fibres consequent thereon, which must be undone by bleaching; the danger of injuring the staple by the action of putrescent water; and, lastly, the diminished value of flax which is much water-retted, are all circumstances which have of late years suggested the propriety of superseding that process entirely by mechanical operations. It was long hoped, that by the employment of breaking machines, the flax merely dried could be freed from its woody particles, while the textile filaments might be sufficiently separated by a subsequent heckling. Experience has, however, proved the contrary. The machines, which consisted for the most part of fluted rollers of iron oi wood, though expensive, might have been expected to separate the ligneous matter from the fibres; but, in the further working of the flax no advantage was gained over the water-retting process. 1. Unretted flax requires a considerably longer time for breaking than retted, under the employment of the same manipulations. 2. Unretted stalks deliver in the breaking and heckling a somewhat greater product than the same weight of flax which has been retted; but there is no real advantage in 740 FLAX. this, as the greater weight of the unretted flax consists in the remainder of ligneous ol glutinous matter, which being foreign to the real fibre, must be eventually removed. In the bleaching process, the water and the alkaline lyes take away that matter, so that the weight of the bleached fibre is not greater from the unretted than the retted flax. 3. The parting of the fibres in the unretted stalks is imperfectly effected by the heckling; the flax either remains coarser as compared with the retted article, and affords a coarser thread, or if it be made to receive greater attenuation by a long-continued heckling, it yields incomparably more torn filaments and tow. 4. The yarn of unretted flax feels harder, less glossy, and rougher; and, on account of these qualities, turns out worse in the weaving than the retted flax. Nor is the yarn of unretted flax, whether unbleached or bleached, in any degree stouter than the yarn of the retted flax. 5. Fabrics of unretted flax require for complete bleaching about a sixth less time and materials than those of the retted. This is the sole advantage, but it is more than counterbalanced by the other drawbacks above specified. The foregoing operations having brought the flax into the ordinary fibrous merchantable state, suitable for the spinner, it now remains to pass through the following processes, by which it is manufactured into yarns for sale or use, viz., 1st, heckling, 2nd, preparing, 3rd, spinning, 4th, reeling, 5th, drying, and 6th, making up. 6. Heckling. The operation of heckling has for its objects, 1st, that of combing or straightening the filaments entangled as coming from the scutching. 2d, that of splitting them, with a view of lessening and equalizing their size. In accomplishing these objects the material is unavoidably divided into two portions. The long and straight fibres constituting the first, called "line," and the short, broken, and confused of the second, " tow." Both the line and tow are capable of being spun, but the line is much the more valuable, being used for the better descriptions of yarns, &c., with greater facility than the tow for the inferior. The aim, therefore, of good heckling is to produce the larger proportion of line from a given quantity of flax, the attainment of which leaves much scope for care and judgment, whether the older method of heckling by hand or the more recent by machine is adopted. In hand heckling the instruments are a comb-fashioned tool, called the heckle or hackle; a surface studded more or less thickly with metal points, called heckle teeth; over which the flax is drawn in such a way that the above three required operations may be properly accomplished. The heckles ordinarily used for hand heckling in this country are in the form of rectangular parallelograms, presenting a line of 7 inches towards the worker and 4 to 5 inches deep. The first tool employed is called the " ruffer," the pins of which are about l inch square at their base, and 7 inches long, and brought to a fine point; the second is the " common 8," which is always used after the " ruffer;" then the " fine 8," the " 10," the "12," the "18." The pins of all these tools are similarly placed to those of the ruffer, but are somewhat shorter in length and are more slender as the tools increase in fineness. In all these tools the pins are held in wooden stocky of about I inch in thickness and covered with sheet tin. This sheet tin, through which the pins are driven, helps to support them and prevent the wood from splitting. These tin covered stocks are only of a size necessary for the extent of pins employed, and are themselves screwed to other larger pieces of board, a little 579 ej 580 j broader and some inches longer than themselves, Ai- *_I _I_ __..L L... _ = and by which they are l 3c' xc.I _.. — -' ultimately fixed to the heckler's bench, inclining _,^- ~ somewhat backward with _ -o ~ their points from the worker, and a sloping JI, \ VV board behind to prevent jazz c lthe flax entering too much in the pins, thus: Fig. 579. end view of a heckle; fig. 580. 55. front view of heckle; fig. 581. heckle, &e. fixed up for working. a pins; b tin covered stock; c foundation board; d beam of table or bench; e back board; f table to receive the tow, &c.; g hand of workman. Such iv the form of heckle used in England, and also the manner they are, of whatever descrip lion, fixed for work. f - FLAX. 74] 582 ^ ___ —^582 ^In Germany the common construe. tion of the heckle is the following; (see Of^^, K fig. 582.) Fig. 582. is the ground plan, andfig. 583.isthesection. Upon /1'UjWi^ V^^^^5!^/ vV"'"''.-^ ^ an oblong plank a b, two circular or U-7^ ^^^^^^'-_ ~square blocks of wood c and d are fixed, in which the heckle teeth stand upright. To give these a 683 IWSlllll B lllllllll 1 stand Iu ~firmer hold they are stuck into holes -2 | / m m \:: / c \, in a brass or iron plate, with which i_ _ I_ t___ _ _ _ i, ithe upper surface of c and d is covered. Both heckles may be either associated upon one board or separated; and of different finenesses; that is, the teeth of the one may be thinner, and stand closer together; because the complete preparation of the flax requires for its proper treatment, a two-fold heckling; one upon the coarse, and one upon the fine heckle; nay, sometimes 3 or 4 heckles are employed of progressive fineness. The heckle teeth are usually made of iron, occasionally of steel, and from 1 to 2 inches iong. Their points must be very sharp and smooth, all at an equal level, and must all graduate very evenly into a cylindrical stem, like that of a sewing needle, without any irregularity.' The face of the heckle block must be uniformly beset with teeth, which is done by different arrangements, some persons setting them in a circle, and others in parallel rows. The coarse heckle is furnished with teeth about one-tenth of an inch thick, one and a quarter of an inch long, and tapering from the middle into a very fine point. In the centre of the circular heckle is a tooth planted; the rest are regularly set in 12 similar concentric circles, of which the outermost is 5b inches in diameter. The fine heckles contain no fewer than 1,109 teeth. Instead of making the points of the teeth round, it is better to make them quadrangular, in a rhombus form, in which ease the edges serve to separate or dissect the fibres. The operation of manual heckling is simple in principle, although it requires much experience to acquire dexterity. The workman having first divided the flax into handfuls or stricks, of which there are 300 to 400 to the cwt., proceeds to grasp one as flatly spread as possible between his forefinger and thumb, by about its middle, and wind the top end round his hand in order the better to prevent the slipping of the fibres; he then begins by a circular swing of his arm to lash the root end into the heckle, taking care to commence as near the extremity as possible, now and then collecting the fibres by holding his left hand in front of the tool, turning the strick from time to time; he thus gradually works up as near as possible to his right hand, when he seizes the ruffed part of the strick and holds it in the same manner as at first, and proceeds by similar treatment to " ruff" the top end; when this is finished the "ruffed" work is taken to the tool called a "common 8," the pins of which are much closer placed than those of the ruffer, and are only 4 or 5 inches long. This "8" is always used after the ruffer, but from it the work can be taken to any of the finer tools, viz. 8, 10, 12, and sometimes 18. It is usual and better to dress both ends over each tool before taking the work to the next. The pins of all these tools are 4 inches long, in order, as was supposed, to have sufficient spring. The flax is not lashed into them as into the ruffers, neither are the ends required to be wound round the hand. But the root end of the flax is always the one to be first worked, and the heckling begun at nearly the extremity of the strick, which on being drawn through the heckle is received by the left hand of the workman, and by it carried back and laid upon the back board and over the point of the pins, for the angle of inclination of the heckles and a slight lowering of the right hand causes it to enter sufficiently on being drawn forward. As it is impossible to ruff or dress entirely up to the hand, when the hold is changed in either operation, there must of necessity be left a certain space to be repassed through the tools; this is called the "shift," but the less length that is required for this purpose the better for the yield of lime. The numerous long fibres that slip from the strick in ruffing must be collected and drawn from the mass of tow attached to them, when they can be relaid in the strick, or kept to be dressed separately under the name of "shorts," and from time to time the short fibres or tow sticking to the teeth of the finer tools are removed. Whenever one half of the length of the strake of flax is heckled, it is turned round to heckle the other half. This process is repeated upon each heckle. From 100 pounds of wellcleaned flax, about 45 or 50 pounds of heckled line may be obtained by the hand labour of 12 hours; the rest being tow, with a small waste in bony particles of dust. The process is continued, till by careful handling little more tow is formed. To aid the heckle in splitting the filaments, three methods have been had recourse to; beating, brushing, and boiling with soap-water, or an alkaline lye. Beating flax either after it is completely heckled, or between the first and second I.__-__ ____ _________________________ 742 FLAX. heckling, is practised in Bohemia and Silesia. Each heckled tress of flax is folded in the middle, twisted once round, its ends being wound about with flaxen threads; and this head, as it is called, is then'beat by a wooden mallet upon a block and repeatedly turned round till it has become hot. It is next loosened out, and rubbed well between the hands. The brushing is no less a very proper operation for parting the flax into fine filaments, softening and strengthening it without risk of tearing the fibres. This process requires in tools, merely a stiff brush made of swines' bristles, and a smooth board, 3 feet long and 1 foot broad, in which a wooden pin is made fast. The end of the flax is twisted two or three times round this pin to hold it, and then brushed through its whole length. Well heckled flax suffers no loss in this operation; unheckled, only a little tow; which is of no consequence, as the waste is thereby diminished in the following process. A cylindrical brush turned by machinery might be employed here to advantage. These have been tried in establishments for machine spinning, but not found advantageous. The boiling of flax with potash lye alone, or with lye and soap, dissolves that portion of the glutinous cement which had resisted the retting, completes the separation of the fibres, and was therefore supposed a good practical means of improving flax. When it is performed upon the heckled fibres, a supplementary brushing is requisite to free it from the dust, soapy particles, &c., but this also is now abandoned. Machine heckling.-As intimated above, the object of all heckling was that of producing a good yield of line with tows of good quality Ihat is to say, free from broken unsplit fibres, lumps and knots: the care and attentik n to do this, together with the expense and uncertain results of the individual skill of workmen, urged manufacturers some time since to attempt the establishment of machines for dressing flax mechanically. Therefore many contrivances have been made with this view, but it was long doubted whether any of them made such good work with so little loss as hand labour. In heckling by the hand, it was supposed the operative would feel at once the degree of resistance, and be able to accommodate the traction to it, or throw the flax more or less deeply among the teeth, according to circumstances, and draw it with suitable force and velocity. For a considerable period these ideas, or rather prejudices as they may now be called, seemed to be confirmed: for the earlier attempts to supersede hand heckling, like those in many other undertakings, though partially favourable, were upon the whole somewhat discouraging: in attaining one point desired another one was lost, for too much still depended upon the care and attention, if not upon the actual skill, of the attendants. Therefore, a review of those machines that really came into operation, to a more or less limited extent, as well as a slight mention of some of those patented, but never publicly shown, may not be useless as a lesson for preventing a repetition of things already known, as well also for illustrating the steps by which these first prejudices have been gradually overcome. The first heckling machine invented, or at least published, was called the " Peter," and was intended to imitate as closely as possible the movements of the hand heckles. In commencing the work, the flax was first divided into small convenient portions or handfuls, of about 4 ounces each, called "stricks," and which, before being taken to the machine, were slightly straightened and dressed over the ordinary hand "ruffer." Each of these stricks was then placed between a pair of short iron bars, one of these bars having an indentation along its middle, and the other a corresponding projection; thus, when tightened together by screws 41 inches apart (such a length being equal to a hand-heckler's grasp), the flax was firmly held while exposed to the action of the heckles, (this pair of bars with screws being called a " holder "). This holder was then suspended from movable levers over a truncated rectangular cylinder, upon the truncated angles of which were fixed, at a certain angle, heckles similar to those used in the manual operation. The levers supporting the holders received from a crank a short up and down motion, so timed in their oscillations as to strike the holder nearly against the points of the pins at the time they were passing under, coming thus as nearly as possible to the effect of a man striking in and drawing thrcugh the heckles, with the exception that theflax remained nearly stationary, and the heckle was drawn through it by the rotation of the cylinder; such machine carried two holders. The tow made and collected in the heckles, was seized and taken off by boys stationed for that purpose, while another at the ring of a bell took out and changed the sides of the stricks to be presented to the action of the heckles, and subsequently withdrew them from the first machine to another similar but with finer heckles, and thus continued till the root end (always the first to be operated upon) was dressed to the desired degree of fineness, when they would be taken to a table where another set of boys, previously to removing the first holder, put on a second to the already heckled part, leaving a short length of 2j or 3 inches to be reheckled. This operation is termed shifting, and the space left the "shift," and is thus performed and so called at the present day; the only change in the holder now in use being, that one screw is used for two stricks instead of two screws for one strick. Fig. 584. will more clearly show the construction of this machine. FLAX. 743 A square truncated cylinder carrying the 584 Q heckles; B oscillating arm or lever for support. ing the holder; c c c framing; D crank and 1 1- Zr shaft; E connecting rod from crank to oscillating arm; F, F, F, F heckles; G G G G back board; | Xholder. The first motion was given by pulleys / on the shaft D, which revolved 4 times to 1 of the heckle cylinder, by the intervention of suitable wheels. The worm and wheels for the / v 11 bell motion were attached in the usual manner __/, -to the shaft of the cylinder.:X3: / ~_~_~-____ ——'-~. Machines of this construction continued in -^~"~ i._______ _'rather limited use without any change or,'i' 5cs!s competition till about the year 1825, when a — a-b] c'N';:;a^ patent was taken for a machkie known as the w pendulum machine. The flax in the holder being suspended and swung backwards and forwards while the heckle remained fixed, thus.::=-' E - - ]' "~ Lthe flax was heckled, stroke for stroke, on each of its sides. The boys as in the last described, snatching off the tow as it was formed, and at certain times, that is at each rise of the pendulum, for it had a rising and falling motion to imitate the hand workers in commencing at the extreme end of the flax, passing the holder from one recess to another of the pendulous table, so as to -arrive at the progressively finer tools when ranged along the machine, but sometimes the different tools were fixed upon the angles of a square cylinder that presented a finer range, the whole length of the machine, by turning up a new angle at eaeh rise of the pendulum, when the labour of the boys was simply to put in the tow and take out from it the flax. The adjoining diagram, (fig. 585.) without entering on any details of a machine that was so little used, will make the theory of its action quite clear..-~.., -. —-—.... A heckle bench sometimes re/..... \..,,volving so as to present different /. ~\ / X degrees of heckles at its various /m } -* ~l ^" \ angles, sometimes stationary with Ip —_5 /} 1 I the gradations of heckles upon its?/ length; B B, pendulum arms; c c, ".f\ /' tequal wheels working into each \, c?....../ -' ^ c *~' other; D D, crank arms; E radial slide-bars to preserve the holder 585\\B A.] //B table vertical; H, holder table;'""\\ Js~i/ f /, F, F, F, F, heckles; G, G, back boards; O\Vi/ I I, direction in which the holders Io I swing; there were the same wheels, I\V \'Y /a & t., at each end of the machine,.-...... -- \.....-.............. and the holder table H reached /( -.........-'..... ^'.from one to the other. The wheels ry''.-.^ c, c, with all attached to them, were */. -* 3:.... —-. ] made to rise and lower upon the' I....v ~.. —----- heckles, and the back-boards G to rise when the heckle bench t /f/ A hi -US turned. (O) 9t 0@ X/ \) About the same time another patent was taken out for a machine, ~ ^s. yf ^E where the holders were suspended X<2~/fw^\ - above one end of a travelling sheet of heckles. This machine also required hand labour to turn and transfer the stricks, though the tow was caused to fall clear from the heckles by mechanical means. The following sketch (fig. 586.) shows the principle upon which this machine works, and though never much employed at,he time of its appearance, has subsequently served as a foundation for those that are now iL tCIe zenith of their prosperity. A A (fig. 586.) sheet of heckles; B support for holders; c, c carrier pulleys for the sheet of heckles. Fig. 587., a larger view of the heckle bar G G, in order better to show the faller D D D in the staples or grooves r, E, and fig. 588. at the end of the heckle-bar G G; F, F, pins of the heckles, between the rows of which the faller D D D acts to push the tow off the pins. There is a clearing faller D to each heckle, which is kept to the bottom of the heckles at that part of their course where they are in contact with the flax, but at the turn F D fly beyond the points, as shown by the effect of the centrifugal force. All thece machines, possessing great similarity of features in regard to the personal 744 FLAX. 588 X E'2 r. attention required, never came into such general operation as to supersede entircly hand-dressing, either from their own defects or prejudices against their employment. About the year 1830, in consequence of the new mode of. pinning, hereafter to be described, being carried on with considerable energy, it was f: und advantageous to cut the flax into 2, 3, or more lengths previously to heckling, which rendered it necessary to have machines peculiarly adapted for this new short description of material. This machine, known as the excentric or circular machine, deserves considerable attention for its own inherent merits, and the extensive utility it has proved to be of in suggesting the principal parts of those by which it has been supplanted. In its original form it was made of a breadth suitable for only one strick, and consisted of a cylinder 3 ft. diameter, upon the whole circumference of which at intervals of 3 or 4 inches were fixed the heckles. As each machine could only carry one description of heckle, it was necessary to employ a series of these machines, called a "class," when the flax required to be dressed over a succession of finer tools, each succeeding machine carrying a finer tool than its predecessor. The heckles were cleared of tow by coming in contact at one part of their revolution with a brush roller, which also revolved in contact with a cylinder covered with card clothing, the points of the pins being in such a direction as to clear the brush from tow, and allow itself to be in its turn cleared by the oscillations of a comb, whence by rollers the tow was brought into a sliver. In order to preserve the continuity of the supply of tow, and maintain the regularity of the sliver produced by it, the holders with the flax were presented to the heckle cylinder in a manner peculiar to this machine, and in endless succession by means of certain circular carriers placed at each end of the heckle cylinder, but excentric thereto, and at such a distance apart as each should bear one end of the holder as it extended across the cylinder parallel *^ \" i.f _ v....58 9......~ FLAX. 745 to its axle. Thus, the holders introduced at that part of'the circumference of these carriers furthest from the heckles were carried forward, while the flax was in operation, till they were brought almost into contact with the points of the pins, when by the intervention of a slide they were withdrawn from the machine, but with one side only of the flax dressed, and that but on one tool; therefore, the holder required replacing in the same machine, in order that the second side of the strick should be dressed as was the first. The holders then required to be carried by hand to each succeeding machine of the class. The preceding figure (589.) shows the leading features of these machines: A A (fig. 589.) heckle cylinder; B B excentric wheel to carry holders in its recesses I, h, h, h, h,; c slide upon which the holders were laid so as to fall into the recesses h, h of wheel B; D slide for taking out holders; E brush cylinder with brushes; G cylinder covered with card clothing; H holder come out; I doffing comb. Tbe space of the holder carrying wheel was filled with holders, and so maintained in endless succession, and thus each served in some measure to keep the end of its preceding one down into the heckles. About 1833, a machine was patented consisting of two parallel cylinders, over which the flax was carried, revolving in its progress so as to present the alternate sides of the strick to the heckles, the progressively finer tools being ranged along these cylinders, so that having passed the length of one cylinder one end was completely finished. When the holder was taken out, "shifted," and replaced, it was carried back along the second cylinder, and thus returned to where it commenced, finished. This machine, however, never was carried further than the experimental one for the patent. Another machine the same year made its appearance, and which for some time enjoyed much celebrity. It consisted of two parallel vertical sheets of heckles running together, and so geared that the heckles of one intersected the interstices of the other. The flax suspended in its holder from a species of trough passed between these two sheets, and was thus heckled simultaneously on each side in its course through the progressively finer heckles from one end of the machine to the other. A, A (590.)-heckle sheets; B B holder trough or slide; c, c, c, c, pulleys for carrying the 590 J= @ A A /, G z:: heckle sheets; D, D brush rollers; r, E rollers covered with card clothing to clear the crushes; F, F doffer combs; G, G, G, G heckles; H holder; I, i brushes. At about the same period a foreign machine was patented, known as Evans's ma-hine, of which the following description will give a correct idea of its principle f action, and also of its holders, which are different from those already described. 746 FLAX. There are two series of combs, seefig. 591., attached to two movable frames represented 5^92 iat a and 6. Each frame is formed by vertical - 591 li - ~ l (~. Bi,.l( ) bars a b, with lateral branches or arms, which carry the heckle points. The branches or arms are parallel, and at equal dis'" ^j~^ p~....tances apart, but fixed in such positions in 8.......... e -1 5each frame that they may occupy the inter9vening space when the frames are brought }b-y b al > < a6 together asfig. 592. The frames are put in _ I':-:: I| i! motion by means of revolving cranks to...i.~~ l which they are attached as shown in fig. l, -— 3.lX 592., and when the cranks turn upon their axes, the branches of one frame pass be. ctween those of the other without touching. r This forms what may be called a set of' combs; the points of the combs of one set being opposed to the points of the combs in the other set. The way in which the series of combs that compose one set act upon the flax, is shown in the side view, fig. 591. When the cranks are nearly vertical, the points of both frames are away from the flax, but as the cranks move round in the direction of the arrows, the frames come into another position, and it is then that the points or heckles of one of the frames a, begin to penetrate the flax, and descending they comb or divide its fibres. The rotation of the cranks continuing, the two frames a and b come into the position shown at fig. 591., the points of the frame a withdrawing from the flax, and those of the frame b approaching and pushing the fibres off from the former, which are now combed by the descending stroke of the points. It will hence be perceived that as the combs of the frame a and b respectively advance, they will push forward the whole of the strick of flax, and render it impossible for the fibres to be raised and entangled, as each frame in advancing clears the fibres from the points which preceded it. A single set, however, of such combs or heckles acting only on one side of the flax would but imperfectly perform the operation of opening its fibres; it is therefore necessary, in order to accomplish the desired object in the most effectual way, that two such sets of combs or heckles should be brought to act on opposite sides of the strick of flax, suspended in the position shown in the figures. The cranks of the two opposite sets of comb-frames or heckles a, b, and c, d, are connected by a pair of toothed wheels e, f, asfig. 593., or by four toothed wheels, by which the heckles are actuated at once, the two sets moving in opposite directions, but with similar speeds, and the combing or heckling of the material will go on in the way shown in the figure last indicated. The tow being collected as drawn off the lower end of the sticks on to a slowly revolving cylinder or brush roller, whence it is doffed by a comb and delivery rollers. The clamps or holders differ considerably from the clamps which are commonly used. I shall therefore particularly describe their construction, before showing them in operation. tfigs. 594. and 595. are views of the clamp in two different positions; a and b are two boards united together by a 594 o__ C m hinge c, at top, which of course allows them to }v], ^ ^ Hshut and open. The lower parts, forming the I IXj// \\ aws of the clamps, are made with teeth or in/RI 1 //! \\ dentations, between which parts the ends of I l I / y \ the flax or hemp are securely held when the!, \ /~ /// \\ clamps are brought together; d d, are two j14 >, i..... ntt A N;' i;j;.J...........P Ililiiili r r I I I i: II I I III I I I I' i' ~ * Ib' III D YD 600.. lect.ing rod., m, n, o, p, q trains of wheels from driving pulley B to cylinder o and card roller F.; the propulsion of the holders is caused by the radial movement of th. lever z. FLAX. 751 caused by the rise and fall of the head. The iollowing figures show the form of the "sheet" machines, but which do not, from their similarity of principle and construction to the foregoing, require a detailed description; as the only differences are c~o'ld tlgi - At ~~~~~~~~~~~~\ 752 FLAX. that a sheet is used to carry the heckles instead of a cylinder, and doffer bars fo knocking out the tow instead of the more complicated arrangement of brush, comb, &c. Those machines that are now employed for finest work are called Marsden's infer secting machine, and combined intersecting. The irtersectin.g machine is so called from the peculiarity of its construction, being somewhat similar in principle to that already described, of two cylinders of heckles carried on cranked bars, but instead of their being so closely placed together, there are but six, eight, or more bars bearing the heckles, forming as it were a sort of a skeleton cylinder, of which there are two, parallel to each other in each machine: the flax passes along the machine between these two cylinders, and is struck by their heckles alternately, and in successive order on its opposite side. ~Marsden's combined intersecting machine has in addition to these cylinders a pair of sheets of heckles, by which the first tool work is performed previously to the flax arriving at the intersecting cylinders, and the flax is rather more severely heckled. In both of these machines the holder slide is provided with a rising and falling motion, as being absolutely necessary for the production of good work: these machines penetrate the flax better than the cylinder, as from its position between the heckles, the flax is rigorously exposed to their effect, but the tow thereby produced is rather more lumpy and uneven, and is, therefore, considered inferior to that from the cylinder machines, see figs. 603. 604. 605. of combined intersecting machine. Fig. 603. end view; fig. 604. side view; fig. 605. sheets; fig. 606. holder; A A A framing; B B holder trough or slide; c jointed rod, having a horizontal motion to push forward the holders by the clicks a, a, which catch the holders in one direction only; D pendiloua 633 IF A _ll ill iill It 11 11111 11/'p1IIIII1 lilli FLAX. ^(*^H. r I MII ^ li'm M ever receiving a reciprocity motion from the radial arm, at thle rising and falling of the sliding head; F support for the pendulous lever D; G, G carriers of the heckle bearing sheets, a, a; i, i heckles fixed to the sheets or straps n; K K card-clothed cylinder for receiving the tow from the brush cylinder; L doffing comb; Mr brush cylinder; a a, o o slide shafts, upon which are keyed the carrier arms r, r of the intersecting heckle bars Q, Q: a. R crank arms fixed to the heckle bars, and guided by their extremities in the slides o, o, by which the peculiar position of the heckles is maintained; s, connector between sliding head and lifter excentric, or cam; T, u the friction bowl for pulling downwards the slide head, to which a tendency is given to rise by balance weights, not necessary to be shown; v wheel commanding excentric to give the oscil~~~=lations to the doffing combs.. In all heckling machines, whether those of sheets or cylinders running in opposite directions, and not therefore requiring the turning motion f or the dl r, or those with the turning motion,;and having therefore but one sheet or cylinder; or again r those callede the interseciving and ciombied itersecting, the hand labour required, and the number of holders or work turned out in a given time, are nearly thesame for similar degrees of dressing, and all these machines are provided th carrihange pons, t inrease orting heckle bars A, Q: R. R crank arms fixed to the heckle bars, and guided by their extrediminish the quantity obf e he c kling in any required degree. The hand labour connectorsists, first, ofdivding hea flax into stric,, for cam;long fax, of 4 orl for pulling downwards the slide head, to which a tendency is given to rise by balance ozs. each, and for cut, essary to 2 ozs.ho Theel commanding these intri o the lders, and when lations to the doffing combs. In all heckling machines, whether those of sheets or cylinders running in opposite directions, and is w orked, tak ing motion for the holder,or the " shift" an replacing them turning motion, and having therefore but one sheet or cylinder; or again those called the intersecting and combined intersecting, the htnd labour required, and the number of holders or work turned out in a given time, are nearly the same for similar degrees of dressing, and all these machines are provided with change pinions, to increase or diminish the quantity of heckling in any required degree. The hand labour consists, first, of-dividing the flax into stricks, for long flax, of 4 or 5 ozs. each, and for cut, 11 to 2 ozs. Then screwing these into the holders, and when one end is worked, taking out the holders, performing the "shift," an d replacing them, 49 I 754 FLAX. ~,. i. -......-'i..., r..........:,,..-^.;....:.......,606 by which it is evident that the manual work is reduced to nearly the lowest possible point; for the taking out the holder and performing the shift are the only operations that can by possibility be done mechanically; and it is desirable that this should be so effected not only with a view of saving the expense in wages, but to avoid the waste and entanglement, and consequent reduction of yield, to which by handling the flax is exposed, and at the same time reduce to the utmost degree all need for reliance upon the care and attention of the workers employed. A holder with this intention was patented about three years since, which, from its novelty of construction, deserves a record, for though not yet in active operation, it only requires time to remove the groundless prejudices opposed alike to this as to all other innovations. Previously, however, to entering upon a description of this holder, it will be necessary, in order to make our account of heckling machines now actually in use complete, to describe one much used in France, and patented for that country, January, 1846. It is there known as the peigneuse mecanique system Busk, from the name of its inventor, an English machinist (whose transferring excentric and double cylinder machines have already been described). Flax heckle, called Peigneuse Mecanique, on t1he system of Busk, as described in a French publication industriel.-It has been found in practice that to obtain the best results, it is absolutely necessary to attack the flax by the end of the strick, and to continue it slowly and gradually till the points of the heckle act on the middle; then to obtain the greatest product in long line and the best quality of tow, it is necessary to heckle it alternately on each side of the strick, continuing thus on the first, second, third and fourth heckle, &c. The machine which we offer to the public as the invention of Mr. Busk, the author of many ameliorations in flax-spinning machines, unites in itself all the different points of perfection indicated, without any of the inconveniences of the rival systems. The force requisite to drive it is hardly one-half of a horse-power; is capable of heckling on any number of heckles, and without increase of hand-work, about 500 kilogrammes (i ton) daily, more or less, according to the nature of the flax. It *s applied with equal advantage to the long or the cut line. It may be conducted or managed by Fr FLAX. 755 4 or 5 children merely, employed to screw and unscrew the clamps (presses), an easy operation. Description of the machine. — Fig. 607. longitudinal elevation of the mechanical heckle. E.|607 {I _: __ n___g_ _ _ _-......'A. Large yli 11c11r i whose cirl umference theiheckleteeth are xed. The distancel I ____________ _________ s 1i - 1 -1 1:i l l llll II', IF J~t~h~UY/n A 1~11 608 X.,' e A, Large cylinder, in tvhose circumference the heckle teeth are fised. Tle distance between the points i-aries according to tle perfection wfhich is desired in thle heckling, 756 FLAX. and the quality of the flax. The length of the cylinder (2 metres 40 cents) admits of multiplying the heckle points, and varying their distances. B. Small plates (planchettes) fixed between the heckles, to determine the depth to which the points shall act in heckling. These plates are moveable, so as to be arranged at pleasure. c. Carriage bearing the pincers in which the stricks are fixed. D. Upright arbours on which the carriage rises and falls by means of the sockets E, fixed to the carriage, to guide its ascent and descent, effected by aid of an excentric placed on the side of the machine. This carriage is balanced by counter weights. One of its sides is furnished throughout all its length with a cast-iron rack, in which all the pincer bearers (which are toothed on their upper part) work. r. The pincer carriers, whose upper part is a toothed wheel, and whose lower part terminates in hooks (crochets) that receive the pincers in wood. Rigid bars connect the pincers in the upper part; so that they all work at the same time. G. Wooden pincers clasping the stricks of flax by means of a screw. H. Cylinder with brushes for removing the tow, which had been retained by the heckle points, and carrying them to the cylinder I, furnished with cards. J. Heckle which deposits its tow into a box placed to receive it. All the pincers G being furnished with flax are fixed in the hooks of the pincer bearers. On setting the machine in motion, the carriage G, commanded by an excentric intended to give it a progressive velocity, calculated proportionally to the thickness of the strick, descends and puts the flax in contact with the heckle teeth fixed round the large cylinder A, actuated by a continuous movement. When this operation is terminated, all the stricks of flax submitted to the action of the cylinder having been heckled on one side, the excentric, which had caused the carriage to descend, makes it mount again; at which moment the other excentric acts destined to communicate to all the pincers the horizontal motion; and, as the pincer bearers are in toothed geer with the carriage, the consequence is that in advancing the pincer bearers pivot on themselves, so that the carriage descending anew, presents to the action of the heckle points the other face of the flax. This action in being thus repeated even to the extremity of the carriage, works on the flax by heckle teeth closer and closer together. When they have arrived at this point, the pincer carriers continue to advance, passing by the back of the machine: but this side of the carriage having no rackwork, the pincer bearers do not pivot (turn round) and proceed without changing position, at which point the heckled flax is replaced by the unheckled. The tow is disengaged by the brush-cylinder, and transmitted to the cylinder mounted with cards: a heckle then detaches it and drops it into a box. Such was the state of heckling machines when the holder above alluded to was first contrived with a view of being applied to this machine, for which it is peculiarly adapted. All the holders that have hitherto been used are similar to those described at the beginning of the article, consisting of two clamps of wood or iron pressed together by screws, except in Evans's machine, where an inclined plane was used for that purpose. But the holders now referred to are on an entirely different principle; the holding pressure being produced by the effect of leverage of the clamps or jaws themselves, which are for this reason, and also for better supporting the end of flax out of operation, made from 7 to 9 inches broad; and while one of their edges are hooked or fastened together by a pair of double-acting hinges, similar to those used at the bottom of turnpike-gates, the others are held together by a clasp, and thus the flax is very firmly grasped or held by the pressure at the joint or hinge, and the end of the flax not exposed to the heckle is held vertical and straight by the breadth of the clamps. These holders do not slide of themselves along a trough, as do the other description, but there are "carriers" for them attached to the sliding and turning apparatus, by which they are carried forward and turned as desired. These carriers are so constructed as to retain the holder by one of its clamps or jaws always vertical, but leaves the other free to fold from one side to the other; when this folding takes place, which is during the dwell of the other holders upon the heckles, that end of the flax which was contained between the clamp becomes liberated, and the previously pendant one is lapped up and enclosed between them, when the rise of the head taking place, the catch replaces itself, and the holder is carried forward to return along the second cylinder of the machine, and ultimately arrives at the place where it was first put in with the line completely dressed. As all these movements are performed automatically by the machine itself, the whole of the wages necessary, when the other holders are used, for taking out, and screwing & unscrewing ing, and replacing them, amounting to nearly half of the whole expense, is saved, besides much indirect trouble and confusion. A 1, A 2, jaws of the holder; B a carriage or frame for supporting the holder; o o, a toothed wheel) having a groove on one side to allow it to be carried by the rails of th! ___ _________________________________________ _____ FLAX. 757 moving head of the machine, of which fig. 609, is a plan or bird's-eye view; D, D, links or bars connecting the series of wheels c, c. These wheels are of such a diameter, that N S 0 609 E' Il 6 Ba I to 610 611 Al: A Awhen propelled from 1 to 2, they will at the same time make one exact half revolution; and thus the holder attached to each presents its opposite side to the heckles at each advance similar to other machines. To cause this half revolution, the teeth of the wheels c, c engage those of the racks E, E and F, F; but the slides are so made as to maintain the wheels in one position from E to F at one end of the machine, and from F to E at the other; G H the position and place where the holder stands to be shifted; and i K when first put in or to be taken out of the machine; L M, axis of heckle cylinder to dress the flax after "shifting;" therefore its coarser tools are at end M; N o axis of cylinder for dressing the root ends; therefore, its coarser tools are at end N. The arrows show the direction of movement of all these parts. The mode of action of the holder is as follows. The jaw A 2 is first laid upon a table, and the flax placed upon it, when the jaw A 1 is caused to engage the pin 3, which are similar at each end of the holder, when it is folded down upon A 2, and the catch fixed to 2 engages the rack fixed to A 2 at 5, and the whole is firmly combined together and placed into the carrier, and maintained by the pins projecting for the purpose from A 1 entering into vertical grooves in the carrier, when, having passed over the heckles on cylinder N o, it ultimately arrives at G I, when, during the descent of the sliding head, the lever attached to the catch 5 strikes against a fixed point, and is thereby lifted out of the rack, thus leaving at liberty the jaw A 2 to turn. This is effected by a projecting pin 2, being actuated by a crank having a suitable intermitting motion, which carries it in the direction of the dotted line, while the hinge pins quit recess 3, and the other enters the recess 4, and the rack engages the catch opposite to the one it has quitted; and thus the shift is completed with a length equal to the thickness of the holder at 3, 4. The cutting of flax, which is done in order the better to select and separate its various qualities, is an operation of some delicacy, and requires a peculiar machine for the purpose, which, though not complicated, requires great nicety in its making and arrangement; for the flax must not be cut-too abruptly, but be gradually reduced to a taper and somewhat natural end. The cutting should be done before the flax is heckled. The machine for the purpose consists of a species of circular saw about 20 in. diameter; but, instead of a single blade, is constructed of 3 or 4 plates of steel, each about i in. thick, and having angular projections from their circumference. This revolves at a considerable velocity, while the flax firmly grasped in each hand by its ends, is still further held and slowly carried against the saw by two pair of grooved pulleys pressed together by a considerable weight. It is thus partly sawn and partly broken through. Flax may be cut into 2, 3, and sometimes 4 divisions: and sometimes the dead harsh fibres that are frequently found at each of its ends only are cut off and used as tow; but more generally the different portions are heckled and used for the purposes they are sorted for. Description offlax cutting machine. (figs. 612, 613.) A A, framing; B, the grooved pulleys for holding and carrying the flax; c c, the driving pulley; D, saw or cutter; 758 FLAX. ~ 2~II 11613 E1, F, wheels for geering together the pair of holding pulleys; o, 1I, I, K, pinions and wheels for producing the proper relative speeds between the cutter and pulleys; L, weight, which by levers m and N, causes the pressure of the holding pulleys. 4th. Preparing.-By this term is understood those preliminary operations through which both line and tow must pass after the heckling and before the spinning process. The mechanism and modes of proceeding for this purpose, which consist of repeated drawings, are similar for "long" line or "cut;' though the dimensions and fineness of the machinery must be made suitable for their various lengths and qualities. But in the preparation of tow a peculiar additional operation is demanded, as a conse quence of the different state of the fibres of which the material is composed;this operation, termed "carding," has for object to bring the highly irregular and entangled mass into a somewhat more homogeneous and uniform state, previously to its being afterwards drawn and equalised in a manner similar to line. In the preparation of line the first operation is called "spreading," and the machine employed a "spreader," or first drawing: those subsequently are the second and third "drawings" (sometimes a fourth is used), and lastly the "roving." It is upon the spreader that the separate stricks of line are first combined and drawn into long uniform bands or ribbons, called "slivers," of determinate lengths. This is effected by subdividing the stricks into two or three portions, and then placing tb hm consecutively slightly elongated; and overlaying each other about Iths of their length upon and in the direction of an endless creeping sheet or apron. The machines are generally made with two of these creeping sheets or aprons, and upon each sheet are thus laid two distinct lines of stricks; each of which forms a thick uniform body of line, capable of being maintained to an indefinite length. These endless creeping sheets supply continuously another part of the machine, where the body of "line " is drawn out to between 20 and 60 times its original length, according to whether it is composed of cut or long flax. This part of the machine comprises a pair of holding or back rollers; an endless succession of bars called fallers, bearing combs of closely ranged steel pins, through which the slivers are drawn; a pair of drawing rollers; an arrangement of diagonal or doubling bars; and a pair of delivering rollers; is generally termed the "gill frame," or "gill head," probably from the French word "aiguilles" (needles), as descriptive of the combs, and to distinguish this machine from those formerly used for the same purpose, which simply consisted of a series of rollers under and over which the line was passed. The following figures 614, 615, show the outline of the present most approved gill spreader or first drawing. A A, general frame of the machine; B, driving pulleys; c, auxiliary frame for endless sheets; D, D, D, D, rollers for carrying the endless sheets or aprons; E, E, conductors to guide and slightly condense the four bodies or slivers of line; F, can for receiving the sliver; *, lever for weight on front or drawing roller; H, lever for weight on back roller; K, delivering roller shaft, spring and bell, which, by the intervention of geering between it and the front roller, is caused to ring when any Jesired length of sliver is delivered. a a, the iron drawing roller or boss; b b b, the woe jen or pressing roller, by the pressure FLAX. 759 of which upon a a the sliver is held during the greater velocity of these rollers over that of c; the holding or back rollers elongate in exact proportion of its augmentation; the holding roller c is in like manner pressed against another in order to assist the " gills' in retaining the fibres; k, k, hooked rods to connect the weighted lever h with the holding roller c, and by the pressure thus caused insure its effect; dd, the sheet or surface of " gills" composed of separate bars, as seen atfig. 614*, 615.*; e, rubber or cleaner of pressing roller b; f, f, conductors to contract laterally the sliver at the moment of drawing; g, p'ate of metal'having diagonal openings at an angle of 45~ (this plate is sometimes called the "doubling bars," having been first made of separate bars) to the original course of the sliver, in order to enable it to be turned in a rectangular direction and guided to the delivering rollers h,h; this direction of the sliver is more distinctly seen at fig. 6174 s, hanger or connector of pressing roller b to its weight lever c; 1, I, the screzws or worm shaft for carrying the gill bar dd; mm, the shaft with bevel wheels by which the screws ii'i / * 6Jl,', 61 "q*""" __ at opposite sides of the frame are caused to move simultaneously; nn, pinions for connecting the upper and lower spirals of each pair; oo, the cams or excentrics for lowering and raising the gill bars; pp, weighted guide lever or bell cranks for guiding the fallei L j v —- --- lv- ------ p *919IB^TIi. ^9 I iy"-l —-------....'XVr_ T 09-l FLAX. 761 in its descent, and moderating the shock caused by its weight when coming in contact with the lower slide or support; q and r, worm and wheel for bell motion; s, t, u, v, o, x, line of wheels from pulley to front roller and from front roller to back; 1, 2, 3, line of geering from back roller to sheet; 4, 5, 6, 7, line of geering from roller to delivering roller; 8, front roller to brush; y y, from back shaft to back roller. The machines for the second, third, and fourth drawings, though in principle essentially the same, yet differ in some of their minor details from the foregoing, as they do not re quire the feeding sheet to supply them, the " sliver," from the spreader having sufficient coherence as to allow itself to be drawn from the cans direct by the back rollers of these machi.es-neither is a bell motion requisite to determine thelength of slivers produced by thom. The subjoined sketches show the general parts requisite (figs. 616, 617.) or. Adn. i I 617 A rt ^ - ^__ A A (fig. 616. 617.), framing; B, driving pulley; c, support of sliver carrier; D, rollel or carrying sliver; E, conductors; F, can containing the slivers from the first drawing; G, receiving can; H H, the heckle carrying spirals; I, the diagonal or doubling bars;,, delivering rollers; L, the drawing rollers; m, rn, m, the retaining rollers. The roving frame is the same in regard to the arrangement of its back and front ~~~~~~ 762 FLAX. rollers and gills, as the drawing frames; and as the position and manner of regulating the spoles are generally the same as adopted for cotton, the description of these parts therefore does not require to be repeated; but an impr vement patented a few years since by Mr. P. Fairbairn, of Leeds, of that part of these frames which relates to regulating the taking up movement of the bobbin merits particular attention, as by it the inconveniences of the older method of a weighted belt and cone, and those of the more recent disc frames, are entirely overcome. The principle of this improvement consists of driving a pulley by pressure between two discs running at equal speeds in opposite directions, as seen at figs. 618, 619, 620. Figs. 618, 619. To obtain the variable speed, instead of using a cone and belt as in some frames, or the pulley and single disc as in others, a b, the horizontal driving discs, the lower one a is keyed to the shaft d, while the upper b is free to turn upon it; i, bevel FNe II | disc a, and itself pressed upon by the weight of disc 6; it is thus driven at speeds varying according to its approach to or from the shaft d, thus answering the purpose of te traversing leather belt of the cone movement; h shaft keyed in the pulley g, from which the variable motion is transferred to the bobbins. A series of preparing machines, termed a " system," consists in general of 1 spreading of 4 slivers at the drawing rollers, united into one by the doubling bars at the delivering roller, 2 frames of second drawing, in all 24 bosses 2 frames, third drawing containing together 36 bosses: if a fourth drawing is required, 2 frames of 24 bosses each, or 48 bosses in all. 180 spindles of roving in 3 frames will well supply 3000 spindles of medium spinning. The mode of using this " system " is, as has already been said, first to spread the stacks of line upon the feeding-sheet of the "spreader," then to receive the sliver or slivers there produced into cans capable of holding 1,000 to 1,200 yards of slivers. Those cans specially intended to receive the slivers from this machine are all made to one regular weight; thus, when filled, the weight of line each contains is correctly ascertained, and by the bell motion the length is also known. Upon this basis is founded the method of producing any desired number of yarn, and by doubling the slivers, a degree of cqualisation that the simple spreading would be unable to effect, for at each drawing and at the roving several of the slivers from the preceding drawing are put together, to be again reduced to one for this object alone. Hence, the weight of a determinate length in yards of the desired yarn being known, a calculation is made, combined of the drafts and number of doublings the material has to undergo, to determine what the weight should be of that length of slivers contained in the cans from the spreader. It is ordinary to put 10 or 15 of these "cans" together, to form what is called a "set," the slivers of which are united at the second drawing with the subsequent drawings and rovings: the combination of two or three slivers at each boss is sufficient. FLAX. 763 Though the above is lescriptive of the "gill" frames now in use, yet it should be understood they are by no means the first or only results of the attempts made to correct the defective principle of the original roller machines, which were incapable of holding or retaining the flax with a sufficient degree of regularity, owing to its unequal length and unadhesive nature. The consequences were that the yarns produced were "lumpy" and unlevel, making it evident that some improved means were necessary for more completely restraining and regulating the drawing of the fibres. The most obvious way to do this was to introduce some mode of partial detention by creating a friction among the fibres to imitate the action of the fingers in hand-spinning. This led to causing the slivers to pass through and among several ranks of serrated pins, which was found very nearly to attain the object, and certainly greatly improved the levelness and uniformity of the slivers. Thus the use of "gills" became general about thirty years since. Those first brought into general use were constructed with circular discs or plates for carrying the faller or gill bar, which at the same time were guided by their ends passing in fixed slides so as to bring the gill in as vertical a position and as near the 6l21 cll ilillB - D II /- E drawing roller as possible. The figures (621,622.) are profile and front views ot the working parts of one of these gills:-A, slotted plate or disc, of which a pair were keyed upon a shaft B, so as to carry each end of the faller, D, passing through the slots c, c; E the fixed excentric slide; G, tI the drawing rollers; E the holding rollers. This was succeeded by the "chain gill," in which the fallers were carried forward by an endless series of connected links, or jointed together " slotted plates," instead of the simple circular. The object of this was to increase the flat surface of gill bars between the holding and drawing rollers, making it more suitable for the longer descriptions of material. The slides and rollers, being similar in these machines to those in the former, are not repeated, but the sketch of five slotted plates is given infig. 623 623 From the evident importance of bringing the retaining effects of the gills as closely as possible to the point where the movement of the drawing fibres is greatest, several attempts have been made to improve the above described gills in this respect. With 764 FLAX. this view Messrs. Taylors & Wordsworth patented a gill of considerable ingenuity, (fig. 624.) which therefore deserves mention, though it never came into use. Its description is as follows:a b the faller or "gill bar" in one piece, which were carried forward by an endless chain; c, d slides placed horizontally over the gill sheet guiding the ends of certain bell-cranks ef, jointed at their angle in the recess fg e of the gill bar, and at their other end to the gill or comb g. By this arrangement, as long as the bell-cranks are in the parallel parts of the slides e, d, the gill teeth will be above the faller a b, but when they arrive at the contracted part the guided ends will be brought into the position Q Q, and consequently the gill depressed is G 2; this is so timed as to cause them to clear the drawing rolier, when, on again continuing their course, they are again caused to rise and penetrate the sliver by the reversed inclination of the slides c,d at the back roller. The objection to this ingenious machine was the largeness of the space suddenly --.. G- 2 624 C,, teft open by the descent of the gill, as the double faller, bell-crank, and gill necessarily occupied a great width. The screw or spiral movement of the fallers, which was soon afterwards invented, quickly superseded all others in use, as by these means the failler was caused, even in the E. r le pn y h decnt oftegla h oul alr elcakadgleesrl FLAX. 765 manner they were first constructed, to approach closer than even in the most perfected construction of the others, to the side of the drawing roller, and still maintain the pins in a vertical position. Recently this object has been more perfectly attained by a patented improved construction adopted by Messrs. P. Fairbairn & Co., whereby the obstacle to the faller wholly touching the roller has been removed, and thus producing the full holding effect of the gill to the latest possible moment. This is effected by employing a method of supporting the spirals by their working in tubular recesses in the side plate of the machine; along these recesses are longitudinal openings through which the faller end passes to enter between the threads of the spiral, and which serve also as slides to support the faller. As by this means the supports or plummet blocks that intervened between the end of the spirals and the roller are suppressed, the faller is enabled to advance to the place they formerly occupied. Fig. 625. and 626. show this comparison of the older and more recent methods. A, B spirals; c, c the parts by which they are sup ported, being in fig. 625. small pivots in plummet block D D, and in fig. 626. hollow tubelike recesses in frame plate c c; E, E pinions to work the upper and lower spiral together; F bearings; G drawing-rollers; H pressing-rollers; r I passage of the faller's descent. Here it may be as well to observe that the same parties have still more lately intro duced another important amelioration in these machines for reiredying the noise and wear and tear which ordinarily attend them by the abrupt and violent descent of the faller. Fig. 627. shows a sectional front view of a head having this improvement 627 applied. A A supports for screws; b, c top and bottom screws; d, d, the new cams fixed on shafts parallel with the screws, and revolving at the same speed. Thus, these cams d, d receive the faller e e at their largest diameter, at the moment they are free to descend, and guide them gradually down to the lower slide. Thus constructed, the " screw gill" continues to be the most esteemed in principle, though not without some serious objections in practice. For the abrupt and angular movements of the " faller " even here not only liberate too suddenly a portion of the fibres that should be but gradually relaxed at the moment of being drawn, but cause considerable wear and tear to itself, the slides, and the gills attached to it; to which cause of destruction must be added the great friction of the worm movement; these, however, in " line" preparing, where the fibres are long and straight, and the drafts employed large, and where, consequently, a comparatively slow movement of the gills is required, are not so much felt as in the preparation of tow, where they become serious. In " tow preparing" the first operation, as before stated, consists of' carding," which is generally repeated over two separate machines, which are respectively called the' breaker" and the "finisher" cards. They are essentially the same in principle, and vary but little in construction, the only difference being that the "breaker" is fed or supplied by the disjointed parcels of tow from a creeping sheet (as the spreader with "line,") and delivers its slivers into a can, whereas the finisher is fed from a bobbin upon which several of the slivers from the " breaker" are united by a machine expressly for that purpose, called a "lap frame;" this card thus receives its supply of work in a very regular form, and previously to delivering it in the form of slivers causes them to pass over a gill, to consolidate and strengthen them before delivering them into the receiving can: it is also generally clothed with a finer description of wire filleting than the breaker. Though it is the better method to card thus the tow tv iee, yet this second carding is sometimes dispensed with; in that case this auxiliary " gill" is similarly fixed to the first card or breaker. The cards employed for tow are machines of considerable weight and importance, the main cylinder, or, as it is sometimes called, " swift," being from 4 to 5 feet diameter and 4 to 8 feet long; those most generally employed are 6 feet long. Previously to entering upon the detailed description of a card, it may be as well first to trace in general terms the progress of its operations, as tending to elucidate the explanation of the machine itself. The tow is first divided by weighing into small parcels of 10 to 20 drachms; these are then shaken out and spread so as to cover certain definite portions of the creeping feeding sheet, by which they are conducted to the first pair of rollers called the feeders. These rollers are covered with a leather band, in which are fixed in close array a number of wire points about - a' ilch long, and having a tangential inclination to the 766 FLAX. circumference of the rolers, which are about 21 inches diameter. The tow, passing at a slow rate of progression between these rollers, is by them gradually presented to the points with which the swift is likewise covered, also set in leather bands, but which are about 2 inches wide these points, the same length as those of the feeders, have an inclined direction pointing to that in which the cylinder turns. The much greater velocity of the " cylinder" combs and somewhat opens and breaks the tow as it slowly arrives in contact, and the inclination of the pins at the same time carries it forward. All such lumps and fibres as are not sufficiently opened and straightened by this first contact, remaining prominent on the surface of points on the cylinder, are carried by it against another roller, whose axis is parallel, and whose wire-covered circumference is brought as near as possible, without absolute contact, in order to catch and retain these prominent lumps and fibres; the points of this roller (called a "worker") are inclined in a direction opposed to the movement of the swift, and, therefore, hold the "tow" to be again combed and straightened as at first it was by the feeders: this is repeated eight or nine times, by having that number of workers to the card; each of these workers has its attendant roller, also covered with wire points, by whose inclination in a contrary direction, and by the greater velocity of the roller, the tow is stripped from the workers, to be again laid on to the cylinder. The strippers, though running at a greater velocity than the workers, are still slower than the cylinder. The tow thus carried forward gradually improving in openness and regularity as it passes each pair of " workers and strippers," finally arrives at the roller called a doffer, of which there are two or three upon a card, the wire points of which are in such a direction as to hook or catch the " tow" "as it flies." The use of these several doffers is, that by placing each succeeding one progressively nearer the swift, the longer and shorter fibres are successively and separately taken off. Each doffer is cleared by an oscillating comb, and the slivers conducted, if intended for the lap machine, into a can by delivering rollers; but if finished, these delivering rollers are as it were the back rollers of the auxiliary gill, patented for this application by Messrs. Fairbairn and Co.; whereby the slivers are not only saved from all danger of derangement in their loose and porous state as direct from a card, but the hitherto double expense of carding, and first drawing is reduced to that of carding alone. e A A, (fg. 627.) framing; B, swift or main cylinder; c, feed rollers, D, D, D, strippers to feed rollers and workers driven by one belt from pulley E, and maintained tight by the Oj --------- -i" I i movable pulley Fr; G, G, G, workers; i, i, I, the three doffers; *, ai, N, intermediate wheels to connect the movement of the doffers with one another; K, iE, iK, oscillating combs for their respective doffers; L, delivering rollers: M, back roller of auxiliary gill- N, gill surface; o, p, drawing rollers; Q, delivering rollers and bell motion for measuring the FLAX. 629 slivers into the cans R; s s, doubling plate; T, pulley for driving auxiliary gills by bell from the pulley E. The lap frame to which allusion has already been made as the necessary adjunct to the cards when double carding is to be performed, is employed to collect together a number of slivers from the "breaker" by winding or lapping them upon a cylindrical piece of wood, which may be described as a bobbin shank, thus producing an equalisation of the slivers of tow as the making up of sets effected in line preparing; from 50 to 60lbs. of tow is the usual complement of one of these bobbins, the length and the diameter, when full, about 22 inches; thus, a 6 feet wide finisher card will take off these bobbins at once; from 15 to 20 is the number of slivers usually wound together, and the completion of a bobbin by the ringing of a bell, connected with the measuring cylinder of the machine. The following is a descriptive drawing of the lap machine. A A A, (fig. 630. & 631.) framing; B, measuring and pressing cylinder; c, c, c, driving pulleys connected with different geering to change the speed as the bobbins fill; D, bobbin or shank intended to be filled; E, table to receive the bobbin when about to be taken from the machine; F, weight to increase the effect of pressure of the measuring cylinder by the connecting rods G, G, G, which are split for part of their length in order to pass the shaft H, and at another gg have racks into which work pinions keyed on the shaft of I~ — ~ -.~630 An A 1 9 r-~~~~~~ 768 FLAX. the hand wheel I, for the convenience of raising and lowering the cylinder and weight The shaft H is divided at the plates K and L., and provided with sockets to receive the end of the bobbin shank a, which is introduced by sliding back the piece i n, and returning it by lever m, and thus is coupled and turns together with two pieces of shaft r, as also the disc plates K and L, which are to serve as temporary ends to the bobbin during the time of its filling, and thus by turning with it avoid that rubbing and felting effect upon the edges of the tow so injurious in the machines formerly constructed and by the bobbin acting as the driver to the cylinder the slivers are drawn tighter, and thereby avoid those plaites that the other machines were so liable to produce. As before mentioned, some objections were found to the working of the screw-gill, of a nature detrimental to the machines themselves, which, though not of great importance in "line," were much aggravated in tow preparing, as the lesser drafts there employed cause a greater wear and tear of the fallers and gills. The objection to these machines, however, is not confined to this point only, but extends also to their effect upon the material itself. The fibres of the tow sliver, as coming from the cad, are in a light and much confused state, which renders them liable to be easily separated; so that the faller, by its sudden descent, has a tendency to draw some down, and become lapped by them, as well as to make so marked a difference in the thickness of the sliver, by the withdrawal of the retaining comb, as materially to injure the quality of the yarn. Thus this " gill" was not enabled to hold its place in tow spinning, when other circumstances led to greater attention being paid to this important branch of the flax business, and it became a desideratum to have a machine free from these defects, and capable of working without derangement, at much greater velocity than was safe with the "screw-gill." These desiderata the " rotary " gill, patented by Messrs. Fairbairn & Co., amply supplies. For in this gill the circular form of the gill sheet obviates the necessity of having several fallers, and the simple motion creates neither friction nor abruptness of effect, while the retention of the fibres being continuous, the slivers produced are perfectly level and uniform, consequently these gills are extensively applied, as the auxiliary gill explained in carding, as well as for the subsequent drawings and rovings of tow, and sometimes, as will be afterwards seen, to coarse spinning. The theoretical construction of these rotary gills will be seen by the annexed sketch. M, (fig. 632.) back rollers, but when applied to a card at top and bottom holding rollers are again employed; N, the rotary gill sheet having the pins inclined backwards, so as to insure the impalement of the sliver when the fibres begin to draw: r and o, the drawing and pressing rollers; the doubling bars or plates are the same to these gills as to the "screw-gills." Subsequently to the carding the preparation of tow is completed by making up sets FLAX. 69 633 A, i, L of cans for the second drawing, as explained for line; these slivers are doubled and drawn once or twice more, and then roved. The drafts used in tow preparing are from 6 to 8, for as the fibres are shorter, it necessitates the employment of less draft. In both line and tow preparing, lesser drafts are employed as the stages advance, the gills finer, and the conductors narrower; also for both materials much attention is requisite to keep the various parts of the machines in good order, free from bent or broken pins, and chipped or indented rollers, for no subsequent operation can cure the defects that may be produced by negligence in these particulars. The drawing and roving frames for tow are shown in figs. 633, 634, 635. A A, (fig. 634.) drawing framing; B, driving pulleys; c, rotary gill sheet; D, drawing roller; E pressing; F, G, pairs of delivering rollers; A, doubling plate; I, back conductor; K back roller wheel with pulley to turn the sliver rail i. A A, (fig. 634 & 635.) roving frame; B, pulley and fly wheel combined; c, drawing roller: D, rotary gill; a a, stand for gill movement. The regulation of the bobbins is effected in the same manner as already described for line roving. 6th. Spinning.-This operation consists in drawing the "rovings" down to the last degree of tenuity desired, and twisting them into hard cylindrical cords, which are called "yarns." There are three modes of performing this operation; the first, and perhaps oldest, is that.where the drawing and twisting are performed altogether, with the material preserved dry, and without breaking or shortening the fibre; the second is that which likewise, without changing the length of the fibres, draws them while dry, but wets them just at the moment before twisting. This method is the nearest imitation of hand spinning, and makes the yarn more solid and wiry than the first; as the fibres of flax losing their elasticity while wet, unite and incorporate better with one another. The third mode of spinning has been much more recently introduced than either of 50 '7e FLAX. 634r? 635 the others, and by it the fibres are wetted to saturation previously to being drawn, whereby they are not only much reduced in length, but their degree of fineness is increased by the partial solution of the gummy matter, inherent in the flaxen material: owing to these circumstances equally good yarns can be produced by this mode of spinning from line and tow of inferior quality, to what could be employed uypon either of the others, and not only that, but much finer yarns can be now spun than were possible previous to its introduction. It has therefore not only nearly superseded all other methods of spinning for yarns from 20's to the finest, but has much increased the extent and importance of the flax manufacture. The only difference in spinning frames for " line or tow," when employed for the older methods, consists in the length of reach, which generally involves the necessity of having separate machines for each material, though sometimes they are made with a capacity to be adapted to either purpose. In the third method the same machines were used promiscuously for "line or tow." The yarns spun wholly dry are used for the coarse description of woven goods, as packing canvass corn sacks, and when partially bleached for sheetings and towellings FLAX. T771 as from its greater elasticity and openness it fills up better in weaving. Those spun 636 partially wetted are employed for a somewhat superior description of linen goods, and the solid silky appearance qualifies them for drills, damasks, &c., as well as for sewing and shoe threads; a somewhat inferior material, by this manner of treatment, makes an equally good yarn as a better material spun dry. The yarn produced from this wet principle is rather inclined to have a cottony appearance, and from the comparative ease with which an inferior material can be made to represent an apparently fine good yarn, the application of yarns thus produced is exceedingly various and somec times deceptive, though when good materials are used, these 33 I iA yarns afford durable and handsome drills, shirtings, lawns, and cambrics, as well as fine sewing threads. "2 The mechanical arrangement for twisting, and then winding the yarn upon a bobbin, is called the "throstle" principle,.aJD supposed to be so called from the whistling noise they create when working at full speed, which is from 2,500 to 4,000 revolutions a minute. The following diagram will explain the principle, which is applied alike to all the modes of spinning above described. A A, (fig. 636.) the spindle; B, the bobbin, loose and independent of the spindle in regard to turning, and rising, and lowering, but through which the spindle passes; c c, the flyer screwed to the spindle top; D, table called bobbin lifter, as while at work it rises and lowers to lay the yarn on the whole bobbin equally; E, a small cord to press on the bobbin by the weight F; G, pulley by which the spindle is driven. Many attempts have been made to improve upon this principle, in order to avoid or lessen the strain upon the thread in its passage from the drawing rollers to the flyer 3 eye; but, till recently, without any degree of success. The only improvement at present. known, and which promises to become general, is that where the necessity to have a top to the bobbin is avoided. It will be seen from the above diagram, that the yarn is compelled to rub the top of the bobbin, and the friction thereby created quickly causes it to become rough; and therefore it has a tendency to catch and break the thread. The desirableness, therefore, of having a clear course for the yarn was evident, and this improvement that we are about to explain produces the effect by employing what is called a coping motion, which, like that used in mule spinning, preserves the layers of thread upon the bobbin ever in a pointed or conical state, and therefore self-supporting without the aid of the wooden end of the bobbin. See COTTON SPINNING. The arrangement of the rollers for holding and drawing the slivers or rovings, as well as the plates and rollers for aiding to retain the twist of the rovings, in order to render their elongation more equable when to be drawn dry and spun upon the older methods, will be seen infig. 637. A, (fig. 637.) roving bobbin; B, back or holding roller; c, carrying roller, d flat plate with a slightly curved face; the carrying roller and plate are so placed as to cause a degree of friction to the roving when passing over them, so as to retain the twist, and thus act as the pins in the "gill frames;" e, tin conductor for contracting the roving at the moment of being drawn; f, metal roller; g, wooden roller pressed against the drawing roller in order to pinch the roving; h, lever and weight. When it is intended to wet the yarn previously to twisting, the trough i is used, in which is water, which is supplied to the roller g by the capillary attraction of a piece of cloth immersed therein, and bearing against the roller by lever k. The machines for " wet" spinning are of a very different construction and appearance; as the close proximity of the holding and drawing rollers prevents the intervention of holding rollers or friction bars, while the force requisite to draw the rovings at the short reaches used, varying from 2} to 4 inches, requires each pair to be deeply and accurately fluted into one another. The water used is heated, in order by the expulsion of the fixed air more rapidly and completely to saturate the rovings while passing through it. The following drawings and description will be sufficient to give an accurate idea of the principle of these machines, which are generally 20 to 30 feet in length, and contain 200 to nearly 300 spindles; that is, 100 to 150 on each side. A A A A, (fig. 638. & 639.) framing; B B, stand for roving bobbins; c, driving pulleys fixed upon the axle of cylinder D, from which pass endless cords to drive the spindles ~72 FLAX. 63\ C, B 638 e e; F, step rail Qf spindles; G, collar rail for ditto; i, bobbin lifter; I i, front roller; K, back rolle, back prller;, back pressing roller;, top pressing roller (these are generally made of box wood, but sometimes of gutta percha); N, N, levers in connection with the excentrie to produce the rise and fall of the bobbin lifter; o o, thread plate Q, Q, saddles or transverse bars resting on the axles of the back and front pressing rollers,so that one lever and weight acts for both by the connecting rod to lever r r, which, in order to cause more pressure on the drawing than on the back roller, is placed on the saddle nearer the former than the latter. 1, 2, 3, 4, 5, 6, 7, 8, train of wheelwork, by wh'ch the movements are dis......./~aJ _'i FLAX. ~ n. |ipmiiiiiMmwiiii 639 nrbuted. a, a, a, the trough of hot water maintained by steam-pipes at the desired temperature; b, b, guide rods or pipes to cause the roving to pass under the water. In order to avoid the rollers becoming indented by the roving always passing on the same place, they are caused to traverse the breadth of the rollers by a traversing guide rail, moved by an excentric at the worm and wheel c; d, flyers, and f, spindles. Here it may be proper to introduce a description of the machines for twisting the yarns when spun into "threads" used for sewing, &c. The yarns spun for this purpose should always be made of a somewhat superior description of line to that employed for the same number of yarns for weaving, and have rather less twist. They are generally taken while wet on the spinning bobbins to the twisting frame, and, when combined together, the union is effected by a torsion in the opposite direction to the original twist of the separate yarns. 6. Reeling. - This operation consists in winding the yarn off the bobbins of the spinning or twisting frames, and forming it into hanks or skeins. The various denominations of the skeins into which yarn is reeled, and then the forms or combinations they are made up into, are as follows:The lea containing 300 yards 10 leas making 1 hank 20 hanks,, 1 bundle 6 bundles,, 1 packet. It is by the standard lea of 300 yards that the description of yarn is known from the number contained in 1 lb. weight; thus No. 20. contains 20 leas or 6000 yards for 1 lb weight. In Scotland, the subdivisions are rather different from the foregoing, which are employed in England and Ireland; the lea, however, remaining the same:38 leas make 1 spindle 6,, 1 rand 12 rands,, 1 dozen. The reeling is peformed upon exceedingly simple machines, generally put in motio, by the hand of the person attending them, though sometimes they are driven by the motive power of the factory. The reel is made sufficiently long to receive twenty bobbins, and the barrel upon the yarn is found in one length; the diameter, however, varies so as to suit the different-sized yarns to be reeled. For the coarsest yarns and down to 16. and 20., the largest circumference is used of 3 yards, from that to about No. 100. 21 yards, and for the finest yarn 1~ yards is found most convenient. These various circumferences are compensated either by putting a great number of threads 774 FLAX. into each "tye," or increasing the number of tyes, so that opposite to each one of the 20 bobbins an entire hank should be formed before taking the yarn off; thus at each "stripping," one bundle is turned off. To facilitate the stripping, one of the rails of the barrel is made to fall in, and thus slacken the hanks; care is taken to leave the leas bands very loose, in order to allow the yarn to be spread out in drying and bleaching. The determinate lengths of yarn, when wound on the reel, are notified by the ringing of a bell connected with the axle of the barrel. Figure'below shows the form of an ordinary hand-reel. A A (fiff. 640.) framing; B B < 640 % A c 7L@.4^ reel barrels; c box or trough to E/__^ -- A"y~~\,~~ receive empty bobbins, &c.; D D 2^ A /5s bobbins in position of being reeled; E E guide rails moveable so as to place the leas side by side on the ree, ff bell wheels~ g g bells for each reel barrel suspended on springs. \B \ To these hand-reels there are fCA A —\ YEst'U s many objections; for it is evident that the correctness of measure de^ B i i1~ ^~ i \ / ~pends entirely upon the attention \g i / M^ y X- \ / ~ of the reeler, and the stoppages vs J^ [\i -A- A.-. arising from the breaking of a thread or the finishing of a bobbin interrupt the work of all the others. Thes.e objections rendered it necessary to attempt some ameliorations of the system by the introduction of a reel that should automatically prevent these causes of error. Such a reel was patented a few years since, and is now in general use in Scotland; it is so contrived as to have the capacity of stopping itself when a thread breaks, when a bobbin finishes, and leas and hanks completed; and having but four or five bobbins in one compartment, the stoppages affect but few at a time; and as this machine can be worked by less skilful persons without possibility of error, much saving is effected both in wages and material. The annexed figure (641.) shows the principle of this;mproved reel. A A (fig 641.) framing; B reels; c, c pendulums on which are hung the bobbins to be wound off; D driving shaft with ratchet wheels opposite to each pendulum, so that when a thread breaks, the pendulum to which it was attached falls into the ratchet wheel, and thus stops it. The drying of wet spun yarns should always, when possible, be done in the open air A 641 oy spreading the hanks upon horizontal poles through them, with another similar pole resting inside upon their lower extremities, in order to keep them straight. If artificial heat is employed, that from steam or hot water is preferable, and it should never exceed 90~ Fahr., as otherwise the yarn is apt to become harsh. FLAX. 775 7. Makingq up. —By this operation is first produced upon the yarns a certain softness and suppleness, and then the hanks are folded and tied up in conveniently-sized packages. In order to give the yarns that soft and mellow feel so agreeable and characteristic of flax yarns, the hanks, when brought from the drying, are what is called shaken down and pin-worked. This is done by separating a few at a time, and passing them on to a strong arm of wood fixed to a wall or pillar, when with a heavy baton put through them, the workman proceeds to stretch the hanks with a sudden check or jerk, which operation he repeats in two or three places so as to thoroughly straighten and shake them loose; he then, using the same baton as a lever, twists them lightly backwards and forwards till the desired degree of suppleness is obtained. A brush is sometimes used to aid the straightening and separating, as well as to increase the gloss on the yarn. iThe hank or hanks will then be found to have assumed a flat shape, as on the reel, which facilitates their folding with a dexterous twist by their middle, when they are laid in square piles upon a table with their twisted folds one upon another. They are maintained in the perpendicular by a few supports fixed in the table. Sometimes these packages, which, according to the sizes of the yarn, congist of from i of a bundle to 5 or 6 bundles, are bound together by some of their own hanks, but sometimes by cords in three or four plh ces of their length. It;s, however, better to employ a bundling press than an ordinary table, as the yarn can then be made up more solidly, thus both improving its appearance, and causing it to occupy less space for packing and stowage. The bundling presses are made upon the same principle, but on a smaller scale, for making up the small packets, in which sewing threads are generally presented for sale, and are upon the following construction, (fgs. 642, 643). 642 643 J) D D I tt A. -i ai L Fig. 642. front view; Fig. 643. profile. A A A frame; B table or flat top of frame; a rising table; D D iron uprights fixed to B; E E bars hinged at one end to uprights D D, to shut across the press, and be caught and latched down by the spring catch L fixed to the upright D along one side of the press; F F racks for lifting the table c by the pinions on shaft G; H crossed levers for turning the shaft G; I ratchet wheel engaging the detent K, and thus retaining the shaft G in any required position, and thus of course maintaining the pressure of table c against the top cross-bars E. 8. Weaving, is the operation by which the yarns are combined into textile fabrics, such as canvas, linen, drills, damasks, &c., and a great variety of other denominations of article for use and ornament. Hitherto the weaving of linens has been carried on by the ancient and well known hand process, so ancient and so well known as to place the operative practising it among the worst paid of any other art. Now, however, there are several extensive and thriving establishments, where machinery has taken the place of much squalid misery, and at much cheaper rates produces to consumers superior articles, and still affords good payment to the operative. The improvements in power weaving which have led to this result are not founded upon one or even a few successful inventions or contrivances, but are the combination of a great many that have occupied much time to mature. Many difficulties had to be overcome in the weaving of flax that did not exist in that of other materials; and for a considerable period the expense of linens rendered their 776 FLAX. consumption so limited, as to make their production by power weaving but a ver) secondary object. The greatest obstacle of a practical nature to the introduction of the automatic weaving of linens was, the stubbornness or want of elasticity in the yarn which caused frequent breakages, and much confusion. In woollen or cotton goods, if a thread or yarn should chance to be a little tighter than the others in the warp, its elasticity will allow it to come up to the general bearing of the others when the weft is struck up by the reed; but in linen, from the want of that elasticity, a thread so situated would break, and by crossing some others cause them, if not to be broken direct by that circumstance, at all events cause an obstruction to the shuttle that would lead to further mischief. Hence it was most material in linens to have such a method of winding the yarns upon the warp beams that should insure the greatest regularity; but strange to say, that point, though now attained, was at first wholly lost sight of. That circumstance, as well as the great mistake of attempting to use the same looms as are found suitable for cotton, produced so much discouragement in the earlier attempts as to give rise to a high degree of prejudice against the possibility of success in this undertaking, which may account for the backwardness in which this branch of th, flax manufacture was found till quite recently. See article FLAX WEAVING LOOM. The new roving machine, called by the ingenious inventor, Mr. W. K. Westley, of Leeds, the SLIVER RovING FRAME, seems to be a philosophical induction happily drawn from the nature of the material itself, and accommodated to its peculiar constitution. It is remarkable for the simplicity of its construction, and, at the same time, for its comprehensiveness; requiring no nicety of adjustment in its application, and no tedious apprenticeship to be able to work it. It is known, that the glutinous matter of the plant may be softened by water, and hardened again by heat; of this fact advantage is taken, in order to produce a roving wholly without twist; that is, in the form of a ribbon or sliver, in which the fibres are held together by the glutinous matter which may be natural to them; or which may, for that purpose, be artificially applied. The sliver roving, as long as it remains dry, possesses all requisite tenacity, and freely unwinds from the bobbin, but on becoming again wetted in the spinning frame, it readily admits, with a slight force, of being drawn into yarn, preserving the fibres quite parallel. The diagram, fig. 644., shows in explanation, that A, is the drawing roller of the roving frame in front of the usual comb. B, the pressing drawing roller. c, a shallow trough of water. D, a cylinder heated by steam. E, a plain iron roller for winding. r, a bobbin lying loose upon the winding roller, and revolving upon it, by the friction B of its own weight. The roving, or sliver, as shown by the dotted line, after leaving the drawing rol644 lers, A, B, passes through the water, in the.C /i \ / trough c, which softens the gluten of the fibres; and then it is carried round by the steam cylinder D, which dries it, and delivers it hard and tenacious to the bobbini F, on which it is wound by the action of the roller E.,~,/. D This is the whole of the mechanism re(~n i^ )~' i.quired in producing the sliver roving. All the complex arrangements of the common cone roving are superseded, and the machine J v~*. at once becomes incomparably more durable, and easier to manage; requiring only half the motive power, and occupying only half the room. A frame of 48 bobbins is only 6 feet long, and affords rovings sufficient to supply 1200 spinning spindles. This machine, though here described, is but little used, being capable of but very limited application. The following sketch shows the arrangement of the machinery in the most important rooms in a modern flax mill of 7000 to 8000 spindles, capable of producing, weekly, about 1900 bundles of line yarn, No. 25.'s to 120.'s; and about 700 bundles of tow yarn, No. 10.'s to 40.'s. There are three systems of long line machinery for No. 25.'s to 70.'s; two systems of FLAX 77 645 10.'s to 40.'s. I _, A, two of Baxter's ag es for long tow. 1 i - P EJ m n i i I i -, a flax-cutting machine. cut line machinery for No. &.'s to 120.'s; and three systems of tow machinery for lcut 10.'s to 40.'s. The building is 56 feet wide and 162 feet long; which is a very suitable and con. venient size, and which admits of the most economical arrangement of the machinery. The following is a description of the machines shown in the preparing room: - A, A, two of Baxter's patent sheet hackling machines for long tow. B, a flax-cutting machine. c, one of P. Fairbairn & Co.'s patent double line of holder hackling machines for cut line. D, D, are two breaker cards 4 feet diameter X 6 feet wide. E, lap machine. F, F, F, are three finisher cards 4 feet diameter X 6 feet wide, with P. Fairbairn & Co.'s patent rotary gill drawing heads attached. G, G, are two patent rotary gill drawing frames for long tow, 12 slivers each. H, H, two ditto regulating roving frames 48 spindles each for long tow. I, is a screw gill second drawing frame of 3 heads for cut line tow. K, is a screw gill third drawing frame of 3 heads for cut line tow. L, a screw gill regulating roving frame of 72 spindles for cut line tow. x, M, M, are three long line first drawing frames or spreaders of 4 bosses each. N, N, N, are three long line second drawing frames of 2 heads each. o, o, o, are three long line third drawing frames of 2 heads each. P, P, H, three long line regulating roving frames 60 spindles each. Q, Q, are two cut line spreaders of 4 bosses each. R, I, two cut line second drawing frames 2 heads each. s, s, two cut line third drawing frames 2 heads each. N, T, two cut line regulating roving frames 72 spindles each. The spinning room contains 34 spinning frames of 184 to 244 spindles each, appor tioned to the several systems as described below. I. System of long line machinery for spinning No. 25.'s to 40.'s. 1 Baxter's patent sheet hackling machine, 6 tools. 1 spreading or first drawing frame, 4 bosses. 1 second drawing frame, 2 heads 4 bosses each. 1 third drawing frame, 2 heads 6 bosses each. 1 patent disc regulating roving frame 60 spindles, 10 spindles per head, 8 inches X 4 inches bobbin. 5 spinning frames 21 inches pitch, 200 spindles each, 1000 spindles. The production of this system is about 66 bundles, or say, 420 lbs. of No. 30.'s yarn per day. II. Two systems of long line machinery for No. 40.'s. to 70.'s. 1 Baxter's patent sheet hackling machine, 8 tools. 2 spreaders or first drawing frames 4 bosses each. 2 second drawing frames, 2 heads of 6 bosses each. 2 third drawing frames, 2 heads of 8 bosses each. 2 patent disc regulating roving frames, 60 spindles each, 12 spindles per head, 6 inches X 31 inches bobbin. 10 spinning frames, 220 spindles each, 21 inches pitch, 2200 spindles. Production about 130 bundles, or 472 lbs. of No. 55.'s yarn per day. 778 FLAX, 646 I 7t 7t 7i I I 1 p p P P t t t t i /, u - 7l ~ P' P P P P p t t t TII. Two systems of three cut line machinery for No. 40.'s to 120.'s (one for 40.'s to 70.'s, and one for 70.'s to 120.'s). 1 flax cutting machine. 1 P. Fairbairn & Co.'s patent double line of holder hackling machine. 2 spreaders or first drawing frames 4 bosses each. 2 second drawing frames, 2 heads each, 6 slivers per head. 2 third drawing frames, 2 heads each, 8 slivers per head. 2 patent disc regulating roving frames, 72 spindles each, 12 spindles per head, 6 X 31 inches bobbin. 5 spinning frames 220 spindles each, 21 inches pitch, = 1100 spindles. 5 spinning frames 244 spindles each, 2j inches pitch, = 1220 spindles. Production about 65 bundles or 236 lbs. of No. 53.'s yarn per day, and about 50 bundles or 105 lbs. of No. 95.'s yarn per day. IV. Two systems of long tow machinery for No. 10.'s to 25.'s. 1 breaker card 4 feet diameter 6 feet wide, doffed by rollers. 1 lap machine. 2 finisher cards 4 feet X 6 feet with P. Fairbairn & Co.'s patent rotary gill draw ing frames attached. 2 patent rotary gill drawing frames 12 slivers each. 2 patent rotary gill disc regulating roving frames, 48 spindles each, 8 inches X 4 inches bobbin. 3 spinning frames, 184 spindles each, 3 inches pitch for No. 10.'s to 18.'s = 552 spindles. 3 spinning frames 200 spindles each, 21 inches pitch for No. 16.'s to 25.'s = 600 spindles. Production about 39 bundles, or 488 lbs. No. 16.'s per day, and about 39 bundles, or 312 lbs., No. 25.'s per day. V. One system of cut tow machinery for No. 25.'s to 40.'s. 1 Breaker card 4 feet diameter 6 feet wide, doffed by combs. 1 Finisher card with P. Fairbairn & Co.'s patent rotary gill drawing frame attached. 1 Screw gill second drawing frame 3 heads each, 4 bosses per head. 1 Screw gill third drawing frame 3 heads each, 6 bosses per head. 1 Screw gill patent disc regulating roving frame 72 spindles,.12 spindles per head, 6 X 31 inches bobbins. 3 spinning frames of 220 spindles each; 2~ inches pitch, = 660 spindles. Production about 36 bundles, or 240 lbs. of No. 30.'s per day. The reeling is generally carried on in the attic above the spinning room, and the number of reels required is about the same as the number of spinning frames. Summary view. There are 3200 spindles long line, producing 196 bundles, or, 890 lbs. of yarn per day. 1152,, long tow,,, 78,, 800,, 2320,, 3 cut line,,, 115,, 340 660,, cut tow,,, 36,, 240,, 7332 spindles 425 bundles 2270 lbs. of yarn per day. The waste in line spinning is generally about 10 per cent., and in tow spinning about 25 per cent., so that the quantity of raw flax required to produce the above stated quantity of yarn would be about 20 cwts. of flax for long line and long tow spinning, and about 6 cwts. of flax for cut line and cut tow spinning. FLAX. 779 Claussen's Patent Process.-The great interest which has of late been excited in the public mind with respect to flax, in part by the enlarged sphere of application which is supposed to be opened out to it by the discoveries of Mr. Claussen, and more par ticularly from the fact, that it is a material of home growth, and capable of production in unlimited quantities in Ireland, would seem to demand from us special comment. We are not the less inclined to this course, as the public is ever ready to take upon trust the practicableness of any new projects, when their promised results chime in with any feeling of sympathy which happens to pervade the' community; thus where the interest of Ireland is concerned, we find that commercial schemes for aiding its advancement are eagerly seized upon, and confided in almost without inquiry; but this is far from a prudent course. There can be no question that the flax trade is the growing manufacture of Ireland, and, as such, too much attention cannot be given to the production of the raw material; it has therefore been encouraged in every legitimate way, but it may be questioned whether the late announcements which have been made of its almost universal applicability to textile fabrics, will not tend to direct capital to too great an extent into this now thriving branch of industry, and thereby quickly induce a false and ruinous competition between manufacturers. Flax, though apparently, from its fibrous character, better suited by nature than either cotton or wool to be formed into thread, nevertheless presents many difficulties to manufacturers, which are quite foreign to the working of these short staples, anld which can only be in part remedied by the adoption of a somewhat different process of manufacture. In contradistinction to cotton, which may be considered the fruit of the plant, flax is the filamentous substance contained in the stalk of the plant. It has therefore to be obtained from stripping off the bark or woody coating, termed the "boon." But, in order to effect this, as well as to detach the fibres from each other, it is necessary to dissolve the gum or resinous sap, which pervades the plant, and binds the several parts together. Various plans have been suggested for attaining this end; and it is upon the efficiency of the process adopted that the ultimate success of the flax trade mainly depends. When it is understood that the growth of the flax plant is principally in the hands of small farmers without capital, and that the bulk of the flax, when reaped, is so disproportionate to the yield for manufacturing purposes as to preclude the removal of the article to any great distances in the state of straw, it will readily be seen, that no process of dissolving the gum or of "retting" as it is termed-requiring the purchase of expensive apparatus, or demanding the exercise of scientific knowledge-can be brought into general use, however efficient that process may prove to be. It cannot, therefore, be wondered al that the old plans of water-retting and dew-retting still prevail, although a far superior method, which we shall presently explain, has been introduced. Retting is simply bringing the plant to a certain stage of decay, which causes a perfect loosening or separation of its fibres. In carrying out the water-retting process pits are dug in the ground and filled with water, and the flax is thrown in in bundles and pressed down by weighted boards, to keep it under water. After a short time, fermentation commences, and in about ten days (more or less, according to the mean temparature) the decaying process will have proceeded sufficiently far; the flax is then taken out and dried, and the boon is removed by hand. The retting may be carried on in either running or stagnant water; but the latter, although the more expeditious method, requires closer watching, to prevent the flax from losing its strength of fibre by over decay. It will be obvious that large masses of vegetable matter exposed to putrefaction must generate such exhalations as are very injurious to the health of the community. Yet this practice not only prevails, but will, as we think, necessarily increase in proportion to the increase in the growth of the plant, unless some energetic means are adopted to put down the practice. Dew-retting 4s a process that is less objectionable, but its operation is far slower, and it is altogether beyond the means of many farmers to adopt. In this instance the flax is strewn thinly over meadow or grass land, and then submitted to the action of the air, dews, and rain, which, in a period varying (according to the mean temperature) between three and six weeks, will effect the required disunion of the plant. This plan has an advantage over the water-retting, inasmuch as the flax is yielded of a brighter colour,-the latter process being very apt to impart a deep stain to the fibres, as well as to destroy their tenacity. The improved plan of retting, above alluded to, was introduced into Ireland from the United States in 1847, by Mr. Schenck of New York. It had been tried there successfully on hemp; the strength of the fibre, when made into cables, having been proved in some of the government navy yards to exceed any that had been retted on the old system. The process was patented in the United Kingdom in 1846, and is now in profitable work near Belfast. A recent inspection of the factory will enable us to state in detail the manner of proceeding to separate the long fine fibres of the flax from the boon. The principal apartment in the building contains a number of large circulai 780 FLAX. vats, in which the flax is steeped, and these are provided with steam-pipes connected to the steam engine boiler. The flax to be operated upon is placed in these vats and piled up to a given height; strong cross-bars of wood, forming a kind of framework, are then laid above the flax and secured to the respective vats,-the object of this framing being to keep the flax down in the vat, as otherwise it would rise as it swelled in fermenting, and protrude above the water. When a mass of flax is thus secured, water is run into the vats, and as it becomes absorbed, more water is added. Steam is now admitted into and made to circulate through the steam-pipe at the b.ttom of the vat, so as to raise the water to about 90~ Fahr., and maintain it at that temperature. In a few hours acetous fermentation is established in the vat, and the decomposition of the resinous or gummy matter in the stalk proceeds with rapidity. After about sixty hours the decomposition is completed, and that without the exudation of any inodorous or noxious effluvium. The water surcharged with the mucilage is then drawn off, the framing is removed, and the flax is taken out of the vat to be dried, either in the open air or by artificial means. Thus, not only is the objection to the old plan, on the score of injury to health, removed, but a considerable economy in point of time is effected; the flax also is less liable to deterioration in colour and strength of fibre, if ordinary care is used in conducting the operation. When the weather is favourable for drying in the open air, the flax, tied up, in tufts or handfuls, is suspended in rows tier above tier, in an open framing, covered in at top by a penthouse roof. This mode of packing admits of a large quantity of flax being stowed in a small compass, and yet allows of a free access of air through the whole mass. When it has hung a sufficient time to dry, it is next submitted to the scutching operation. Or, instead of open air drying, the flax, in damp weather, is piled loosely in a drying chamber, into which a current of air, heated after Messrs. Davison & Symington's method, is passed, and the moisture is quickly expelled. The cost of this operation, as carried on at the works, must be very trifling, as the waste steam from the engine, which works on the high-pressure principle, is found amply sufficient for heating the air; an advantage consequent on this mode of heating is, that no carelessness on the part of the attendants will render the air liable to be heated to an extent that would injure the flax. The flax having been retted and dried, is next carried to the rolling or crushing mill, and there passed, by hand, between rotating horizontal rollers, which crack the boon already loosened by the retting process, and spread, or partially separate, the long fibres. The flax, as it is delivered out of the machine, is gathered up by boys, and handed to others, who submit it by handfuls to the action of rotating knives. These knives are attached to the face of a vertical wheel, several of which are mounted on one and the same shaft, at about three feet apart, and receive motion from the engine. There is an attendant stationed at every wheel, whose duty is to submit the flax to the action of the knives, by holding it over a fixed bar, contiguous thereto, and allowing the rotating knives to strike the flax in the direction of its length. When the boon on the half length of the flax is broken away or knocked off, the flax is turned over and the other end is subjected to similar treatment. To further clear the flax of the woody particles, it is again submitted to a similar operation before another set of wheels,-the action of the knives being, in this instance, more thorough and searching, as the flax has now approached nearer to a stick of fine fibres. Having undergone this treatment, the flax is now ready for sale in the market; and it is in this state that it enters the flax mill to be acted upon by the heckling-machine, for the removal of the tow or short staple, prior to undergoing the various operations of preparing and spinning, to convert it into yarn. From this description, it will be understood, that, so long as the cultivation of flax is in the hands of small farmers, Mr. Schenck's process is not likely to put the old practice out of use; for the water-retting is carried on at little or no outlay of money; and the cleaning of the flax by hand is made a sort of wet-day occupation: the bulk of the flax in the state of dry straw,-which, as we have before said, is so disproportionate to the amount of useful fibre as virtually to prevent its carriage to any distant part prior to undergoing the retting operation-scarcely exceeds, when carried to the market, 20 per cent. of its original weight. M. Claussen's patented process (the merits of which have been so confidently paraded), does not seem to be in favour with the Irish flax spinners, although the specimens contained in the Exhibition appeared to the eye to realize everything that could be wished: but here, as in many other manufactures, it is not the attainment of a high degree of excellence that is the difficulty, but the cost at which such a result may be arrived at. Thus flax may be dressed from the straw, as, indeed, it was once proposed to be done, without being subjected to the retting process. The waste of material, however, soon showed the impracticability of the plan, although a good article was produced; it is possible, therefore, that M. Claussen's specimens may have been obtained without regard to cost. We do not assert this as a fact, but rather to show, that in commercial matters uo just conclusions can be arrived at without the question of cost being taken into account. His mode of treating the flax will be readily understood from the following FLAX. 781 description, which we have compiled from his specification. The straw, having been stripped of its seeds, is steeped in a solution of caustic alkali, of about the strength of 1~ Twaddle's hydrometer, either in a boiling state, which renders an immersion of six hours sufficient, or at a temperature of 150~ Fahr., which will necessitate the continuance of an immersion for about twelve hours. By this means the glutinous matters which connect the fibres with the woody portions of the plant, are dissolved, and the colouring matters contained in the straw are discharged and prevented from staining the fibres. When the flax is required to be spun in long staple, the straw is next steeped for about two hours in dilute sulphuric acid, containing one part of acid to from two to five hundred parts of water, for the purpose of ridding it of the alkali which it has taken up; the straw is then removed from the acid-bath and well washed in water: this is one process. But the one which has raised the public curiosity, is that which purports te.plit the fibres into fine filaments like those of cotton or wool. This operation is effected as follows:-The straw is put into a bath containing a strong solution of bicarbonate of soda, and allowed to remain there for three or four hours. When well saturated with the bicarbonate, it is immersed in water, acidulated with sulphuric acid, in the proportion of one part of acid to two hundred parts of water; the sulphuric acid will then combine with the soda and effect the disengagement of carbonic acid gas in the fibrous tubes, which gas, by its expansive force, will split the fibres into fine filaments, having the appearance of fine cotton wool, and capable of similar treatment. This splitting process may be applied to the plant either in the state of straw, or after it has been retted and brought to the state of long fibre; and it is therefore capable of general application, as far as the inconvenience arising from bulk is concerned. What manufacturers will eventually say to working up fibres that have been steeped in sulphuric acid, may depend upon the means taken to extract this corroding substance from the flax; but at present we think there is a strong feeling against its use. Mr. Claussen's patent process for treating flax is described as follows, in his specification of March, 1851:" 1. My said invention, in so far as respects improvement in bleaching, has reference to the bleaching of all kinds of vegetable productions, and of fabrics or articles composed of such productions, and consists of the following improved processes. In the usual methods of bleaching fabrics, such as calico, the goods are first immersed in a bleaching liquor (commonly the solution of hypochlorite of lime,'the chloride of lime' of commerce), and then are steeped in a bath of water, acidulated with sulphuric acid. By this plan, the chlorine is set free, either in its.simple form, or in combination with oxygen (as chlorous or hypochlorous acids), or in chemical union with the hydrogen of the water (as hydrochloric acid), and thus either is wasted, by its escape, or is rendered injurious to the fabric, by remaining too long in contact with it. " Now instead of this I adopt the following process, whereby the whole, or a great portion of the chlorine, or chloro-compound, is kept in a combined state, and recovered for further use. By the term'chloro-compound,' I do not mean a salt containing'chlorine,' but an acid having'chlorine' for its base, such as chlorous or hypochlorous acid. " In this process, then, of bleaching, I take the goods, after they have passed through the bleaching liquor (say a solution of the hypochlorite of lime), and then steep them in a strong solution of some salt, whose acid has a more powerful affinity for lime than hypochlorous acid; thus a strong solution of sulphate of magnesia may be employed, the sulphuric acid of which, having a strong affinity for lime, combines with the earthy base of the bleaching salt above-mentioned, and forms sulphate of lime, and the chlorocompound being thus liberated unites with the magnesia of the sulphate of magnesia, and forms a new salt (hypochlorite of magnesia), having bleaching properties similar to the lime-salt first employed. " This newly formed compound may be, in the next instance, used as a primary bleaching agent, and may again be subjected to the process of double decomposition, as in the foregoing example. Thus, the goods having been exposed to the action of hypochlorite of magnesia in solution, may then be steeped in a liquid holding in solution some carbonate or other salt, for whose base the hypochlorous acid has a greater affinity than for the magnesia. In such a case, the carbonic acid having also a strong attraction for the magnesia, combines with it, to form a carbonate of that earth, and the liberated chloro-compound, instead of escaping, or remaining so long in contact with the goods as to injure them, combines with the base of the carbonate employed to produce decomposition, and forms a new salt, having bleaching properties. This salt may also be brought under the same laws of double decomposition, as exemplified before, and with similar results. "Thus, if the carbonate employed in the foregoing instance had been carbonate of barytes, and a solution of sulphate of magnesia or of lime were brought into contact with the resulting chloro-compound salt of barytes, a precipitate of the base, as a 782 FLAX. ulphate of barytes, will take place, and the chloro-compounds will unite with the lime or magnesia, to form a bleaching salt. " I would mention, however, that, in bleaching flax, or other like vegetable material for making linen, no compounds should be used which are likely, during their decomposition, to evolve any gaseous matters, such as carbonic acid or chlorine, as, by their development and expansion in the fibrous tubes, the flax, or any similar material, would be rendered not so fit for spinning with the ordinary flax spinning machinery; but in bleaching flax, or any similar material which is to be combined with other materials for spinning and felting, according to my invention, compounds evolving gas may be safely used, as I shall hereafter more fully specify and explain. "For the purpose of bleaching by the method of double decomposition, I do not confine myself to the compounds already mentioned as examples, nor to any particular salts or class of salts; but I claim a right to use salts, which, when placed under the like circumstances, as bef re exemplified in the case of goods treated by the hySochlorite of lime and the sulphate of magnesia, will be subject to the same chemical law of decomposition, and will produce the same result. However, I may particularise as among the salts suitable for decomposing the chloro-compounds, or assisting themselves in the process of bleaching, the carbonates (such as the carbonate or bicarbonate of soda), sulphates (as sulphate of magnesia, &c.), nitrates (as nitrate of soda, &c.), acetates (as acetates of potash and of lead, &c.), prussiates (as prussiates of potash, &c.), chromates (as chromate and bichromate of potash, &c.), tartrates (as tartrate and bitartrate of potash, &c.); but I repeat that I do not confine myself to these, which are merely given as examples. "Another mode of bleaching which I sometimes employ, and which is espec allS applicable to goods composed of both animal and vegetable fibre, is as follows:-I take the goods, after they have been steeped in any of the ordinary bleaching liquors, such as the solution of hypochlorite of lime (chloride of lime), and while they are still wet, expose them to the fumes of sulphur, slowly burning in a suitable chamber or stove. xn this case, I have two powerful bleaching agents at work, viz., the hypochlorite compound, and the sulphurous acid produced by the combustion of the sulphur. A portion of the sulphurous acid combines with the base of the chloro-compound salt, to form a sulphate of lime or magnesia, as the case may be, and a small portion of sulphuric acid may also in this case be formed, which, with the earth or base, would form a sulphate. In this way the chlorine, or chloro-compound, remaining in the wetted goods is liberated, and -allowed to act freely upon the articles to be bleached. In this last method of bleaching I have ascertained that there may be occasionally substituted for the ordinary and known bleaching liquids certain chromates, manganates, and hypermanganates, &c. " Secondly. My improvements in the preparation of materials for spinning and felting have special relation to flax and hemp, and other plants, to which the same may be applicable: and the processes I use to prepare the same, though possessed of some features common to the whole, vary according to the purposes to which the fibre obtained from the said materials is to be applied, that is to say, according as the fibre is required to be long or short, fine or coarse, and the machinery in which it is to be spun is adapted to the spinning of one or other sort of fibre. By the term'fibre,' as used throughout the specification, I mean that portion of each plant which is capable of being spun or felted; and my invention applies to the'fibre' surrounding the stema of dicotyledonous plants, and to that existing in the stems and leaves of monocotyledonous plants. "In the following exemplifications of my improved modes of preparation, I shall throughout suppose flax or hemp to be the material operated upon. " If I have to deal with the plant from the time of its being first cut down or pulled for use, I take it in the state of straw (after the seed had been stripped from it), and subject it to the following, which I call my'primary process':"I first steep the straw in a solution of a caustic alkali of about 1~ of Twaddle's hydrometer, and for such a length of time as may be most convenient. If despatch is required, I use the solution in a boiling state; in which case an immersion of about six hours is sufficient. If more time can be conveniently allowed, I employ a solution of a temperature of about 150~ Fahr., and prolong the immersion for about twelve hours; and so in proportion to the degree of temperature. The solution may be even used at a lower temperature, with a corresponding prolongation of time, but in no case need the immersion exceed a couple of days at the utmost. "The object of the preceding treatment is two-fold:-first to decompose, dissolve, or remove (more or less, as required), the glutinous, gummy, or other matters, which connect the fibre with the woody portions of the plants; and second, to discharge or decompose any oleaginous, colouring, or extraneous matter contained in the straw, with. out allowing the matters so discharged to stain the fibre; and these results are obtained FLAX.'83 by the action of the alkaline solution. In the preceding mode of preparing vegetable materials, I generally use a solution of caustic soda; but other alkaline liquors will answer the purpose,-such as a solution of caustic potash, or of lime dissolved in or diffused in water, or, indeed, any substance having the like power of removing, discharging, or decomposing the colouring, glutinous, gummy, or other foreign matters contained in the straw, and which would interfere with the whiteness of the fibre, or with its ready separation and manufacture. " If the fibre is required to be long, like that now commonly spun in flax machinery, I subject the straw to a second process, for the purpose of getting rid of any of the alkali still adhering to the straw or fibre, and for the purpose of completing (if necessary) the removal of any glutinous, gummy colouring, or extraneous matters. "To this end I will take the straw from the alkaline solution, and steep it for about two hours in water acidulated by sulphuric acid, in the proportion of about one part of the acid to from two to five hundred parts of water. Some other dilute acids will also answer this purpose, such as dilute muriatic acid, &c.; but sulphuric acid is to be preferred. Or, I transfer the straw, while yet wet with the alkaline solution, to a suitable chamber or stove, where I subject it to the action of sulphurous acid, or the fumes produced by the slow combustion of sulphur. In both cases, the acid combines with any free alkali remaining on the straw or fibre, to form a sulphite or sulphate, according to the acid employed; while an excess of either sulphuric or of sulphurous acid will complete the decomposition, discharge, or removal of the glutinous, colouring, and other matters. "I next remove the straw from the acid bath, or sulphur chamber or stove, and wash or otherwise treat it with water, till all soluble matters are removed. "If the fibre is required to be discolorised, the straw may now be exposed to one of the bleaching processes which I have already described, or to any of the other known bleaching processes. It may then be dried, and made ready for breaking and crushing, by the means ordinarily followed in the manufacture of long flax. " I would mention here that, in some cases it will be found advantageous to pass the straw between rollers, or to break it roughly or partially, before subjecting it to the process above described, for the purpose of facilitating the action of the chemical agents upon it. "By the aforesaid method, I am enabled to remove from the straw certain matters, which water alone can discharge. The fibre thus prepared is also freer to heckle, and the straw more easy to scutch, than fibre and straw treated in the ordinary way. Much time and much material are also saved; while the noxious exhalations attendant upon the water-rotting system are wholly prevented. "If the fibre is required to be short, so that it may be felted or carded, and adapted for spinning on cotton, silk, wool, worsted or tow-spinning machinery, either alone or in combination with cotton, hair, fur, silk, or shoddy, I take the fibre, after treating it by the processes just described, and divide it in proper lengths, by some suitable instrument or machine. I then transfer the straw or fibre to a bath containing a strong solution of bicarbonate, or even carbonate of soda, or any other similar compound; but the first two of these are to be preferred, as most abounding in carbonic acid. In this bath I allow it to remain for about three or four hours, during which time the fibre becomes well saturated with the salt. I then immerse the materials, impregnated with the solution of the carbonates before named, for about a couple of hours in water acidulated by sulphuric acid, of about the strength of one part of acid to two hundred parts of water. Or, instead thereof, I expose the saturated materials, while wet, to the action of burning sulphur in a suitable chamber or stove. "In this operation it appears that a certain portion of gas being developed in the fibrous tubes, splits and divides them by its expansive power into filaments, having the character and appearance of fine cotton wool; in which state they may be dyed and manufactured like cotton or wool. "The same means of effecting the splitting of the fibre may of course be employed in the preparation of long fibre, and I do not limit myself to its rise for the preparation of short fibres alone, but when the fibre is of its original length, the solution employed takes a longer time to penetrate the interior. "The decomposition of the bicarbonate of soda or other suitable compound, with which the fibre is saturated, may be also effected by means of electric agency, when a like evolution of gas and splitting up of the fibre will take place. "After the fibre has been subjected to the splitting process, it must be carefully washed to remove all soluble matters, and then dried. "The splitting process may be applied to the plant, either in the straw (the wood of which is to be afterwards removed by proper means and machineryX or in the state of long fibre, whether prepared by my before-described process, or by any of the usual and known processes. "Thirdly, my invention, in so as it relates to improvements in yarns and felta, 784 FLAX. consists in composing the same of the following new combination of materials. 1 manufacture a yarn which I call'flax cotton yarn,' composed partly of flax fibre prepared and cut into short lengths, as aforesaid and partly of cotton, varying the proportions at pleasure. This yarn is much stronger than yarn composed of cotton alone, and also much whiter and more glossy, while it is equally capable of being spun in the ordinary cotton spinning machinery. " I also manufacture yarns composed in like manner, partly of hemp fibre or of jute, or of phormium tenax, or of other like vegetable fibre (china grass excepted), prepared and cut into short lengths, as aforesaid, and partly of cotton, which yarns each possess the same properties (more or less) as the flax-cotton yarn. "I manufacture also a yarn, which I call'flax-wool yarn,' composed partly of flax prepared and cut into short lengths as aforesaid, or of any other like vegetable fibre (cotton and china grass excepted) and partly of wool, or of that description of it called'tschudy,' or partly of fur or hair, or partly of any two or more of the said materials; which yarn is stronger than any yarn composed of wool alone. Some wools also, which are too short to be spun by themselves, may, by being mixed with flax fibre, cut into short lengthsq form a material very suitable for spinning. "I manufacture also a yarn, composed partly of flax or other like vegetable fibre (china grass excepted), prepared and cut into short lengths, as aforesaid, and partly of waste silk, that is, silk of the short lengths in which it exists before reeling, or silk rags cut into short lengths and carded. " Lastly, flax-felts, of a fineness and softness equal to the best felts composed wholly of wool, and superior to them in point of durability, are also produced by a mixture of flax fibre, prepared and cut into short lengths, as aforesaid, with wool, fur, hair or any other feltable material. "And I declare that what I claim, as secured to me by the said letters patent, is as follows:"First,-I claim the method of bleaching by double decomposition, before described, whereby the various bleaching agents and compounds used may be recovered and economised. " Second,-I claim the method of bleaching by the combined action of chlorides, or carbonates, or chromates, or any other bleaching agent, with fumes of sulphur, as before described. "Third,-I claim the preparing of flax and hemp, and of all vegetable fibre capable of being spun or felted, from whatever description of plants obtainable, by steeping the plant from which the fibre is derived, while in the state of straw, stem, leaf, or fibre, first in a solution of caustic soda, or other solution of like properties, and then in a bath of dilute sulphuric or other acid, as before exemplified and described. "Fourth,-I claim the preparing of the said vegetable fibre for spinning in cotton and silk machinery, and for being confined with cotton, wool, raw silk, or other materials of short staple, by firstly steeping the same in a solution of caustic soda, or other solution of like properties. Secondly, steeping them in a bath of dilute sulphuric or other suitable acid, or exposing them to the fumes of sulphur. Thirdly, saturating them with a solution of bicarbonate of soda or any other like agent, and then decomposing such salt, however such decomposition may be effected; and, fourthly, cutting them up into short lengths, all as before exemplified and described. "Fifth,-I claim the employment generally in the preparation of flax, hemp, and other sorts of vegetable fibre, of the mode of splitting by gaseous expansion, as before described, whether the fibre is long or short, and whatever may be the purpose to which the same is to be applied. "Sixth,-I claim the manufacture of yarns and felts from a combination of flax, or like vegetable fibre (china grass excepted), prepared and mixed, as aforesaid, with cotton wool,'tschudy,' silk waste, fur, and hair, all or any of them as before exemplified and described." Another process for treating flax is shortly to be introduced, which is said to surpass that of M. Claussen in its results. This is the patented invention of Mr. Bower, of Hunslet, but as his specification is not yet enrolled, we withhold, for obvious reasons, the details of his plan, and forbear to express any opinion of its practicability. The treatment of flax, in its early stages, is a matter of vast importance to this country; and perhaps there is no one problem throughout our manufactures whose solution would better repay the successful experimenter, than how the facilities for working cotton and wool are to be communicated to flax.-Newton's Journal, October, 1851. Mr. D. F. Bower obtained in March, 1851, a patent for retting and preparing flax, in which he submits the flax, after steeping it for six days in cold or hot water, to the pressure of rollers once and again, with steeping, in order to expel the glutinous matter, and then dries it. Line is treated with dilute water of ammonia, or alkaline saline solution. He also avails himself of the air-pump, along with the above solvents, for the extraction of the gluten by means of hot water. FLAX. 785 With the object of giving the flax grower the means of rendering his produce fit for the market, Mr. M'Pherson, of Edinburgh, has constructed a portable breaking and scutching machine, suitable for a farmstead. It consists of two rectangular wooden cases, of unequal size, connected together side by side, the smaller containing the breaking apparatus, and the larger the parts for scutching the flax. The small case is provided with a horizontal table, having a fluted surface, whereon the flax is laid; and over the table a fluted roller is caused to travel, for the purpose of cracking the boon, or woody portion of the flax plant. The axes or pivots of the roller move in horizontal guides, which can be lifted by depressing a treadle, for the purpose of raising the roller, and the traverse of the roller is effected by its connection, through a rod, with a crank on the end of a short horizontal shaft, which is caused to revolve by horse or other power. The shaft also carries a spur wheel, gearing into a pinion upon another horizontal shaft, that extends through the large case. Upon this second shaft (within the large case) are fixed two discs or bosses, to which four pairs of long radial arms are bolted; and to the outer ends of each pair of arms is fastened a wooden beater, of a L shape, in the transverse section. At the top of the large case two channels are made to receive the clamps, in which the stricks of flax to be scutched are held to receive the blows of the beaters. The flax is first laid upon the fluted table, and submitted to the action of the traversing roller until the boon is broken up and sufIEciently loosened from the fibre; it is then removed, and secured in given quantities between a pair of clamps, in such a manner that one-half the length of the plant is pendent therefrom. Clamps or holders thus filled are successively passed into one of the channels in the large case, and as they are pushed forwards towards the other end of the machine, the stricks of flax are brought under the action of the rotating beater, whereby the pendent portion of the flax is cleared of its boon. When this is effected, the holders are removed from the channels and opened, to turn the end of the flax; the clamps are then again tightened and introduced into the other channel, to bring the other end, in like manner, under the action of the beaters. When the apparatus is in full operation, both channels will be full of holders; and the introduction of a fresh holder at one end is the means whereby a holder, containing a strick of scutched flax, is discharged at the opposite end. This machine, according to the statement of the inventor, is calculated, by the application of from three to four horse power, to clean half an acre of flax per diem. Mr. Plummer, of Newcastle-upon-Tyne, has exhibited machinery, and of a new con struction, for breaking and scutching flax, and for heckling what is technically known as "cut line." The breaker consists of a cast-iron framing, carrying five fluted rolles of similar diameters, and connected together by geering wheels, so that the driving of the axle of one by a band and pulley will cause the other to rotate at the same speed. This machine is provided with two platforms, the one for conducting the flax to the rollers, and the other for guiding it out of the machine. The rollers are so arranged as to bite the flax three times during its passage through the machine; and the top rollers are weighted, for insuring a proper amount of pressure being put upon the flax. The scutching machine consists of a rotary vertical disc inclosed in a casing, and carried by an axle working in suitable bearing, supported by the frame of the machine. On each side of the disc radial beaters, or wooden knives, having a bevelled edge on their inner face, are fixed; but on one side of the disc the beaters are alternated by radial brushes, the object being to submit the flax, first to the action of the beaters only, and then to effect tl a more thorough separation of the boon from the fibre by the combined action of brushes and a second set of beaters. An opening is formed in the front of the case through which the flax is introduced by hand to the action of the beaters. When one end is cleaned, the operator turns ends, and again submits the flax to the scutching operation. By the use of a solid disc in place of radial arms (as hitherto used) for carrying the beaters, it would seem that greater speed than hitherto applied may be used without the risk of breaking the staple, as the objection presented by the arms, of causing the flax to lash round them, and thereby get broken when working at great speed, is necessarily avoided. The next stage of treating flax is to subject it to the action of the heckling machine, whereby the flax is combed out, and its fibres are subdivided to the extent required; the short entangled fibres being at the same time removed from the more valuable staple. The extent to which the separation is carried is to produce a yield of only from 50 to 80 lbs. of "dressed line," as the more valuable staple is termed, out of 112 lbs. of scutched flax, the remainder constituting the raw material known as tow, which in general goes to form an inferior description of yarn. If the flax is intended to be spun to a fine quality of yarn, or a "high number," it is cut into two, three, or more lengths, before being submitted to the heckling machine; the coarser parts of the staple, that is. the extremities, being separated from the others, t(, form a medium 51 786 FLAX. quantity of yarn, while the middle portions are selected for conversion into fine yarn. The action of the heckling machine, as far as the operation itself is concerned, is the same whether the long or short staple be heckled; but, to effect the operation economically, that is, without making an undue amount of tow, different constructions of machines are preferred for dressing the long and the cut lihe. For heckling the latter kind of staple, Mr. Plummer exhibited a machine embracing some novel points deserving of notice. It is of that class of machines which have two heckle cylinders revolving in opposite directions, and dressing both sides of the strick of flax simultaneously, but which have hitherto met with very partial success, as the cost with which they work scarcely compensates for the waste of material they occasion, from the fact of two sets of heckles entering the strick simultaneously, and tearing through it without the power of yielding to the entangled or interlocked fibres. Now, in order to remedy this evil in part, one of the cylinders is mounted on sliding bearings; so that each strick of flax, on being first presented to the heckle-pins, will be partially combed by the cylinder, which is mounted in stationary bearings, before the traversing cylinder approaches to act upon the strick. These cylinders are furnished with three grades of heckle-pins, and the rows on the first, or coarsest set, are alternated by rows of brushes. The motion for traversing the holders, containing the stricks of flax through the machine, is somewhat novel and ingenious. Mounted near one end of the holder trough (which receives its up-and-down motion for bringing the length of stricks gradually under the operation of the heckle cylinders by the ordinary arrangements of mechanism):s a short axle, which carries three pinions, two of which take into vertical racks, attached to the end framing; and the central pinion geers into a rack formed on a horizontal reciprocating bar, carried by the trough, and provided with loose penc*nt fingers. As the trough ascends to take in a fresh holder, the pinions, working on the fixed vertical racks, are rotated, and thus the central pinion is made to draw forward its rack with the sliding rod; by which means the pendent fingers are brought in contact with the holders, and caused to propel them forward. On the descent of the trough, the reverse action takes place; and the reciprocating bar being slidden back, the fingers, which are hinged so as to pass back over the holders, are brought to a proper position for propelling them forward on the next ascent of the trough; this reciprocating bar is common to many heckling machines, but the mode of actuating it appears to us to be both new and simple. On the ascent of the trough to receive another holder, and discharge at the same time a holder of heckled flax, the traversing cylinder is caused to retire by a simple mechanical contrivance, and thus allow of the strick of flax just received into the machine, as well as those, which, in consequence, have been shifted forward to a finer set of heckle pins, to be brought, first under the action of the heckle cylinder, which works in stationary bearings, and then under the action of the pins of the traversing cylinder, as before explained; the ascent of the trough being made the means of driving back the cylinder, and its descent allowing of its moving forward to operate upon the flax. The heckle cylinders are cleaned as usual by rotating brushes; and an endless band of lattice-work is provided for gathering the tow into a proper receptacle. Whether or no this machine is destined to take a permanent place in our flax manufactories, a mere inspection of it in its quiescent state is not sufficient to enable us to judge: as regards compactness, it has greatly the advantage of the double cylinder machines of Messrs. Lawson & Sons, of Leeds, whose cont:ibution we shall next notice; but we can give no opinion of their relative merits in other respects. This firm has made by far the largest display of flax machinery; and, indeed, the credit is mainly due to them that the Great Exhibition has represented this important branch of our manufactures. Their contribution may be briefly stated to have included a complete set of machinery for heckling, spreading, drawing, and roving long and cut flax; also for carding, drawing, and roving tow; for spinning coarse and fine flax yarn; and likewise for manufacturing thread. For treating short flax, a pair of cylinder heckling machines were exhibited. The cylinders, instead of being set abreast of each other, and acting simultaneously on the flax, are mounted in a line, and revolve in opposite directions, so that the flax is dressed, first on one side by one cylinder, and then on the opposite side by the other cylinder. The objection to this arrangement is, as before indicated, the want of compactness; as machines working on this principle are required to be double the length of those which turn the strick and heckle both sides on the same heckle-pins, or heckle it simultaneously on both sides. To remedy this objection, however, Messrs. Lawson apply two troughs to the machine, and are thus enabled to submit two rows of stricks to the action'of the same rotating heckle cylinder. The mode of traversing tie flax holders through the machine is analogous to that described in reference to Mr. Plummer's machine, and therefore need not to be repeated. The cylinders are furnished with two grades of heckle-pins; and between each row, rising gnd falling plates (which take their motion from excentrics) are fitted for the purpose FLAX.'787 of determining the depth that the heckle-pins shall enter the stricks. Between the rows of the finer grade of heckles, small flat brushes being set in one edge of the rising and falling plates form a sort of bed for the flax to lie on while under the action of the heckles. The stricks, in passing over one cylinder, are heckled on one side; they are then brought under the action of the second cylinder, which, revolving in an opposite direction, will finish the other side of the strick. The machine exhibited by this firm for operating upon long fibres is provided with two endless bands of heckles, set side by side, and arranged so as to present an inclined surface to the flax. These bands are set at opposite inclines, and revolve in different directions, for the purpose of operating upon different sides of the stricks of flax. These are the only arrangements of heckling and machinery which the Exhibition contained. It must, therefore, be considered as very deficient in this respect, as the rival inventions of Messrs. Marsden, of Manchester, and Messrs. Combe, of Belfast, for turning the stricks of flax, and causing them to be operated upon on both sides by the same cylinder (which have recently been the cause of so much litigation) are unrepresented. So also is a still more recent improvement of Messrs. Combe, for heckling both sides of the strick without turning, by the use of but one cylinder. In this machine (which we have had recently an opportunity of seeing in action at Belfast) the means of operating on both sides of the strick is obtained by merely reversing the direction of rotation of the cylinder, while the trough is ascending to take in a fresh holder. Another arrangement of a promising character, for passing once through the machine, has recently been devised by Messrs. Harding, Cocker, & Co., of Lille; but as this machine was not included in their contribution to the Exhibition, we conclude that it is not yet brought into the market. The flax, after leaving the heckling machine, is slightly combed by hand, and sorted into parcels, according to the quality of the staple; it is then packed away in a cool, dry, dark room, and by lying there for a few months its quality is said to improve. When the flax is taken from the "dressed line store," it is subjected to the action of the following machines, for the purpose of converting it into yarn, viz.; 1. The first drawing frame, or spreader, the use of which is to convert the flax, as delivered from the heckling machine, into a continuous sliver or band of filaments; 2. The second drawing frame, by which the sliver is attenuated; 3. The third drawing frame, whereby several slivers from the second drawing frame are united together and redrawn, to obtain a finer sliver, with greater regularity of fibre; 4. The roving frame, which further elongates the sliver, and converts it into a spongy cord or roving; 5. The throstle frame, which extends the spongy or loose roving, and spins it into yarn. The flax drawing frame is very different in construction to that formerly described as employed for drawing cotton, although the action is precisely analogous. Its constructions and mode of operation may be thus briefly described: at the back of the machine is an endless travelling feedcloth, on which the stricks of flax are laid, so as to overlap each other, and which carries the flax to what are termed the back holding rollers. In front of these rollers, and arranged parallel thereto, is a series of "gills" or straight bars furnished with hecklepins, whose office is to receive the flax as it is delivered from between the holdingrollers, and carry it forward to the drawing-rollers. These gills are supported and traversed by their extremities, taken into the threads of two screw shafts, set at right angles to the holding rollers, which shafts, as they rotate, carry the gills forward. When they have arrived at the end of the shaft they severally fall, and are received by a pair of screw shafts below, having a quicker thread, which carry them back to the holding rollers, and a sweep, on the end of these shafts, lifts the gills up again into geer with the upper screw shafts. Thus an endless chain, as it were, of gills is provided, which, having a somewhat greater speed than the holding rollers, combs the flax straight and delivers it with perfectly parallel fibres to the drawing rollers. By these the sliver is drawn to the requisite fineness, and then, passing between a pair of calendering rollers, it is delivered to a can. The cans of sliver, thus produced, are now set up behind the second drawing frame, to undergo the second operation. This frame, and also the third, are similar in construction to the first; the only difference being, that they are fed from cans instead of by a cloth; and as the progress of drawing out the sliver advances, the size of the working parts are required to be less, and the fineness of the gills to be increased. The operation of drawing is the same in all cases; but in the second and third frames, the sliver is doubled, to give it an evenness, or structural equality, as it is elongated. Messrs. Lawson have exhibited screw gill spreaders (as the first drawing frame is termed) for both long and cut flax; also gill frames for completing the drawing of the long and short fibre, but further than being well made machines, they present no points for comment. Messrs. Higgins & Sons have also exhibited a screw gill spreader and a second drawing frame for long lines. In the former of these Ilachines the front top rollers are weighted by an arrangement of compound levers, which is said to have the advantage '788 FLAX. of convenience over the ordinary plan; and in the latter, the roller and gills are driven at the middle instead of the side of the machine; thus relieving the rollers of a great portion of the strain to which they are ordinarily exposed, and permitting of the use of smaller rollers, which, for some descriptions of work, is considered of importance. The sliver, as it is delivered into cans from the third drawing frame, is taken to the roving frame to be still further reduced and wrought into a loose thread; but as this operation is precisely similar, whether for long line, cut line, or tow, it may be well to explain briefly the means of bringing tow to a proper state for undergoing the first spinning process before spehking of the roving frame. The tow, which we have said is the short and irregular fibres combed out of the strick of flax by the heckling machine, is subjected to the action of a carding engine, somewhat similar in construction to that used for carding cotton. It consists principally of a large central cylinder, covered with wires, cards, and surrounded by card rollers termed " workers " and " strippers," revolving in contact therewith. The tow is carried into the machine by an endless travelling cloth, which delivers it to a pair of feed rollers, situate below the main cylinder, whereby it is transferred to the large cylinder. By this it is brought under the action of the workers, when combed or carded; and it is then stripped or " doffed " from the cylinder by card rollers, which in their return are relieved of the staple by doffer combs; these take it off in the form of a sliver, and it is eventually delivered from the machine by delivering rollers into cans. In order to prevent the liability of the sliver breaking by being pressed down into the cans, and also to avoid the necessity of using a separate machine for performing the first drawing operation, it has lately been the practice to apply one or more gill-drawing heads to the carding engine, according to the number of strippers employed and slivers produced, and carry on the carding and the first drawing processes simultaneously. This arrangement, patented by Messrs. Fairbairn & Co., was applied to Messrs. Lawson & Son's carding engine. It is provided with three strippers, which are capable (by being set at different distances from the main cylinder) of taking off different lengths of staple from the card surface, and thereby sorting out or dividing the qualities of the tow. In this machine, however, there is but one gill-head; all the slivers, therefore, are united in the first drawing process, and form together a continuous sliver; the completion of the operation of drawing tow is precisely similar to that already described with reference to long and cut line. To obtain a flax roving, it is usual,.after drawing the sliver to the required amount, to put in its slight twist. Messrs. Higgins exhibited a roving frame with six heads and sixty spindles, for producing roving of this kind. This roving frame is, in fact, to de scribe it shortly, a drawing frame, with the addition of spindles; the gills and roller? being driven according to their improved plan, before noticed. The roving frame for cut flax exhibited by Messrs. Lawson, is intended to produce a roving without twist, which, for obtaining fine qualities of yarn, is very desirable; the gummy matter in the flax is here taken advantage of to give the roving the necessary cohesive property. A correct notion of the construction of this roving frame may be best conveyed by tracing the progress of the sliver through the machine. The sliver passes from the can over a pulley through fixed guides over travelling gills, between a pair of drawing rollers, then into a trough containing hot water (for the purpose of dis. solving the gummy matter in the flax), then over a heated cylinder which dries the staple, and finally it is wound on to a bobbin, which rests upon and turns in contact with a horizontal fluted roller. Rovings thus produced are capable, it is said, of being drawn to almost any degree of fineness, with little reference to the material; because one fibre can be glued to another; at any portion of its length a roving can be made. Messrs. Lawson also contributed machinery for wet and dry spinning, viz., a dry tow spinning frame, with 100 spindles; a fine spinning frame for spinning the roving through cold water; a double water frame, with 136 spindles; and a double twisting frame with 96 spindles. The only noticeable novelty in these machines (the construction of which will be understood from the description already given of cotton spinning machinery) is a new tape motion for driving the spindles. A spinning frame, by Messrs. Higgins, containing 144 spindles was also exhibited; but further than being a specimen of good design and workmanship, it calls for no special remark. Retting of 7Flax.-Mr. Watt's system of flax retting may be briefly described as follows:-The flax straw is delivered at the works by the grower, in a dry state, with the seed on. The seed is separated by metal rollers, and afterwards cleaned by fanners. The straw is then placed in close chambers, with the exception of two doors, which serve the purpose of putting in and discharging the straw. The top, which is of cast iron, serves the double purpose of a top and condenser. The straw is then laid on a perforated false bottom of iron, and the doors being closed, and made tight by means of screws, steam is driven in by a pipe round the chambers, and between the bottoms; and, penetrating the mass, at first removes certain volatile oils contained in the plant, and afterwards is condensed on the bottcm of the iron tank, and descends as a continuous shower of condensed water, saturating the straw. This water is a decoction of extractive matter, to which attach the fibrous and more porous portions. This liquor is run off from time to time, the more concentrated portions being used for feeding. FLAX.'-78 The process is shortened by using a pump, or such an arrangement as rapidly washes the mass, with the water allowed to accumulate. In about eight or twelve hours. varying with the nature of the straw, it is removed from the chambers, and, having been robbed of its extractive matter, it is then passed through the rollers for the purpose of removing the epidermis, or skin of the plant, and of discharging the greater part of the water contained in the saturated straw, and while in the wet and swollen state, splitting it up longitudinally. The straw then (being free of all products of decomposition) is easily dried, and in a few hours ready for scutching. In the experimental trial, personally superintended, throughout all its details, by the Committee, a quantity of flax straw, of ordinary quality, was taken from the bulk of the stock at the works, weighing 13 cwts. with the seed on. After the removal of the seed, which, on being cleaned thoroughly from the chaff, measured 38 Imperial bush., the straw was reduced in weight to 10 cwt. 1 qr. 21 lbs. It was then placed in the vat, where it was subjected to the steaming process for about eleven hours. After steeping, wet-rolling, and drying, it weighed 7 cwt. 0 qrs. 11 lbs.; and, on being scutched, the yield was 187 lbs. of flax; and of scutching tow, 12 lbs. 6+ ozs. fine, and 35 lbs. 3 ozs. coarse. The yield of fibre, in the state of good flax, was, therefore, at the rate of 13+ lbs. from the cwt. of straw with seed on; 18 lbs. from the cwt. of straw without seed; 261 lbs. from the cwt. of steeped and dried straw. The time occupied in actual labour, in the processes, from the seeding of the flax to the commencement of the scutching, was 13 hours, to which, if 11 hours be added for the time the flax was in the vat, 24 hours would be the time required up to this point. The scutching, by four stands, occupied six hours sixteen minutes. But, in this statement, the time required for drying is not included, as, owing to some derangement in the apparatus, no certain estimate could be made of the actual time required in that process. It would appear, however, that about thirty-six hours would include the time necessary, in a well-organized establishment, to convert flax straw into fibre for the spinner. The cost of all these operations, in this experiment, leaving out the drying, for the reasons noted, appeared to be under 101. per ton of clean fibre, for labour, exclusive of general expenses. A portion of the fibre was sent to two spinning-mills to be hackled, and to have a value put upon it. The valuation of the samples varied from 561. to 701. per ton, according to the quality of the stricks of fibre sent, and the yield on the hackle was considered quite satisfactory. On the results of this experiment, which was necessarily of a limited nature, the Committee think it best to offer no general remarks. They are sufficiently favourable to speak for themselves. It remains to be ascertained whether the qualities of flax fibre prepared by this method are such as to suit the spinner and manufacturer. They have been informed, by a spinner who has been trying some flax prepared by Mr. Watt's system, that the yarn made from it appears equal in all respects to what is ordinarily spun from good Irish flax, of the finer sorts. They believe that, before long, information will be given by several individuals who are about to carry out more extended trials on the spinning and manufacturing departments. The Committee conceive that the most prominent and novel feature of this plar. consists in the substitution of maceration, or softening, for fermentation. In the steep ing of flax, both by cold and hot water, the fibre is freed from the substance termed gum, by the decomposition of the latter, while in Watt's system the maceration of the stems loosens the cuticle and gum, which are further separated mechanically in the crushing operation, and, after the drying of the straw, readily part with the wood, under the action of the scutch-mill. Before concluding this statement, the Committee wish to call attention to a very curious feature in Mr. Watt's invention. The water from the vats, in place of being offensive and noxious, as is the case with ordinary steep water, contains a certain amount of nutritive matter. This arises from its being an infusion of the flax stems, in place of holding in suspension or solution the products of the decomposition of the gum, and other substances contained in the stems. The inventor is now employing this water, along with the chaff of the seed-bolls, for feeding pigs. It is of much interest, therefore, to note in how far this may be found practically to answer, as, between the seed, the chaff, and the water, by far the greatest portion of what the flax plant abstracts from the soil, would thus be returned in the shape of manure. However this may turn out, the avoidance of all nuisance in smell, and of the poisonous liquid which causes some damage among fish when let off into rivers, is a matter of some consequence, Appended to this report is a note of the time occupied in the different processes during the experiment, and of the number of persons employed in each. It is to be hoped that so promising a plan may, on more extended experience, be found fully to warrant the high anticipations formed from what is already known concerning it. (Signed on behalf of the Committee), RICHARD NIVEN, Chairmar. t4eitast. Sd Nov.. 1852 190 FLAX, APPENDIX; Note of the time )ccupied, and of the number of persons employed in each of the processes witnessed by the Committee, c-n the experimental trial of Mr. Watt's system of preparing flax fibre:No. of persons employed. Time occupied. Men. Women and Boys. Hours. Minutes. Seeding, - - - - 4 8 1 15 Placing in Vat, - - - - 3 4 0 15 Cleaning Seed, - - - - 1 0 3 0 Taking out of Vat, - - - 2 3 0 30 Wet-rolling and putting in Drying Room, - - - 1 16 2 20 Rolling for Scutching, - - 0 11 1 8 Stricking for do., - - 0 7 4 47 Total, 11 49 13 15 Scutching, - - - - 4 0 6 16 Cultivation of Flax in Flanders.-There is a very fine long variety of flax which is cultivated in the'neighbourhood of Courtray, in Flanders; it requires a very good soil to grow in, and the stem is so long and slender, that, if it were not supported, the least wind would break it and lay it flat, in which case, the quality of the flax would be much impaired and the quantity reduced. To prevent this, short stakes are driven into the ground in a straight line, at 8 or 10 feet from each other, and long slender rods are tied to them with oziers, about 1 foot or 18 inches from the ground, forming a slight railing to support the flax; a number of these are placed in the same manner at a short distance from each other in parallel lines all over the field, and the flax is thus prevented from being beat down. A better method, which is not commonly adopted, is to have stakes in regular rows, and thin ropes tied to them, instead of rods; by having these lengthwise and others across them at right angles, a kind of large net is spread over the whole field, and none of the flax can possibly be laid flat. By using cheap rope, or strong tar-twine from old cables, the expense is not very great, and much less room is taken up than by the rods. When the flax is pulled, the stakes are taken up, and removed to a dry place till they are wanted again. The most common variety of flax is of a moderate length, with a stronger stem; if it is not sown very thick it will throw out branches at top and produce much seed; it is therefore a matter of calculation whether it will be most profitable to have finer flax with less seed, or an inferior quality with an abundance of seed. There is a small variety which does not rise above a foot, grows fast, and ripens its seed sooner. When linseed is the principal object, this variety is preferred; but the flax is shorter, and also coarser. Another variety of flax has a perennial root, and shoots out stems to a considerable height. It came originally from Siberia, and, was much recommended at one time, but its cultivation did not spread. If it were sown in wide rows, and kept free from weeds by hoeing, it might, perhaps, be profitably cultivated for the seed; and if the flax is inferior in quality, it might still be of some value for coarse manufactures; it requires, however, to be renewed every three or four years and sown in fresh ground. The soil best adapted to the growth of flax is a deep rich loam, in which there is much humus, or vegetable mould. It should be mellow and loose to a considerable depth, with a sound bottom, neither too dry nor too moist; either extreme infallibly destroys the flax; it is therefore not suited either to hot gravelly soils or cold wet clays, but any other soil may be so tilled and prepared as to produce good flax. It thrives well in the rich alluvial land of Zealand and the Polders, but it is also raised with great success in the light san!s of Flanders, but much more careful tillage and manuring are required. The land on which flax is sown must be very free from weeds, the weeding of this crop being a very important part of the expense of cultivation. These circumstances suggest the best mode of preparing the land. A long fallow, such as is some times given to the land in Essex, including two winters and a summer, may be a good preparation on the heavier loams, which should be trenched, plougled, and worked deep; the manure should be dung fully rotten, or a compost of earth and dung; it should be put on the land in autumn, and well incorporated before the seed is sown. If the land is sufficiently clean, a crop of potatoes well manured may be substituted with advantage for the fallow; but at least double the usual quantity of dung should be given to this crop, that enough may remain in the ground for the flax. Lime may be used if the soil contains a great portion of clay; but in the lighter loams there is some doubt of its advantage for flax. At all events it should not be used immediately before the flax is sown, but for some previous crop. Peat-ashes are excellent; they improve the soil and keep off insects, which are apt to injure the roots of the flax. For want of peat-ashes, those made by the burning of weeds and earth in a smothered fire are a good substitute. But the most effective manure is the sweepings of the streets in towns, mixed with the emptying of privies, and the cleaning out of the butchers' stalls and shambles. On lilrht soils much manure i. Plquired: and where night-soil cannot be obtained in FLAX.'791 sufficient quantities, rape-cakes, from which the oil has been expressed, dissolved in cow's urine, form the best manure. In many parts of Flanders, 500 rape-cakes are used for every acre of flax, besides the usual quantity of Dutch ashes and of liquid manure, which is the drainigs of dunghills, and the urine of cattle collected in a cistern, and allowed to become putrid. In southern climates flax is sown before winter, because too great heat would destroy it. It is then pulled before the heat of summer. In northern climates the frost, and especially the alternations of frost and thaw, in the early part of spring, would cause the flax to perish; it is, consequently, sown as early in spring as may be, so as to avoid the effect of hard fiost. This is in March or April, in Great Britain and Ireland, and in Holland and Flanders. In no country is the ground better prepared for the growth of flax than in Flanders; and it may, therefore, be interesting to follow the whole process of Flemish cultivation for several crops, preparatory to that of flax, which is the most important produce in that country, and that which, when well managed, gives the greatest profit to the farmer. The best flax grows near Courtray. The soil is a good deep loam, rather light than heavy. It is not naturally so rich as the soil of the Polders in Flanders and Zealand, but the tillage and cultivation are far more perfect, and the produce, if not more abundant, is of a finer quality. Every preceding crop has a reference to the flax, and is so cultivated as to improve the texture of the soil, which is abundantly manured, in order to leave a considerable surplus in the ground. If the land has not been trenched all over with the spade, to the depth of 18 or 20 inches, it has been equally well stirred by the narrow open drains, which are dug out 12 or 15 inches deep every year, between the stitches, in which it is laid by the plough. These drains or water furrows are a foot wide, and from a foot to 18 inches deep. The earth taken out of them is spread evenly over the land after the corn is sown. When the ground is ploughed again, care is taken that the place of these water-furrows shall be shifted a foot on each side. Thus, in six years, the whole soil is deepened and thoroughly mixed with whatever manure has been put on. This produces the same effect as trenching, and even more perfectly. The whole of the land in which the best flax grows has been so treated for several generations, and may be looked upon as a species of compost 18 inches deep. Potatoes or colza are usually planted with a double portion of manure, after which wheat is sown, slightly manured; then rye with turnips sown the same year, after the rye. These are taken up in September or October, and stored for winter use. The land has been well weeded while the turnips were growing, and all the manure is decomposed and mixed with the soil. It is ploughed in stitches before winter, some manure having being previously spread over it if necessary: and it is left to the mellowing effects of frost and snow. As soon as the winter is over, and the snow is melted, the final preparation goes on. Deep ploughing and harrowing further divide and pulverize it; the surface is laid as level and as smooth as possible; and if there is no fear of too much wet, which in this light loam soon disappears, the whole is laid flat and level as a bowling-green, or else divided into beds, with water-furrows between them. On this the liquid manure is poured out, and the Dutch ashes spread, if any are used, or the rape-cakes, as mentioned before. The harrows are drawn over the land, and it is left so a few days, that the manure may sink in. It is then again harrowed, and the linseed is sown broadcast by hand, very thick, and even about 1~ cwt. to the acre. A bush harrow or a hurdle is drawn over, merely to cover the seed, which would not vegetate were it buried half an inch deep. According to the state of the land, it is rolled or not, or the seed is trodden in by men, as is done with fine seeds in gardens. This is only in the lightest soils. Most commonly the trainean is drawn over the lan This is a wooden frame with boards nailed closely over it, which is drawn flat over the ground, to level and gently press it. In a short time the plants of flax come up thick and evenly, and with them also some weeds. As soon as the flax is a few inches high, the weeds are carefully taken out by women and children, who do this work on their hands and knees, both to see the weeds better, and not to hurt the flax with their feet. They tie pieces of coarse flax round their knees, and creep on with their face to the wind if possible. This is done that the tender flax which has been bent down by creeping over it, may be assisted by the wind in rising. This shows what minute circumstances are attended to by this industrious people. The weeding is repeated till the flax is too high to allow of it. The seed which is used is generally obtained from Riga, it being found that the flax raised from home-grown seed is inferior after the first year. But many intelligent men maintain that if a piece of ground were sown thin with linseed, so that the flax could rise with a strong stem and branch out, and if the seed were allowed to ripen, the Flemish seed would be as good as that from Riga; but it still remains to be proved whether it would be cheaper to raise it or to import it. When the flax begins to get yellow at the bottom of the stem, it is time to pull it, if very fine flax is desired, such as is made into thread for lace or fine cambric; but then the seed will be of little or no value. It is therefore generally left standing until the capsules which contain the seed are fully grown, and the seed formed. Every lax 792 FLAX. growerjudges for himself what is most profitable on the whole. The pulling then begin, which is done carefully by small handfuls at a time. These are laid upon the ground tc dry, two and two obliquely across each other. Fine weather is essential to this part of the operation. Soon after this they are collected in the larger bundles, and placed with the root end to the ground, the bundles being slightly tied near the seed end; the other end is spread out that the air may not have access, and the rain may not damage the flax. When sufficiently dry they are tied more firmly in the middle, and stacked in long narrow stacks on the ground. These stacks are built as wide as the bundles are long, and about 8 or 9 feet high. The length depends on the crop: they are seldom made above 20 or 30 feet long. If the field is extensive, several of these stacks are formed at regular distances; they are carefully thatched at top, and the ends, which are quite perpendicular, are kept up by means of two strong poles driven perpendicularly into the ground. These stacks look from a distance like short mud walls, such as are seen in Devonshire. This is the method adopted by those who defer the steeping till another season. Some carry the flax as soon as it is dry under a shed, and take off the capsules with the seed by rippling, which is drawing the flax through an iron comb fixed in a block.of wood; the capsules which are too large to pass between the teeth of the comb are thus broken off and fall into a basket or cloth below. Sometimes, if the capsules are brittle, the seed is beaten out by means of a flat wooden bat, like a small cricket bat. The bundles are held by the root end, and the other end is laid on a board and turned round with the left hand while the right with the bat breaks the capsules, and the linseed falls on a cloth below. The flax may then be immediately steeped: but the most experienced flax-steepers defer this operation till the next season. In this case it is put in barns, and the seed is beat out at leisure in winter. When flax is housed, care must be taken that it be thoroughly dry; and if the seed is left on, which is an advantage to it, mice must be guarded against, for they are very fond of linseed, and would soon take away a good share of the profits by their depredations. Steeping the flax is a very important process which requires experience and skill to do it properly. The quantity and colour depend much on the mode of steeping, and the strength of the fibre may be injured by an injurious mode of performing this operation. The object of steeping is to separate the bark from the woody part of the stem, by dissolving a glutinous matter which causes it to adhere, and also destroying some minute vessels which are interwoven with the longitudinal fibres, and keep them together in a kind of web. A certain fermentation or incipient putrefaction is excited by the steeping, which must be carefully watched and stopped at the right time. The usual mode of steeping is to place the bundles of flax horizontally in the shallow pool or ditches of stagnant water, keeping them under water by means of poles or boards with stones or weights laid upon them. Water nearly putrid was supposed the most efficacious; and the mud is often laid over the flax to accelerate the decomposition, but this has been found to stain the flax, so that it was very difficult to bleach it or the linen made from it afterwards. The method adopted by the steepers of Courtray, where steeping flax is a distinct trade, is different. The bundles of flax are placed alternately with the seeed end of the one to the root end of the other, the latter projecting a few inches; as many of these are tied together near both ends as form a thick bundle about a foot in diameter. A frame made of oak-rails nailed to strong upright pieces in the form of a box 10 feet square and 4 deep, is filled with these bundles set upright and closely packed. The whole is then immersed in the river, boards loaded with stones being placed upon the flax till the whole is sunk a little under the surface of the water. The bottom does not reach the ground, so that the water flows over and under it. There are posts driven in the river, to keep ths box in its place, and each steeper has a certain portion of the bank, which is a valuable Property. The flax takes somewhat longer time in steeping in this manner thap,,it does in stagnant or putrid water, and it is asserted by those who adhere to the old method that the flax loses more weight; but the colour is so much finer, that flax is sent to be steeped in the Lys from every part of Flanders. When it is supposed that the flax is nearly steeped sufficiently, which depends on the temperature of the air, the flax being sooner steeped in warm weather than in cold, it is examined carefully every day, and towards the latter part of the time several times in the day, in order to ascertain whether the fibres really separate from the wood the whole length of the stem. As soon as this is the case the flax is taken out of the water: even a few hours more or less than is necessary will make a difference in the value of the flax. If it is not steeped enough, it will not be easily scutched, and the wood will adhere to it. If it has been too long in the water, its strength is diminished and more of it breaks into tow. The bundles are now untied, and the flax is spread evenly in rows slightly overlapping each other on a piece of clean smooth grass which has been mown or fed off close. Fine weather is essential to this part of the process, as rain would now much injure the flax. It is occasionally turned over, which is done dexterously by pushing a long slender rod under the rows, and taking up the flax near the end which overlaps the next row and turning it quite over. Thus, when it is all turned, it overlaps as before, but in the contrary direction. It remains spread out upon the grass for a fortnight, more or less according to the seasor, till the woody part becomes brittle, and some of the finest fibres FLAX. 793 separate from it of their own accord. It is then taken uI,, and as soon as it is quite dry it is tied up again in bundles, and carried into a barn to be broken and heckled at leisure during the winter. The total annual production of flax in Belgium amounts, by a recent estimation, to about forty millions of pounds. Its total value is calculated at about two millions and a half sterling. This flax is of very superior quality, and is principally employed in the manufacture of the finest. class of fabrics. Attempts are being now made on a large scale to cultivate this important plant in England and Ireland. Belgium exports about five millions of pounds of flax to England. That flax grown in the Courtray district is universally considered to be of the finest quality. FLAX WEAVING LooM.-A A A, Fig. 648., frame of loom; B, beam on which the yarn for warp is wound; c cloth receiving beam; D driving pulleys and fly-wheel; E hand 647 rail for supporting the reed; F swords of supports of going part; a picking sticks lot driving the shuttle; a leather straps for connecting the picking sticks with their actuating levers L; M, N, jaws of a clamp to cause the retaining friction on the collars of the beam B, by which friction the quantity of weft is regulated; o end of lever, bearing the weight by wvch the jaws are brought together; P, lever, keyed at one end to the upright shaft Q, and connected with the other to the fulcrum of the weighted lever o; a lever, one end of which is also keyed to the upright shaft Q, and the other is provided with a wood sole, and is pressed by a strong spring against the yarn wound upon the beam B. It will be seen that, as the yarn is taken off the beam B, and its diameter consequently reduced, the lever r moves the fulcrum of the weighted lever o, and thus regulates the pressure upon the clamps M and N, causing an equal tension upon the yarn from the full to the empty beam; a treddles, actuated by the cams b, driven by the wheels c, d, e, from the picking shaftf; g, g shuttle boxes at each end of the going part; h, h arrangement of levers to conduct equally each end of the geers S, i. This loom has also, in addition to the ordinary stopping arrangement connected with the shuttle, one also for relaxing the reed in case the shuttle should be arrested in its course across the warp, whereby the danger, ordinarily incurred by that accident, of breaking many threads in the warp, is avoided; it will also be seen that the bands called picking bands are superseded by the ends of the picking levers striking the shuttle direct; thus, by these improvements, drills are currently woven in this loom at the rate of 120 to 130 picks per minute. 1850 1851 Imports of flax and tow, or codilla of hemp and flax - - - cwts. 1,822,918 1,194,184 Linen yarn exported - - - - bs. 18,220,688 18,518,273 Linen manufactures exported (including linen yarn, S81,3121. and 935,9391.) declared value - ~ 4,839,779 5,053,792 794 FLINT. 648 FLINT. (Pierre a fusil, Fr.; Feuerstein, Germ.) The fracture of this fossil is perfectly conchoidal, sometimes glossy, and sometimes dull on the surface. It is very hard, but breaks easily, and affords very sharp-edged splintery fragments; whence it is a stone which strikes most copious sparks with steel. It is feebly translucid, has so fine and homogeneous a texture as to bear polishing, but possesses little lustre. Its colours are very various, but never vivid. The blackish-brown flint is that usually found in the white chalk. It is nearly black and opaque, loses its colour in the fire, and becomes grayish-white, and perfectly opaque. Flints occur almost always in nodules or tubercular concretions of various and very irregular forms. These nodules, distributed in strata among the chalk, alongside of one another and almost in contact, form extensive beds; interrupted, indeed, by a multitude of void spaces, so as to present, if freed from the earthy matter in which they are imbedded, a species of network with meshes, very irregular both in form and dimension. The nodules of silex, especially those found in the chalk, are not always homogeneous and solid. Sometimes there is remarked an organic Torm towards their centre, as a madrepore or a shell, which seems to have served as their nucleus; occasionally the centre is hollow, and its sides are studded over with crystals of quartz, carbonate of iron, pyrites, concretionary silex or calcedony, filled with pulverulent silica nearly pure, or silex mixed with sulphur; a very singular circumstance. Flints are observed to be generally humid when broken immediately after being dug out of the ground; a property which disappears after a short exposure to the air. When dried they become more brittle and more splintery, and sometimes their surfaces get covered at old fractures with a thin film or crust of opaque silex. Flints calcined and ground to a powder enter into the composition of all sorts of fine pottery ware. The next important application of this siliceous substance is in the formation of gunflints, for which purpose it must be cut in a peculiar manner. The following characters distinguish good flint nodules from such as are less fit for being manufactured. The best are somewhat convex, approaching to globular; those which are very irregular, knobbed, branched and tuberose, are generally full of imperfection. Good nodules seldom weigh more than 20 pounds; when less than 2, they are not worth the working. They should have a greasy lustre, and be particularly smooth and fine grained. The colour may vary from honey-yellow to blackish-brown, but it should be uniform throughout the lump, and the translucency should be so great as to render letters legible through a slice about one-fiftieth of an inch thick, laid down upon the paper. The FLINT. 795 fracture should be perfectly smooth, uniform, and slightly conchoidal; the last property being essential to the cutting out of perfect gun flints. Four tools are employed by-the gun-flint makers. First, a hammer or mace of iron with a souare head, from 1 to 2 pounds weight, with a handle 7 or 8 inches long. The tool is not made of steel, because so hard a metal would render the strokes too harsh, or dry, as the workmen say, and would shatter the nodules irregularly, instead of cutting them with a clean conchoidal fracture. Second, a hammer with 2 points, made of good steel well hardened, and weighing from 10 to 16 ounces, with a handle 7 inches long passing through it in such a way that the points of the hammer are nearer the hand of the workman than the centre of gravity of the mass. Third, the disc hammer or roller, a small solid wheel or flat segment of a cylinder, parallel to its base, only two inches and a third in diameter, and not more than 12 ounces in weight. It is formed of steel not hardened, and is fixed upon a handle 6 inches long, which passes through a square hole in its centre. Fourth, a chisel tapering and bevelled at both extremities, 7 or 8 inches long, and 2 inches broad, made of steel not hardened; this is set on a block of wood, which serves also for a bench to the workmen., To these 4 tools a file must be added, for the purpose of restoring the edge of the chisel from time to time. After selecting a good mass of flint, the workman executes the four following operations on it. 1. He breaks the block. Being seated upon the ground, he places the nodule of flint on his left thigh, and applies slight strokes with the square hammer to divide it into smaller pieces of about a pound and a half each, with broad surfaces and almost even fractures. Te blows should be moderate, lest the lump crack and split in the wrong direction. 2. He cleaves or chips the flint. The principal point is to split the flint well, or to chip off scales of the length, thickness, and shape adapted for the subsequent formation of gun-flints. Here the greatest dexterity and steadiness of manipulation are necessary; but the fracture of the flint is not restricted to any particular direction, for it may be chipped in all parts with equal facility. The workman holds the lump of flint in his left hand, and strikes with the pointed hammer upon the edges of the great planes produced by the first breaking, whereby the white coating of the flint is removed in small scales, and the interior body of the flint is laid bare; after which he continues to detach similar scaly portions from the clean mass. These scaly portions are nearly an inch and a half broad, two inches and a half long, and about one-sixth of an inch thick in the middle. They are slightly convex below, and consequently leave in the part of the lump from which they were separated a space slightly concave, longitudinally bordered by two somewhat projecting straight lines or ridges. The ridges produced by the separation of the first scales must naturally constitute nearly the middle of the subsequent pieces; and such scales alone as have their ridges thus placed in the middle are fit to be made into gun-flints. In this manner the workman continues to split or chip the mass of flint in various directions, until the defects usually found in the interior render it impossible to make the requisite fractures, or until the piece is too much reduced to sustain the smart blows by which the flint is divided. 3. He fashions the gzn-flints. Five different parts may be distinguished in a gunflint. 1. The sloping facet or bevel part, which-is impelled against the hammer of the lock. Its thickness should be from two to three twelfths of an inch; for if it were thicker it would be too liable to break; and if more obtuse, the scintillations would be less vivid. 2. The sides, or lateral edges, which are always somewhat irregular. 3. The back or thick part opposite the tapering edge. 4. The under surface, which is smooth and rather concave. And 5. The upper face, which has a small square plane between the tapering edge and the back, for entering into the upper claw of the cock In order to fashion the flint, those scales are selected which have at least one of the above-mentioned longitudinal ridges; the workman fixes on one of the two tapering borders to form the striking edge, after which the two sides of the stone that are to form the lateral edges, as well as the part that is to form the back, are successively placed on the edge of the chisel in such a manner that the convex surface of the flint which rests on the forefinger of the left hand, is turned towards that tool. Then with the disc hamn.er he applies some slight strokes to the flint just opposite the edge of the chisel underneath, and thereby breaks it exactly along the edge of the chisel. 4. The finishing operation is the trimming, or the process of giving the flint a smooth and equal edge; this is done by turning up the stone and placing the edge of its tapering end upon the chisel, in which position it is completed by five or six slight strokes of the disc hammer. The whole operation of making a gun-flint, which I have used so many words to describe, is performed in less than one minute. A good workman is able to manufacture 1,000 good chips or scales in a day (if the flint-balls be of good quality) 796 FLOUR OF WHEAT. or 500 gun-flints. Hence, in the space of three days, he cat easily cleave and finish 1,000 gun-flints without any assistance. A great quantity of refuse matter is left, for scarcely more than half the scales are good, and nearly half the mass in the best flints is incapable of being chipped out; sc that it seldom happens that the largest nodules furnish more than 50 gun-flints. Flints form excellent building materials; because they give a firm hold to the mortar by their irregularly rough surfaces, and resist, by their nature, every vicissitude of weather. The counties of Kent, Essex, Suffolk, and Norfolk, contain many substantia. specimens of flint-masonry. FLOOKAN. The name given by the Cornish miners to a vein of clay-stone, often nearly vertical. FLOOR CLOTH MANUFACTURE has become of late years a very large branch of trade. The cloth is a strong somewhat open canvas, woven of flax with a little hemp, and from 6 to 8 yards wide, being manufactured in appropriate looms, chiefly at Dundee. A piece of this canvas, from 60 to 100 feet in length, is secured tight in an upright open frame of oaken bars, in which position it receives the foundation coats of paint, 2 or 3 in number, first on the back side, and then on the front; but it is previously brushed over with glue-size, and rubbed smooth with pumice stones. The foundation paint made with linseed oil and ochre, or any cheap colouring matter, is too thick to be applied by the brush, and is therefore spread evenly by a long narrow trowel, held in the right hand, from a patch of it laid on just before with a brush in the left hand of the workman. Each foundation coat of the front surface is smoothed by pumice whenever it is hard enough to bear the operation. When both sides are dry, the painted cloth is detached froli the frame, coiled round a roller, in this state transferred to the proper printing room, where it is spread flat on a table, and variously figured and coloured devices are given to it by wooden blocks, exactly as in the block printing of calicoes, and in the wood printing of books. The blocks of the floor cloth manufacture are formed of two layers of white deal and one of pear tree timber, placed with their grain crossing one another alternately. There is of course a block for each colour in the pattern, and in each block those parts are cut away that correspond to the impression given by the others; a practice now well understood in the printing ot two or more colours by the press. The faces of the blocks are so indented with fine lines, that they do not take up the paint in a heavy daub from the flat cushion on which it is spread with a brush, but in minute dots, so as to lay on the paint (somewhat thicker than that of the house painter) in a congeries of little dots or teeth, with minute interstices between. Applied in this way, the various pigments lie more evenly, are more sightly, and dry much sooner than if the prominent part of the block which takes up the colour were a smooth surface. The best kinds of floor cloth require from two to three months for their production. FLOSS, of the puddling furnace, is the fluid glass floating upon the iron produced by the vitrification of the oxides and earths which are present. FLOSS-SILK (Filoselle, Bourre de soie, or fleuret, Fr.), is the name given to the portions of ravelled silk broken off in the filature of the cocoons, which is carded like cotton or wool, and spun into a soft coarse yarn or thread, for making bands, shawls, socks, and other common silk fabrics. The floss or fleuret, as first obtained, must be steeped in water, and then subjected to pressure, in order to extract the gummy matter, which renders it too harsh and short for the spinning wheel. After being dried it is made still more pliant by working a little oil into it with the hands. It is now ready Lo be submitted to the carding engine. (See COTTON MANUFACTURE.) It is spun upon the flax wheel. The female peasants of Lombardy generally wear clothes of homespun floss silk. Of late years, by improved processes, pretty fine fabrics of this material have been produced, both in England and France. M. Ajac, of Lyons, presented at one of the French national exhibitions of the objects of industry, a great variety of scarfs and square shawls, of bourre de soie, closely resembling those of cachemire. FLOUR; the finely ground meal of wheat, and of any other corns or cerealia. See BREAD. FLOUR OF WHEAT, Adulterations of, to detect.-The first method is by specific gravity. If potato flour be added, which is frequently done in France, since a vessel which contains one pound of wheat flour will contain one pound and a half of the fecula, the proportion of this adulteration may be easily estimated. If gypsum or ground bones be mixed with the flour, they will not only increase its density still more; but they will remain after burning away the meal. The second method is by ascertaining the quantity of gluten which the suspected sample will afford, by the process prescribed under the article BREAD. The two fol lowing chemical criteria may also be employed. 1st. Nitric acid has the property of colouring wheat flour of a fine orange yellow whereas it affects the colour neither of fecula nor starch FLY POWDER. 79, 2nd. Pure muriatic acid colours good wheat flour of a deep violet, but dissolves fecula or starch, and forms with it a light, colourless, viscous fluid, decomposable by alkalis. It may also be observed, that as fecula absorbs less water than flour, this affords a ready means of detection. The adulteration with bean or pea flour may be detected by pouring boiling water upon it, which developes the peculiar smell of these two substances. FLOWERS (Fleurs, Fr.; Blumen, Germ.) of benzoin, of sulphur, of zinc, &c., is the appellation given by the older chemists to such substances as were obtained in a pulverulent or rather minutely crystalline form by the process of sublimation. FLOWERS, ARTIFICIAL, MANUFACTURE OF. The art of representing by flowers, leaves, plants, &c., vegetable nature in her ornamental productions, constitutes the business of the artificial florist. The Italians appear to have been the first people in Europe who excelled in the art of making artificial flowers; but of late years the French have been most ingenious in this branch of industry. Ribbons folded in different forms and of different colours were originally employed for imitating flowers, by'being attached to wire stems. This imitation soon gave way to that by feathers, which are more delicate in texture, and more capable of assuming a variety of flower-like figures. But a great difficulty was encountered in dyeing them with due vivacity. The savages of South America manufacture perfect feather flowers, derived from the brilliant plumage of their birds, which closely resemble the products of vegetation. The blossoms and leaves are admirable, while the colours never fade. The Italians employ frequently the cocoons of the silk-worm for this purpose; these take a brilliant dye, preserve their colour, and possess a transparent velvety appearance, suitable for petals. Of late years, the French have adopted the finest cambric for making petals, and the taffeta of Florence for the leaves. M. de Bernardiere employs whalebone in very thin leaves for artificial flowers; and by bleaching and dyeing them of various hues, he has succeeded in making his imitations of nature to be very remarkable. The colouring matters used in flower dyeing are the following: - For red; carmine dissolved in a solution of carbonate of potash. For blue: indigo dissolved in sulphuric acid, diluted and neutralised in part by Spanish whitening For bright yellow; a solution of turmeric in spirit of wine. Cream of tartar brightens all these colours. For violet; archil, and a blue bath. For lilac; archil. Some petals are made of velvet, and are coloured merely by the application of the finger dipped in the dye. FLUATES, more properly fluorides (Eng. and Fr.; Flussaure, Germ.); compounds of fluorine and the metals; as fluor spar, for example, which consists of fluorine and calcium. FLUOR SPAR. (Chaux flutattee, Fr.; Spath fluor, Germ.) This mineral often exhibits a variety of vivid colours. It crystallizes in the cubic system; with regular octahedral and tetrahedral cleavages; spec. grav. 3-1 to 3-2; scratches cale spar, but is scratched by a steel point; usually phosphorescent with heat; fusible at the blowpipe into an opaque head; acted on by the acids, with disengagement of a vapour which corrodes glass; its solution affords precipitates with the oxalates, but nut with ammonia. Its constituents are, fluorine, 48'13; calcium, 51'87 in 100. Fluor spar occurs subordinate to metallic veins; as to those of lead, is Derbyshire; of tin, in Saxony and Bohemia; but it is found also in masses of veins, either in crystalline rocks, associated with quartz, heavy spar,.&c., as in Auvergne, Forez, Vosges, Norberg in Sweden; Norway; Petersburg; near Hall; Gourock, in Scotland, &c.; or among secondary limestones, slates, and sandstones, in Derbyshire, Cumberland, Cornwall, and New Jersey. It exists also in the amygdaloids of Scotland, and in the volcanic products of Mount Somma at Vesuvius. The variously coloured specimens, called Derbyshire spar, are worked upon the turning lathe into vases and other ornamental objects. FLUX, (Eng. and Fr.; Fluss, Germ.) signifies any substance capable of promoting the fusion of earths or metallic ores by heat. White flux is the residuum of the deflagration in a red hot crucible, of a mixture of two parts of nitre, and one of cream of tartar. It is in fact merely a carbonate of potash. Black flux is obtained when equal parts of nitre and tartar are deflagrated. It owes its colour to the carbonaceous matter of the tartaric acid, which remains unconsumed; the quantity of nitre being too small for that purpose. The presence of the charcoal renders this preparation a convenient flux for reducing calcined or oxidized ores to the metallic state. Limestone, fluor-spar, borax, and several earthy or metallic oxides are employed as fluxes in metallurgy. FLY POWDER; the black coloured powder obtained by the spontaneous oxidizement of metallic arsenic in the air. 798 FORMULZE, CHEMICAL. FODDER; is the name of a weight by which lead and some other metals are sold in this country. Its varies in its amount in different parts of the kingdom; being in Northumberland estimated at 21 cwts., and in other counties 22, 23 or even more cwts. FONDUS; is the name given by the French to a particular style of calico printing resembling the rainbow, in which the colours are graduated or melted (fondus) into one another, as in the prismatic spectrum. See PAPER HANGING, for a description of the process. FORGE; (Eng. and Fr.; Feuer, Germ.) is the name either of the furnace, where wrought iron is hammered and fashioned with the aid of heat, or the great workshop where iron is made malleable. The former is called a smith's forge, the latter a shiningling mill. See IRON. Fig. 649. represents a portable F 649 truck forge of a very commodious construction. A is the cylindric t \ -- leather bellows, pressed down by ( a helical spring, and worked by l means of the handle at B, which moves the horizontal shaft c, with ^ its two attached semi-circulariI D levers and chains. D, is the pipe 1 // i which conducts the blast to the nozzle at E. The hearth may be / covered with a thin fire-tile or 1/ A with cinders. F. is a vice fixed to... h*^? l the strong rectangular trame. - rl This apparatus answers all the ordinary purposes of a smith's forge; and is peculiarly adapted to ships, s and to the execution of engineer- ing jobs upon railways, or in the country. The height is 2 feet 6 inches; the length is 2 feet 9 inches; the width 2 feet. Weight. about 2 cwt. FORGERY, PREVENTION.-Forgeries of Bank cheques and other cash documents are proposed to be prevented under the patent recently granted to Messrs. Henry Glynn and Rudolph Appel. They prepare paper by mixing its pulp with solution of nitrate or sulphate of copper, to which mixture alkaline saline matter is added, to produce a cupreous precipitate (phosphate of sode being preferred), so that reddened litimus paper will be rendered blue by it. One ounce of nitrate of copper is sufficient for two gallons of the pulp, or even more if the cupreous colour is objectionable. The pulp is to be then washed with water. A mixture of equal parts of white soft soap and old palm oil is to be dissolved in boiling water, using half a pound of soap to one gallon df water. Into this saponaceous solution, the paper impregnated with the said pulp is to be dipped, and then sized. They also prevent a transfer being taken with paper, by washing it with solution of sulphate of copper, drying it, and dipping it in phosphate of soda strong enough to convert the sulphate into a phosphate. FORMIATES; are compounds of formic acid, with the salifiable bases. Many of them are susceptible of crystallization. FORMIC ACID, (Acide FormiqZue, Fr.; Ameisansaure, Germ.) exists in the bodies of wood ants, associated with the malic or acid of apples. The artificial formation of this animal secretion, is one of the most remarkable triumphs of modern chemistry. If 10 parts of tartaric acid, 14 of black oxide of manganese, 15 of concentrated sulphuric acid, and from 20 to 30 of water be mixed and distilled in a retort, formic acid will be the liquid product; while carbonic acid will be disengaged. It may also be generated from other mixtures. This acid is transparent and colourless, of a pungent sour smell, a strongly acid taste, of specific gravity 1-1168 at 60~ F., and may be re-distilled without suffering any change. It contains in its most concentrated form 191 per cent. of water. The dry acid, as it exists in the formiates, is composed of 32-54 carbon, 2'68 hydrogen, and 64'78 oxygen: or of two volumes carbonic oxide gas, and one volume of vapour of water. It reduces the oxides of mercury and silver to the metallic state. It has not hitherto been applied to any use in the arts. FORMULE, CHEMICAL, are symbols representing the different substances, simple and compound. FORMULE, CHEMICAL. 801 Name. Formula. Oxygen=100. Hydrogen=l. Oxygen.. 100-000 16-026 Hydrogen... H 62398 1'000 2H 12-4796 2-000 Nitrogen.. N 88-518 14-186 2N 177-086 28-372 Phosphorus... P 196-155 31-436 2P 392-310 68-872 Chlorine. C1 221-325 35-470 2C1 442-650 70-940 Iodine.... I 768781 123-206 21 1537-562 246-412 Carbon. C 76-437 12-250 2C 152-875 24-500 Boron.. B 135-983 21-793 2B 271-966 43-586 Silicon.. Si 277-478 44-469 Selenium.. Se 494-582 79-263 Arsenic.. As 470-042 75-329 2As 940-084 150-659 Chromium... Cr 351-819 56-383 2Cr 703-638 112-766 Molybdenum... Mo 598525 95-920 Tungstenium... Tu or W 11832'0 189-621 Antimony.. Sb 806-452 129-243 2Sb 1612-904 258-486 Tellurium.. Te 806-452 129-243 Tantalum.. Ta 1153-715 184-896 2Ta 2307-430 369 792 Titanium. Ti 389-092 62-356 Gold (aurum).. Au 1243-013 199-207 2Au 2486-026 398-415 Platina. Pt 1215-220 194-753 Rhodium... R 750680 120-305 2R 1501-360 240-610 Palladium.. Pd 714-618 114-526 Silver (argentum).. Ag 1351-607 216-611 Mercury (hydrargyrus) Hg 1265-822 202-863 2Hg 2531-645 405 725 Copper (cuprum).. Cu 395-695 63-415 2Cu 791-390 126-829 Uranium. U 2711-360 434-527 2U 5422-720 869-154 Bismuth. Bi 1330-376 213-208 2Bi 2660-752 426-416 Tin (stannum).. Sn 735294 117-839 Lead (plumbum).. Pb 1294498 207-458 2Pb 2588-996 414-917 Cadmium. Cd 696-767 111-665 Zinc.. Zn 403*226 64-621 Nickel. Ni 369-675 59-245 Cobalt.. Co 368-991 59-135 2Co 737-982 118-270 Iron (ferrum)... Fe 339-213 54-363 2Fe 678-426 108-725 Manganese... Mn355787 57019 2Mn 711-575 114038 Cerium.. Ce 574-718 92 105 2Ce 1149-436 184-210 Zirconium.. Zr 420-238 67-348 2Zr 840-476 134-696 Yttrium.. Y 401-840 64-395 Beryllium (glucinum).Be 331-479 53123 2Be 662-958 106-247 802 FORMULAE, CHEMICAL. Name. Formula. Oxygen= 100. Hydrogen=1. Aluminum...Al 171167 27-431 2A1 342-234 54-863 Magnesium.. Mg 158-353 25-378 Calcium. Ca 256-019 41-030 Strontium. Sr 547-285 87-709 Barytum.. Ba 856-88 137325 Lithium L 127-757 20-474 Natrium (sodium). Na 290897 46-620 2Na 581-794 93-239 Kalium (potassium). K 489-916 78-515 Ammonia. 2N 2H3 214-474 34-372 Cyanogen..2NC 329-911 52-872 SlJphureted hydrogen..2HS 213'644 34239 Hydrochloric acid.. 2H C1 455-129 72-940 Hydrocyanic acid..2HNC 342-390 54-872 Water... 2H 112-479 18-026 Protoxyde of nitrogen, 2N 277-036 44-398 Deutoxyde of nitrogen N 188-518 30-212 Nitrous acid.. 2N 477-036 76-449 Nitric acid. 2N 677-036 108-503 Hyposulphurous acid.. S301-165 48-265 Sulphurous acid. S 401-165 64-291 Hyposulphuric acid. 2S 902-330 144-609 Sulphuric acid.. S 501165 80-317 Phosphoric acid..2P 892-310 143-003 Chloric acid. 2C1 942-650 151-071 Perchloric acid 2C1 1042650 167'097 lodic acid..21 2 037 562 326'543 Carbonic acid.. C 276-437 44-302 Oxalic acid.. 2C 452-875 72-578 Boracic acid.. 2B 871-966 139-743 Silicic acid. Si 577-478 92-548 Selenic acid.. Se 694-582 111-315 Arsenic acid...2As 1440-084 230-790 Protoxyde of chrome..2Cr 1003-638 160-840 Chromic acid.. Cr 651819 104-462 Molybdic acid..Mo 898-525 143-999 Tunstic, or wolfram acid. W 1483-200 237-700 Oxyde of antimony..2Sb 1912-904 306-565 Antimonious acid. Sb 1006-452 161296 2Sb 2012-904 322-591 Antimonic acid.. 2Sb 2112-904 338-617 FORMULE, CHEMICAL. 808 Name. Formula. Oxygen= 100. Hydrogen=l Oxyde of tellurium. Te 1006-452 161-296 rantalic acid... 2Ta 2607-430 417-871 Titanic acid.. Ti 589-092 94-409 Protoxyde of gold. I 2Au 2586-026 414-441 Peroxyde of gold. 2Au 2786-026 446'493 Oxyde of platina. Pt 1415-220 226-086 Oxyde of rhodium *.. 2R 1801-360 228-689 Oxyde of palladium..Pd 814-618 130-552 Oxyde of silver. g 1451-607 232-637 Protoxyde of mercury. 2Hg 2631645 421-752 Peroxyde of mercury.. Hg 1365-822 218-889 Protoxyde of copper.. 2Cu 801-390 142-856 Peroxyde of copper.. Cu 495695 79-441 Protoxyde of uranium..U 2811-360 450-553 Peroxyde of uranium.. 2U 5722-720 917-132 Oxyde of bismuth.. 2Bi 2960-752 474-49 Protoxyde of tin. Sn 835-294 133-866 Peroxyde of tin.. Sn 935-294 149-892 Oxyde of lead... Pb 1394-498 223-484 Minium...2Pb 2888-996 462-995 Brown oxyde of lead. Pb 1494-498 239-511 Oxyde of cadmium.. Cd 796-767 127-691 Oxyde of zinc. Zn 503-226 80-649 Oxyde of nickel.. Ni 469-675 75-271 Oxyde of cobalt.. Co 468-991 75-161 Peroxyde of cobalt.. 2Co 1037-982 166-349 Protoxyde of iron.. Fe 439-213 70-389 Peroxyde of iron.. 2F 978-426 156-804 Protoxyde of manganese. Mn 455-787 73-045 Oxyde of manganese.. 2Mn 1011575 162-11.7 Peroxyde of manganese. Mn 555-787 89-071 Manganesic acid.. 2Mn 1211'575 194-169 Protoxyde of cerium.. Ce 674-718 108132 Oxyde sf cerium.. 2Ce 1449-436 232-289 Zirconia... 2Zr 1140-476 182-775 Yttria... Y 501840 80-425 Glucina, or berryllia.. 2Be 962-958 154-325 52 804 FOUNDING. Name Formula. Oxygen= 100. Hydrogen —1. Alumina... 2A 642-334 109-942 Magnesia.. Mg 258-353 41 404 Lime.. Ca 356-019 57-056 Strontia.. Sr 647-285 103-735 Baryta... Ba 956-880 153-351 Lithia.. L 227-757 36-501 Natron, or soda.. N1a 390-897 62-646 Peroxyde of sodium.. 2Na 881'794 141-318 Kali, or potassa.. K 589-916 94-541 Peroxyde of potassium. K 789-916 126-593 Sulphate of potassa.. KS 1091-081 174-859 Protosulphate of iron.. Fe S 940-378 150-706 Persulphate of iron.. 2Fe S3 2481-906 397-754 Protochloride of iron.. Fe 2C1 781-863 125-303 Perchloride of iron..2Fe 2C13 2006-376 321-545 Protochloride of mercury. 2Hg 2C1 2974-295 476-666 Perchloride of mercury. Hg 2C1 1708-472 273-803 Ferrocyanide of iron.. Fe 2NC-2K 2NC 2308-778 3706008 Alum.... KS-2A1 S3+242H 5936-406 951-378 Feldspar... KS 2 Si+2Al S 3542162 567-673 FOUNDING of metals, chiefly of Iron. The operations of an iron foundry consist in re-melting the pig-iron of the blast furnaces, and giving it an endless variety of forms, by casting it in moulds of different kinds, prepared iA appropriate manners. Coke is the only kind of fuel employed to effect the fusion of the cast-iron. The essential parts of a well-mounted iron foundry are, 1. Magazines for pig-irons of dfferent qualities, which are to be mixed in certain proportions, for producing castings of peculiar qualities; as also for coal, coke, sands, clay, powdered charcoal, and cow-hair for giving tenacity to the loam mouldings. 2. One or more coke ovens. 3. A workshop for preparing the patterns and materials of the moulds. It should contain small edge millstones for grinding and mixing the loam, and another mill for grinding coal and charcoal. 4. A vast area, called properly the foundry, in which the moulds are made and filled with the melted metal. These moulds are in general very heavy, consisting of two parts at least, which must be separated, turned upside down several times, and replaced very exactly upon one another. The casting is generally effected by means of large ladles or pots, in which the melted iron is transported from the cupola, where it is fused. Hence, the foundry ought to be provided with cranes, having jibs moveable in every direction. 5. A stove in which such moulds may be readily introduced as require to be entirely deprived of humidity, and where a strong heat may be uniformly maintained. 6. Both blast and air furnaces, capable of melting speedily the quantity of cast-iron to be employed each day. 7. A blowing machine to urge the fusion in the furnaces. Fig. 650 represents the general plan of a well-mounted foundry. a is a cupola furnace, of which the section and view will be afterwards given; it is rapable of containing 5 tons of cast-iron. a is a similar furnace, but of smaller dimensions, for bringing down 14 tons. c" is a furnace like the first, in reserve for great castings. FOUNDING. 805 b, b, b, b, a vast foundry apartment, whose floor, to a yard in depth, is formed of san. and charcoal powder, which have already been used for castings, and. are ready for heap 650 ing up into a substratum, or to be scooped out when depth is wanted for the moulds. There are i'.. jbesides several cylindrical pits, from five to seven yards in depth, placed near the furnaces. They La L^tkN H ~ ~ are lined with brick work, and are usually left ful..6" <^l^^ ~Ul of' moulding sand. They are emptied in order to J': ^ ^ Baaaa. ssa,, s3 i receive large moulds, care being had that their top K p i ( > ^ ) l } is always below the orifice from which the melted 9 5 k) / 0 / _ metal is tapped. ~ E~ These moulds, and the ladles full of melted aK a e Ametal, are lifted and transported by the arm of one j ) g ~or more men, when their weight is moderate; but lyXm a-"~', n ^ if it be considerable, they are moved about by |I" x^g n' cranes whose vertical shafts are placed at c, d, e, in correspondence, so that they may upon occasion transfer the load from one to another. Each crane is composed principally of an. upright shaft, embraced at top by a collet, and turning below upon a pivot in a step; next of a horizontal beam, stretched out from nearly the top of the former, with an oblique stay running downwards, like that of a gallows. The horizontal beam supports a moveable carriage, to which the tackle is suspended for raising the weights. This carriage is made to glide backwards or forwards along the beam by means of a simple rack and pinion mechanism, whose long handle descends within reach of the workman's hand. By these arrangements in the play of the three cranes, masses weighing five tons may be transported and laid down with the greatest precision upon any point whatever in the interior of the three circles traced upon fig. 650 with the points c, d, e, as centres. c, d, e, are the steps, upon which the upright shafts of the three cranes rest and turn. Each shaft is 16 feet high. f, f, is the drying stove, having its floor upon a level with that of the foundry. f',f, is a supplementary stove for small articles. g, g, g, are the coking ovens. h, is the blowing machine or fan. i, is the steam-engine, for driving the fan, the loam-edge stones, k, and the charcoal mill. i", are the boiler and the furnace of the engine. k', workshop for preparing the loam and other materials of moulding. 1, is the apartment for the patterns. The pig-iron, coals, &c. are placed either under sheds or in the open air, round the above buildings; where are also a smith's forge, a carpenter's shop, and an apartment mounted with vices for chipping and rough cleaning the castings by chisels and files. Such a foundry may be erected upon a square surface of about 80 yards in each side, and will be capable, by casting in the afternoon and evening of each day, partly in large and partly in small pieces, of turning out from 700 to 800 tons per annum, with an establishment of 100 operatives, including some moulding boys. Of making the moulds.-1. Each mould ought to present the exact form of its object. 2. It should have such solidity that the melted metal may be poured into it, and fill it entirely without altering its shape in any point. 3. The air which occupies the vacant spaces in it, as well as the carbureted gases generated by the heat, must have a ready vent; for if they are but partially confined, they expand by the heat, and may crack, even blow up the moulds, or at any rate become dispersed through the metal, making it vesicular and unsound. There are three distinct methods of making the moulds: 1. In green sand; 2. In baked sand; 3. In loam. To enumerate the different means employed to make every sort of mould exceeds the limits prescribed to this work. I shall merely indicate for each species of moulding, what is common to all the operations; and I shall then describe the fabrication of a few such moulds as appear most proper to give general views of this peculiar art. Moulding in green sand.-The name green is given to a mixture of the sand as it comes from its native bed, with about one twelfth its bulk of coal reduced to powder, and damped in such a manner as to form a porous compound, capable of preserving the forms of the objects impressed upon it. This sand ought to be slightly argillaceous, with particles not exceeding a pin's head in size. When this mixture has once served for a mould, and been filled with metal, it cannot be employed again except for the coarsest castings, and is generally used for filling up the bottoms of fresh moulds. For moulding any piece in green sand, an exact pattern of the object must be pre 806 FOUNDING pared in wood or metal; the latter being preferable, as not liable to warpimg, swelling or shrinkage. A couple of iron frames form a case or box, which serves as an euvelope to the mould Such boxes constitute an essential and very expensive part of the furniture of a foundry It is a rectangular frame, without bottom or lid, whose two largest sides are united by a series of cross bars, parallel to each other, and placed from 6 to 8 inches apart. The two halves of the box carry ears corresponding exactly with one another; of which one set is pierced with holes, but the other has points which enter truly into these holes, and may be made fast in them by cross pins or wedges, so that the pair becomes one solid body. Within this frame there is abundance of room for containing the pattern of the piece to be moulded with its incasing sand, which being rammed into the frame, is retained by friction against the lateral faces and cross bars of the mould. When a mould is to be formed, a box of suitable dimensions is taken asunder, and each half, No. 1 and No. 2, is laid upon the floor of the foundry. Green sand is thrown with a shovel into No. 1, so as to fill it; when it is gently pressed in with a rammer. The object of this operation is to form a plain surface upon which to lay in the pattern with a slight degree of pressure, varying with its shape. No. 1 being covered with sand, the frame No. 2 is laid upon it, so as to form the box. No. 2 being now filled carefully with the green sand, the box is inverted, so as to place No. 1 uppermost, which is then detached and lifted off in a truly vertical position; carrying with it the body ot sand formed at the commencement of the operation. The pattern remains imbedded in the sand of No. 2, which has been exactly moulded upon a great portion of its surface. The moulder condenses the sand in the parts nearest to the pattern, by sprinkling a little water upon it, and trimming the ill-shaped parts with small iron trowels of different kinds. He then dusts a little well-dried finely-sifted sand over all the visible surface ot the pattern, and of the sand surrounding it; this is done to prevent adhesion when he replaces the frame No. 1. He next destroys the preparatory smooth bed or area formed in this frame, covers the pattern with green sand, replaces the frame 1 upon 2, to reproduce the box, and proceeds to fill and ram No. 1, as he had previously done No. 2. The object of this operation is to obtain very exactly a concavity in the frame No. 1, having the shape of the part of the model impressed coarsely upon the surface formed at the beginning, and which was meant merely to support the pattern and the sand sprinkled over it, till it got imbedded in No. 2. The two frames in their last position, along with their sand, may be compared to a box of which No. 1 is the lid, and whose interior is adjusted exactly upon the easxosed pattern. If we open this box, and after taking out the pattern, close its two halves again, then pour in melted metal till it fill every void space, and become solid, we shall obviously attain the wished-for end, and produce a piece of cast iron similar to the pattern. But many precautions must still be taken before we can hit this point. We must first lead through the mass of sand in the frame No. 1 one or more channels for the introduction of the Tnelted metal; and though one may suffice for this purpose, another must be made for letting the air escape. The metal is run in by several orifices at once, when the piece has considerable surface, but little thickness, so that it may reach the remotest points sufficiently hot and liquid. The parts of the mould near the pattern must likewise be pierced with small holes, by means of wires traversing the whole body of the sand, in order to render the mould more porous, and to facilitate the escape of the air and the gases. Then, before lifting off the frame No. 1, we must tap the pattern slightly, otherwise the sand enclosing it would stick to it in several points, and the operation would not succeed. These gentle jolts are given by means of one or more pieces of iron wire which have been screwed vertically into the pattern before finally ramming the sand into the frame No. 1, or which enter merely into holes in the pattern. These pieces are sufficiently long to pass out through the sand when the box is filled; and it is upon their upper ends that the horizontal blows of the hammer are given; their force being regulated by the weight and magnitude of the pattern. These rods are then removed by drawing them straight out; after which the frame No. 1 may be lifted off smoothly from the pattern. The pattern itself is taken out, by lifting it in all its parts at once, by means of screw pins adjusted at the moment. This manoeuvre is executed, for large pieces, almost always by several men, who, while they lift the pattern with one hand, strike it with the ather with small repeated blows to detach the sand entirely, in which it is generally more engaged than it was in that of the frame No. 1. But in spite of all these precautions, there are always some degradations in one or other of the two parts of the mould; which are immediately repaired by the workman with damp sand, which he applies and presses gently with his trowel, so as to restore the injured forms. Hitherto I have supposed all the sand rammed into the box to be of one kind; bat I' —------— ~~~~~~~~~~~~~~~~~~~~~ —-"~~~~~~ I FOUNDING. 807'ran economy, the green sand is used only to form the portion of the mould next the pattern, in a stratum of about an inch thick; the rest of the surrounding space is filled with the sand of the floor which has been used in former castings. The interior layer round the pattern is called, in this case, new sand. It may happen that the pattern is too complex to be taken out without damaging the mould, by two frames alone; then 3 or more are mutually adjusted to form the box. When the mould, taken asunder into two or more parts, has been properly repaired, its interior surface must be dusted over with wood charcoal reduced to a. very fine powder, and tied up in a small linen bag, which is shaken by hand. The charcoal is thus sifted at the moment of application, and sticks to the whole surface, which has been previously damped a little. It is afterwards polished with a fine trowel. Sometimes, in order to avoid using too much charcoal, the surfaces are finally dusted over with sand, very finely pulverized, from a bag like the charcoal. The two frames are now replaced with great exactness, made fast together by the ears, with wedged bolts laid truly level, or at the requisite slope, and loaded with considerable weights. When the casting is large, the charcoal dusting, as well as that of fine sand, is suppressed. Everything is now ready for the introduction of the fused metal. Moulding in baked or used sand.-The mechanical part of tih? process is the same as of the preceding. But when the castings are large, and especially if they are tall, the hydrostatic pressure of the melted metal upon the sides of the mould cannot be counteracted by the force of cohesion which the sand acquires by ramming. We must in that case adapt to each of these frames a solid side, pierced with numerous small holes to give issue to the gases. This does not form'one body with the rest of the frame, but is attached extemporaneously to it by bars and wedged bolts. In general, no ground coal is mixed with this sand. Whenever the mould is finished, it is transferred to the drying stove, where it may remain from 12 to 24 hours at most, till it be deprived of all its humidity. The sand is then said to be baked or annealed. The experienced moulder knows how to mix the different sands placed at his disposal, so that the mass of the mould as it comes out of the stove may preserve its form, and be sufficiently porous. Such moulds allow the gases to pass through them much more readily than those made of green sand; and in general the castings they turn out are less vesicular, and smoother upon the surface. Sometimes in a large piece, the three kinds of moulding, that in green sand, in baked sand, and in loam, are combined to produce the best result. Moulding in loam.-This kind of work is executed from drawings of the pieces to be moulded, without being at the expense of making patterns. The mould is formed of a pasty mixture of clay, water, sand, and cow's-hair, or other cheap filamentous matter, kneaded together in what is called the loam mill. The proportions of the ingredients are varied to suit the nature of the casting. When the paste requires to be made very light, horse dung or chopped straw is added to it. I shall illustrate the mode of fabricating loam moulds, by a simple case, such as that of a sugar pan. Fig. 651 is the pan. There is laid upon the floor of the foundry an annular platform of cast-iron, a b, fig. 652; and upon its centre c, rests the lower extremity of a vertical shaft, adjusted so as to turn freely upon itself, while it makes a wooden pattern, e f, fig. 653, describe a surface of revolution identical with the internal surface reversed of the boiler intended to be made. The outline, e g, of the pattern is fashioned so as to describe the surface of the edge of the vessel. Upon the part a d b d,fig. 652, of thl flat cast-iron ring, there must next be constructed, with bricks laid either flat or on their edge, and clay, a kind of dome, h i k, fig. 653, from two to four inches thick, 652 ffi~A ~ 653 651 according to the size and weight of the piece to be moulded. The external surface of the brick dome ought to be everywhere two inches distant, at least, from the surface described by the arc e f. Before building up the dome to the point i, coals are to be placed in its inside upon the floor, which may be afterwards kindled for drying the mould. The top is then formed, leaving at i, round the upright shaft of revolution, only a very small outlet. This aperture, as also some others left under the edges of the iron ring, enable the moulder to light the fire when it becomes necessary, and to graduate it so as to make it last long enough without needing more fuel, till the mould be quite finished and dry. The combustion should be always extremely slow. OCver the brick dome a pasty layer of loam is applied, and rounded with the mould 808 FOUNDING. g ef; this surface is then coated with a much smoother loam, by means of the concave edge of the same mould. Upon the latter surface, the inside of the sugar pan is cast; the line e g having traced, in its revolution, a ledge m. The fire is now kindled, and as the surface of the mould becomes dry, it is painted over by a brush, with a mixture of water, charcoal powder, and a little clay, in order to prevent adhesion between the sur face already dried and the coats of clay about to be applied to it. The board g e f is now removed, and replaced by another, g' e' f', fig. 654, whose edge e' f' describes the outer surface of the pan. Over the surface e, f, a layer of loam is applied, which is turned and polished so as to produce the surface of revolution e' f', as was done for the surface ef; only in the latter case, the line e' g' of the board does not form a new shoulder, but rubs lightly against m. The layer of loam included between the two surfaces e f, e' f, is an exact representa. tion of the sugar pan. When this layer is well dried by the heat of the interior fire, it must be painted like the former. The upright shaft is now removed, leaving the small vent hole through which it passed to promote the complete combustion of the coal. There must be now laid horizontally upon the ears of the platform d -. fig. 652, another annular platform p q, like the former, but a little larger, and wither any cross-bar. 654 655 656 The relative position of these two platforms is shown in fig. 656. Upon the surface e' f', fig. 655, a new layer of loam is laid, two inches thick, of which the surface is smoothed by hand. Then upon the platform p q, fig. 656, a brick vault is constructed, whose inner surface is applied to the layer of loam. This contracts a strong adherence with the bricks which absorb a part of its moisture, while the coat of paint spread over the surface e' f', prevents it from sticking to the preceding layers of loam. The brick dome ought to be built solidly. The whole mass is now to be thoroughly dried by the continuance of the fire, the draught of which is supported by a small vent left in the upper part of the new dome; and when all is properly dry, the two iron platforms are adjusted to each other by pin points, and p q is lifted off; taking care to keep it in a horizontal position. Uprn this platform are removed the last brick dome, and the layer of loam which had been applied next to it; the latter of which represents exactly by its inside the mould of the surface e'f', that is, of the outside of the pan. The crust contained between e f and e' f' is broken away, an operation easily done without injury to the surface e f, which represents exactly the inner surface of the pan; or only to the shoulder m, corresponding to the edge of the vessel. The top aperture through which the upright shaft passed must be now closed; only the one is kept open in the portion of the mould lifted off upon p q; because through this opening the melted metal is to be poured in the process of casting. The two platforms being replaced above each other very exactly, by means of the adjusting pin points, the mould is completely formed, and ready for the reception of the metal. When the object to be moulded presents more complicated forms than the one now chosen for the sake of illustration, it is always by analogous processes that the workman constructs his loam moulds, but his sagacity must hit upon modes of executing many things which at first sight appear to be scarcely possible. Thus, when the forms of the interior and exterior do not permit the mould to be separated in two pieces, it is divided into several, which are nicely fitted with adjusting pins. More than two cast-iron rings or platforms are sometimes necessary. When )vals or angular surfaces must be traced instead of those of revolution, no upright shaft is used, but wooden or cast-iron guides made on purpose, along which the pattern cut-out board is slid according to the drawing of the piece. Iron wires and claws are often interspersed through the brick work to give it cohesion. The core, kernel, or inner mould of a hollow casting is frequently fitted in when the outer shell is moulded. I shall illustrate this matter in the case of a gas-light retort, fig. 657. The core of the retort ought to have the form e e e e, and be very solid, since it cannot be fixed in the outer mould, for the casting, except in;?. part standing out of the retort towards m m. It must be modelled in loam, upon a piece of cast-iron called a lantern, made expressly for this purpose. The lantern is a cylinder or a truncated hollow cone of cast-iron, about half an inch thick; and differ. ently shaped for every different core. The surface is perforated with holes of about half an inch in diameter. It is mounted by means of iron cross-bars, upon an iron axis, FOUNDING. 809 which traverses it in the direction of its length. Fig. 658 represents a horizontal section through the axis of the core; g h is the axis of the lantern, figured itself at i k 657 658 k i; o i i o is a kind of disc or dish, perpendicular tc the axis, open at i i, forming one piece with the lantern, whose circumference o o presents a curve similar to the section of the core, made at right angles'to its axis. We shall see presently the two uses for which this dish is intended. The axis g h is laid upon two gudgeons, and handles are placed at each of its extremities, to facilitate the operation in making the core. U?-nU the whole surface of the lantern, from the point h to the collet formed by the disb? hacord as thick as the finger is wound. Even two or more coils may be applied, as occasion requires, over which loam is spread to the exact form of the core, by applying with the hand a board, against the dish o o, with its edge cut out to the desired shape; as also against another dish, adjusted at the time towards h; while by means of the handles a rotatory movement is given to the whole apparatus. The hay interposed between the lantern and the loam, which represents the crust of the core, aids the adhesion of the clay with the cast-iron of the lantern, and gives passage to the holes in its surface, for the air to escape through in the casting. When the coie is finished, and has been put into the drying stove, the axis g h is taken out, then the small opening which it leaves at the point h, is plugged with clay. This is done by supporting the core by the edges of the dish, in a vertical position. It is now ready to be introduced into the hollow mould of the piece. This mould executed in baked sand consists of three pieces, two of which, absolutely t t o o similar, are represented, fig. 659, at p q, the third is PB 1 2 s | P A 1P shown at r s. The two similar parts p q, present each the longitudinal half of the nearly cylindrical portion l l p 8 of the outer surface of the gas retort; so that when 659 660 they are brought together, the cylinder is formed; r s;S contains in its cavity the kind of hemisphere which forms the bottom of the retort. Hence, by adding this part of the mould to the end of the two others, the i; | 1 p J iresulting apparatus presents in its interior, the exact q u tn9 e mould of the outside of the retort; an empty cylin9'" (f: M 7 - B X- f drical portion t t, whose axis is the same as that of the rS j,; } * r \ cylinder u u, and whose surface, if prolonged, would be S s A ir*y everywhere distant from the surface u u, by a quan~: s tity equal to the desired thickness of the retort. The diameter of the cylinder t t is precisely equal to that of the core, which is slightly conical, in order that it may enter easily into this aperture t t, and close it very exactly when it is introduced to the collet or neck. The three parts of the mould and the core being prepared, the two pieces p q, must first be united, and supported in an upright position; then the core must be let down into the opening t t, fig. 660. When the plate or disc o o of the core is supported upon the mould, we must see that the end of the core is everywhere equally distant from the edge of the external surface u u, and that it does not go too far beyond the line q q. Should there be an inaccuracy, we must correct it by slender iron slips placed under the edge of the disc o o; then by means of a cast-iron cross, and screw bolts v v, we fix the core immoveably. The whole apparatus is now set down upon r s, and we fix with screw bolts the plane surface q q upon r r; then introduce the melted metal by an aperture z, which has been left at the upper part of the mould. When, instead of the example now selected, the core of the piece to be cast must go beyond the mould of the external surface, as is the case with a pipe open at each end, the thing is more simple, because we may easily adjust and fix the core by its two ends. In casting a retort, the metal is poured into the mould set upright. It is important to maintain this position in the two last examples of casting; for all the foreign matters which may soil the metal during its flow, as the sand, the charcoal, gases, scoriae, being ess dense than it, rise constantly to the surface. The hydrostatic pressure produced by a high gate, or filling-in aperture, contributes mucn to secure the soundness and solidity of the casting. This gate-piece being superfluous, is knocked off almost immediateiy L~~~~~~L~U ~~~~V VIl 810 FOUNDING. after, or even before the casting cools. Very long, somewhat slender pieces, are usually cast in moulds set up obliquely to the horizon. As the metal shrinks in cooling, the mould should always be somewhat larger than the object intended to be cast. The iron founder reckons in general upon a linear shrinkage of a ninety-sixth part; that is, one eighth of an inch per foot. Melting of the cast tron. — The metal is usually melted in a cupola furnace, of which the dimensions are very various. Fig. 661 represents in plan, section, and elevation, one of these furnaces of the largest size; being capable of founding 5 tons of cast iron at a time. It is kindled by laying a few chips of wood upon its bottom, leaving the orifice c open, and it is then filled up to the throat with coke. he fire is lit at c, and in a quarter or half an hour, when the body of fuel is sufficiently kindled, the tuyhre blast is set in action. The flame issues then by the mouth as well as the orifice c, which has been left open on purpose to consolidate it by the heat. Without this precaution, the sides, which are made up in argillaceous sand after each day's work, would not present the necessary resistance. A quarter of an hour afterwards, the orifice c is closed with a lump of moist clay, and sometimes, when the furnace is to contain a great body of melted metal, the clay is supported by means of a small plate of cast iron fixed against the furnace. Before the blowing machine is set a going, the openings g g g had been kept shut. Those of them wanted for the tuyeres are opened in succession, beginning at the lowest, the tuyeres being raised according as the level of the fused iron stards higher in the furnace. The same cupola may receive at a time from one to six tuyeres, through which the wind is propelled by the centrifugal action of an eccentric fan cr ventilator. It does not appear to be ascertained whether there be any advantage in placing more than two tuyeres-facing each other upon opposite sides of the furnace. Their diameter at the nozzle varies from 3 to 5 inches. They are either cylindrical or slightly conical. A few minutes after the tuyeres have begun to blow, when the coke sinks in the furnace, alternate charges of coke and pig iron must be thrown in. The metal begins to melt in about 20 minutes after its introduction; and successive charges are then made every 10 minutes nearly; each charge containing from 2 cwts. to 5 cwts. of iron, and a quantity proportional to the estimate given below. The amount of the charges varies of course with the size of the furnace, and the speed required for the operation. The pigs must be previously broken into pieces weighing at most 14 or 16 pounds. The vanes of the blowing fan make from 625 to 650 turns per minute. The two cupolas represented fig. 661, and another alongside in the plan, may easily melt 61 tons of metal in 2| hours; 661 fI.~-.~......ct id, 21 tons per hour This result is three or four times greater than what was o'//~/~~~~: d;l'1~~//// /////'c o ~''c..-... I ......".. ~ A large main pipe of zinc or..v. -......: sheet iron is fitted to the ori. fice of the slide valve. It is %~s^^S?~~~~ 7~ Asquare at the beginning, or i~,; [only rounded at the angles FOUNDIN(t. 813 but at a little distance it becomes cylindrical, and conducts the blast to the divaricating points. There, each of the branches turns up vertically, and terminates at b b, fig. 662, where it presents a circular orifice of 7. inches. Upon each of the upright pipes b, the ane end of an elbow-tube of zinc c c c c, fig. 662, is adjusted rather loosely, and the other end receives a tuyere of wrought iron d d, through the intervention of a shifting hose or collar of leather c c d, hooped with iron wire to noth the tube and the tuyere. The portion c c c c may be raised or lowered, by sliding upon the pipe b, in order to bring the nozzle of the tuyere d d, to the requisite point of the furnace. The portiop c c c c may be made also of wrought iron. A power of 4 horses is adequate to drive this fan, for supplying blast to 3 furnaces. The founders have observed the efflux of air was not the same when blown into the atmosphere, as it was when blown into the furnaces; the velocity of the fan, with the same impulsive power, being considerably increased in the latter case. They imagine that this circumstance arises from the blast being sucked in, so to speak, by the draughl "~'the furnace, and that the fai then supplied a greater quantity of air. The following experimental researches show the fallacy of this opinion. Two water syphons, e e e, f f f, made of glass tubes, one fifth of an inch in the bore, were inserted into the tuyere, containing water in the portions, g g g, h h h. The one of these manometers for measuring the pressure of the air was inserted at k, the other in the centre of the nozzle.'The size of this glass tube was too small to obstruct in any sensible degree the outlet of the air. It was found that when the tuyeres of the fan discharged into the open air, the expenditure by a nozzle of a constant diameter was proportional to the number of the revolutions of the vanes. It was further found, that when the speed of the vanes was constant, the expenditure by one or by two nozzles was proportional to the total area of these nozzles. The following formulae give the volume of air furnished by the fan, when the number of turns and the area of the nozzles are known. 25-32 S n Volume = (1) 1'000,000 0-86'6'7 S n Volume = - (2) 1,000,000 The volume is measured at 32~ Fahr., under a pressure of 29'6 inches barom. S = is the total area of the orifices of the tuyeres in square inches. n = the number of turns of the vanes in a minute. After measuring the speed of the vanes blowing into the atmosphere, if we introduce the nozzle of discharge into the orifice of the furnace, we shall find that their speed immediately augments in a notable degree. We might. therefore, naturally suppose that the fan furnishes more air in the second case than in the first; but a little reflection will show that it is not so. In fact, the air which issues in a cold state from the tuyere encounters instantly in the furnace a very high temperature, which expands it, and contributes, along with the solid matters with which the furnace is filled, to diminish the facility of the discharge, and consequently to retard the efflux by the nozzles. The oxygen gas consumed is replaced by a like volume of carbonic acid gas, equally expansible by heat. Reason leads us to conclude that less air flows from the nozzles into the furnace than into the open atmosphere. The increase in the velocity of the vanes takes place precisely in the same manner, when after having made the nozzles blow into the atmosphere, we substitute for these nozzles others of a smaller diameter, instead of directing the larger ones into the furnace. Hence we may conceive that the proximity of the charged furnace acts upon the blast like the contraction of the nozzles. When the moving power is uniform, and the velocity of the vanes remains the same, the quantity of air discharged must also be the same in the two cases. Two tuyeres, one 5 inches in diameter, the other 41, and which, consequently, presented a total area of 351 square inches, discharged air into one of the furnaces, from a fan whose vanes performed 654 turns in the minute. These two nozzles being briskly withdrawn from the furnace, and turned round to the free air, while a truncated pasteboard cone of 3} inches diameter was substituted for the nozzle of 4j inches, whereby the area of efflux was reduced to 29'3 square inches, the velocity of the vanes continued exactly the same. The inverse operation having been performed, that is to say, the two original nozzles having been smartly replaced in the furnace, to discover whether or not the moving power had changed in the interval of the experiment, they betrayed no perceptible alteration of speed. From the measures taken to count the speed, the error could not exceed 3 revolutions per minute, which is altogether unimportant upon the number 654. 814 FREEZING. It follows, therefore, that when the vanes of the fan have the velocity of 654 turns pel minute, the expenditure by two nozzles, whose joint area is 35~ square inches, both blowing into a furnace, is to the expenditure which takes place, when the same nozzles blow into the air, as 35-5 is to 29'3; that is, a little more than four fifths. If this be, as is probable, a general rule for areas and speeds considerably differen. from the above, to find the quantity of air blown into one or more furnaces by the fan, we should calculate the volume by one of the above formulae (1) or (2), and take four fifths of the result as the true quantity. The fan A C here represented is of the best eccentric form, as constructed by Messrs. Braithwaite and Ericsson. D is the circular orifice round the axis by which the air is admitted; and c c B is the eccentric channel through which the air is wafted towards the main discharge pipe E. FOUNTAIN; a stream of water rising up through the superficial strata of the earth. See ARTESIAN WELLS. FOXING is a term employed by brewers to characterize the souring of beet in the process of its fermentation or ripening. FRANKFORT BLACK is made by calcining vine branches, and the other refuse lees of the vinegar vats in Germany. They must be previously washed. FREEZING. (Congelation, Fr.; Gefrierung, Germ.) The three general forms, solid, liquid, and gaseous, under one or other of which all kinds of mattel exist, seem to be immediately referable to the influence of heat; modifying, balancing, or subduing the attraction of cohesion. Every solid may be liquefied, and every liquid may be vaporized, by a certain infusion of caloric, whether this be regarded as a moving power or an elastic essence. The converse of this proposition is equally true; for many gases, till lately styled permanent, may be liquefied, nay, even solidified, by diminution of their temperature, either alone, or aided by a condensing force, to bring their particles within the sphere of aggregative attraction. When a solid is transformed into a liquid, and a liquid into a gas or vapor, a quantity more or less considerable of heat is absorbed, or becomes latent, to use the term of Dr. Black, the celebrated discoverer of this great law of nature. When the opposite transformation takes place, the heat absorbed is again emitted, or what was latent becomes sensible caloric. Upon the first principle, or the absorption of heat, are founded the various artificial methods of producing cold and congelation. Tables exhibiting a collective view of all the Frigorific Mixtures contained in Mr. Walker's publication, 1808. I.-Table consisting of Frigorific Mixtures, composed of ice, with chemical salts and acids. Frigorific Mixtures with Ice. MIXTURES. Thermometer sinks. Degree of cold produced. Snow, or pounded ice - 2 parts ( to - 50 Muriate of soda - 1 Snow, or pounded ice - 5 parts: Muriate of soda - - 2 I to -- 12 * Muriate of ammonia- - 1 I ____ Snow, or pounded ice -24 parts Muriate of soda - - 10 r t -- ~ Muriate of ammonia - 5 Nitrate of potash - - 5 Snow, or pounded ice - 12 parts _ Muriate of soda - -5 to- 25~ Nitrate of ammonia- - 5 Snow - - 3 parts From + 320 to - 23~ 55 Diluted sulphuric acid - 2 1 _ Snow - 8 parts From + 32~ to - 27 59 Snow - - 7 parts From + 32~ to - 30~ | 62 Diluted nitric acid - - 4 __ Snow - - 4 parts From + 320 to - 400 72 Muriate of lime - - 5 Snow - 2 parts ) From + 32~ to- 500 82 Cryst. muriate of lime - 3 __ Snow - - parts From + 320 to - 51~ 83 _Potash - - FREEZING. 815 N. B.-The reason for the omissions in the last column of the preceding table is, the thermometer sinking in these mixtures to the degree mentioned in the preceding column, and never lower, whatever may be the temperature of the materials at mixing. II.-Table, consisting of Frigorific Mixtures, having the power of generating or creating cold, without the aid of ice, sufficient for all useful and philosophical purposes, in any part of the world at any season. Frigorific Mixtures without Ice. MIXTURES. Thermometer sinks. Degree of cold produced. Muriate of ammonia - -5 parts Nitrate of potash - - 5 Frorm + 50~ to + 10~ 40~ Water - - - 16 Muriate of ammonia - 5 parts Nitrate of potash - - 5 From + 50~ to + 4~ 46 Sulphate of soda - - 8 From 50to + 4 Water - - -16_ Nitrate of ammonia - 1 part From 50 to 4 46 Water - - -1 Nitrate of ammonia - - 1 part Carbonate of soda. - - 1 From + 50~ to- 7~ 57 Water - - - 1____ Sulphate of soda - 3 parts From 50 to 30 53 Diluted nitric acid - - 2 Sulphate of soda - - 6 parts Muriate of ammonia - 4 Nitrate of potash - - 2From 50 to 10 60 Diluted nitric acid - -4 Sulphate of soda - - 6 parts - Nitrate of ammonia - - 5 From - 50~ to -14~ 64 Diluted nitric acid - - 4 Phosphate of soda - 9 parts From +50o -12 62 Diluted nitric acid - 4 Fom 50 to - 124 62 Phosphate of soda - - 9 parts Nitrate of ammonia - - 6 From - 50~ to - 21~ 71 Diluted nitric acid - - 4 Sulphate of soda - 8parts From +- 50 to 00 50 Muriatic acid - - - 5 Sulphate of soda - 5parts From + 50 to + 347 Diluted sulphuric acid - 4 1 I N. B.-If the materials are mixed at a warmer temperature than that expressed in the table, the effect will be proportionably greater; thus, if the most powerful of these mixtures be made when the air is + 85~, it will sink the thermqmeter to +- 2. III.-Table consisting of Frigorific Mixtures selected from the foregoing Tables, and combined so as to increase or extend cold to the extremest degrees. Combinations of Frigorific Mixtures. MIXTURES. Thermometer sinks. Dere of dcld I produced. Phosphate of soda - -5 parts I Nitrate of ammonia - - 3 From 0~ to - 34~ 34~ Diluted nitric acid - - 4 _] Phosphate of soda - - 3parts Nitrate of ammonia - - 2 From- 34 to-50~ 16 Diluted mixed acids - - 4 Snow - - k3 parts From 0~ to-46~ 46 Diluted nitric acid - 2 I ~,~~____. 816 FUEL. TABLE III.-continued. MIXTURES Thermometer sinks. Deg. of cold produced. Snow - -8 parts Diluted sulphuric acid - 3 From - 10~ to - 56~ 46 Diluted nitric acid - - 3 Snow - - -- - 1 part From - 20 to- 60 40 Diluted sulphuric acid. - -1 Snow -teof e3 part From + 200 to- 48~ 68 Muriate of lime 4 parts Frm | 53 SnowV - 3 parts From + 100 to - 540 64 Muriate of lime - - to Snow - - - parts Diluted sulphuric acid - -l10 From - 68 to -91 | 235 Snow -- Ipart From O to - 660 66 Cryst. muriate of lime - 2- Snow-1 part i From- 401 to- 730 33 Cryst. muriate of lime - - 3 Snow....- 1 parts From- 680 to -911 T Diluted sulphuric acid - -10 2 N. B.-The materials in the first column are to be cooled, previously to mixing, to the temperature required, by mixtures taken from either of the preceding tables. Water absorbs.1000 degrees of heat in becoming vapor; whence, if placed in a saucer within an exhausted receiver, over a basin containing strong sulphuric acid, it will freeze by the rapid absorption of its heat into the vapor so copiously formed under these circumstances. But the most powerful means of artificial refrigeration is afforded by the evaporation of liquefied carbonic acid gas; for the frozen carbonic acid thus obtained has probably a temperature 100~ under zero; so that when a piece of it is laid upon quicksilver, it instantly congeals this metal. The more copious discussion of this subject belongs to chemical science. FRENCH BERRIES; Berries of Avignon. FRICTION, counteraction of; see LUBRICATION. FRIT; see ENAMEL and GLASS. FUEL (Combustible, Fr.; Brennstoff, Germ.) Such combustibles as are used for fires or furnaces are called fuel, as wood, turf, pitcoal. These differ in their nature and in their power of giving heat. I. Wood, which is divided into hard and soft. To the former belong the oak, the beech, the alder, the birch, and the elm; to the latter, the fir, the pine of different sorts, the larch, the linden, the willow, and the poplar. Under like dryness and weight different woods are found to afford equal degrees of. heat in combustion. Moisture diminishes the heating power in three ways; by diminishing the relative weight of the ligneous matter, by wasting heat in its evaporation, and by causing slow and imperfect combustion. If a piece of wood contain, for example, 25 per cent. of water, then it contains only 75 per cent. of fuel, and the evaporation of that water will require -L part of the weight of the wood. Hence the damp wood is of less value in combustion by -2 or 2 than the dry. The quantity of moisture in newly felled wood amounts to from 20 to 50 per cent.; birch contains 30, oak 35, beech and pine 39, alder 41, fir 45. According to their different natures, woods which have been felled and cleft for 12 months contain still from 20 to 25 per cent. of water. There is never less than 10 per cent. present, even when it has been kept long in a dry place, and though it be dried in a strong heat, it will afterwards absorb 10 or 12 per cent. of water. If it be too strongly kiln dried, its heating powers are impaired by the commencement of carbon ization, as if some of its hydrogen were destroyed. It may be assumed as a mean of many experimental results, that 1 pound of artificially dried wood will heat 35 pounds of water from the freezing to the boiling point; and that a pound of such wood as contains from 20 to 25 per cent. of water will heat 26 pounds of ice-cold water to the same degree. It is better to buy wood by measure than by weight, as the bulk is very little increased by moisture. The value of different woods for fuel is inversely as their moisture, and this may easily be ascertained by taking their shavings, drying them in a heat of 140~ F., and seeing how much weight they lose. From every combustible the heat is diffused either by radiation or by direct communication to bodies in contact with the flame. In a wood fire the quantity of radiating heat is to that diffused by the air as 1 to 3; or it is one fourth of the whole heating power FUEL. 817 II. Charcoal. The different charcoals afford, under equal weights, equa quantities ot heat. We may reckon, upon an average, that a pound of dry charcoal is capable of heating 73 pounds of water from the freezing to the boiling point; but when it has been for some time exposed to the air, it contains at least 10 per cent. of water, which is partially decomposed in the combustion into carbureted hydrogen, which causes flame, whereas pure dry charcoal emits none. A cubic foot of charcoal from soft wood. weighs, upon an average, from 8 to 9 pounds, and from hard wood 12 to 13 pounds; and hence the latter are best adapted to maintain a high heat in a small compass. The radiating heat from charcoal fires constitutes one third of the whole emitted. III. Pitcoal. The varieties of this coal are almost indefinite, and give out very various quantities of heat in their combustion. The carbon is the heat-giving constituent, and it amounts, in different coals, to from 75 to 95 per cent. One pound of good pitcoal will, upon an average, heat 60 pounds of water from the freezing to the boiling point. Small coal gives out three fourths of the heat of the larger lumps. The radiating heat emitted by burning pitcoal is greater than that by charcoal. IV. The coke of pitcoal.-The heating power of good coke is to that of pitcoal as 75 to 69. One pound of the former will heat 65 pounds of water from 32~ to 212~; so that its power is equal to nine tenths of that of wood charcoal. V. Turf or peat.-One pound of this fuel will heat from 25 to 30 pounds of water from freezing to boiling. Its value depends upon its compactness and freedom from earthy particles; and its radiating power is to the whole heat it emits in burning as 1 to 3. VI. Carbureted hydrogen or coal gas.-One pound of this gas, equal to about 24 cubic feet, disengages, in burning, as much heat as will raise 76 pounds of water from the freezing to the boiling temperature. In the following table the fourth column contains the weight of atmospherical air, whose oxygen is required for the complete combustion of a pound of each particular substance. Pounds of water Pounds of boiling Weigh. af atmospheric Species of combustible. which a pound can water evaporated by air at 32~, to burn heat from 0~ to 212~. 1 pound. 1 pound. Perfectly dry wood - 35-00 6-36 5-96 Wood in its ordinary state 26-00 4-72 4-47 Wood charcoal - - 7300 13-27 11-46 Pitcoal - - - 60-00 10-90 9-26 Coke - - - 6500 11-81 11-46 Turf - - - 3000 5-45 4-60 Turf charcoal - 64-00 11-63 9-86 Carbureted hydrogen gas- 76-00 13-81 14-58 Oil ) Wax - - 78-00 14-18 15-0( Tallow Alcohol of the shops - 52-60 9-56 11-60 The quantity of air stated in the fourth column is the smallest possible required to burn the combustible, and is greatly less than would be necessary in practice, where much of the air never comes into contact with the burning body, and where it consequently never has its whole oxygen consumed. The heating power stated in the second column is also the maximum effect, and can seldom be realized with ordinary boilers. The draught of air usually carries off at least 1 of the heat, and more if its temperature be very high when it leaves the vessel. In this case it may amount to one half of the whole heat or more; without reckoning the loss by radiation and conduction, which, however, may be rendered vdry small by enclosing the fire and flues within proper non-conducting and non-radiating materials. It appears that, in practice, the quantity of heat which may be obtained from any combustible in a properly mounted apparatus must vary with the nature of the object to be heated. In heating chambers by stoves, and water boilers by furnaces, the effluent heat in the chimney which constitutes the principal waste may be reduced to a very moderate quantity, in comparison of that which escapes from the best constructed reverberatory hearth. In heating the boilers of steam engines, one pound of coal is reckoned adequate to convert 7- pounds of boiling water into vapor; or to heat 411 pounds of water from the freezing to the boiling point. One pound of fir of the usual dryness will evaporate 4 pounds of water, or heat 22 pounds to the boiling temperature; which.is about two thirds of the maximum effect of this combustible. According to Watt's experiments upon the great scale, one pound of coal can boil off, with the best built boiler, 9 pounds of water; the deficiency from the maximum effect being here 10, or nearly one sixth. In manre cases, the hot air which passes into the flues or chimneys may be bene. 818 FUEL. ficially applied to the heating, drying, or roasting u( objects; but ~re ought to be taken that the draught of the fire be not thereby impaired, and an imperfect combustion of the fuel produced. For at a low smothering temperature both carbonic oxyde and carburet. ed hydrogen may be generated from coal, without the production of much heat in the fire-place. To determine exactly the quantity of heat disengaged by any combustible in the act of burning, three different systems of apparatus have been employed: 1. the calorimeter of Lavoisier and Laplace, in which the substance is burned in the centre of a vessel, whose walls are lined with ice; and the amount of ice melted, measures the heat evolved; 2. the calorimeter of Watt and Rumford, in which the degree of heat communicated to a given body of water affords the measure of temperature; and 3. by the quantity of water evap. orated by different kinds of fuel in similar circumstances. If our object be to ascertain-the relative heating powers of different kinds of fuel, we need not care so much about the total waste of heat in the experiments, provided it be the same in all; and therefore they should be burned in the same furnace, and in the -ame way. But the more economically the heat is applied,'i.e greater certainty will r ^~~b.there be in the results. The apparatusfig. 663, is simple and well adapted to make such comparative trials of fuel. The little furnace is 663 ^n-llHa ~6 - ifcovered at top, and transmits its burned a r by c, through a spiral tube immersed in a cistern of water, having a thermometer inserted near its top, and another near its bottom, into little side orifices a a, while the effluent air escapes from the:~ JcC upright end of the tube b. Here also a thermometer bulb may be placed. The average indication of the two thermometers gives the mean temperature of the water. As the water evaporates from the cistern, it is supplied from a vessel placed alongside of it. The experiment should be begun when the furnace has acquired an equaiility of temperature. A throttle valve at c serves to regulate the draught, and to equalize it in the different experiments by means of the temperature of the effluent air. When the water has been heated the given number of degrees, which should be the same in the different experiments, the fire may be extinguished, the remaining fuel weighed, and compared with the original quantity. Care should be taken to make the combustion as vivid and free from smoke as possible. On the measurement of heat, and the qualities of different kinds of coal, I made an elaborate series of experiments. a few years agro. of which the following is an outline. The first and most celebrated, though probably not the most accurate apparatus for measuring the quantity of heat transferable from a hotter to a colder body, was the calorimeter of Lavoisier and Laplace. It consisted of three concentric cylinders of tin plate, placed at certain distances asunder; the two outer interstitial spaces being filled with ice, while the innermost cylinder received the hot body, the subject of experiment. The quantity of water discharged from the middle space by the melting of the ice in it, served to measure the quantity of heat given out by the body in the central cylinder. A simpler and better instrument on this principle would be a hollow cylinder of ice of proper thickness, into whose interior the hot body would be introduced, and which would indicate by the quantity of water found melted within it the quantity of heat absorbed by the ice. In this case, the errors occasioned by the retention of water among the fragments of ice packed into the cylindric cell of the tin calorimeter, would be avoided. One pound of water at 172~ F., introduced into the hollow cylinder above described, will melt exactly one pound of ice; and one pound of oil heated to 172~ will melt half a pound. The method of refrigeration, contrived at first by Meyer, has been in modern times brought to great perfection by Dulong and Petit. It rests on the principle, that two surfaces of like size, and of equal radiating force, lose in like times the same quantity cf heat when they are at the same temperature. Suppose for example, that a vessel of polished silver, of small size, and very thin in the metal, is successively filled with different pulverized substances, and that it is allowed to cool from the same elevation of temperature; the quantities of heat lost in the first instant of cooling will be always equal to each other; aud if for one of the substances, the velocity of cooling is double of that for another, we may conclude that its capacity for heat is one half, when its weight is the same; since by losing the same quantity of heat, it sinks in temperature double the number of degrees. The method of mixtures.-In this method, two bodies are always employed; a hot body which becomes cool, and a cold body, which becomes hot, in such manner that all FUEL. 819 the caloric which goes out of the former is expended in heating the latter. Suppose for example, that we pour' a pound of quicksilver at 212~ F., into a pound of water at 32~; the quicksilver will cool and the water will heat, till the mixture by stirring acquires a common temperature. If this temperature was 122~, the water and mercury would have equal capacities, since the same quantity of heat would produce in an enual nass of these two substances equal changes of temperature, viz., an elevation of 90~ in the water and a depression of 90~ in the mercury. But in reality, the mixture is found to have a temperature of only 37'0, showing that while the mercury loses 17420 the water gains only 5~0; two numbers in the ratio of about 32 to 1; whence it is concluded, that the can acity of mercury is 1 of that of water. Corrections must be made for the influence of the vessel and for the heat dissipated during the time o the experiment. The following calorimeter, founded upon the same principle as t. it of Count Rumford, but with certain improvements, may be considered as an et —'lly correct instrument for measuring heat, with any of the preceding, but one of much more general application, since it can determine the quantity of heat disengaged in combustion, as well as the latent heat of steam and other vapors. 664 I' (Scale about i inch to the toot.) It consists of a large copper bath, e,f (fig. 664), capable of holding 100 gallons of water. It is traversed four times, backward and forward, in four different levels, by a zig-zag horizontal flue, or flat pipe d, c, nine inches broad and one deep, ending below in a round pipe at c, which passes through the bottom of the copper bath e, f, and receives there into it the top of a small black lead furnace h. The innermost crucible contains the fuel. It is surrounded at the distance of one inch by a second crucible, which is enclosed at the same time by the sides of the outermost furnace; the strata of stagnant air between the crucibles serving to prevent the heat from being dissipated into the atmosphere round the body of the furnace. A pipe a, from a pair of cylinder double bellows, enters the ash-pit of the furnace at one side, and supplies a steady but gentle blast, to carry on the combustion, kindled at first by half an ounce of red-hot charcoal. So completely is the heat which is disengaged by the burning fuel absorbed by the waoer in the bath, that the air discharged at the top orifice g, has usually the same temperature as the atmosphere. The vessel is made of copper, weighing two pounds per square foot; it is 5. feet long, 11 wide, 2 deep, with a bottom 5' feet long, and 1 broad, upon an average. Including thie zig-zag tin plate flue, and a rim of wrought iron, it weighs altogether 85 pounds. Since the specific heat of copper is to that of water as 94 to 1,000; the specific heat of the vessel is equal to that of 8 pounds of water, for which, therefore, the exact correction is made by leaving 8 pounds of water out of the 600, or 1,000 pounds used in each experiment. In the experiments made with former calorimeters of this kind, the combustion was maintained by the current or draft of a chimney, open at bottom, which carried off at the top orifice of the flue a variable quantity of heat, very difficult to estimate. When the object is to determine the latent heat of steam and other vapors, they mav be introduced through a tube into the orifice g, the latent heat being deduced from the elevation of temperature in the water of the bath, and the volume of vapor expended 53 820 FUEL. from the quantity of liquid discharged into a measure glass from the bottom outlet c [n this case, the furnace is of course removed. Tile heating power of the fuel is measured by the number of degrees of temperature which the combustion of one pound of it, raises 600 or 1,000 pounds of water in the bath, the copper substance of the vessel being taken into account. One pound of dry wood charcoal by its combustion causes 6,000 pounds of water to become 20~ hottes. For the sake of brevity, we shall call this calorific energy 12,000 unities. In like circumstances, one pound of Llangennoek coal will yield by combustion 11,500 unities of caloric. One pound of charcoal after exposure to the air gives out in burning only 10,500 unities; but when previously deprived of the moisture which it so greedily imbibes from the atmosphere, it affords the above quantity. One pound of Lambton's Wall's-end coals, affords 8,500 unities; and one of anthracite 11,000. It must be borne in mind that a coal which gives off much unburnt carburetted hydrogen gas, does not afford so much heat, since in the production of the gas a great deal of heat is carried off in the latent state. I have no doubt, that by this distillatory process, from one third to one fourth of the total calorific effect of many coals is dissipated in the air. But by means of such a furnace as the patent Argand invention of Mr. C. W. Williams, the whole heat produceable by the hydrogen as well as the carbon is obtained; and it should be borne in mind that a pound of hydrogen in burning gener ates as much heat as three pounds of carbon. Mr. Berthier proposes to determine the proportion of carbon in coals arc other kinds of fuel, by igniting in a crucible a mixture of the carbonaceous b.atter w.th litharge, both finely comminuted, and observing the quantity of lead which is reduced. For every 34 parts of lead, he estimates 1 part of carbon, apparently on the principle, that when carbon is ignited in contact with abundance of litharge, it is converted into carbonic acid. Each atom of the carbon is therefore supposed to seize two atoms of oxygen, for which it must decompose two atoms of litharge, and revive two atoms of lead. Calling the atom of carbon 6, and that of lead 104, we shall have the following ratio:-6: 104X2:: 1: 34.66, being Berthier's proportion, very nearly. On subjecting this theory to the touchstone of experiment, I have found it to be en tirely fallacious. Having mixed very intimately 10 grains of recently calcined charcoal with 1,000 grains of litharge, both in fine powder, I placed the mixture in a cruc.m.e which was so carefully covered, as to be protected from all fuliginous fumes, and exposed it to distinct ignition. No less than 603 grains of lead were obtained; whereas by Berthier's rule, only 340 or 346.6 were possible. On igniting a mixture of 10 grains of pulverized anthracite from Merthyr Tydfil, with 500 grains of pure litharge (previously fused and pulverized), I obtained 380 grains of metallic lead. In a second similar experiment with the same anthracite and litharge, I obtained 450 grains of lead; and in a third only 350 grains. It is therefore obvious that this method of Berthier is altogether nugatory for ascertaining the quantity of carbon in coals, and is worse than useless for judging of the calorific qualities of different kinds of fuel. In my researches upon coals, I have also made it one of my principal objects to determine the quantity of sulphur which they may contain; a point which has been hitherto very little investigated in this country at least, but which is of great consequence, not only in reference to their domestic combustion, but to their employment by manufacturers of iron and gas. That good iron can not be produced with a sulphureous coal, however well coked, has been proved in France by a very costly experience. The presence of a notable proportion of sulphur in a gas coal is most injurious to the gaseous products, because so much sulphuretted hydrogen is generated as to require an operose process of washing or purification, which improverishes the gas, and impairs its illuminating powers by the abstraction of its olefiant gas, or bicarburetted hydrogen. In proof of this proposition, I have only to state the fact, that I found in a specimen of coal gas as delivered from the retorts of one of the metropolitan companies, no less than 18 per cent. of olefiant gas, while in the same gas, after being passed through the purifiers, there remained only 11 per cent. of that richly-illuminating gas. By using a gas-coal, nearly free from sulphur, such as No. 4, in the subjoined list, I think it probable that 10 per cent. of more light may be realized than with the common more sulphureous coal. This is an important circumstance which the directors of gasworks have hiterto neglected to investigate with analytical precision, though it is one upon which their success and profits mainly depend. How little attention indeed has been bestowed upon the sulphureous impregnation of pit-coal may be inferred from the fact that one of our professional chemists of note, in a public report, upon a great commercial enterprise, stated that a certain coal analyzed by him was free from sulphur, which coal I found by infallible chemical evidence to contain no less than 7 per cent. of sulphur, being about the double of what is contained in English coals of average quality. The proportion of sulphur may in general be inferred from the appearance and quantity of the ashes. If these be of a red or ochrey color, and amount to above 10 per cent., we may be sure that the coal is eminently FUEL. 821 snlphureous. The coal above referred to afforded fror- 15 to 16 per cent. of ferrugin ous ashes. I believe that sulphur exists in coal generally, though not always in the state ol pyrites, either in manifest particles, or invisibly disseminated through their substance. The readiest method of determining rigidly the quantity of sulphur in any compound, is to mix a given weight of it with a proper weight of carbonate of potassa, nitre, and common salt, each chemically pure, and to ignite the mixture in a platinum crucible. A whitish mass is obtained, in which all the sulphur has been converted into sull)hate of potassa. By determining with nitrate of baryta the amount of sulphuric acid produced, that of the sulphur becomes known. By means of this process applied to dif. ferent samples of coals, I obtained the following results:Gas Sulphur in Gas Sulphur in Coals. 10d parts. Coals. 10o parts. No. 1 - 3-00 No. 5 - - - - 250 2 - - - - 390 6 - - 520 3 - - - - 242 7 - - - 340 4 - - - - 380 8 - - - - 350 Coals for puddling cast iron, Sulphur in to be converted into steel, 10(0 parts No. 1, hard foliated or splent coal, specific gravity 1'258 0*80 2, ditto - - - - 1-290 0*96 3, ditto - - -- - - 1273 3-10 4, cubical and rather soft - - - 1-267 0'80 Thi lasi coal being rich in bitumen, would prove an excellent one for the production of a pure coal gas. See PITCOAL. FUEL, ECONOMY OF. In the report of the Transactions of the Institution of Civil Engineers for February, 1838, the results of exact comparisons between the performance of different steam-engines exhibit this economy in a remarkable manner. It is there shown that a condensing engine of the most perfect construction, and in perfect condition, ot the common low pressure crank-kind, not working expansively, performs a duty of not more than 20 or 21 millions of lbs. raised one foot high, by 90 or 94 lbs. of coal; or ten lbs. of coal per horse power per head The following table exhibits the relative value of different engines in lbs. of coal per horse power per hour:Cornish Pumping Engine - --- 157 Bolton and Watt's Single Engine - - - - 4'82 Cornish Double Engine - - - 325 Bolton and Watt's Double Engine - - - - 10'5 The greatest duty performed by the measured bushel of 84 lbs. was 86- millions of Ibs. There was raised by the Huel Towan engine in Cornwall 1,085 tons (of water) one foot high for one farthing. Hence the weight of a man (1L cwt.) would be raised ten miles for one penny! In order to raise steam with economy, the surface of water in the boiler, exposed to the fire, ought not to be less thon 10 square feet per horse power; but the usual allowance in Lancashire is only 74; and by Messrs. Boulton and Watt, 5 square feet. The values of the mean of the Cornish, Warwick, Londop, Lancashire, and locomotive experiments, as reported by Mr. Josiah Parkes, were respectively 21, 18, 134, and 10 cubic feet of water evaporated by 112 lbs. of coals, from water heated to 212~ F. FUEL, GRANT'S PATENT. This fuel is composed of coal-dust and coal-tar pitch; these materials are mixed together, under the influence of heat, in the following proportions:-20 lbs. of pitch to 1 cwt. of coal-dust, by appropriate machinery consisting of crushing-rollers for breaking the coal in the first instance sufficiently small, so that it may pass through a screen the meshes of which do not exceed a quarter of an inch asunder; 2dly, of mixing-pans or cylinders, heated to the temperature of 220~, either by steam or heated air; and, 3dly, of moulding machines, by which the fuel is compressed, under a pressure equal to five tons, into the size of a common bick; the fuel bricks are then whitewashed, which prevents their sticking together, either ir. the coal bunkers or in hot climates. The advantages of Grant's fuel over even the btst coal may be stated to consist, first, in its superior efficacy in generating steam, which may be thus stated-200 tons of this fuel will perform the same work as 30t t)ns of coal, such as are generally used; secondly, it occupies less space; that is to say, 500 tons of it may be stowed in an area which will contain only 400 tons of coal;.hirdly, it is used with much greater ease by the stokers or firemen than coal, and it creates little or no dirt or dust, considerations of some importance when the delicate machinery of a steam-engine is considered' fourthly, it produces a very small propor tion of clinkers, and thus it is far less liable to choke and destroy the furnace bats and 822 FUEL. boilers than coal; fifthly, the ignition is so complete that comparatively little smoke, &nd only a small quantity of ashes, are produced by it; sixthly, from the mixture of the patent fuel, and the manner of its manufacture, it is not liable to enter into spontaneous ignition. FUEL CHIEFLY PIT COAL. "Considering the vast importance of the subject, it is somewhat remarkable that no exact mode of determining the true value of coal as a fuel has ever yet been invented. Of the methods hitherto in use there is not one which deserves the title even of an approximation to the truth. The plan of Berthier, as has been well shown by Dr. Ure, is beyond all things fallacious, though this very plan is that most relied on by the experimenters connected with the late Admiralty investigation respecting the coals best suited for the steam navy. It needs, however, but a moment's reflection to see that this process of Berthier can never afford a correct result, for the agent employed is litharge, a substance not acted on at all until exposed to heat more than sufficient for the expulsion of the volatile constituents of coal, and moreover a substance capable of being reduced at high temperatures by the carbonic oxide gas of the fire employed to effect the assay. Here then are two enormous sources of error; for in the first place the hydrogenous constituents of the coal can never be estimated at all, and in the second the litharge by mere exposure in a crucible to the action of the fire will give metallic lead exactly the same as if coal existed in it, so that not the least dependence in the world can be placed in this method. Numerous and carefully conducted experiments have fully confirmed the original observations of Dr. Ure upon this matter, and, in fact, the results from four crucibles, each charged with the same quantities of coal and litharge, taken from the same massive powder, and placed side by side in the same furnace, and treated in all respects exactly alike, have shown a discordance equal to the numbers 117, 142, 156, and 163. To think of attaching any value to any of these, or to the average which they present, is to lose sight of the most important province of chemistry in its relation to the arts. "Another, and certainly a preferable method, is to consume a given amount of each coal in a calorimeter, so as to measure the total heat disengaged during combustion. But here, again, we meet with difficulties more than enough to destroy all confidence in the results. Thus it is not possible thoroughly to consume the whole of the fuel in this way. Of the volatile constituents of the coal, a portion always passes off unburnt in the shape of carburetted hydrogen, tar, and soot, whilst of the carbon or fixed constituents, part is constantly lost in the form of carbonic oxide gas. So that no real estimate of the calorific value of a coal can be arrived at in this way, and even comparative experiments are worthless fiom the great inequalities which prevail in the ratio of the volatile and fixed ingredients in different coals, as well as from the changes induced by accidental variations of draught through the body of the fuel. Of course the same objections apply to what are called practical experiments, conducted with any one particular form of furnace or setting of a boiler. The form of furnace, as is well known, requires to be adapted to the fuel, and not the fuel to the furnace: nevertheless, in the Admiralty experiments already alluded to, the only form of furnace and boiler employed was that called the Cornish setting, though this particular form was expressly invented for, and will, as is notorious, do justice to no other kind qf coal than anthracite. Hence the parliamentary reports which chronicles the results of the Procrustean theorem, though yet almost wet from the press, is even now rapidly on its road to the buttershop, there to expiate, by the humblest of services, its previous utter inutility to the public. To know the precise amount of heat evolved from coals during their combustion, must, as has been before remarked, be a subject of the greatest possible interest, for until the total calorific power be taken into account, it is impossible for us to appreciate the loss which ensues under the existing modes of consuming fuel. At present it seems generally agreed, that ordinary Newcastle coal will evaporate about 8 times its weight of water, or in other words, that a ton of such coal will boil off or con vert into steam 17,920 lbs. of water. If, however, we proceed to a practical analysis of this very coal, by examining the heating power of its gaseous and fixed constituents, after these have been separated from each other, we shall find that the above is very fai short of the most moderate estimate that can be formed of the heat which must be disengaged; and whether the difference be lost by imperfect combustion, or by the action of the chimney, or in what other way, remains still to be decided by those who seek to improve our present modes of consuming fuel. The following table represents the actual heat evolved, and of water evaporated, by the different constituents of one ton of the Newcastle coal called Pelton; and it must be remembered, that so far as chemical research has yet gone, the heat evolved from a combustible is in proportion to the amount of oxygen consumed, and has no connection with the particular mechanical state of the combustible. For instance, there is no reason to suppose that gaseous carbon, if we possessed such a substance, would evolve either more or less heat than its qquivalent -weight of solid carbon, in combiping with the same quantity of oxygen gas. Whether, therefore, we regard the constituents of coal as existing in the solid or gaseaou L_ —--------------------------- FUEL. 823 form, does not, according to our present knowledge, alter the proportion of heat which these constituents would give out during their perfect oxidation. Now one ton of Pelton coal affords 10,000 cubic feet of gaseous matters, 10 gallons or about 125 lbs. of tar, and 41 bushels or 1680 lbs. of coke; and, by experiment, it has been found that the above gas before purification will boil off for every cubic foot consumed 10t ounces of water; that 3 gallons of tar are equal to about one bushel of coke; and' that the coke will boil off 10 times its weight of water Hence we have the total amount of water evaporated as under: 10,000 cubic feet of gas at 10A ounces per foot = 6537 lbs. 10 gallons of tar equal to 3'33 bushels of coke = 1365 lbs. 1680 lbs. of coke at 10 lbs. per lb. - - = 16800 lbs. Total 24702 or upwards of 11 lbs. of water for every lb. of coal. It happens, however, that even this estimate is too low, and that actual experimern; on this very coal shows its true heating power to be not less than 12. To elucidate this it becomes necessary, however, to enter into an explanation of the means employed for ascertaining the precise amount of heat evolved by any combustible during its complete oxidation, and which is perhaps the only approach to accuracy that has yet been proposed with this view. A copper vessel, shaped like a parallelogram, and having in its ends two small openings provided with stop cocks, has also in its lower surface a large opening of two inches in diameter, terminating in a tube or neck of about two inches in length and fitted with an earthenware plug or stopper. This parallelogram is enclosed in another and larger one, capable of holding in addition 20 lbs. of water. The smaller vessel should have an internal capacity of about half a cubic foot, or 800 cubic inches, and the different openings must pass out of and through the larger vessel. The earthenware stopper is to be provided with two small openings, in which pass two insulated copper wires, and on the top of the stopper is a cavity capable of holding 50 grains of coal in coarse powder, through which a fine platinum wire passes connected with the terminal ends of the two copper wires, and over the whole a cage of stout platinum wire is placed so as to prevent the coal from being thrown out during the experiment, and also to insure the complete combustion of all the volatile and fuliginous matter. To use this apparatus, 50 grains of the coal in question are placed in the cavity of the stopper, and the necessary connections being made by means of a fine platinum wire, the cage is applied, and the whole inserted in the neck or opening left for it, and which it hermetically closes: as soon as this is completed, a current of oxygen gas is made to traverse the smaller vessel by means of the stop-cocks in the sides, and this is continued until the atmospheric air being almost wholly expelled, the vessel remains full of oxygen gas; when this is the case water must be poured into the larger vessel, and a piece of ice introduced into it until the temperature has fallen about 5~ below that of the apartment, when the ice must be withdrawn, and the coal lighted by means of a small galvanic battery, the poles of which need be applied but for a moment to the copper wires which pass through the earthenware stopper. Ignition instantly ensues, and is finished in two or three seconds, when the heat of the water in the larger vessel must be ascertained by a delicate thermometer, after proper agitation. It is of course necessary to take the usual precautions followed in experiments of this kind, and to surround the whole of the larger vessel by non-conductors of caloric, having carefully determined beforehand the absorption of heat due to the apparatus, so that this may be added to that of the water; the water itself should either be actually weighed or measured with great accuracy at a mean temperature, and the ice must also be weighed before and after immersion. The accompanying sketch in section will perhaps facilitate the comprehension of this instrument. ^A~ ^==^~~ _~' A, cover made of wood; B, larger A-~ - -- 3 vessel of copper; c, smaller vessel of copper; D, entrance for oxygen gas; 3B E, exit for atmospheric air; F, platinum cage; G, earthenware stopper!~c (~ | with cavity in top; H H, copper wires for conveying electricity, between the VF | upper extremities of which a fine plas| t. I~~ ~ tinum wire is loosely stretched which "Gil ^ W sl^ passes through the mass of powdered coal. The results hitherto obtained by _________ _____ ___ \t this apparatus are not very extensive, but nevertheless they embrace sub 824 FUEL. stantially many of the best established coals, and as might d priori be imagined, they moreover demonstrate in an undeniable manner the superiority of bituminous over anthra. citic coals and coke,-a position directly the reverse of the absurd assumptions and foregone conclusions contained in the parliamentary report of Sir H. de la Beche and Dr. Playfair. The following is a tabular view of these results, with a column showing the evaporative power of each, deduced by assuming 980 as the latent heat of steam. Lbs. of Water Unities of Caloric. capable of being evaporated by 1 lb. of Coal. N EWCASTLE: Pelton -- - - - - 14800 15-1 lbs Garesfield (Bates) -.. 15200 155 Hastings Hartley - - - 16175 165 - West Hartley - - - - 16280 166 - Bates Hartley - -.. 15985 163 - Newcastle Hartley..- 16330 166 - Heaton - - - 15075 156 - Gosford - - - 15000 153 - Killingworth - -..- 14875 151 - DURHAM: Hetton - - -.15660 160 - Lambton.. 15450 157 - Rainton -.-.. 14995 153 - YORKSHIRE: Woodthorpe 13780 14-0 - Mortemly.. 14010 14-3 - NORTH WALES: Brymbo -...... 1385 141 - Ruabon -....14200 14'5 - SOUTI WALES: Anthracite No. 1. - - 13090 133 - Anthracite No. 2. - 12875 131 - Neath (Bituminous) - - 18845 140 - IRELAND: Anthracite..- 12990 132 - WIGAN: Cannel Ince Hall.- -- 14340 146 - ScoTrcH: Lesmahago Cannel - - -. 12285 125 - NEWCASTLE: Ramsey's Cannel - 14420 14-7 - Comparing these results with the actual working of most of the above bituminous coals, it appears that very nearly one half of all the heat evolved is lost in practice, and either passes off in the shape of unconsumed fuel, or is wasted in the chimney. With a view to ascertain how much of the loss is due to this latter circumstance, Mr. F. J. Evans, the eminent engineer of the Westminster station of the Chartered Gas Company, made some time ago an experiment bearing upon this subject, and in which the loss of heat is necessa.ily very high, from the fact that the substance heated by the furnace was almost white hot, whereas in a steam boiler the temperature never exceeds 300~ of Fahr. Mr. Evans's experiment, which shows no trifling amount of ingenuity, nevertheless demonstrates that not more than 3 per cent. of the fuel passes off by the heat of the chimney; consequently at least 15 times this amount must be lost by imperfect combustion, and fly away in the shape of carburetted hydrogen, tarry vapour, or carbonic oxide; thus leaving a wide field for improvement in burning and applying fuel. We give the following in Mr. Evans's own words. FULLER'S EARTH. 825 "'Experiments on waste heat: to determine the quantity of heat going away to the chimney from a setting of 8 retorts. A deal box was constructed of the following dimlensions; length 5 feet 6 inches, width 11 inches, and depth 7 inches, and quite water-tight. Within this box, and running through it, was placed an iron tube of the following dimcisions; length 81 inches, width 9 inches, depth 3 inches. This tube formed by subsequent arrangement a portion of the flue through which the air from the furnace passed to the chimney, as is shown in the sketch below, where A represents an iron plate closing the main flue, and compelling the hot air to pass through the iron tube contained in th3 wooden box, into which water was ultimately placed, as will be explained. 4, MAIN FLUE E WOODEN BOX FOR WATERKL IRON' TUBE OR TEMPORARY L "'Matters being thus arranged, and the iron plate at A securely fixed, it r-ccssarily followed that all the heat from the setting of 8 retorts passed tl-rough the 81 inches of iron tube contained in the box, and would therefore impart heat to the water placed in that box, which was filled with this fluid at 71~ Fahr. to the e: tent of 112 lbs. This water being kept in constant motion afforded the annexed thermol -etric indications.'emperature of water. Commenced experiment at 6'45 - -- 71~ Observation made at 6-48 - - - - - 82 "' 6-51 - - - 94 (" 6-54 - - - - - 110 " 6657 - - - - - 114 7-01 - - - - 132 706 - - - - - 148 (" 1-07 - - - - - 150 Thus showing that 112 lbs. of water were raised 89~ in 22 minutes, which is equal to 252 lbs. of water at 32~ made to boil in each minute. Conseque tly in 24 hours 3628-8 lbs. of such water might be made to boil, or 604'1 lbs. of water be converted into steam in the same period of time, and as coke will evaporate, according to Lavoisier, more than 10 times its weight of water, this implies the consumption of nearly 60, lbs. of coke, the heat of which is entirely lost in the chimney. And if this be compared with the total coke consumed for 24 hours in the same setting of retorts, it amounts to about 3 per cent. only, and is therefore under the circumstances remarkably trifling.' Hence it would appear, as has been before remarked, that some very considerable improvements are needed in the present mode of consuming bituminous coals. The probability is, that a flat boiler surface exposed freely to a single sheet of flame fiom such coals is the best form, for it is certain that long narrow flues act like the meshes of wire gauze upon the volatile constituents, and cool them down below the point at which ignition can go on. In support of this view we have only to recollect that though the gases fiom a blast furnace will burn freely when they first issue from the furnace and are white hot, yet after being once cooled down to the ordinary temperature they refuse altogether to burn or afford heat. The use of long and narrow flues, with combustibles of low accendibility, is therefore highly improper, and sufficiently explains the miserable results arrived at by the Admiralty coal i vestigators with a Cornish boiler." —fr. L. Thompson. FULGURATION; designates the sudden brightening of the melted gold'nd silver in the cupel of the assayer, when the last film of vitreous lead and copper leaves their surface. FUILER'S EARTH, (Terre d foulon, Argile Smectique, Fr.; Walkererde, Germ.) is a soft, friable, coarse or fine grained mass of lithomarge clay. Its colour is Ereenish, or yellowish gray; it is dull, but assumes a fatty lustre upon pressure with the fingers, feels unctuous, does not adhere to the tongue, and has a specific gravity varyiLT from 1-82 to 2'19. It falls down readily in water, into a fine powder, with extrication of air bubbles, and forms a non-plastic paste. It melts at a high heat into a brown slag Its constituents are 53'0 silica; 10-0 alumina; 9-75 red oxide of iron; 1-25 magnesia; G'5 li!ne; 24 water, with a trace of potash. Its cleansing action upon woollen stuffs depends upon its power of absorbing greasy matters. It should be neither tenaci us qor sandy; for in the first case, it would not diffuse itself well through wa t 826 FULLING MILL. and in the secon it would abrade the cloth too much. The finely divided silica is ont of its useful ingredients. Fuller'> earth is found in several counties of England; but in greatest abundance i Bedfordshire, Berkshire, Hampshire, and Surry. In the county of Surry there are great quantities of fuller's earth found about Nut. field, Ryegate, and Blechingley, to the south of the Downs, and sor:e, but of inferior quality, near Sulton and Croydon, to the north of them. The most considerable pits are near Nutfield, between which place and Ryegate, particularly on Redhill, about a mile to the east of Ryegate, it lies so near the surface as fiequently to be turned up by the wheels of the wagons. The fuller's earth to the north of the road between Redhill and Nutfield, and about a quarter,f a mile from the latter place, is very thin; the seam in general is thickest on the swell of the hill to the south of the road. It is not known how lone this earth has been dug in Surry; the oldest pit now wrought is said to have lasted between 50 and 60 years, but it is fast wearing out. The seam of fuller's earth dips in different directions. In one, if not in more cases, it inclines to the west vith a considerable anile. There are two kinds of it, the blue and the yellow; the former, on the eastern side of the pit, is frequently within a yard of the surface, being covered merely with the soil-a tough, wet, clayey loam. A few yards to the west, the blue kind appears with an irony sand-stone, of nearly two yards in thickness, between it and the soil. The blue earth in this pit is nearly 16 feet deep. In some places the yellow kind is found lying upon the blue; there seems, indeed, to be no regularity either in the position or inclination of the strata where the fuller's earth is found, nor any mark by which its presence could be detected. It seems rather thrown in patches than laid in any continued or regular vein. In the midst of the fuller's earth are often found large pieces of stone of a yellow color, translucent and remarkably heavy, which have been found to be sulphate of barytes, encrusted with quartzose crystals. These are carefully removed from the fuller's earth, as the workmen say they often spoil many tons of it which lie about them. There is also found with the yellow fuller's earth a dark brown crust, which the workmen consider as injurious also. In Surry the price of fuller's earth seems to have varied very little, at least for these last 80 years. In 1730, the price at the pit was 6d a sack, and 6s. per load or ton. In 1744, it was nearly the same. It is carried in wazons, each drawinz fiorn three to four tons, to the beginning of the iron railway near Westham, along which it is taken to the banks of the Thames, where it is sold at the different wharves for about 25s. or 26s. per ton. It is then shipped off either to the north or west of England. The next characteristic stratum, owing to its forming a ridge of conspicuous hills through the country, is the Woburn land, a thick ferrllinous stratum, which below its middle contains a stratum of fuller's earth. This is thicker and more pure in Aspley and Hogstyeend, two miles north west of Woburn. than in any known place. Fuller's earth is found at Tillington, and consumed in the neighboring fulling mills. Mode of preparing fuller's earth:After baking it is thrown into cold water, where it falls into powder, and the separation of the coarse from the fine is effectually accomplished, by a simple method used in the dry color manufactories, called washing over. It is done in the following manner: Three or four tubs are connected on a line by spoutf from their tops; in the first the earth is beat and stirred, and the water, which is continually running from the first to the last through interme&_'te ones, carries with it and deposites the fine whilst the coarse settles in the first. The advantages to be derived from this operation are, that the two Kinds will be much fitter for their respective purposes of cleansing coarse or fine cloth; for without baking the earth they would be unfit, as before noticed, to incorporate so minutely with the water in its native state; it would neither so readily fall down, nor so easily be divided into different qualities, without the process of washing over. When fuel is scar e for baking the earth, it is broken into pieces of the same size, as mentioned above, and then exposed to the heat of the sun. The various uses of fuller's earth may be shortly explained. According to the above method, the coarse and fine of one pit being separated, the first is used for cloths of an inferior, and the second for those of a superior quality. The yellow and the blue earths of Surry are of different qualities naturally, and are, like the above, obtained artificially, and used for different purposes. The former, which is deemed the best, is employed in fulling the kerseymeres and finer cloths of Wiltshire and Gloucestershire, whilst the blue is principally sent into Yorkshire for the coarser cloths. Its effect on these cloths is owing to the affinity which alumine has for greasy substances; it unites readily with them, and forms combinations which easily attach themselves to different stuffs, and thereby serve the purpose of mordants in some measure. The fullers generally tpply it before they use the soap. FULLING; for the theory of the process, see FELTING and WOOL. FULLING MILL. Willan and Ogle obtained a patent in 1825 for improved ful FULMINATES. 827 667 ling machinery, designed to act in a similar way to the ordinary stocks, in which cloths are beaten, for the purpose of wash ing and thickening them; but the standard ^^ C c'"^^^ ^^ alid the bed of the stocks are made of iron instead of wood as heretofore; and a steam \d Y vessel is placed under the bed, for heating a\ 7 the cloths during the operation of fulling, c\ \ / //;;^;;;;N / ewhereby their appearance is said to be greatly improved. Fig. 667 is a section of the fulling machine or stocks; a is a cast-iron pillar, male h(Alow for the sake of lightness; b is the bed of the stocks, made also of iron, e\ \\^ _ and polished smooth, the side of the stock being removed to show the interior; c is the lever that carries the beater d. The cloths are to be placed on the bed b, at bottom, and water allowed to pass through the stock, when by the repeated blows of the beater d, which is raised and let fall in the usual. ay, the cloths are beaten, and become cleansed and fulled. A part of the bed at e, is made hollow, for the purpose of forming a steam box, into which steam from a boiler is introduced by a pipe with a stop-cock. This steam heats the bed of the stock, and greatly facilitates, as well as improves the process of cleansing and fulling the cloths. The smoothness of the surface of the polisl:' metal, of which the bed of the stock is constituted, is said to be very much preferable to the roughness of the surface of wood of which ordinary fullinu stocks are made, as by these iron stocks less of the nap or felt of the cloth is removed, and its appearance when finished is 7try much superior to cloths fulled in ordinary stocks. In the operation of fulling, the cloths are turned over on the bed, by tie falling of the beaters, but this turning over of the cloths will depend in a great measure upon the form of the front or breast of the stock. In these improved stocks, therefore, there is a contrivance by which the form of the front may be varied at pleasure, in order to suit cloths of different qualities; f, is a moveable curved plate, constituting the front of the stock; its lower part is a cylindrical rod, extending along the entire width of the bed, and being fitted into a recess, forms a hinge joint upon which the curved plate moves; g, is a rod attached to the back of the curved plate f, with a screw thread upon it; this rod passes through a nut h, and by trniing this nut, the rod is moved backward or forward, and consequently the position of the curved plate altered. The nut h, is a wheel with teeth, taking into two other similar toothed wheels, one on each side of it, which are likewise the nuts of similar rods jointed to the back of the curved plate f; by turning the central wheel, therefore, which may be done by a winch, the other two wheels are turned also, and the curved plate moved backward or forward. At the upper part of the plate there are pins passing through curved slots, which act as guides when the plate is moved. The patentees state in conclusion, that steam has been employed before for heating cloths while fulling them, they therefore do not exclusively claim its use, except in the particular way described; the advantages arising from the construction of iron stocks, with polished surfaces in place of wooden ones, together with the moveable curved plates described, are in their opinion "sufficiently important to constitute a patent right.' FULMINATES, or fulminating powders. Of these explosive compounds, there are several species; such as fulminating gold, mercury, platinum, silver; besides the old fusible mixture of nitre, sulphur, and potash. The only kind at all interesting in a manufacturing point of view is the fulminate of mercury, now so extensively used as a priming to the caps of percussion locks. Having published a paper in the Journal of the Royal Institution for 1831, upon gunpowder (see GUNPOWDER), the result of an elaborate suite of experiments, I was soon afterwards requested by the Hon. the Board of Ordnance to make such researches as would enable me to answer, in a satisfactory practical manner, a series of questions upon fulminating powders, subservient to the future introduction of percussion muskets into the British army. The following is a verbatim copy of my re-ort upon the subject:To the Secretary of the Board of Ordnance. " SFR,-I have the honor of informing you, for the instruction of the Honorable the Master General and the Board of Ordnance, that the researches on fulminating maercury, alhicl I undertook by their desire, have been brought to a satisfactory conclusion, after 828 FULMINATES. a numerous, diversified, and somewhat hazardous series of experiments. The following are the questions submitted to me, with their respective answers:Question 1. What proportions of mercury, with nitric acid and alcohol of certain strengths, will yield the greatest quantity of pure fulminate of mercury? rAnswer. One hundred parts, by weight, of mercury, must be dissolved with a centle heat, in 1000 parts (also by weight) of nitric acid, spec. er. 1-4; and this solution, at the temperature of a'bout 130~ Fahr., must be poured into 830 parts by weight of alcohol spec. er. 0-330.-Note. 830 parts of such alcohol, by weight, constitute 1000 by measure and 1000 parts of such nitric acid, by weight, constitute 740 by measure. Hence, in round numbers, one ounce weight of quicksilver must be dissolved in 71 oz. measures of the above designated nitric acid, and the resulting solution must be poured into 10 oz measures of the said alcohol. Question 2. What is the most economical and safe process for conducting the manipu lation, either as regards the loss of nitrous gas and residuum, or as respects danger to the operator; also, what is the readiest and safest mode of mixing the fulminate intimately with its due proportions of common gunpowder. Answer. The mercury should be dissolved in the acid in a glass retort, the beak of which is loosely inserted into a large balloon or bottle of glass or earthenware, whereby the offensive fumes of the nitrous aas disengaged during the solution, aie, in a consider able measure, condensed into liquid acid, which should be returned into the retort. A! soon as the mercury is all dissolved, and the solution has acquired the prescribed temperature of about 130~, it should be slowly poured, through a glass or porcelain funne', into the alcohol contained in a glass matrass or bottle capable of holding fully 6 times the bulk of the mixed liquids. In a few minutes bubbles of gas will proceed fiom the bottom of the liquid; these will gradually increase in number and magnitude till a gen. eral fermentative commotion, of a very active kind, is generated, and the mixture assumes a somewhat frothy appearance. A white voluminous gas now issues from the orifice of the matrass, which is very combustible, and must be suffered to escape freely into the air, at a distance from any flame. These fumes consist of an ethereous gas, holding mercury in suspension or combination. I have made many experiments with the view of condensing this gas, or, at least, the mercury, but with manifest disadvantage to the perfection of the process of producing fulminate. When the said gas is transmitted, through a glass tube, into a watery solution of carbonate of soda, a little oxyde of mercury is, no doubt, recovered; but the pressure on the fermentative mixture, thouah slight, necessary to the displacement of the soda solution, seems to obstruct or impair the generation of the fulminate; this effect is chiefly injurious towards the end of the operation, when the gaseous fumes are strongly impregnated with nitrous gas. When this is not allowed freely to come off, a portion of subnitrate or nitrate of mercury is apt to be formed, to the injury of the general process and the product. As soon as the effervescence and concomitant emission of gas are observed to cease, the contents of the matrass should be turned out upon a paper double filter, fitted into a glass or porcelain funnel, and washed by the afftsion of cold water till the drainings no longer redden litmus paper. The powder adhering to the matrass should be washed out and thrown on the filter by the help of a little water. Whenever the filter i; thorouohly drained, it is to be lifted out of the funnel, and opened out on plated copper or stone ware, heated to 212~ Fahr. by steam or hot water. The fulminate, being thus dried, is to be put up in paper parcels of about 100 erains each; the whole of which may he after. wards packed away in a tight box, or a bottle with a coik stepper. The excellence of the fulminate may be ascertained by the following characters. It consists of brownishgray small crystals which sparkle in the sun, are transparent when applied to a slip of glass with a drop of water, ard viewed by transmitted light. These minute spanales are entirely soluble in 130 times their weioht of boiling water; that is to say, an imperial pint of boiling water will dissolve 67 grs. ot pure filminate. Whatever remains indicates impurity. From that solution beautiful pearly spangles of fulminate fall down as the liquid cools. It may now be proper to show within what nice and narrow limits the best proportions of the ingredients used in making the fulminate of mercury lie. The following are selected from among many experiments instituted to determine that point, as well as the most economical process. 1. According to the formula given by the celebrated chemist Berzelius, in the 4th vol. of his "Traitd de Chimie," recently published (p. 383), the mercury should be dissolved in 12 times its weight of nitric acid, sp. gr. 1-375; and alcohol of sp. gr. 39850, amounting to 16-3 times the weight of the mercury, should be poured at intervals into the nitric solution. The mixture is then to be healed till effervescence with th( characteristic cloud of gas appears. On the action becoming violent, alcohol is to be poured in from time to time to repress it, till additional 16.3 parts have been em. ployed. On this process I may remark, that it is expensive, troublesome, dangerous, and un. productive of genuine pure fulminate. One fifth more nitric acid is expended very FULMINATES. 829 nearly than what is necessary, and almost four times the weight of alcohol which is beneficial. Of alcohol at 0'83, 8'3 parts by weight are sufficient; whereas Berzelius prescribes nearly 4 times this quantity in weight, though the alcohol is somewhat weaker being of sp. gr. 0'850. By using such an excess of alcohol, much of the fulminate is alpt to be revived into globules of quicksilver at the end of the process, as I showed in my paper on this subject published in the Journal of the Royal Instit-tion two years aco. There is no little hazard in pouring the alcohol into the nitric solutin; for at each affusion an explosive blast takes place, whereas by pouring the solution into the alcohol, as originally enjoined by the Hon. Mr. Howard, the inventor of the process, no dancer whatever is incurred. 100 parts of mercury treated in the way recommended by Berzelius afforded me only 112 parts of fulminate. instead of the 130 obtained by my much more economical and safe proportions and proces from the same weight of 4uicksilver. 2. If 10 parts of nitric acid of sp. er. 1-375 be used for dissolving 1 of quicksilver, and if 14 parts of alcohol of sp. gr. 0*85 be thereafter mixed with the solution, the pro. duct of such proportions will either be not granular, and therefore not fulminating, or it will be partially gianular and partially pulverulent, being a mixture of fulminate and subnitrate of mercury ill adapted for priming detonating caps. Instead of 130 parts of genuine fulminate, as I do obtain, probably not more than 10 parts of powder will be produced, and that of indifferent quality. In fact, whenever the ethereous %ermentation is defective, or not vigorous, little true fulminate is generated; but much of.he mercury remains in the acidulated alcoholic liquid. 3. If the alcohol be poured in successive portions, and of proper strength (sp. gr. 0'83), into a proper nitric solution of mercury, the explosive action which accompanies each affusion dissipates much of the alcohol, and probably impairs the acid, so that the subsequent ethereous fermentation is defective, and little good fulminate is formed. From 100 iarts of mercury submitted to this treatment, I obtained in one experiment, carefully made, only 51 parts of a powder, which was impalpable, had a cream color, and was not explosive either by heat or percussion. 4. When, with 100 parts of mercury. 800 of nitric acid of sp. gr. 1*375, are employed with 650 of alcohol of sp. gr.'846. no fulminate whatever is generated. 5. When, with the proper proportions of mercury, acid, and alcohol, the process is advanced into a proper energy of fermentative commotion, if the matrass be immersed in cold water so as materially to repress that action, the process will be impaired, and will turn out ultimately defective both as to the quantity and quality of the fulminate. It is therefore evident that a certain energy or vivacity of etherization is essential to the full success of this curious process, and that anything which checks it, or obstructs its taking place, is injurious and to be avoided. When my proportions are observed in making fiilminating mercury, somewhat less than one fourth of the nitric acid used in making the solution remains in the alcoholic mixture along with the fulminate. When other proportions are taken, much more acid remains. This acid is not recoverable to any useful or economical purpose, nor is the alcohol that is associated with it. Many distillations, with various reagents, have led me to this practical conclusion. In fact, when the process is most complete, as described in the first paragraph, the alcohol is entirely and profitably employed in etherization, an generating fulminic acid. I have made a series of analytical experiments on the pure fulminate of mercury, with the view of determining its composition, the quantity of quicksilver present in it, and consequently the loss of mercury in the operation. I have stated that my maximum product of fulminate from 100 grs. of quicksilver is 130 grs. Occasionally, from slight differences in the temperature of the mixture, or the ambient atmosphere, 2 grs. less may be obtained. A. I dissolved 130 grs. with a gentle heat in muriatic acid contained in a small matrass, adding a few drops of the nitric to quicken the solution. On evaporating it to dryness, with much care to avoid volatilization of the salt, I obtained 125 grs. of corrosive sublimate or bi-chloride of mercury. But 125 grs. of this bi-chloride contain only 91'1 grs. of quicksilver. Therefore, by this experiment, 130 grs. of fulminate contain no more than 91'1 of mercury, indicating an exhalation of 8-9 parts in the form of fumes, or a retention in the residuary liquid of some of these 8'9 parts, out of the 100 originally employed. B. In another experiment for analysis, 130 grs. dissolved as above, were thrown lown by carbonate of soda. 95 grs. of black.xyde of mercury were obtained, which are equivalent to 91'2 grs. of quicksilver; affording a confirmation of the preceding result. C. 130 grs. of fulminate were dissolved in strong muriatic acid, and the solution was Jecomlosed by crystals of proto-muriate of tin v.' a boiling temperature. The mercury was precipitated in globules to such amount as to verify the two preceding experirents. lRegarding fulminate of mercury as a bi cyanate, that is, as a compound of one atom 830 FULMINATES. or one equivalent prime of deutoxyde of mercury, and two primes of cyanic acid, we slall find its theoretical composition to be as follows, hydrogen being the radix, or 1. 2 primes of Cyanic or Fulminic Acid = 34 X 2 = 68 24 Deutoxyde of Mercury = 216 76 284 100 As these 284 parts of fulminate contain 200 of quicksilver, so 142 parts of fulminate will contain 100 of quicksilver. Whence it appears, that when only 130 parts of fulminate can be obtained in practice fiom 100 of quicksilver, 8- parts of quicksilver out of the 100 are unproductive, that is, are expended in the etherized gas, or left in the resilduary acidulous liquid. By the above experimental and theoretical analysis 91'5 parts of quicksilver enter into the composition of 130 parts of true crystalline fulninate. The complete accordance here exhibited between theory and practice removes every shadow of doubt as to the accuracy of the statements. 100 parts of fulminate consist ofMercury 704 Peroxyde 76-0 Oxycen 566 Fulminic acid - 24 00 0 Question 3. May the gas or vapor produced by the inflammation of the fulminate of mercury, when combined with a portion of gunpowder, be considered in its nature corrosive of iron or brass? Answer. I have suggested to Mr. Lovell, of Waltham Abbey works, that the fulminate may be probably diluted most advantageously with spirit varnish made of a proper consistence by dissolving sandarach in alcohol. When well mixed with this varnish, a small drop of the mixture will suffice for priming each copper cap or disc; and as the spirit evaporates immediately, the fulminate will be fixed to the copper beyond the risk of shaking or washing away. On the Continent, tincture of benjamin is used for the same purpose; but as that balsanic resin leaves in combustion a voluminous coal, which sandarach does not, the latter, which is the main constituent of spirit varnish, seems better adapted for this purpose. It is sufficiently combustible, and may be yet made, by a due pioportion, to soften the violence of the explosive mercury on the nipple of the touch-hole. Fulminate prepared by my formula has no corrosive influence whatsoever on iron or steel; and, therefore, if such a medium of applying it, as I have now taken leave to suogest, should be found to answer, all fears on the score of corrosion may for ever be set at rest. Ques/ion 4. How far is the mixture (of fulminate and gunpowder) liable to be affected by the moisture of the atmosphere, or by the intrusion of water; and will such an accident affect its inflammability when dried again? Answer. Well made fulminate, mixed with gunpowder and moistened, undergoes no change, nor is it apt to get deteriorated by keeping any length of time in a damp climate or a hazy atmosphere. Immersion in water would be apt to wash the nitre out of the pulverine; but this result would be prevented if the match or priming mixture were liquefied or brought to the pasty consistence, not with water, but spirit varnish. Such detonating caps would be indestructible, and might be alternately moistened and dried without injury. Question 5. Is it at all probable that the composition would be rendered more inflammable or dangerous of use by the heat of tropical climates?./Aunser. No elevation of temperature of an atmospheric kind, compatible with hu. man existence, could cause spontaneous combustion of the fulminating mercury, or the detonating matches made with it. In fact, its explosive temperature is so high as 367r of Fahrenheit's scale, and no inferior heat will cause its detonation. Question 6. Is the mercurial vapor or gas arising from the ignition of a great number of primers, and combined with the smoke of gunpowder in a confined space (as in the case of troops in close bodies, squares, casemates, &c.), likely in its nature to be found prejudicial to human health?.nswer. I have exploded in rapid succession of portions, 100 grains of fulminate of mercury (equivalent to 300 or 400 primers), in a close chamber of small dimensions, without experiencing the slightest inconvenience at the period, or afterwards, though my head was surrounded by the vapors all the time of the operation. These vapors are, in fact, so heavy that they subside almost immediately. When the fulminate mixed with pulverine is exploded in the primers by condensed masses of troops, the mercury will cause no injury to their health, nor 100th part of the deleterious impression on weak lungs which the gases of exploded gunpowder might by possibility inflict. These gases are all, theoretically speaking, noxious to respiration; such as carbonic acid gas, azote, carbureted hydrogen, and sulphureted hydrogen, a deadly gas. Yet the soldier who should betray any fear of gunpowder smoke would be an object of just ridicule." FULMINATES. 831 In the following September, I executed for the Board of Ordnance a set of experi. ments, complementary to those of the memoir, with the view of ascertaining the best manner of protecting the fulminate when applied to the copper caps, froml being detached by carriage, or altered by keeping. The following were my results and conclusiops. "1. Fulminate of mercury moistened upon copper is speedily decomposed by the superior affinity of the copper over mercury, for oxygen and fulminic acid. Dryness -is, therefore, essential to the preservation of the fullminate; and hence charcoal, which is apt to bect.me moist, should not be introduced into percussion caps destined for distant service. 2. An alcoholic solution of sandarach, commonly called spirit varnish, acts powerfully on copper, with the production of a green efflorescence, which decomrpces fuj minate of mercury. Indeed, sandarach can decompose the salts 3f copper. It is therefore ill adapted for attaching the fulminate to copper caps. 3. An alcoholic solution of shellac acts on copper, though more feebly than the sandarach. 4. A solution of mastic in spirits of turpentine, whether alone or mixed with fulmi. sate, has no action whatever on bright copper, but protects it from being tarnished. Such a varnish is very cheap, dries readily, adheres strongly, screens the fulminate from damp, and does not impair or counteract its detonating powers. This, therefore, is, in my opinion, the fittest medium for attaching the fulminate, and for softening the force of its impulsion in any degree preportional to the thickness of the varnish." Fulminate of mercury is obtained in white grains, or short needles, of a silky lustre, which become gray upon exposure to light, and detonate either by a blow or at a heat un-,ler 370' F.; with the disengagement of azote, carbonic acid, as also of aqueous and mercurial vapors; to the sudden formation of which gaseous products the report is due. It detonates even in a moist condition; and when dry it explodes readily when struck between two pieces of iron, less so between iron and bronze, with more difficulty between marble and glass, or between two surfaces of marble or glass. It is hardly possible to explode it by a blow with iron upon lead; and impossible by striking it with iron upon wood. It fulminates easily when rubbed between two wooden surfaces; less so between two of marble, two of iron, or one of iron against one of wood or marble. The larger its crystals, the more apt they are to explode. By damping it with i per cent. of water, it becomes less fulminating; the part of it struck still explodes with a proper blow, but will not kindle the adjoining portion. Though moistened with 30 per cent. of water, it will occasionally explode by trituration between a wooden muller and a marble slab, but only to a small extent, and never with any danger to the operator. When an ounce of it, laid upon the bottom of a cask, is kindled, it strikes a round hole down through it, as if it had been exposed to a four-pound shot, without splintering the wood. If a train of fulminate of mercury be spread upon a piece of paper, covered with some loose gunpowder, in exploding the former the latter will not be kindled, but merely scattered. When gunpowder, however, is packed in a cartridge, or otherwise, it may be certainly kindled by a percussion cap of the fulminate, and more completely than by a priming of gunpowder. 8$ parts of gunpowder exploded by a percussion cap, have an equal projectile force as 10 exploded by a flint lock. If we add to this economy in the charge of the barrel, the saving of the powder for priming, the advantage in military service of the percussion system will become conspicuous. The French calculate that 1 kilogramme of mercury will furnish 14 kil. (21 lbs. nearly) of fulminate, which will be sufficient to charge 40,000 percussion caps. For this purpose they grind the crystalline salt al)ng with 30 per cent. of water upon a marble table with a wooden muller; mixing with every 10 parts of the fulminate 6 of gunpowder. A consistent dough is thus obtained, which, being dried in the air, is ready for introducing into the bottoms of the copper caps. One quarter of a grain of the fulminate is said to be fully sufficient for one priming. Mr. Lovell, of the Royal Manufactory of Arms, has lately executed a series of experiments upon priming powders. His trials, which occupied nearly 18 months, were made for the purpose of ascertaining what is the advantage in point of force obtained by using percussion primes. He had anticipated some extra energy would be imparted to the charge of powder in the barrel, because he had repeatedly proved that a good strong cap, exploded by itself on the nipple of the musket (without any charge of gunpowder), will exert sufficient force upon the air within the barrel to blow a candle out at a distance of 12 feet from the muzzle. He concluded also that stopping the escape of fluid from the vent, as is done by the cap, would have some effect, but he attributed most to the quickness and energy with which the powder of the charge is ignited by the vivid stream of flame, generated by the percussion prime. The trials were made from one and the same barrel, having a percussion lock on one side and a flint lock on the other. The balls were fired against Austen's recoiling target, a very delicateplegometer, beginning with a charge of 150 grains (the present musket charge), and descending by 10 grains at a time (firing...... 832 FURNACE descending by 10 grains at a time (firing 30 rounds with each weight), down to 5C grains. The machine marked the decrease of force at each reduction in the charge very satisfactorily, and the result of the whole average was that 8'84 parts of gunpowder fired by percussion are equal to 10 parts fired by the flint. To find out what sort of liberties might be taken with fulminate of mercury in handling it, he placed 3 grains on an anvil, putting tle end of a steel punch gently on the top of it, and while so placed he covered the fulminate over with a drachm of dry gunpowder. He then ignited the fulminate by a blow on the punch with the hammer, but not a grain of the gunpowder was lighted, though it was blown about in all directions. He then placed a train of fulminate as thick as a quill, and about 3 feet long, on a table, and covered it over entirely with gunpowder except about an inch at one enC; tis lie lighted with hot iron, when the whole train went off without blazing a grain of the gunpowder, which lie swept together and blew up afterwards with a match. He then took a tin box containing 500 copper caps, made a hole in the top of the box, and through this hole ignited one of the caps in the middle, by means of the punch and hammer on the outside; only two other caps besides the one struck exploded; Zo injury was sustained by the remainder, except being discoloured. This he tried repeatedly, and always with the same kind of result, never more than 3 or 4 caps exploding. He then made a steel rammer red hot, and passed it through the hole in the box right in amongst the caps, but it only ignited them where the iron came in actual contact with the priming composition; when, however, he placed a few grains of gunpowder loose among the caps, the hot iron lighted this, and produced a flame that blew off the whole of them. The same thing has been tried at Woolwich, where large packages of percussion caps (some thousands) have been fired at with musquet balls, and only a few of the caps actually hit by the ball exploded; but when any cartridges were connected with the packages, the whole, caps and all, were blown up. The flame of the fulminate is therefore hazardous, but being so very ethereal, it requires for making primes an admixture of sonie combustible matter, as a little gunpowder, to condense or modify the flame. FULMINIC ACID; (Acid fulminique, Fr.; Knallseare, Germ.) is the explosive constituent of the fulminating mercury of 66 e; Howard, and the fulminating silver of 66 c Brugnatelli, being generated by the reaction of alcohol and the acid nitrates of these metals. It is a remarkable chemical \1 ^ ~fact, that fulminic acid has exactly the a same composition as cyanic acid; though the salts of the latter possess no detonating property, and afford, in their decomposition by an oxygen acid, ammonia with carbonic acid; while those of the former afford ammonia and prussic acid. All attempts to insulate fulminic acid have proved unsuccessful, as it explodes with M )the slightest decomposing force. It consists, by weight, of 2 primes of carbon, 1 of azote, and 1 of oxygen; or of two volumes of carbonic acid, and one of azote. a/n ~e\~ ^""*. When two different bodies, like the above, ( 0) ~S> O3 I M c have the same composition, they are said V > r ___\11 1 to be isomeric. - W [ \' ^ FUMIGATION, is the employment of ~ _ d V i < fumes or vapours to purify articles of apparel, and goods or apartments supposed to be imbued with some infectious or con-.' _' _ __.... tagious poison or fumes. The vapours o.f -_ -~ — =c I. _ wvinegar, the fumes of burning sulphur, explosion of gunpowder, have been long prescribed and practised, but they have in all, ^-^- ~ — ~ piprobability little or no efficacy. The dif_t-~ — _i ^^~~~~ ffusion of such powerful agents as chlorine gas, muriatic acid gas, or nitric acid vapour, should alone be trusted to for thl destruction of morbific effluvia. FUR: see PELTRY. FURNACE OF ASSAY. Under ASSAY. I have referred to a furnace con.,- - ------ _ _ structed by Messrs. Anfrye and d'Arcet FUSEL OIL. 833 which gives some peculial facilities and economy to the ancient process by fire. It had originally a small pair of bellows attached to it, for raising the heat rapidly to the proper vitrifving pitch. The furnace, 171 inches high, and 7- inches wide, made of pottery or fine clay, is represented fig. 668., supported upon a table, having i pair of bellows beneath it. The laboratory is at b, the blow-pipe of the bellows at d. with a stop-cock, and the dome is surmounted by a chimney a, c, in whose lower part there is an opening with a sliding door, for the introduction of the charcoal fuel. The furnace is formed in three pieces; a dome, a body, and an ash-pit. A pair of tongs, a stoking-hook, and( cupel, are seen to the right hand, and the plan of the stone-ware grate, pierced with conical holes, and a poker, are seen to the left. This grate suits the furnace represented under ASSAY. The following are comparative experiments made by means of this furnace: Numbers. Silver employed. Lead employed. Time of Assay. Standards. Charcoal used. 1 1 Grain 4 Grains. 12 minutes. 947 milliemes. 173 Grailns 2 - - 11 950 86 3 - - 13 949 93 4 -- - 10 949 [ 60 Each assay was therefore performed at an average in 11~ minutes, and not much more than a quarter of a pound of charcoal was used. An experiment of verification in the ordinary assay furnace showed tihe standard to be 949 thousandths. This furnace becomes a very convenient one for melting small quantities of motals in analyses, by removing the muffle, and closing the several apertures with their appropriate stoppers. A small pedestal may be thee set in the middle of the grate, to support a crucible, which may be introduced through the opening h. Coke may also be used as fuel, either by itself or mixed with charcoal. For descriptions of various furnaces, see ASSAY; BEER; COPPER; EVAPORATION; IRON; METALLURGY; ORES; SILVER; TIN, &C. FUR-SKIN DRESSING. Fur-skins are usually dressed by placing them in their dried state in tubs, where they undergo a treading operation with men's feet, until they are sufficiently soft and bend easily. The skins if large are sewn up, the fur being turned inwards; but if small skins, such as ermine, are being dressed, they require no sewing. This sewing is preparatory to the greasing with butter or Jard, and is intended to protect the fur from the grease, and to promote the softening in the succeeding treading operation. The skins are next wetted, and their flesh is removed; or they are fleshed and then hung up to dry. They are again subjected to treading in tubs containing sawdust; and afterwards in tubs containing plaster of Paris, or whitening, sprinkled between the skins. They are then beaten with a stick, and combed; when the dressing is completed. M. Pierre Thirion proposes, in his patent of June, 1845, to soften the skins, not by treading, but by beating stocks, of a construction like the fulling mill. They are next sewn up, and again fulled in a strong vessel, where they are forced upwards by the beaters, turned over and over, and thus speedily softened. They are now fleshed, and then returned to the beating stocks, and mahogany or other sawdust is sprinkled upon the fur, before the beating is renewed. They are next placed in a heated barrel, furnished within with radial pins for turning the goods over and over, in order that they may be acted upon by various dry substances, which are thrown into the barrel, and absorb the fat from tlh skins. Tllrough the hollow shaft of the barrel, steam is introduced, which heats the skins, softening the fat, which is then absorbed by sand, flour, or any other desiccative powder. It is proper to take the skins out of the barrel from time to tirhe to comb them. Such as have been sufficiently acted upon may then be set aside. They are lastly freed from the dust by being subjected to a grated cylinder in a state of rotation, and then combed by hand. FUSEL OIL is the German name of the offensive smelling oil which exists in alcohol, as distilled from the fermented infusions of malt, and corn meal of all kinds, as also from the fermented wash of potatoes, and of beets, &c. A like oil occurs in tle alcohol distilled from the fermented must of grapes, and the juices of many sweet fruits. This oil is not, however, identical from these several sources; as may indeed be inferred from the diversity in the flavours of the different liquors. But they all agree in being somewhat less volatile than water, and therefore make their appearance chiefly in the spirits towards the end of the distillation process. It is to the presence of this oil that the milkiness of the last, and also sometimes of the first, portions of the spirit that come over, called feints, owe their opalescence and their penetrating odour. When the milky fluid is redistilled, alcohol and water first pass over with very little oil, but if the heat of the still be moderate, the oil may be made a residuum, and obtained in a tolerably oncentrated state. Tle oil from potatoes was first analyzed by Dumas, and was shown by him to be composed of 68'2 per cent. of carbon, 13'6 of hydrogen, and 18'2 of oxygen; according to the formula CloH1nO. HO. It belongs therefore to the class of 834 FUSTIAN. alcohols, one whose radical is CoHn, or amyle, and is an amyl oxyhydrate; just as common alcohol is an oxyhydrate of ethyle. The potato amyle spirit is a colourless fluid of an acrid burning taste, and of a most offensive, penetrating, durable smell. When the vapour of it. is inhaled it produces an oppressive nausea, headache, giddiness, and retching. It has a poisonous action on the animal system. By oxydizing agents it is converted into valerianic (Baldrian) acid. According to Balard the amyle spirit occurs along with the senanthic ether in the oil, which contaminates brandy, and is probably derived from the husks of the grapes. This noxious spirit exists most abundantly in the whisky of malt, and especially in that from raw grain; and is now an article of considerable sale, being used to burn in lamlps, to dissolve copal and other resins for varnish making and other purposes. Besides this liquid amyle spirit corn spirits contain a concrete fatty matter, of a brown colour, an acid reaction, and an offensive smell and taste. It has a green tinge, which' I believe is derived from the copper worm of the still. Mulder has shown that this fatty product consists of an easily fusible and a (difficultly fusible portion. The former he regards as the ether of uenanthic acid; consisting of 85 carbon, 10-3 hydrogen, and 4'8 oxygen, and is therefore quite different from the amyle spirit. Margaric acid is mixed with the less fusible portion. He says that one million parts of malt whisky contain 30 of senanthic acid, 9 of zenanthic ether. and 5 of corn oil (amyle spirit). There are probably many varieties of these oils of crude alcohol. FUSIBILITY. That property by which solids assume the fluid state. Some chemists have asserted that fusion is simply a solution in caloric; but this opinion includes too many yet undecided questions, to be hastily adopted. Fusibility of Metals, as given by M. Thenard. Centigr. 1. Fusible below a Mercury -39~ red heat. Potassium +50 Gay Lussac and Thenard. Sodium 90 Tin 210 Newton. Bismuth 2 Neton. Lead 260 Biot. Tellurium A little less fusible than lead.-Klaproth. Arsenic Undetermined. Zinc 370~ Brongniart. Antimony A little below a read heat. Cadmium Stromeyer. Pyrometer of Wedgewood.,2 Infusible below a Silver 20 Kennedy. red heat. Copper 27 Wedgewood. Gold 32 Cobalt A little less difficult to melt than iron. Iron 130 Wedgewood. 158 Sir G. M'Kenzie. Manganese 160 Guyton. Nickel As manganese.-Richter. Palladium ) Molybdenum Nearly infusible; and to be obtained at a TUranium forge heat only in stmall buttons. Tungsten Chromium Titanium Cerium Osmium Infusible at the forge frnace. Fusible al Iridium r the oxyhydrogen blowpipe. See BLOW. Rhodium PIP:. Platinumr Columbium FUSIBLE METAL. See ALLOY. FUSTET. (Fustec, Fr.) The wood of the rhus cotinus, a fugitive yellow dye. FUSTIAN is a species of coarse thick tweeled cotton, and is generally dyed of an olive, leaden, or other dark color. Besides the common fustian, which is known by the name of pillow (probably pilaw), the cotlon stuffs called corduroy, velverett, velveteen, thicksett, used for men's wearing apparel, belong to the same fabric. The commonest kind is merely a tweel of four, or somtimtes five leaves, of a very close stout texture, -and very narrow, seldom exceeding 17 or 18 ioches Mn breadth. It is cut from the loom in half pieces, or ends, as they are usul;1ly termed, about 35 yards long, and after undergoing the subsequent operations of dyeing, dressing, and folding, is ready for the market FUSTIAN. 835 The draught and cording of common fistian is very simrpt. being eenerally a regular or unbroken tweel of four or five leaves. Below are specimens of a few ditferent kinds, selected fiom those most general in Lancashire. The number of leaves of heddles are represented by the lines across the paper, and the cording by the ciphers in the little squares, those which raise every leaf being distinguished by these marks, and those which sink them left blank, as more particularly explained in the article TEXTILE FABRIC. 01 velvet, there are properly only two kinds, that with a plain, and that with a tweeled, or, as it is here called, a Genoa ground, or back. When the material is silk, it is called velvet, when cotton, velveteen; and this is the sole difference. In the same way a common tweeled cloth, when composed of silk is called satin; when of cotton, fustian or jean * of woollen, plaiding, serge, or kerseymere; and in the linen trade is distinguished by a variety of names according to the quality or fineness, or the place where the article is manufactured. No. 1.-Pillow Fustian. No. 2.-Plain Velveret.!0 ~ I I 4 5 10 I 1 I i I I 3 1 I 1o I 1 3 2 6 1l 1 I 1 5 I I 1 6 I 2 3 IO 1 1 10 l 0 2 i t 1 1 5 1 4 1 10 1o 1 6 2431 46231 5 Of the above, each contains four leaves of heddles or healds; that represented by No. I is wrought by four treddles, and that which is distinguished by No. 2 by five; the succession of inserting the threads of warp into the heddles will be discovered by the figures between the lines, and the order in which the treddles are to be successively pressed down by the figures below. No. 3.-Double Jean. No. 4.-Plain Thickset. ~01 ITol 1 I I O I I 1 8 11 0 I I 2 I1 0! 0 I 6 4 I 10 01 l 1 3 4 I I I 1 0l I 5 2 1 1 0 1 1 4 I o0 I I I 1 7 3 1 4231 46231 5 7 These, like the former, are wrought with leaves. No. 3 requires four, and No. 4 five treddles. The succession of inserting the threads of warp, and of working the treddles, are marked by the respective numbers between and under the lines, as in the former example. Both are fabrics of cloth in very general use and estimation as low priced articles. No. 5.-Best Thickset. No. 6.-Velvet Tuft.!O i1 I o1to 3 1 I 1 l I 1 5 3 1 I I I I 101l 5 4 I 1lo1 l I 1 4 2 I 101 I I I a 1l0 I 10 l01 4 2 I lO l 1 I 6 4 ~ I I I l 10 1 5 3 1 6 4 2 3 1 6 4 2 3 1 5 These are further specimens of what may be, and is, executed with four leaves, and in both examples five treddles are used. With two other specimens we shall conclude our examples of this description of work, and shall then add a very few specimens of the more extensive kinds. No. 7.-Cord and Velveret. No. S.-Thickset Cord. I 1Ol I i 1 3 1 3 1 1l 1 OlOl 5 3 1 I 10o 10 I I 5 7 5 I 0 I l 4 2 0 o I 0 l0 6 8 2 I 9! I 7 I 110 1 4 2 f 4 Ij j O' i i 0 8 6 4 2 3 1 5 4 3 2 - i 6 5 In these the succession of drawing and working are marked like the fcrmer. The next are examples of patterns wrought with six leaves. No. 9 has eight, and No. 10 five heddles 54 _.. I 836 FUSTIAN. No. 9.-Double Cord-iroy. No. 10.-Genoa Thickset. I I 1l lO t j I i 1 I 10101 I 1 1 l 01 I 1 ____ __l l 0 2 10101010101 I I 1 3 10l 0100 1 3 _l l l1 1l 10l 4 1 1 0110101 4 l0 I I I ol 5 10o1 1 00 5T 1t1 Il( I I I I 6 I 1011 I 6__ _ 2 4 6 8 10 12 3 1 4 2 5 3 1 75 861197 11 9 1 2 10 In both these the warp is inserted into the heddles the same way. The difference is entirely in the application of the cords, and in the succession of pressing u.wn the treddles. We now give four specimens of the flushed and cut work, known by the name of velveteen. They are also upon six leaves, and the difference is solely in the cording and in the treading. No. 11. Queen's Velveteens. No. 12. o 1 O1 1lo l I 1 o I I oI T 1 | | 11 01 I 2 | 1 i 10 1 2 i 1 01 l I 1 3 49 I I 1O1l 1 3 o I l 101010 4 I 101o 10l 101 4 Ol 0 l 0 1 5 I I I | I lo l 5 101 10 1 1 6 1l11 10l1 1 6 1212842 2 4 3 1 57 6 687 5 9 11 10 10 12 11 9 No. 13.-Plain Velveteen. No. 14.-Genoa Velveteen. I I I (1 1 I I 10101 101 1 l 1 1 1 2 I 1 I01O1 I I 2 I I l01 3 6 010! l 10l 1 3 o101 1 4 I I 110ol1O l I1 4 | | l 05 4 1 1O01 l 1 1I 5 i l o1 10 6 | I0 101o I 1 6 13 2 4 8 2 4 8123 1 576 6 75 10 11 9 The additional varieties of figure which might be given are almost endless, but the limits of this article will not admit a further detail. Those already given are the articles in most general use. The varieties of fancy may be indulged to a great extent; but it is universally found, that the most simple patterns in every department of ornamental weaving are those which attract attention and command purchasers. We shall therefore only add two examples of king's cord or corduroy, two of Genoa and common velvet, and two more of jean. These will be found below. No. 15.-King's Cord. No. 16.-Dutch Cord. O" 0 10 | 1 1 0 4 1 0 Il Il 2 I 1O 0l 1 l 5 2 |I I 0 1 01 I 1 7 3 I4 l I 0 l 6 3 I 01l0 1 8 4 4 I OlOl 7 I 0 I 101l0 5 101l 101 1l0 8 10 10 I1 1 6 4 101Ol 1o010 9 138642 64231 57 5 No. 17.-Genoa Velvet. No. 18.-Plain Velvet. I 101 I! 1 4 I I I I I I -ololo l I 2 0 I I I I 1 2 I 10 I I 1 3 0 I I I I I i 3 l _ 0I I I I, I 4 0I oI......... 1 - 6 75 75 10 11 9 After the fustian cloth is taken from the loom beam, it is carried to the cutter, who rips up the surface-threads of weft, and produces thereby a hairy-looking stuff. FUSTIC. 837 Preparatory to its being cut, the cloth is spread evenly upon a table about six feet long, upon each end of which a roller mounted with a ratchet-wheel is fixed; the one to give off, and the other to wind up the piece, in the above six-feet lengths. The knife is a steel rod about two feet long, and three eighths of an inch square, having a square handle at the one end; the other end is tapered away to a blade, as thin as paper. To prevent this point fiom turning downwaids and ilnjuing the cloth, its under side is covered by a guide which serves to stiffen it, as well as to prevent its lower edge firom cutting the fustian. The operative (male or female) grasps the handle in the right hand, and insinuating the projecting point of the guide under the weft, pushes the knife smaitly foiward through the whole length of six feet, with a certain dexterous movement of the shoulder and right side, balancing the hody meanwhile, like a fencer, upon the left foot. This process is repeated upon every adhesive line of the weft. The next process to which fusiians are exposed is steeping in hot water, to take out the dressing paste. They are then dried, reeled, and brushed by a machine, &c. From twenty to thirty pieces, each eighty yards lonv, may be brushed in an hour. The breadth of the cloth is twenly inches. The maceration is performed by immersing the bundled pieces in tanks of water, heated by waste steam; and the washing by means of a reel or winch, kept revolving rapidly under thp action of a stream of cold water, for an hour or longer. Afier being thus ripped up, it is taken to the brushing or teazling machine, to make it sld'y. This consists of a series of wooden rollers, turning fieely upon iron axles, and covered with tin-plate, rough with the burs of punched holes; and blocks of wood, whose concave tinder surfaces are covered with card-cloth or card-brushes, and which are made to traverse backwards and forwards in the direction of the axes of the revolving rollers, during the passage of the cloth over them. After they are brushed in.he machine, the goods are singed by passing their cut surface over a cylinder of iron, laid in a horizontal direction, and kept red hot by a flue. See SINGEING. They are now brushed again by the machine, and once more passed over the singeing surface. The brushing and singeing are repeated a third, or even occasionally a fourth time, till the cord acquires a smooth polished appearance. The goods are next steeped, washed, and bleached, by immersion in solution of chloride of Jlie. They are then dyed by appropriate chemical means. After which they are padded (imbued by the padding machine of the calico printers) with a solution of glue, and passed over steam cylin(lers to stiffen them. Smooth fustians, when cropped or shorn before dyeing, are called moleskins; but when shorn after being dyed, are called beaverteen: they are both tweeled fabrics. Cantoon is a fuistian with a fine cord visible upon the one side, and a satiny surface of yarns running at rioht angles to the cords upon the other side. The satiny side is sometimes smoothed by singeing. The stuff is strong, and has a very fine aspect. Its price is one shilling and sixpence a yard. Common plain fustian, of a brown or drab color, with satin top, is sold as low as sevenpence a yard. A fustian, with a small cord running in an oblique direction, has a very agreeable appearance. It is called diagonal. Moleskin shorn, of a very strong texture, and a drab dyed tint, is sold at 20d. per yard. The weight of 90 yards of the narrow velveteen, in the green or undressed state, is about 24 pounds. The goods made for the German, Italian, and Russian markets are lighter, on account of the peculiarity in the mode of levying the import duty in these countries. Velveteens as they come from the loom, are sold whplesale by weight, and average a price of 20d. per pound. They are usually woven with yarns of Upland and Brazil cotton wool, spun together for the warp; or, sometimes, New Orleans alone. The weft is usually Upland, sometimes mixed with East India cotton wools. Trouser velveteens are woven 19 inches wide, if they are to be cut up; if not, they are woven 30 inches, and called beaverteen. Cutting or cropping fustians by hand is a very laborious and delicate operation. The invention of an improved apparatus for effecting the same end with automatic precision and despatch, was therefore an object of no little interest to this peculiar manufac ture of Manchester. An ingenious machine, apparently well calculated for this purpose, was made the subject of a patent by Messrs. William Wells and George Scholefield, of Salford, in November, 1834. FUSTIC. (Bois jaune, Fr.; Gelbholz, Germ.) The old fustic of the English dyer, as the article fustet is their yellow fustic. It is the wood of the Mortus tinctoria. It is light, nDt hard, and pale yellow with orange veilns; it contains two coloring matters, one resinous, and another soluble in water. The latter resembles weld, but it has more of an )range cast, and is not so lively. 838 GALL-NUTS. Its decoctions in water are brightened by the addition of a little glue, and more by cut Iled milk. This wood is rich in color, and imparts permanent dyes to woollen stuffs, when aided by proper mordants. It unites well with the blue of the indigo vat, and Saxon blue, in producing green of various shades. Alum, tartar, and s6lution of tin, render its color more vivid; sea salt and sulphate of iron deepen its hue. From 5 to 6 parts of old fustic are sufficient to give a lemon color to 16 parts of cloth. The color of weld is however purer and less inclining to orange; but that of fustic is less affected by acids than any other yellow dye. This wood is often employed with sulphate of iron in producing olive and brownish tints, which agree well with its dull yellow. For the same reason it is much used for dark greens. G. GABRONITE is a yellowish stony substance, of a greasy lustre and spec. gr.=2'74; aflbrding no water by calcination; fusible at the blowpipe into an opaque glass; soluble in muriatic acid; solution affords hardly any precipitate by oxalate of ammonia. This mineral is distinguished by the large quantity of soda which it contains; its constituents being-silica, 54; alumina, 24; soda, 17'25; magnesia, 1l5; oxyde of iron, 1'25; water, 2. It belongs to the species Nepheline. GADOLINITE, called also Yttrite and Ytterbite, is a mineral of a black, brownish, or yellowish color, granular, or compactly vitreous, and conchoidal fracture; of spec. grav. 4-23; readily scratching glass; fusible at the blowpipe into an opaque glass, sometimes with intumescence. It affords, wita acids, a solution that lets fall, with caustic soda, a precipitate partly re-soluble in carbonate of ammonia. It is remarkable for containing from 45 to 55 per cent. of the earth Yttria; its remaining constituents being silica, 25-8; oxyde of cerium, 17'92; oxyde of iron, 11*43. This mineral is very rare, having been hitherto found only in the neighborhood of Fahlon and Ytterby, in Sweden; its peculiar constituent was discovered by Professor Gadolin. GALACTOMEITER, or LACTOMETER, is an instrument to ascertain the quality of milk; an article often sophisticated in various ways. Fresh milk, rich in cream, has a less specific gravity than the same milk after it has been skimmed; and milk diluted with water becomes proportionably lighter. Hence, when our purpose is to determine the quantity of cream, the galactometer may consist merely of a long graduated glass tube standing upright upon a sole. Having filled 100 measures with the recent milk, we shall see, by the measures of cream thrown up, its value in this respect. A delicate longranged glass hydrometer, graduated from 1'000 up to 1-060, affbrds the most convenient means of detecting the degree of watery dilution, provided the absence of thickening materials has been previously ascertained by filtration. Good fresh milk indicates from 1'030 to 1*032; when the cream is removed, 1'035 to 1'037. When its density is less than 1-028, we may infer it has been thinned with water. GALBANUM is a gum-resin, which occurs sometimes in yellow, shining tears, easily agglutinated; of a strong durable smell; an acrid and bitter taste; at other times in lumps. It exudes either spontaneously or from incisions made into the stem of the bubon galbanum, a plant of the family of umbelliferce, which grows in Africa, particularly in Ethiopia. It contains 67 of resin; 19-3 of gum; 6-4 of volatile oil and water; 7-5 of woody fibres and other impurities; with traces of acid malate of lime. GALENA, (Plomb sulfure, Fr.; Bleiglanz, Germ.;) is a metallic looking substance of a lead-gray color, which crystallizes in the cubical system, and is susceptible of cleavages parallel to the faces of the cube; spec. gr. 7-7592; cannot be cut; fusible at the blowpipe with exhalation of sulphureous vapors; is easily reduced to metallic lead. Nitric acid first dissolves it, and then throws down sulphate of lead in a white precipitate; the solution affording, with plates of zinc, brilliant laminae of lead (arbor Saturni.) It consists of sulphur, 13; lead, 85; with a little iron, and sometimes a minute quantity of silver. This is the richest ore of lead, and it occurs in almost every geological formation, in veins, in masses, or in beds. It is almost always accompanied by sulphuret of zinc, different salts of lead, heavy spar, fluor spar, &c. Galena in powder, called Alquifoux, is employed as a glaze for coarse stoneware. GALIPOT is a name of a white semi-solid viscid rosin found on fir-trees; or an inferior sort of turpentine, poor in oil. GALLATES; salts consisting of gallic acid combined with bases; the most important being that with oxyde of iron, constituting a principal part of the black dye. GALLIC ACID is the peculiar acid extracted from gall-nuts; which see. GALLIPOLI OIL is a coarse olive oil, containing more or less mucilage; imported from seaport so named, of the province of Otranto, in the kingdom of Naples. GALL-NUTS, or GALLS, (Noix de Galle, Fr.; Galldipfel, Germ.;) are excrescences found upon the leaves and leaf-stalks of a species of oak, called Quercus infectoria, which grows in the Levant. They are produced in consequence of the puncture?f the female of the gall wasp (Cynips folii quercus), made in order to deposite he! I i. _,__ _ _ _ __ _ _ _ __ _ _ _ __ _ _ _ __ _ _ _ __.__ __ _ _ __ _____ _ _ _ __ _.___ _ _ _ __ _ _.__ _ _ _ __ _ _ ____ _ _ __ _ _ _,__ _ _ GALL-NUTS. 839 eggs; round which the juice of the tree exudes, and dries in concentric portions. When the insect gets fully formed, it eats through the nut, and flies off. The Levant galls are of two different appearances and qualities; the first are heavy compact, imperforated, the insect not having been sufficiently advanced to eat its way through the shell; prickly on the surface; of a blackish or bluish green hue; about the size of a musket-ball. These are called black, blue, or Aleppo galls. The second are light, spongy, pierced with one or more holes; smooth upon the surface, of a pale grayish or reddish yellow color, generally larger than the first, and are called white galls. Besides the galls of the Levant, others come from Dalmatia, Illyria, Calabria, &c.; but they are of inferior quality, being found upon the Quercus Cerris; they are smaller, of a brownsh color, and of inferior value. The further south the galls are grown, they are reckoned the better. Galls consist principally of three substances; tannin or tannic acid; yellow extractive; an( gallic acid. Their decoction has a very astringent and unpleasant bitter taste. The following are their habitudes with various reagents:Litmus paper is powerfully reddened. Stannous chloride (protomuriate of tin) produces an isabel yellow precipitate. Alum; a yellowish gray precipitate. Acetate of lead; a thick yellowish white precipitate, Acetate of copper; a chocolate brown precipitate. Ferric sulphate (red sulphate of iron); a blue precipitate. Sulphuric acid; a dirty yellowish precipitate. Acetic acid brightens the muddy decoction. The galls of the Quercus Cerris and common oak (Galles a l'epine, Fr.; Knoppern, Germ.) are of a dark brown color, prickly on the surface, and irregular in shape and size. They are used chiefly for tanning in Hungary, Dalmatia, and the southern provinces of the Austrian states, where they abound. Tannin or tannic acid is prepared as follows: Into a long narrow glass adopter tube shut at its lower orifice with a cotton wick, a quantity of pounded galls are put, and slightly pressed down. The tapering end of the tube being inserted into a matrass or bottle, the vacant upper half of the tube is filled with sulphuric ether, and then closed with a ground-glass stopper. Next day there will be found in the bottle a liquid in two distinct strata; of which the more limpid occupies the upper part, and the other, of a sirupy consistence and amber color, the lower. More ether must be filtered through the galls, till the thicker liquid ceases to augment. Both are now poured into a funnel, closed with the finger, and after the dense liquor is settled at the bottom, it is steadily run off into a capsule. This, after being washed repeatedly with ether, is to be transferred into a stove chamber, or placed under the receiver of an air pump, to be evaporated. The residuary matter swells up in a spongy crystalline form of considerable brilliancy, sometimes colorless, but more frequently of a faintly yellowish hue. This is pure tannin, which exists in galls to the amount of from 40 to 45 per cent. It is indispensable that the ether employed in the preceding process be previously agitated with water, or that it contain some water, because by using anhydrous ether, not a particle of tannin will be obtained. Tannic acid is a white or yellowish solid, inodorous, extremely astringent, very soluble:n water and alcohol, much less so in sulphuric ether, and uncrystallizable. Its watery solution, out of contact of air, undergoes no change; but if, in a very dilute. state, t be lect exposed to the atmosphere, it loses gradually its transparency, and lets fall a slightly grayish crystalline matter, consisting almost entirely of gallic acid. For procuring this acid in a perfectly pure state, it is merely necessary to treat that solution thus changed with animal charcoal, and to filter it, in a boiling state, through paper previously washed with dilute muriatic acid. The gallic acid will fall down in crystals as the liquid cools. If the preceding experiment be made in a graduated glass tube containing oxygen over mercury, this gas will be absorbed, and a corresponding volume of carbonic acid gas will be disengaged. In this case the liquor will appear in the course of a few weeks as if traversed with numerous crystalline colorless needles of' galic acid. Tannin or tannic acid consists of carbon 51-56; hydrogen 4'20; oxygen 44-24. From the above facts it is obvious that gallic acid does not exist ready formed in gallnuts, but that it is produced by the reaction of atmospheric oxygen upon the tannin of these concretions. Gallic acid is a solid, feebly acidulous and styptic to the taste inodorous, crystallizing in silky needles of the greatest whiteness; soluble in about 100 times its weight of cold, and in a much smaller quantity of boiling water; more soluble in alcohol than in water, Jut little so in sulphuric ether. Gallic acid does not decompose the salts of protoxy le of iron, but it forms, with the sulphate of the peroxyde, a dark blue precipitate, much less insoluble than the tannate Df iron. Gallic acid takes the oxvye from the acetate and nitrate of lead, and thrrws I___________________. _____ - - - - -____________ 840 GALL OF ANIMALS. flwn a white gallate unchangeable in the air, when it is mixed with that acetate and nitrate. It occasions no precipitate in solutions of gelatine (isinglass or glue), by which criterion its freedom from tannin is verified. Gallic acid occurs but seldom in nature; and always united to brucine, veratrine, oi lime. Its constituents are carbon 49'89; hydrogen 3'49; oxygen 46-62. Il the crystalline state it contains one atom of water, which it loses by drying. Scheele obtained gallic acid by infusing pounded galls for 3 or 4 days in 8 times their weight of water, and exposing the infusion to the air, in a vessel covered loosely with paper. At the end of two months, the liquor had almost all evaporated, leaving some mouldiness mixed with a crystalline precipitate. The foimer being removed, the deposite was squeezed in a linen cloth, and then treated with boiling water. The solution, being gradually evaporated, yielded crystals of gallic acid, granular or star-like, of a grayish color. These crystals might be whitened by boiling their solution along with a little animal charcoal. About one fifth of gallic acid may be obtained by Scheele's process from good gall-nuts. From a decoction of 500 parts of galls, Sir H. Davy obtained 185 parts of solid extract; which consisted of 130 parts of tannin; 31 parts of galic acid with extractive; 13 parts of mucilage; 12 parts of lime and salts. Hence gall-nuts would seem to contain, by this statement, more than two thirds of their weight of tannin. This result is now seen, from the above experiments of Pelouze, to have been incorrect, in consequence of the admixture of yellow extractive in Davy's tannin. The use of galls in many processes of dyeing, and in making black ink, is detailed under their respective heads. GALL OF ANIMALS, or OX-GALL, purification of. Painters in water colors, scourers of clothes, and many others, employ ox-gall or bile; but when it is not purified, it is apt to do harm from the greenness of its own tint. It becomes therefore an important object to clarify it, and to make it limpid and transparent like water. The following process has been given for that purpose. Take the gall of newly killed oxen, and after having allowed it to settle for 12 or 15 hours in a basin, pour the supernatant liquor off the sediment into an evaporating dish of stone ware, and expose it to a boiling heat in a water bath, till it is somewhat thick. Then spread it upon a dish, and place it before a fire till it becomes nearly dry. In this state it may be kept for years in jelly pots covered with paper, without undergoing any alteration. When it is to be used, a piece of it of the size of a pea is to be dissolved in a table spoonful of water. Another and probably a better mode of purifying ox-gall is the following. To s pint of the gall boiled and skimmed, add one ounce of fine alum in powder, and leave the mixture on the fire till the alum be dissolved. When cooled, pour into a bottle, which is to be loosely corked. Now take a like quantity of gall, also boiled and skimmed, add an ounce of common salt to it, and dissolve with heat; put it when cold into a bottle, which is likewise to be loosely corked. Either of these preparations may be kept for several years without their emitting a bad smell. After remaining three months, at a moderate temperature, they deposite a thick sediment, and become clearer, and fit for ordinary uses, but not for artists in water colors and miniatures, on account of their yellowish-green color. To obviate this inconvenience, each of the above liquors is to be decanted apart, after they have become perfectly settled, and the clear portion of both mixed together in equal parts. The yellow coloring matter still retained by the mixture coagulates immediately and precipitates, leaving the ox-gall perfectly purified and colorless. If wished to be still finer, it may be passed through filtering paper; but it becomes clearer with age, and never acquires a disagreeable smell, nor loses any of its good qualities. Clarified ox-aall combines readily with coloring matters or pigments, and gives them solidity either by being mixed with or passed over them upon paper. It increases the brilliancy and the durability of ullramarine, carmine, green, and in general of all delicate colors, whilst it contributes to make them spread more evenly upon the paper, ivory, &c. When mixed with gum-arabic, it thickens the colors without communicating to them a disagreeable glistering appearance; it prevents the gum from cracking, and fixes the colors so well that others may be applied over there without degradation. Along with lamp black and gum, it forms a good imitation of China ink. When a coat of ox-gall is put upon drawings made with black lead or crayons, the lines can no longer be effaced) but may be painted over safely with a variety of colors previously mixed up with the same ox-gall. 3Miniature painters find a great advantage in employing it; by passing it over ivory, it removes completely the unctuous matter from its surface; and when ground with the Kolors, it makes them spread with the greatest ease, and renders them fast. It serves also for transparencies. It is first passed over the varnished or oiled paper and is allowed to dry. The colors mixed with the gall are then applied, and canno, afterwards be removed by any means. It is adapted finally for taking out spots of grease and oil I - GARlANCINE. 841 GALL OF GLASS, called also sandiver, is the neutral salt skimmed off the surface of nelted crown glass; which, if allowed to remain too long, is apt to be reabsorbed in part, and to injure the quality of the metal, as the workmen call it. GALVANIZED IRON, is the somewhat fantastic name newly given in France to iron tinned by a peculiar patent process, whereby it resists the rusting influence of damp air, and even moisture, much longer than ordinary tin plate. The following is the prescribed process. Clean the surface of the iron perfectly by the joint action of dilute acid and friction, plunge it into a bath of melted zinc, covered with sal-ammoniac, and stir it about till it be alloyed superficially with this metal; when the metal thus prepared is exposed to humidity, the zinc is said to oxidise slowly by a galvanic action, and to protect the iron from rusting within it, whereby the outer surface remains for a long period perfectly white, in circumstances under which iron tinned in the usual way would have been superficially browned and corroded with rust. GALVANO-PLASTIC is the German name of Electro-Metallurgy. GAMBOGE; (Gomme Gutte, Fr.; Gutti, Germ.) is a gum resin, concreted in the air, from the milky juice which exudes from several trees. The gambogia gutta, a tree which grows wild upon the coasts of Ceylon and Malabar, produces the coarsest kind of gamboge; the guttcefera vera (Stalaygmites cambogioides) of Ceyio;. and Siam affords the best. It comes to us in cylindrical lumps, which are outwardly brown yellow, but reddish yellow within, as also in cakes; it is opaque, easily reducible to powder of specific gravity 1'207, scentless, and nearly devoid of taste, but leaves an acrid feeling in te ththroat. Its powder and watery emulsion are yellow. It consists of 80 parts cf a hyacinth red resin, soluble in alcohol; and 20 parts of gum; but by another analysis. of 89 of resin, and 10-5 of gum. Gamboge is used as a pigment, and in miniature painting, to tinge gold varnish; in medicine as a powerful purge. It should never be employed by confectioners to colour their liqueurs, as they sometimes do. GANGUE. A word derived fiom the German gang, a vein or channel. It signifies the mineral substance which either encloses or usually accompanies any metallic ore in the vein. Quartz, lamellar carbonate of lime, sulphate of baryta, sulphate and fluate of lime, generally form the gangues; but a great many other substances become such when they predominate in a vein. In metallurgic works the first thing is to break the mixed ore into small pieces, in order to separate the valuable from the useless parts, by processes called stamping, picking, sorting. See METALLURGY and MINES. GARANCINE, is a dyeing substance prepared from madder, called in the French language garance. A patent was granted in August, 1843, to Mr. F. Steiner, for the manufacture of Garancine from used madder, formerly thrown away, as being exhausted of its dyeing principle. His process is as follows:-" A large filter is constructed outside the building in which the dye-vessels are situated, formed by sinking a hole in the ground, and lining it at the bottom and sides with bricks without any mortar to unite them. A quantity of stones or gravel is placed upon the bricks, and over the stones or gravel common wrappering, such as is used for sacks. Below the bricks is a drain to take off the water which passes through the filter. In a tub adjoining the' filter is kept a quantity of dilute sulphuric acid, of about the specific gravity of 105, water being 100. Hydrochloric acid will answer the several purposes. hut sulphuric acid is preferred as more economical. A channel is made from the dye-vessels to the filter. The madder which has been employed in dyeing is run from the dye-vessels to the filter; and while it is so running, such a portion of the dilute sulphuric acid is run in and mixed with it as changes the colour.of the solution and the undissolved madder to an orange tint or hue. This acid precipitates the colouring matter which is held in solution, and prevents the undissolved madder from fermenting or otherwise decomposing. When the water has drained from the madder through the filter, the residuum is taken from off the filter and put into bags. The bags are then placed in an hydraulic press, to have as much water as possible expressed fiom their contents. In order to break the lumps which have been formed by compression, the madder or residuum is passed through a sieve. To 5 cwt. of madder in this state, placed in a wood or lead cistern, 1 cwt. of sulphuric acid of commerce is sprinkled on the madder through a lead vessel similar in form to the ordinary watering-can used by gardeners. An instrument like a garden spade or rake is next used, to work the madder about, so as to mix it intimately with the acid. In this stage the madder is placed upon a perforated lead plate, which is fixed about five or six inches above the bottom of a vessel. Between this plate and the bottom of the vessel is introduced a current of steam by a pipe, so that it passes through the perforated plate and the madder which is upon it. During this process, which occupies from or.e to tw hours, a substance is produced of a dark brown colour approaching to black. This substance is garancine and insoluble carbonized matter. W hen cool, it is ulaced upon a filter and washed with clear cold water until the wateI 842 GAS. passes from it without an acid taste. It is then put into bags and pressed with an hyllraulic press. The substance is dried in a stove and ground to a fine powder under orl.inary madder stones, and afterwards passed through a sieve. In order to neutralize any acid that may remain, from 4 to 5 lbs. of dry carbonate of soda for every hundre4 weight of this substance is added and intimately mixed. The garancine in this state is ready for use." GARNET (Grenat, Fr.; Granat, Germ.); is a vitreous mineral of the cubic system, of which the predominating forms are the rhomboidal dodecahedron and the trapezohedron; specific gravity varying from 3'35 to 4-24; fusible at the blowpipe. Its constituents are, silica, 42; alumina, 20-0; lime, 340; protoxide of iron, 4. Garnets are usually disseminated, and occur in all the primitive strata from gneiss to clay slate.'The finer varieties, noble garnet or Almandine, and the reddish varieties of Grossulaire (Essonite), are employed in jewelry; the first are called the Syrian or oriental; the others, hyacinth. In some parts of Germany garnets are so abundant as to be used as fluxes to some iron ores: in others, the garnet gravel is washed, pounded, and emrldoved as a substitute for emery. The garnets of Pegu are most highly valued. Factitious garnets may be made by the following conlposition:-Purest white glass, 2 ounces; glass of antimony, 1 ounce; powder of cassius, 1 grain; manganese, 1 grain. GAULTHERIA OIL; an aromatic oil, called in commerce wintergreen oil. It is obtained from a shrub of the Ericeen family, (Gaultheria procuimbens L., Canadian tea.) The oil occurs in all parts of the plant, but mostly in the flowers, and may be extracted by alcohol, but not by water from the dried or scentless plant. The same oil is obtained from the bark of sweet birch, by distilling it with water, whereby it results from'the mutual action of a body like emulsion upon a body like amygdalin. The oil is c.ourless, but becomes reddish in the air, as it is found in commerce. Its specific gravity is 1 173, and its boiling point 211~ C.; it distils at the constant heat of 220~; it has then a gravity 1-18: the watery solution of the oil produces with the red salts of iron a violet tint, which becomes with excess of oil very deep and rich. Its constituents are C,, = 1200 631i6 Hs 100 5-26 06 = 600 31-58 1900 10000 If we distil the oil with an excess of caustic potash, wood spirit comes over, and the remainder consists of salicylate of potash. The oil is a natural compound wood ether, which may be prepared artificially by distilling togetler two parts of salicylic acid with two parts of dry wood spirit, and one part of oil of vitriol. The ether is separable from the distilled liquor by means of chlorcalcium. Bromine and chlorine act violently upon the oil. The gaultheria oil combines without decomposition into a peculiar class of salts. GAULTHERINE. When the pulverized dried bark of betula lenta's exhausted with cold alcohol of 95~, it can afford no more oil. The fluid which contains the gaultherine has a slight bitterish taste, and by evaporation it forms a dry gummy mass which at a high heat leaves a coaly residual. Oil of vitriol dissolves the gaultherine with a red colour and a flavourl of the oil. GAS (Eng. and Fr.; Gaz, Germ.) is the generic name of all those elastic fluids which are permanent under a considerable pressure, and at the temperature of zero of Fahrenheit. In many of them, however, by the joint influence of excessive cold and pressure, the repulsive state of the particles may be balanced or subverted, so as to transform the elastic gas into a liquid or a solid. For this most interesting discovery, we are indebted to the fine genius of Mr. Faraday. The following table exhibits the temperatures and pressures at which certain gases are liquefied. Becomes liquid Name of the gas. _ Calculated boiling point; Sulphurous arid - - 59~ F. 3 atmospheres. - 4~ Fahr. Chlorine. - - 60 4 - 22 Ammonia - - - 50'65 - 64 Sulphureted'hydrogen - - 50 17 - 142 Carbonic acid. - - 32 36 - 229 Hydrochloric or muriatic acid - 50 50 - 249 Deutoxide of azote - - 45 50 -- 254 ---—.. —-— _ —— _ - GAS-LIGHT. 843 Liquid carbonic acid becomes solidified, into a snowy-looking substance, by its own rapid evaporation. Oxygen, hydrogen, and azote, have hitherto resisted all attempts tc divest them of their elastic form. For this purpose, it is probable that a condensing force equal to that of 650 atmospheres, will be required. The volume of auy gas is, generally speaking, inversely as the pressure to which it is exposed; thus, under a double pressure its bulk becomes one half; under a triple pressure, one third; and so on. For the change of volume in gaseous bodies by heat, see EXPANSION. Ammonia, carbonic acid, carbureted hydrogen, chlorine, muriatic acid, sulphurous acid, sulphureted hydrogen, are the gases of most direct interest in the arts and manu. factures. Their detailed examination belongs to a work on chemistry. GAS-LIGHT. (Eclairage par gas, Fr.; Gaslicht, Germ.) Dr. Clayton lemonstrated, by numerous experiments in 1737 and 1738, that bltumino0~; pit-coal subjected to a red heat in close vessels, afforded a great deal of an air similar to the fire-damp of mines, but which burned with a brighter flame. It does not appear that this species of factitious air was ever produced from pit-coal for the purpose of artificial illumination till 1792, when Mr. William Murdoch, engineer to Messrs. P-lton and Watt, employed toal gas for lighting his house and offices, at Redruth in Cori. tall. The gas was generated in an iron retort, whence it was received in a gasometer, distributed in different situations by pipes, and finally burned at small apertures which could be opened and stopped at pleasure. He moreover made this light moveable, by confining the gas in portable tin-plate vessels, and burning it wherever he pleased. Between this period and 1802, Mr. Murdoch continued at intervals to make similar experimcnts; and upon occasion of the national illumination in the spring of the latter year, at the peace of Amiens, he lighted up part of the Soho manufactory with a public display of gaslights. The earliest application of this artificial light, on a large systematic scale, was made at Manchester; where an apparatus for lighting the great cotton mills of Messrs. Philips and Lee, was fitted up in 1804 and 1805, under the direction of Mr. Murdoch. A quantity of light, nearly equal to 3000 candles, was produced and distributed in this builling. This splendid pattern has been since followed very generally in Great Britain, and more or less in many parts of the continents of Europe and America. By the yeai 1822, gas-lighting in London had become the business of many public companies. At the Peter street station, for example, 300 retorts had been erected, supplying 15 gasometers, having each an average capacity of 20'626 cubic feet, but, being never quite filled, their total contents in gas might be estimated at 309,385 cubic feet. The extent of main pipes of distribution belonging to this station was then about 57 miles, with two separate mains in some of the streets. The product of gas was from 10,000 to 12,000 cubic feet from a chaldron of coals. The annual consumption of coals was therefore altogether 9282 chaldrons, affording 11,384,000 cubic feet of gas, allowing 153 retorts to be in constant daily action, upon an average of the year; and illuminating 10,660 private lamps, 2248 street lamps, and 3894 theatre lamps. At the Brick-lane works, 371 retorts were fixed in 1822, 133 being worked on an aver age of summer and winter. There were 12 gasometers, charged with an average quantity of gas amounting to 197,214 cubic feet. Of coals, 8060 chaldrons were annually consumed; 96,720,000 cubic feet of gas were generated; for the supply of 1978 public lamps, and 7366 private ones, connected with main pipes 40 miles long. At the Curtain-road gas establishment, there were 240 retorts; but the greatest number worked in 1821 was only 80, and the lowest 21. The six gasometers had an average contents of 90,467 cubic feet. Of coals, 3336 chaldrons were annually consumed, yield ing 40,040,000 cubic feet of gas, that supplied 3860 private lamps, and 629 public ones, by means of mains 25 miles long. The above three stations belonged to the London GasLioht and Coke Company. The City of London Gas-Light Company, Dorset street, had built up 230 retorts, and 6 gasometers, while two were preparing; having a total capacity of 181,282 cubic feet. Of private lamps 5423 were lighted, and 2413 public ones, from mains extending 50 miles. The quantity of coals carbonized amounted to 8840 chaldrons; producing 106,080,000 cubic feet of gas. The South London Gas-Light and Coke Company had mounted at Bankside 143 retorts, with 3 gasometers; the contents of the whole being 41,110 cubic feet, connected with mains from 30 to 40 miles long. At their other station, in Wellington street, 9 large gasometers were then erecting, with a capacity of 73,565 cubic feet, which were to be supplied with gas from Bankside, till retorts were mounted for them. The Imperial Gas-Light and Coke Company had at that time 6 gasometers in progress at their Hackney station. In 1822 there were thus four great companies, having in all 47 gasometers at work, capable of containing 917,940 cubic feet of gas, supplied by 1315 retorts, which generated 844 GAS-LIGHT. per annum upwards of 397,000,000 cubic feet of gas, by which 61,203 private lamps, and 7268 public or street lamps, were lighted in the metropolis. Besides these public comn panies, there were likewise several private ones. 1. Of the generalion of illuminating gases.-Pure hydrogen gas bumns with too feeble a flame to be employed for illumination. But carbureted hydrogen having the property of precipitating its carbon in the act of burning, its solid particles become incandescent, and diffuse a vivid light. The more carbon it contains, the more brightly does it burn This gas exists in two distinct states of combination. In the first, two measures of hy. drogen gas are combined with one measure of the vapor of carbon, forming together one measure whose specific gravity is of course the sum of the weights of the constituents, or 0-559; atmospherical air being 1'000. This is the gas which is found in mines, and is also evolved in ditches from decomposing vegetable matter. In the second, two measures of hydrogen gas are combined with two of gaseous carbon, forming also one volume or measure whose weight or specific gravity is 0-985. This was at one time called the olefiant gas, because when mixed with chlorine an oily looking compound was produced. It may be called as well oil gas, because it is generated in considerable quantities hy the igneous decomposition of oil. Thus the olefiant gas contains in the same volume double the quantity of carbon of common carbureted hydrogen, and it burns with a proportionably brighter flame. The gaseous oxyde of carbon, as well as sulphureted hydrogen gas, burns with a feeble blue light, bat the latter produces in combustion sulphurous acid, an oflensive and noxious gas. By dry distillation or carbonization in close vessels, all bodies of vegetable and animal origin disengage carbureted hydrogen gas; even charcoal, when placed in ignition in contact with steam, by decomposing the water, produces abundance ot carbonic acid, carbureted hydrogen, hydrogen, and carbonic oxyde. After separating the carbonic acid with lime water, that mixed gas contains in 100 measures, 20 of carbureted hydrogen; the rest being hydrogen and carbonic oxyde, so that the gaseous mixture cannot be used for illumination. The best substances for furnishing a gas rich in Itminiferous materials are, pitcoal, especially the cannel coal, resin, oil, fats of all kinds, tar, wax, &c. In some cases the gases evolved during the igneous decomposition of bones and other animal matters for the production of ammonia, may be employed for procuring light, but they are apt to emit a fetid odor. When coals are heated in a cast-iron retort to ignition, the progress of decomposition is as follows. First, and before the retort becomes red hot, steam issues along with the atmospheric air. When the retort begins to redden, tar distils in considerable quantity with some combustible gas, of which hydrogen mixed with ammoniacal gas forms a part. The evolution of gas increases as the retort becomes hotter, with a continual production of tar and ammoniacal liquor as well as sulphurous acid from the pyrites of the coal, which unites with the ammonia. When the retort has come to a bright cherry red heat, the disengagement of gas is most active. By and by the gaseous production diminishes, and eventually ceases entirely, although the heat be increased. In the retort a quantity of carbonized coal or coke remains, while tar is found at the bottom of the receiver, covered with the ammoniacal liquor, and combined with carbonic and sulphurous acids, and sulphureted hydrogen. If, during this distillation, the combustible gas be collected and examined at the several stages of the process, it is found to differ extremely in its luminiferous powers. That which comes off before the retort has acquired its proper temperature, gives a feeble light, and resembles the gas obtained by the ignition of moist charcoal, consisting chiefly of hydrogen. That evolved when the retort has just acquired throughout a vivid red heat, is the best of all, consisting chiefly of bi-carbureted hydrogen or olefiant gas. From good coal, it consists, for example, in 100 measures, of 13 of olefiant gas, 82'5 of carbureted hydrogen, 3-2 carbonic oxyde, 1-3 azote; the mixture having a specific gravity of 0'650. At a later period, as after 5 hours, it contains 7 measures of olefiant gas, 56 of carbureted hydrogen, 11 of carbonic oxyde, 21-3 of hydrogen, 4-7 of azote; the specific gravity of the whole being 0500. Towards the end of the operation, asafter 10 hours, it contains twenty measures of carbureted hydrogen, 10 of carbonic oxyde, 60 of hydro. gen, 10 of azote, with a specific gravity of only 0'345. The hydrogen becomes sulphureted hydrogen, if there be much pyritous matter in the coal. The larger proportion of the gas is disengaged during the first hour, amounting to about one fifth of the whole; in the three fo)llowing hours the disengaaement is tolerably uniform, constituting in all fifty. four hundredths; in the sixth hour, it is one tenth; in the seventh and eighth hours sixteen hundredths. From these observations are derived the rules for the production of a good light gas from coals. They show that the distillation should commence with a retort previously heated to a cherry red, since thereby good gas is immediately produced, and a portion of the tar is also converted into gas, instead of being simply distilled over into the con. denser pit; that this heat should he steadily continued during the whole operation. rnom 5 to 8 hours; th'at it should not be increased, especially towards the end, for feal GAS-LIGHT. 845 Df generating carbonic oxyde and hydrogen gases, as well as of injuring the retort when the cool;ng agency of gasefication has become feeble; and that the operation should be stopped some time before gas ceases to come over, lest gases with feeble illuminating powel should impoverish the contents of the gasometer. Upon the average, a pound of good coai affords four cubic feet of gas, or a chaldron=26 cwts. London measure, affords from 12,000 to 15,000 cubic feet, according to the form of the retort, and the manner of firingit. When oil, fats, rosin, tar, &c. are employed for the production of a light gas, it is not sufficient to introduce these substances into the retorts, and to heat them, as is done with coals. In this case, the greater part of them would distil over in the state of volatile oils. and very little gas be generated, only as much as corresponded to the quantity of fat, &c. in immediate contact with the retort. It becomes therefore necessary to fill the retorts with pieces of brick cr coke; and to keep them in ignition, while the oil, &c. is slowly introduced into their interior. The fats instantly assume the vaporous state, and thus coming into contact upon an extensive surface with the ignited bricks, are decomposed into combustible gases. A small portion of carbonaceous matter remains in the retort, while much olefiant gas is formed, possessing a superior illuminating power to common coal gas, and entirely free from sulphureous impregnation. The best oil gas is generated at a dull red, a heat much below what is requisite for the decomposition of coal. A more intense heat would indeed produce a greater volume of gas, but of a poorer quality, because the olefiant gas thereby deposites one half of its carbon, and is converted into common carbureted hydrogen. Oil affords at a lively red heat, gases which contain in 100 measures, 19 of olefiant gas, 32-4 of carbureted hydrogen, 12'2 of carbonic oxyde gas, 32-4 of hydrogen, and 4 of azote; the mean specific gravity being only 0'590. At a more moderate temperature it yields 22-5 of the olefiant, 50'3 carbureted hydrogen, 15~5 carbonic oxyde, 7'7 hydrogen, and 4 azote, with a specific gravity of 0-758. It contains when generated by dull ignition, as is usual in works on the manufacturing scale, in 100 parts fiom 38 to 40 of olefiant gas, and besides the carbureted hydrogen, a few per cent. of carbonic oxyde and azote, with a specific gravity of 0'900, and even upwards. One pound of oil or fluid fat affords 15 cubic feet of gas; of tar affords about 12 cubic feet; of rosin or pitch, 10 cubic feet. When the oil aas is compressed by a force of from 15 to 20 atmospheres, as was the practice of the Portable Gas Company, about one fifth of the volume of the gas becomes liquefied into an oily, very volatile fluid, having the specific gravity 0'821. It is a mixture of three fluids (consisting of carbureted hydroaen), of different degrees of volatility. The most volatile of these boils even under 32~ F. Some of the vapor of this gas-oil is mixed with the olefiant gas in the general products of decomposition; in consequence of which they are sometimes richer in carbon than even olefiant gas, and have a higher illuminating power. Oil gas contains about 22 per cent. and coal gas about 31 per cent. of this oily vapor. In the estimations of the composition of the gases given above, this vapor is included under olefiant gas. This vapor combines readily with sulphuric acid, and is thus precipitated from the gaseous mixture. The amount of olefiant gas is shown, by adding to the gas, contained over water, one half of its volume of chlorine, which, in the course of an hour or two, condenses the olefiant gaa into an oily looking liquid (chloride of hydrocarbon.) After the mixture, the gases must be screened from the light, otherwise the common carbureted hydrogen would also combine with the chlorine, while water and carbonic acid would make their appearance. The oil employed for affording gas is the crudest and cheapest that can be bought; even the blubber and sediment of whale oil are employed with advantage. After all, however, coal is so much cheaper, and the gas produced from it is now so well purified, that oil and rosin are very little used in gas apparatus. A.ppara/us for Coal Gas.-Coal gas, as it issues fiom the retort, cannot be directly employed for illumination; for it contains vapors of tar and coal oil, as also steam impregnated with the carbonate, sulphite, and hydrosulphuret of ammonia. These vapors would readily condense in the pipes through which the gas must be distributed, and would produce obstructions; they must therefore be so far removed by previous cooling, as to be liable to occasion no troublesome condensation at ordinary temperatures. The crude coal gas contains moreover sulphureted hydrogen, whose combustion for light would exhale an offensive sulphureous odor, that ought to be got ril of as much as possible. Carbonic acid and carbonic oxyde gases, generated at first from the decomposition of the steam by the ignited coal, enfeeble the illuminating power of the gas, and should be removed. The disengagement of gas in the retorts is never uniform, bitt varies with the degree of heat to which they are exposed; for which reason the gas must be received in a gasometer, where it may experience uniform presure, and be discharged uniformly into the pipes of distribution, in order to ensure a steady discharge of gas, and uniform intensity of light in the burners. A coal gas appa. ratus ought therefore to be so constructed as not only to generate the gas itself, but to fulfil the above conlitions. 846 GAS-LIGHT. In fig. 669, such an apparatus is represented, where the various parts are shown con aected with each other, in section. A is the furnace with its set of cylindrical or elliptical retorts, five in number. Fror each of these retorts, a tube b proceeds perpendicularly upwards, and then by a curvt 669 cr saddle-tube, it turns down horizontal cylinder under B, shut at each end with a screw cap, and ao ^...^...... m i~f descends to beneath its middle, so as to dip about an inch into X 1-=1 __ _] _E^E l. l( x the water contained in it. From 1___l[ one rend of this cylinder the tube L1 "I"""""!"!! I ^ Ji| ^d passes downward, to connect ufit~' Il itself with a horizontal tube N - ____-_-_ _l, 1r|S which enters into the tar pit or -- - _ _ | cistern c, by means of the verti...\...aaaCtj _ _~-I T -,__ _ cal branchf. This branch reach T_-fT-" _\ R - _L llies to near the bottom of the cy-.- _ - -- llindrical vessel, which sits on the -~-_~_-I- Il 1_ 1 1 sole of the tar cistern. From the - - -ilill other side of the vertical branch f,the main pipe proceeds to the a^^^^^r:1:K c i condenser D, and thence by the pipe 1, into the purifier E; from 6:- - - >i2 which the gas is immediately transmitted by the pipe p into the Fi^ o.aK o1gasometer F. 7'll 31^ -The operation proceeds in the - _l *11| 2 a1.._- jle 2 following way:-As soon as gas _ f1p *> \ -|l~ aI n| ^t begins to be disengaged from the "''':I" i gnl itgnited retort, tar and ammonill _ Amp= Till %;J ~~P C ll acal liquor are deposited in the I m"'lf I cylindrical receiver B, and fill it c>[ -|| tliJ1l:~| up till the superfluity runs over || - fa^ ~ - by the piped, the level being constantly preserved at the line shown in the figure. By the same.67~13 1 X____ K tarry liquid, the orifices of the 6I3 _ several pipes b, issuing from the 15;Wi |-=ri. yg ^ retorts, are closed; whereby the J /| 1~-b I A z.gas in the pipe d has its combjKth'~ i munication cut off with the gas, - \1 in the retorts. Hence if one of t=^S^ ~ 0;inI \^ ^j 1 iithe retorts be opened and emptied, it remains shut off from the lo/ ^: I it 111 | rest of the apparatus. This in>ih~ 11 ijgl~; n11' sulation of the several retorts is Ill | the function of the pipe under B, IJ Z Gl1___ ^ and therefore the recurved tube b No ~ md c- must be dipped as far under the - ) r surface of the tarry liquid, as to be in equilibrio with the pressure of the gas upon the water in the purifier. The tube b is closed at l |l l IItop with a screw cap, which can t p m { ^ 1|1, be taken off at pleasure, to permit the interior to be cleansed. Both by the overflow from the receiver-pipe B, and by subse. quent condensation in the tube d, tar and ammoniacal liquor collect progressively in the cistern or pit under c, by which mingled liquids'the lower orifice of the vertical tubef is closed, so that the gas cannot escape into the empty space of this cistern. These liquids flow over the edges of the inner vessel when it is full, and may from time to time be irawn off by the stopcock at the bottom of the cistern. Though the gas has, in its progress hitherto, deposited a good deal of its tarry and ammoniacal vapors, yet, in consequence of its high temperature, it still retains a con. siderable portion of them, which must be immediately abstracted, otherwise the tar GAS-LIGHT. 847 would pollute the lime in the vessel E, and interfere with its purification. On this ac count the gas should, at this period of the process, be cooled as much as possible, in order to condense these vapors, and to favor the action of the lime in the purifier E, upon the sulphureted hydrogen, which is more energetic the lower the temperature of the gas. The coal gas passes, therefore, from the tube f into the tube h of the condenser D, which is placed in an iron chest g filled with water, and it deposites more tar and arnmoniacal liquor in the under part of the cistern at t, t. When these liquids have risen to a certain level, they overflow into the tar-pit, as shown in the figure, to be drawn off by the stop,.k as occasion may require. The refrigerated gas is now conducted into the purifier E, which is filled with milk of lime, made by mixing one part of slaked lime with 25 parts of water. The gas, as it enters by the pipe 1, depresses the water in the wide cylinder n, thence passes under the perforated disc in the under part of that cylinder, and rising up throughlinnumerable small holes.is distributed throughout the lime liquid in the vessel mn. By contact with the lime on this extended surface, the gas is stripped of its sulphureted hydrogen and carbonic acid, which are condensed into the hydro-sulphuret and carbonate of lime; it now enters the gasometer F in a purified state, through the pipe p t. and occupies the space I. The aasometer, pressing with a small unbalanced force over the counterweight s, expels it through the main u u, in communication with the pipes of distribution through the buildings or streets to be illuminated. The parts A B c D E and F. of which this apparatus consists, are essential constituents of every good coal-gas work. Their construction rests upon peculiar principles, is susceptible of certain modifications, and therefore deserves to be considered in detail. The Retorts. - These are generally made of cast iron, though they have occasionally been made of baked clay, like common earthenware retorts. The original form was a cylinder, which was changed to an ellipse, with the long axis in a horizontal direction, then into the shape of the letter D with the straight line undermost, and lastly into a semi-cylinder, with its horizontal diameter 22 inches, and its vertical varying from 9 to 12. The kidney form was at one time preferred, but it has been little used of late. The form of retort represented in fig. 670 has been found to yield the largest quantity 670 j!of good gas in the shortest time, and with 670 D o^ lthe least quantity of firing. The length is Z,/ m /,^^^ 77, and the transverse area, from one foot to a foot and a half square.'The arrows;t......i^.,show the direction of the flame and draught ^///X/W^,* \ /j j S///^^fi in this excellent bench of retorts, as ^/ m// o /1^'^ / M^ mcanted by Messrs. Barlow., Ass ^ A.d ^The charge of coals is most conveniently God /P' l Ey introduced in a tray of sheet iron, made I Nl 5somewhat like a grocer's scoop, adapted to / the size of the retort, which is pushed home,Xi i^Ad^ ^^ // g to its further end, inverted so as to turn out the contents, and then immediately withdrawn. The duration of the process, or the time of completing a distillation, depends upon /the nature of the coal and the form of the ____________ retort. With cylindrical retorts it cannot /. ogs / //// be finished in less than 6 hours, but with elliptical and semi-cylindrical retorts, it may be completed in 4 or 5 hours. If the distillation b_ continued in the former for 8 hours, and in the latter for 6, gas will continue to be obtained, but during the latter period of the operation, of indifferent quality. The Receiver. - If the furnace contains only 2 or 3 retorts, a simple cylindrical vessel standing on the ground half filled with water, may serve as a receiver; into which the tube from the retort may be plunged. It should be provided with an overflow pipe for the tar and ammoniacal liquor. For a range of several retorts, a long horizontal cylinder is preferable, like that represented at B in fig. 671. Its diameter is from 10 to 15 inches. This cylinder may be so constructed as to separate the tar from the ammoniacal liquor, by means of a syphon attached to one of its ends. The Condenser. — The condenser, represented in fig. 669, consists of a square chest g, made of wrought iron plates open at top, but having its bottom pierced with a row of holes, to receive a series of tubes. To these holes the upright four-inch tubes h h are secured by flanges and screws, and they are connected in pairs at top by the curvel oi saddle tubes. The said bottom forms the cover of the chest t, t. which is divided by ver tical iron partitions, into half as many compartments as there are tubes. 848 GAS-LIGHT. These partition plates are left open at bottom, so as to place the liquids of each cor partment in communication. Thereby the gas passes up and down the series of tubes; in proceeding from one compartment to another. The condensed liquids descend irno the box t, t, and flow over into the ta. 61 1 cistern, when they rise above the leve. t, t. The tar may be drawn off from p~~B l[ l] ~ ltime to time by the stopcock. Through B- IT] --- ^-_-^ - ithe tube k, cold water flows into the condenser chest, and the warm water d |||1_ ________. ~ L passes away by a pipe at its upper edge. Tl e extent of surface which the gas requires for its refiigeration before it is admitted into the washing-lime apparatus. depends upon the iemnerature of the milk of limc, and the quantity of gas generated in a certain time. It may be assumed as a determination sufficiently exact, that 10 square feet |@s~ ~==E j < c~ ~of surface of the condenser can coot a cubic foot of gas per minute to the temperature of the cooling water. For example, suppose a furnace or arch with 5 retorts of 150 pounds of coal each, to produce in 5 hours 3000 cubic feet of gas, or 10 cubic feet per minute, there would be required, for the cooling surface of the condenser, 100 square feet = 10 X 10. Suppose 100,000 cubic feet ot gas to be produced in 24 hours, for which 8 or 9 such arches must be employed, the condensing surface must contain from 800 to 900 square feet. The Purifier. -The apparatus represented in the preceding figure is composed of a cylindrical iron vessel, with an air tioht cover screwed upon it, through which the cylinder n is also fixed air-tight. -The bottom of this cylinder spreads out like the brim of a hat, forming a horizontal circular partition, which is pierced with holes. Through a stuffing box, in the cover of this interior cylinder, the vertical axis of the agitator passes, which is turned by wheel and pinion work, in order to stir up the lime from the bottom of the water in the purifier. The vessel o serves for introducing fi esh milk of lime, as also for letting it of' by a stopcock when it has become too foul for further use. The quantity of lime should be proportioned to the quantity of sulphureted hydrogen and carbonic acid contained in the gas. Supposing that in good coal gas there is 5 per cent. of these gases, about one pound and a half of lime will be requisite for every hundred cubic feet of coal gas generated, which amounts to nearly one sixteenth of the weight of coal subjected to decomposition. This quantity of lime mixed with the proper quantity of water will form about a cubic foot of milk of lime. Consequently, the capacity of the purifier, that is, of the interior space filled with liquid, may be taken at four sevenths of a cubic foot for every hundred cubic feet of gas passing through it in one operation; or for 175 cubic feet of gas, one cubic foot of liquor. After every operation, that is, after every five or six hours, the purifier must be filled afiesh. Suppose that in the course of one operation 20,000 cubic feet of gas pass through the 20,000 machine, this should be able to contain 000 = 114 cubic feet of milk of lime; whence its diameter should be seven feet, and the height of the liquid three feet. If the capacity of the vessel be less, the lime milk must be more frequently changed. 2n some of the large gas works of London the purifier has the following construction, whereby an uninterrupted influx and efflux of milk of lime takes place. Three single purifiers are so connected together, that the second vessel stands higher than the first, and the third than the second; so that the discharge tube of the superior vessel, placed somewhat below its cover, enters into the upper part of the next lower vessel; consequently, should the milk of lime in the third and uppermost vessel rise above its ordinary level, it will flow over into the second, and thence in the same way into the first; from which it is let off by the eduction pipe. A tube introduces the gas from the condenser into the first vessel, another tube does the same thing for the second vessel, &c., and the tube of the third vessel conducts the gas into the gasometer. Into the third vessel, milk of lime is constantly made to flow from a cistern upon a higher level. By this arrangement, the gas passing through the several vessels in proportion as it is purified, comes progressively into contact with purer milk of lime, whereby its purification becomes more complete. The agitator, provided with two stirring paddles, is GAS-LIGHT. 849 kept in continual rotation. The pressure which the gas has here to overcome is naturally three times as great as with a single purifier of like depth. Fig. 672 is a simple form of purifier, which has been found to answer well in practice. Through the cover of the vessel A a, the wide cylinder e d is inserted, having its lower end pierced with numerous holes. Concentric with that cyinder is the narrower one s z, bound above with the flange a b, but open at top and bottom. The under edge g h of this cylinder descends a few inches below the end cd of the outer one. About the middle of the vessel the perforated shelf in n is placed. The shaft of the agitator 1, passes through a stuffing box upon the top of the vessel. The gas-pipe g, proceeding from the condenser, enters through the flange a b in the outer cylinder, while the gas-pipe h goes from the cover to the gasometer. A stopcock upon the side, whose orifice of discharge is somewhat higher than the under edge of the outer cylinder, serves to draw off the milk of lime. As the gas enters through the pipe g into the space between the two cylinders, it displaces the liquor till it arrives at the holes in the under edge of the, ter cylinder, through which, as well as under the edge, it flows, and then passes up through the apertures of the shelf m n into the milk of lime chamber; the level of which is shown by the dotted line. The stirrer, 1, should be turned by wheel work, though it is here shown as put in motion by a winch handle. In order to judge of the decree of purity of the gas aftet its transmission through the lime machine, a slender syphon tube provided with a stopcock may have the one end inserted in its cover, and the other dipped into a vessel containing a solution of acetate of lead. Whenever the solution has been rendered turbid by the precipitation of sulphuret of lead, it should be renewed. The saturated and fetid milk of lime is evaporated in oblong cast-iron troughs placed in the ash-pit of the furnaces, and the dried lime is partly employed for luting the apparatus, and partly disposed of for a mortar or manure. By this purifier, and others of similar construction, the gas in the preceding parts of the apparatus, as in the retorts and the condenser, suffers a pressure equal to a column of water about two feet high; and in the last described purifier even a greater pressure. This pressure is not disadvantageous, but is of use in two respects; 1. it shows by a brisk jet of gas when the apparatus is not air-tight, and it prevents common air from entering into the retorts; 2. this compression of the gas favors the condensation of the tar and ammoniacal liquor. The effect of such a degree of pressure in expanding the metal of the ignited retorts is quite inconsiderable, and may be neglected. Two contrivances have, however, been proposed for taking off this pressure in the purifier. In fig. 673, m m are two similar vessels of a round or rectangular form, furnished at their upper border with a groove filled with water, into which the under edge of the cover fits, so as to make the vessel air-tig-t. The cover is suspended by a cord or chain, which goes over a pulley, and may be raised or lowered at pleasure. The vessels themselves have perforated bottoms, r r', covered with wetted moss or hay sprinkled over with slaked and sifted quicklime. The gas passes through the loosely compacted matter of the first vessel, by entering between its two bottoms, rises into the upper space 1, thence it proceeds to the second vessel, and, lastly, through the pipe u, into the gasometer. 674 This method, however, requires atwice as much lime as the former, without increasing the purity of D All the gas. E { The second method consists in l C,'G \ ^,A compressing the gas by the ac-:C ^^~\^%3 ^tion of an Archimedes screw, to l Id I$ v K w such a degree, before it is admitd t led into the purifier, as that it -^ may overcome the pressure of' the column of vater in that vessel. Fig. 674 exhibits this apparatus in section. D D is the ___|_ Archimedes worm, the axis of Ad^i?~=' Xip~~ ~which revolves at bottom upon the gudgeon e; it possesses a three-fold spiral, and is turned ____^1 B: Ain the opposite direction to that al X la t=- ^_ — _____ ____" _ in which it scoops the water, fiC ^r_;g _ 41 _~- ^.^ ^ g The cistern which contains it has an air-tight cover. The gas to be purified passes through the pipe c into the space n, over the water level d; the upper cells of the worm scoop in the gas at this point, and 850 GAS-LIGHT. carry it downwards, where it enters at g into the cavity E of a second cistern. In ordet that the gas, after it escapes from the bottom of the worm, may not partially return through g into the cavity D, an annular plate g h is attached to its under edge, so as to turn over it. The compressed gas is conducted from the cavity E through the pipe G into the purifying machine; a is a manometer, to indicate the elastic tension of the gas in D. On the top of the worm a mechanism is fitted for keeping it in constant rotation. A perfect purification of light-gas from sulphureted hydrogen, either by milk of lime or a solution of the green sulphate of iron, is attended with some difficulty, when carried so far as to cause no precipitation of sulphuret in acetate of lead, because such a degree of washing is required as is apt to diminish its illuminating power, by abstracting the vapor of the rich oily hydrocarburet which it contains. Moreover, the coal gas obtained towards the end of the distillation contains some sulphuret of carbon, which affords sulphurous acid on being burned, and can be removed by no easy method hitherto known. The lime in the purifier disengrages from the carbonate and hydro-sulphuret cf ammonia carried over with the gas, especially when it has been imperfectly cooled in the condenser, a portion of ammoniacal gas, which, however, is not injurious to its illuminating power. The best agent for purifying gas would be the pyrolienite of lead, were it not rather ex pensive, because it would save the trouble of stirring, and require a smaller and simpler apparatus. The Gasometer.-The gasometer serves not merely as a magazine for receiving the gas when it is purified, and keeping it in store for use, but also for communicating to the gas in the act of burning such a uniform pressure as may secure a steady unflickering flame. It consists of two essential parts; 1. of an under cistern, open at top and filled with water; and 2. of the upper floating cylinder or chest, which is a similar cistern inverted, and of somewhat smaller dimensions, called the gas-holder; see F, fig. fi69. The best form of this vessel is the round or cylindrical; both because under equal capacity it requires least surface of metal, and it is least liable to be warped by its own weight or accidents. Since a cylindrical body has the greatest capacity with a given surface when its height is equal to its semi-diameter, its dimensions ought to be such that when elevated to the highest point in the water, the height may be equal to the radius of the base. For example, let the capacity of the gas-holder in cubic feet be k, the semi-diameter of its base be x, the height out of the water be h; 3 /h is =x = I This height may be increased by one or two feet, according to its 3-14 magnitude, to prevent the chance of any gas escaping beneath its under edge, when it is raised to its highest elevation in the water. The size of the gasometer should'be proportional to the quantity of gas to be con sumed in a certain time. If 120,000 cubic feet be required, for instance, in 10 hours for street illumination, and if the gas retorts be charged four times in 24 hours, 30,000 feet of gas will be generated in 6 hours. Hence the gasometer should have a capacity of at least 70,000 cubic feet, supposing the remaining 50,000 cubic feet to be produced during the period of consumption. If the gasometer has a smaller capacity, it must be supplied from a greater number of retorts during the lighting period, which is not advantageous, as the first heating of the supernumerary retorts is wasteful of fuel. Some engineers consider that a capacity of 30,000 cubic feet is the largest which can with propriety be given to a gasometer; in which case they make its diameter 42 feet, and its height 23. When the dimensions are greater, the sheet iron must be thicker and more expensive; and the hollow cylinder must be fortified by strong internal cross braces. The water cistern is usually constructed in this country with cast-iron plates bolted together, and made tight with rust-cement. In cases where the weight of water required to fill such a cistern might be inconvenient to sustain, it may be made in the form represented in fig. 675; which, however, will cost nearly twice as much. Parallel with the side of the cistern, a second cylinder c, of the same shape, but somewhat smaller, is fixed in an inverted position to the bottom of the first, so as to leave an annular space B B between them, which is filled with water, and in which the floating gasometer A plays up and down. The water must stand above the cover of the inverted cylinder. a and b are the pipes for leading the gas in and out. Through an opening in the masonry upon which the gasometer apparatus rests, the space c may be entered, in order to make any requisite repairs. The water cistern may also be sunk in the ground, and the sides made tight with hydraulic mortar, as is shown in fig. 675, and to make it answer with less water, a concentric cylindrical mass of masonry may be built at a distance of 2 or 3 inches within it. Every large gasometer must be strengthened interiorly with cross iron rods, to stiffen both its top and bottom. The top is supported by rods stretching obliquely down to GAS-LIGHT. 851 the sides, and to the under edge an iron ring is attached, consisting of curved cast iron bars bolted together; with which the oblique rods are connected by perpendicular ones. 676 675 c J.......... t E- J! ~_ 1; 711 1'/ IZI I -I - -.'J;'.'.j II i I........... E: Other vertical rods stretch directly from the top to the bottom edge. Upon the periphery of the top, at the end of the rods, several rings are made fast, to which the gas-holder is suspended, by means of a common chain which runs over a pulley at the centre. Upon the other end of the chain there is a counterpoise, which takes off the greater part of the weight of the gas-holder, leaving only so much as is requisite for the expulsion of the gas. The inner and outer surfaces of the gas-holder should be a few times rubbed over with hot tar, at a few days' interval between each application. The pulley must be made fast to a strong frame. If the water cistern be formed with masonry, the suspension of the gas-holder may be made in the following way. A A, fig. 676, is a hollow cylinder of cast iron, standing up through the middle of the gasometer, and which is provided at either end with another small hollow cylinder G, open at both ends and passing through the top, with its axis placed in the axis of the gas-holder. In the hollow cylinder G, the counterweight moves up and down, with its chain passing over the three pulleys B, B, B, as shown in fig. 676. E F are the gas pipes made fast to a vertical iron rod. Should the gasometer be made to work without a counterweight, as we shall presently see, the central cylinder A A, serves as a vertical guide. In proportion as the gas-holder sinks in the water of the cistern, it loses so much of its weight, as is equal to the weight of the water displaced by the sides of the sinking vessel; so that the gas-holder when entirely immersed, exercises the least pressure upon the gas, and when entirely out of the water, it exercises the greatest pressure. In order to counteract this inequality of pressure, which would occasion an unequal velocity in the efflux of the gas, and of course an unequal intensity of light in its flame, the weight of the chain upon which the gas-holder hangs is so adjusted as to be equal, throughout the length of its motion, to one half of the weight which the gas holder loses by immersion. In this case, the weight which it loses by sinking into the water, is replaced by the portion of the chain which, passing the pulley, and hanging over, balances so much of the chain upon the side of the counterweight; and the weight which it gains by rising out of the water, is counterpoised by the links of the chain which, passing over the pulley, add to the amount of the counterweight. The pressure which the gas-holder exercises upon the gas, or that with which it forces it through the first main pipe, is usually so regulated as to sustain a column of from one to two inches of water; so that the water will stand in the cistern from one to two inches higher within, than without the gas-holder. The following computation will place these particulars in a clear ligjt. Let the semi-diameter of the gas-holder, equal tc the vertical extent of its motion into and out of the water, = x; let the weight of a foot square of the side of the gas-holder, including that of the strengthening bars and ring, which remain plunged under the water, bec=p; then 55 852 GAS-LIGH' l. -he weight of the gas-holder in its highest position = 3 p - x2; 2. the weight of the sides of the gas-holder which play in the water = 2p r xi %. the cubic contents of the immersed portion of the gas-holder - 2p 7rf_; 4. its loss of weight in water = 12 400 400 p r xe; 5. the weight of the gas-holder in its lowest position = px2 ( 112 p 7r (3 -400 )-=2'72 p 7r x2; 56 6. the weight of n inches, height of water _= 2 n x2; 7. the amount of the counterweight = 7r x2) 3 p- -;-' 112 8. the weight of the chain for the length x = 80800 p 7r x. If we reduce the weight of the gas-holder in its highest and lowest positions to th height of a stratum of water equal to the surface of its top, this height is that of the column of water which would press the gas within the gasometer, were no counterweight employed; it consists as follows: 9. for the highest position =; 56 10. for the lowest =272p; 50 For the case, when the height of the gas-holder is different from its semi-diameter, let this height = m x; then the height of the water level is11. for the highest position = p (1+2 m; 12. for the lowest = p1 + 172m; 13. the counterweight = 7r x (1 ( 2m)- 56n); I 14. the weight Qf the equalizing chain=- p r m 1 2. 800 _Icr example, let the diameter of the gas-holder be 30 feet, the height 15 (the contents in cubic feet will be 10,597), p =-4 pounds; then the counterweight for a height of an inch and a half of water pressure = 3532 pounds; the weight of the chain for a length of 15 feet = 395 pounds. Were no counterweight employed, so that the gas-holder pressed with its whole weight upon the gas, then the height of the equivalent column of water in its highest position == 2-56 inches; and in its lowest, 2-33. The counterweight may hence be lessened at pleasure, if the height of the pressing water-column n be increased. The weight of the equalizing or compensating portion of the chain remains the same. When n = 2 inches, for instance, the counterweight = 1886 pounds. The velocity with which the gas passes along the mains for supplying the various jets of light, may be further regulated by opening the main-cock or slide-valve in a greater or less degree. Gasometers whose height is greater than their semi-diameter, are not only mnore costly in the construction, but require heavier counterweights and equilibration chains. The above estimate is made on the supposition of the gas in the gas-holder being of the,ame specific gravity as the atmospherical air, which would be nearly true with regard to oil gas under the ordinary pressure. But coal gas, whose specific gravity may be taken on an average at about 0-5, exercises a buoyancy upon the top of the gas-holder, which of course diminishes its absolute weight. Supposing the cubic foot of gas to be = 0'0364 pounds, the buoyancy will be = 0'0364 xr x3 pou-nds; a quantity which deserves to be taken into account for large gasometers. Hence, 15. the weight of the gas-holder in its highest position = 3 p 7r x2 —01143 x3; 56n 16. the counterweight - 7r x2 (3p- P - 01143 X2; 112 0'1143 x3 17. the weight of the chain for the length x=- - P if x 22 8 D 00 2 18. The height of the water pressure for the highest position, without the counterwei _3 p r-0-1143 x 56 7r.', ), 19. the same for the lowest position =- in feet. _ _ _ ----- _- -. —. —. —. _ _-. —. GAS-LIGHT 853 The preceding valaes of p and x are, (16) = 3147; (17) = 203; (18) = 2-44 inches; (19) = 2-33 inches. Fhe water columns in the highest and lowest situations of the gas-holder here diffei about 0'1 of an inch, and this difference becomes still less when p has a smaller value, for example, 3 pounds, or when the diameter of the gas-holder is still greater. It would thus appear that for coal-gas gasometers, in which the height of the gas-holder does not exceed its semi-diameter, and especially when it has a considerable size, neither a compensation chain nor a counterweight is necessary. The only thing requisite, is to preserve the vertical motion of the gas-holder by a sufficient number of guide rods or pillars, placed either within the water cistern, or round about it. Should the pressure of the gas in the pipe proceeding from the gasometer, be less than in the gasometer itself, this may be regulated by the main valve, or by water valves of various kinds. Or a small intermediate regulating gasometer may be introduced between the great gas-holder, and the main pipe of distribution. With a diameter of 61 feet in the gas-holder, the pressure in the highest and lowest positions is the same. The gasometers employed in storing up gas until required for use, occupy, upon the old plan, much space, and are attended with considerable expense in erecting. The water tank, whether sunk in the ground or raised, must be of equal dimensions with the gasometer, both in breadth and depth. The improved construction which we are about to describe, affords a means of reducing the depth of the tank, dispensing with the bridge of suspension, and of increasing at pleasure the capacity of the gasometer, upon a given base; thus rendering a small apparatus capable, if required, of holding a large quantity of gas, the first cost of which will be considerably less than even a strall gasometer constructed upon the ordinary plan. Mr. Tait, of Mile-End Road, the inventor, Jas, we believe, been for some years connected with gas establishments, and is therefore fully aware of the practical defects 6`7 e or advantages of the different constructions of I~| /~~\ gasometers now in use. Fig. 617 is a section of Mr. Tait's improved contrivance; a a is the 67~A y tank, occupied with water, b b two iron coli e e: umns, with pulley-wheels on the top, c c, ____________________ I chains attached to a ring of iron, d d, extendC- {6 ing round the gasometer, which chains pass over the pulley-wheels, and are loaded at their ~J~."f i extremities, for the purpose of balancing the I 5 weight of the materials of which the gasometer is composed. =| - — ~' | The gasometer is formed by 2 or 3 cylinders,'F.='~'.-'.."'' sliding one within the other, like the tubes of a telescope; e, e, e, is the first or outer cyl 1/^1^~~~ ^^^ ^^~^1^ - inder, closed at the top, and having the ring ____ [ IEiES Sof iron d, passing round it, by which the whole is suspended; ff, is the second cylinder, sliding freely within the first, and there may be a third \ and fourth within these if necessary. When there is no gas in the apparatus, all the cylinders are slidden down, and remain one within the other immersed in the tank of water; but when the gas rises through the water pressing against the top of the gasometer, its buoyancy causes the cylinder e to ascend. Round the lower edge of this cylinder a groove is formed by the turning in of the plate of iron, and aas it rises, the edge takes hold of the top rim of the cylinderf, which is )verlapped for that purpose. The groove at the bottom of the cylinder fills itself with water as it ascends, and by the rim of the second cylinder falling into it, an air-tight hydraulic joint is produced. Thus, several cylinders may be adapted to act in a small tank of water, by sliding one within the other, with lapped edges forming hydraulic joints, and by supporting the apparatus in the way shown, the centre of gravity will always be below the points of suspension. A gasometer may be made upon this plan of any diameter, as there will be no need of frame-work, or a bridge to support it; and the increasing weight of the apparatus, as the cylinders are raised one after the other, may be counterpoised by loading tme ends of the chains c c. The water in the gasometer need not be renewed;. but merely so much of it as evaporates or leaks out, is to be replaced. Indeed, the surface of the water in the cistern gets covered with a stratumir of coal oil, a few inches deep, which prevents its evaporation, and allows the gas to be saturated with this volatile substance, so as to increase its illuminating powers. The gasometer may be separated from the purifier by an intermediate vessel, srech sas is represented fig. 6f78, with which the two gas pipes are connected. A is the i ~________ 854 GAS-LIGHT. tylindrical vessel of cast iron a, the end of the gas pipe which comes from the purifier fl - - a -, cimmersed a few inches deep into the liquid with jEp /.o _ i ~ pwhich the vessel is about two thirds filled; b is the gas-pipe which leads into the gasometer; c is a perpendicular tube, placed over the bottom of the vessel, and reaching to within one third of the top, through which the liquid is introduced 678 into the vessel, and through which it escapes when it overflows the level d. In this tube the liquid stands towards the inner level higher, in propord c tion to the pressure of the gas in the gasometer. ~~A ____-__ - t~ V The fluid which is condensed in the gas-pipe b, and in its prolongation from the gasometer, runs off into the vessel A; and therefore the latter must be laid so low that the said tube may have the requisite declivity. A straight stopcock may also be attached to the side over the bottom, to draw off any sediment. II. APPLICATION OF LIGHT-GAS. 1. Distribution of the pipes.-The pressure by which the motion of the gas is maintained in the pipes, corresponds to a certain height of water in the c.tern of the gasometer. From the magnitude of this pressure, and the quantity of gas which in a given time, as an hour, must be transmitted through a certain length of pipes, depends the width or the diameter that they should have, in order that the motion may not be retarded by the fiiction which the gas, like all other fluids, experiences in tubes, and thereby the gas might be prevented from issuing with the velocity required for the jets of flame. The velocity of the gas in the main pipe increases in the ratio of the square root of the pressing column of water upon the gasometer, and therefore by increasing this pressure, the gas may be forced more rapidly along the remoter and smaller ramifications of the pipes. Thus it happens, however, that the gas will be discharged from the orifices near the gasometer, with superfluous velocity. It is therefore advisable to lay the pipes in such a manner, that in every point of their length the velocity of discharge may be nearly equal. This may be nearly effected as follows:From experiment it appears that the magnitude of the friction, or the resistance which the air suffers in moving along the pipes, under a like primary pressure, that is, for equal initial velocity, varies with the square root of the length. The volume of gas discharged from the end of a pipe is directly proportional to the square of its diameter, and inversely as the square root of its length; or, calling the length L, the diameter D, the cubic D2 feet of gas discharged in an hour k; then k = * Experience likewise shows, tha V/L for a pipe 250 feet long, which transmits in an hour 200 cubic feet of gas, one inch is a sufficient diameter. 1 D )D2 Consequently, 200: k --- -; and D-== /k V/-~ 144 V 250 vL 0455,000 From this formula the following table of proportions is calculated. Number ot bic feet per hour. Length of pipe, in feet. Diameter, in inches 50 100 0-40 250 200 1-00 500 600 1-97 700 1000 2-65 1000 1000 316 1500 1000 3-87 2000 1000 4-47 2000 2000 5-32 2000 4000 6-33 2000 6000 7-00 6000 1000 7-75 6000 2000 9-21 8000 1000 8-95 8000 2000 16-65 These dimensions are applicable to the case where the body of gas:s transmitted through GAS-LIGHT. 855 p;pes without being let off in its way by burners, that is, to the mains which conduct the gas to the places where it is to be used. If the main sends off branches for burners, then for the same length the diameter may be reduced, or for like diameter the length may be greater. For example, if a pipe of 5'32 inches, which transmits 2000 cubic feet through a length of 2000 feet, gives off, in this space, 1000 cubic feet of gas; then the remainder of the pipe, having the same diameter, can continue to transmit the gas through a length of 2450 feet = (450 00) 2 with undiminished pressure for the purposes of lighting. Inversely, the diameter should be progressively reduced in proportion to the numbor of jets sent off in the length of the pipe. Suppose, for instance, the gasometer to discharge 2000 cubic feet per hour, and the la t point of the jets to be at a distance of 4000 feet. Suppose also that from the gasomet r to the first point of lighting, the gas proceeds through 1000 feet of close pipe, tle diameter of the pipe will be here 4'47 inches; in the second 1000 feet of length, suppose the pipe to give off, at equal distances, 1000 cubic feet of gas, the diameter in this length (calculated at 1500 cubic feet for 1000 feet long)- 3-87 inches; in the third extent of 1000 feet, 600 cubic feet of gas will be given off, and the diameter (reckoning 700 cubic feet for 1000 feet long) will be 2-65 inches; in the fourth and last space (for 200 cubic feet in 1000 feet long) the pipe has a diameter of only an inch and a half, for which, in practice, a two-inch cast iron pipe is substituted; this being the smallest used in mains, into which branch pipes can be conveniently inserted. The same relations hold with regard to branch pipes through which the gas is transmitted into buildings and other places to be illuminated. If such pipes z ake frequent angular turnings, whereby they retard the motion of the gas, they must be a third or a half larger in diameter. The smallest tubes of distribution are never less than one fourth of an inch in the bore. Where, from one central gas work, a very great quantity of light is required in particular localities, there ought to be placed near these spots gasometers of distribution, which, being filled during the slack hours of the day, are ready to supply the burners at night, without making any considerable demand upon the original main pipe. Suppose the first main be required to supply 8000 cubic feet in the hour, for an illumination of 8 hours, at the distance of 2000 feet, a pipe 101 inches in diameter would be necessary; but if two or three gasometers of distribution, or station gasometers, be had recourse to, into which the gas during the course of 24 hours would flow through the same distance continuously from the central gas works, the quantity required per hour from them would be only one third of 8,000 = 2666-6 cubic feet; consequently the diameter for such a pipe is only 6-15 inches. All the principal as well as branch pipes, whose interior diameter exceeds an inch and a half, are made of cast iron from 6 to 8 feet long, with elbow pipes cast in them where it is necessary. These pipe lengths are shown in fig. 679, having at one end a wide socket a, and at the other a nozzle b, which fits the former. After inserting the one in the other in their proper horizontal position, a coil of hemp soaked with tar is driven home at the junction; then a luting of clay is applied at the mouth, within which a ring of lead is cast into the socket, which is driven tight home with a mallet and blunt chisel. 680 _ 679 = cl; ~D ~ A JB F E The pipes should be proved by a force pump before being received into the gas works; Iwo or three lengths of them should be joined before laying them down, and they should be placed at least two feet below the surface, to prevent their being affected by changes of temperature, which would loosen the joints. The tubes for internal distribution, when uf small size, are made of lead, copper, wrought iron, or tin. 856 GAS-LIGHT Instead of a stopcock for letting off the gas in regulated quantities from the gasometer, a peculiarly formed water or mercurial valve is uslally employed. Figr 68C shows the mode of construction for a water trap or lute, and is, in fact, merely a gasometer in miniature. c D E F is a square cast iron vessel, in the one side of which a pipe A is placed in communication with the gasometer, and in the other, one with the main n. The moveable cover or lid H G I K has a partition, rL IM in its middle. If this cover be raised by its counterweight, the gas can pass without impediment from A to; but if the counterweight be diminished so as to let the partition plate L M sink into the water, the communication of the two pipes is thereby interrupted. In this case the water-level stands in the compartment A so much lower than outside of it, and in the compartment B, as is equivalent to the pressure in the gasometer; therefore the pipes A and B must project thus far above the water. In order to keep the water always at the same height, and to prevent it from flowing into the mouths of these pipes, the rim c D of the outer vessel stands somewhat lower than the orifices A B; &a.d thence the vessel may be kept always full of water. It a quicksilver valve be preferred, it may be constructed as shown in fig. 681. A B are c 683 the terminations of the two gas pipes, \683 ETa ~ which are made fast in the rectangular iron vessel M. E is an iron vessel of the _v^ |____1 | same form, which is filled with quicksilver 684 up to the level a, and which, by means of the screw G, which presses against its od K } b C Xq A, ma bottom, and works in the fixed female screw S LXor c c, may be moved up or down, so that the vessel M may be immersed more or less into the quicksilver. The vessel M is furnished with a vertical partition m; the passage of the gas from A to B is therefore obstructed f when this partition dips into the quickM silver, and from the gradual depression of 681 r -: _h the vessel E by its screw, the interval be ~i I- - ------- tween the quicksilver and the lower edge 1B A of the partition, through which the gas must enter, may be enlarged at pleasure, iU[~ ] -~ 1. _ whereby the pressure of the gas in B may an 1I-1Ibe regulated to any degree. The transverse section of that interval is equal to y a E ~ the area of the pipe or rather greater; the -'4_~_. breadth of the vessel M from A to B._... _.... _. amounts to the double of that space, and _...._:ts length to the mere diameter of A or B. cU/^ l^ ^The greatest height to which the partition m can rise out of the quicksilver, is also equal to the above diameter, and in this C ^^ ilh C case the line a comes to the place of b. The vertical movement of the outer vessel p —-- — ~ D- E, is secured by a rectangular rim or hoop, - I _ which surrounds it, and is made fast to the upper part of the vessel M, within which C~!~o ~ guide it moves up and down. Instead of the lever D D, an index with a graduated plate may be employed to turn the screw, and to indicate exactly the magnitude in 682 Ai the opening of the valve. /// \ > Y\\ In order to measure the quantity of gas ei^^s\^5^ Y which passes through a pipe for lightirg a factory, theatre, &c., the gas-meter is employed, of whose construction a sufficientiy precise idea may be formed from the consideration of fig. 682, which shows the ina'\i\\s — - — r^ ~ strument in a section perpendicular to its - a axis. Within the cylindrical case a, there is a shorter cylinder b b, shut at both ends. iiill!iiiand moveable round an axis, which is divided into four compartments, that communicate by the opening d, with the interval between this cylinder and the outer case The mode in which thi GAS-LIGHT. 837 cyllnder turns round its axis is as follows:-The end of the tube c, which is made fast to the side of the case, and by which the gas enters, carries a pivot or gudgeon, upon which the centre of its prop turns; the other end of the axis runs in the cover, which here forms the side of a superior open vessel, in which, upon the same axis, there is a toothed wheel. The vessel is so far filled with water, that the tube c just rises above it, which position is secured by the level of the side vessel. When the gas enters through the tube c, by its pressure upon the partition e (fig. 682), it turns the cylinder from right to left upoa its axis, till the exterior opening d rises above the water, and the gas expands itself in the exterior space, whence it passes off through a tube at top. At every revolution, a certain volume of gas thus goes through the cylinder, proportional to its known capacity. The wheel on the axis works in other toothed wheels, whence, by means of an index upon a graduated disc or dial, placed at the top or in front of the gas-meter, the number of cubic feet of gas, which pass through this apparatus in a given time, is registered. n. Employment of the gas for lighting.-The illuminating power of different gases burned in the same circumstances, is proportional, generally speaking, to their specific gravity, as this is to the quantity of carbon they hold in combination. The following table exhibits the different qualities of gases in respect to illumination. Density or specific gravity [ok ______ ________________~_ -__ Proportion of light affo.f;cd by coal *I gas to oil gas. Coal gas. Oil gas. 0-659 0-818 100: 140 0-578 0-910 100: 225 0-605 1-110 100: 250 0-407 0-940 100: 354 0-429 0-965 100: 356 0-508 1-175 100:310 Mean 0.529 096 j 100: 272 In the last three proportions, the coal gas was produced from coals of middle quality in the first three proportions, from coals of good quality; and therefore the middle pr~ portion of 100 to 270 may be taken to represent the fair average upon the great scale On comparing the gas from bad coals, with good oil gas, the proportion may become 100 to 300. Nay, coal gas of specific gravity 0-4, compared to oil gas of 1-1, gives the proportion of 1 to 4. A mould tallow candle, of 6 in the pound, burning for an hour, is equivalent to half a cubic foot of ordinary coal gas, and to four tenths of a foot of good gas. The flame of the best argand lamp of Carcel, in which a steady supply of oil is maintained by pump-work, consuming 42 grammes = 649 grains English in an hour, and equal in light to 9-38 such candles, is equivalent to 3-75 cubic feet of coal gas per hour. The sinumbra lamp, which consumes 50 grammes = 772 grains English, of oil per hour, and gives the light of 8 of the above candles, is equivalent to the light emitted by 3-2 cubic feet of coal gas burning for an hour. A common argand lamp, equal to 4 candles, which consumes 30 grammes = 463 grains English per hour, is represented by 1-6 cubic feet of gas burning during the same time. A common lamp, with a flat wick and glass chimney, whose light.is equal to 1-13 tallow candles, and which consumes 11 grammes = 169-8 grains English per hour, is represented by 0-452 of a cubic foot of gas burning for the same time. Construction of the Burners.-The mode of burning the gas as it issues from the jets has a great influence upon the quantity and quality of its light. When carbureted hydrogen gas is transmitted through ignited porcelain tubes, it is partially decomposed with a precipitation of some of its carbon, while the resulting gas burns with a feebler flame. Coal gas, when kindled at a small orifice in a tube, undergoes a like decomposition and precipitation. Its hydrogen, with a little of its carbon, burns whenever it comes into contact with the atmospherical air, with a bluish colored flame; but the carbonaceous part not being so accendible, takes fire only when mixed with more air; therefore at a greater distance from the beak, and with a white light from the vivid ignition of its solid particles. Upon this principle pure hydrogen gas may be made tc burn with a white instead of its usual blue flame, by dusting into it particles of lamp black, or by kindling it at the extremity of a tube containing finely pulverized zinc. The metallic particles bezome ignited, and impart their bright light to the pale blue flame. Even platinum wire and asbestos, when placed in the flame of hydrogen gas, serve to whiten it. Hence it has been concluded, that the intensity of light which a gas is capable of affording is proportional to the quantity of solid particles which it I 858 (FGAS-LIGHT contains, and can precipitate in the act of burning. Carbonic oxyde gas burns witL the feeblest light next to hydrogen, because it deposites no carbon in the act of burning Phosphureted hydrogen gives a brilliant light, because the phosphoric acid, into which its base is converted during the combustion, is a solid substance, capable of being ignited in the flame. Olefiant gas, as also the vapor of hydro-carbon oil, emits a more vivid light than common coal gas; for the first is composcd of two measures of hydrogen and two measures of the vapor of carbon condensed into one volume; while the last contains only one measure of the vapor of carbon in the same bulk, and combined with the same proportion -f hydrogen. Olefiant gas may therefore be expected to evolve a double quantity of 2arbon in its flame, which should emit a double light. The illuminating power of the flame of coal gas is, on the contrary, impaired, when, by admixture with other species of gas which precipitate no carbon, its own ignited particles are diffused over a greater surface. This happens when it is mixed with hydrogen, carbonic oxyde, carbonic acid, and nitrogen gases, and the diminution of the light is proportional to the dilution of the coal gas. In like manner the illuminating power of coal gas is impaired, when it,s consumed too rapidly to allow time for the separation and ignition of its carbonaceous matter; it burns, in this case, without decomposition, and with a feeble blue flame. 1. This occurs when the light-gas is previously mixed with atmospherical air, because the combustion is thereby accelerated throughout the interior of the flame, so as to prevent the due separation of carbon. A large admixture of atmospherical air makes the flame entirely blue. 2. When it issues, with considerable velocity, from a minute orifice, whereby the gas, by expansion, gets intimately mixed with a large proportion of atmospherical air. If the jet be vertical, the bottom part of the flame is blue, and the more so the less carbon is contained in the gas. The same thing may be observed in the flame of tallow, wax, or oil lights. The burning wick acts the part of a retort, in decomposing the fatty matter. From the lower part of the wick tie gases and vapors of the fat issue with the greatest velocity, and are most freely mixed with the air; while the gases disengaged from the upper part of the wick compose the interior of the flame, and being momentarily protected from the action of the atmosphere, acquire the proper high temperature for the deposition of carbon, which is then diffused on the outer surface in an ignited state, and causes its characteristic white light. Hence with coal gas, the light increases in a certain ratio with the size of the flame as it issues from a larger orifice, because the intermixture of air becomes proportionately less. 3. If by any means too great a draught be given to the flame, its light becomes feebler by the rapidity and completeness with which the gas is burned, as when too tall a chimney is placed over an argand burner, see Jig. 683. Fig. 684, c, is a view of the upper plate, upon which the glass chimney b rests. The gas issues through the smaller openings of the inner ring, and forms a hollow cylindrical flame, upon the outside as well as the inside of which the atmospherical air acts. The illuminating power of this flame may be diminished at pleasure, according as more or less air is allowed to enter through the orifices beneath. With a very full draught the light almost vanishes, leaving only a dull blue flame of great heating power, like that of the blowpipe, corresponding to the perfect combustion of the gas without precipitation of its carbon. 4. On the other hand, too small a draught of air is equally prejudicial; not merely because a portion of the carbon thus escapes unconsumed in smoke, but also because the highest illuminating power of the flame is obtained only when the precipitated charcoal is heated to whiteness; a circumstance which requires a considerable draught of air. Hence the flame of dense oil gas, or of oil in a wick, burns with a yellow light without a chimney; but when it is increased in ntensity by a chimney draught, it burns with a brilliant white flame. From the consideration of the preceding facts, it is possible to give to coal gas its highest illuminating power. The burners are either simple beaks perforated with a small round hole, or circles with a series of holes to form an argand flame, as shown in fig. 684, or two holes drilled obliquely, to make the flame cross, like a swallow's tail, or with a slit constituting the sheet of flame called a bat's wing, like most of the lamps in th! streets of London. These burners are mounted with a stopcock for regulating the quantity of gas. The height of the flame, which with like pressure depends upon the size of the orifice, and with like orifice upon the amount of pressure, the latter being modified by the stopcock, is, for simple jets in the open air, as follows - Length of the flame 2 3 4 5 6 inches. Intensity of the light - 55-6 100 150 197-8 247.4 Volume of gas consumed - 60-5 101-4 126-3 143-7 182-2 Light with equal consumption 100 109 131 150 150 When the length exceeds five inches, nothing is gained in respect to light. For oil GAS-LIGHT 859 gas the same statements will serve, only on account of its superior richness in carbon, it does not bear so long a flame without smoke. Thus: Length of the flame - 1 2 3 4 5 inches. Intensity of the light - 22 63-7 96-5 141 178 Gas consumed - - 33-1 78-5 90 118 153 Light with equal consumption 100 122 159 181 174 The diameter of the orifice for single jets, or for several jets from the same beak, is' one twenty-eighth of an inch for coal gas, and one forty-fifth for oil gas. When several jets issue from the same burner, the light is'improved by making all the flames unite into one. In this case the heat becomes greater, for the combined flame presents a smaller surface to be cooled, than the sum of the smaller flames. The advantage gained in this way may be in the ratio of 3 to 2, or 50 per cent. In an argand burner the distances of the orifices for coal gas should be from L- to -~ of an inch, and for oil gas Tk6-' If the argand ring has 10 orifices, the diameter of the central opening should be = -4 of an inch; if 25 orifices, it should be one inch for coal gas; but for oil gas with 10 orifices, the central opening should have a diameter of half an inch, and for 20 orifices, one inch. The pin holes should be of equal size, otherwise the larger ones will cause smoke, as in an argand flame with an uneven wick. The glass chimney is not necessary to promote the combustion of an argand coal gas flame, but only to prevent it from flickering with the wind, and therefore it should be made so wide as to exercise little or no influence upon the draught. A narrcsv chimney is necessary merely to prevent smoke, when a very strong light with a profusion of gas is desired. Oil gas burned in an argand beak requires a draught chimney, like a common argand lamp, on account of the large quantity of carbon to be consumed. The most suitable mode of regulating the degree of draught can be determined only by experiment, and the best construction hitherto ascertained is that represented in fig. 685. Fig. 686 exhibits the ~ C _p view from above, of the rim or ring c, upon which | -|b the chimney b stands, and which surrounds the perOt ~ j Il~o forated beak. The ring is made of open fretwork, to permit the free passage of air upwards to strike the outside of the flame. The thin annular dsic d, 686 \ e a 685 which is laid over its fellow disc c, in the bottom Yd b/ aJ ) fi - ~of the chimney-holder, being turned a little one way _ fi m l a or other, will allow more or less air to pass through for promoting more or less, the draught or ven=^^^: ^^^111 gtilation. The draught in the central tube of the burner may be regulated by the small disc e, whose diameter is somewhat smaller than that of the ring f of the burner, and which, by turning the milled head f, of the screw, may be adjusted with the greatest nicety, so as to admit a greater or smaller body of air into the centre of the cylindrical flame. In mounting gas-lights, and in estimating beforehand their illuminating effects, we must keep in mind the optical proposition, that the quantity of light is inversely as the square of the distance from the luminous body, and we must distribute the burners accordingly. When, for example, a gas-light placed at a distance of en feet, is required for reading or writing to afford the same light as a candle placed at a distance of twa feet; squaring each distance, we have 100-4; therefore 1 0 - 25, shows us that 25 such lights will be necessary at the distance of 10 feet. Concerning portable gas-light, with the means of condensing it, and carrying it from the gas wor.s to the places where it is to be consumed, we need say nothing, as by the improvements lately made in the purification and distribution of coal gas, the former system has been superseded. It is well known that light gas deteriorates very considerably by keeping, especially when exposed to water over an extensive surface; but even to a certain degree over oil, or in close vessels. An oil gas which when newly prepared has the specific gravity of 1-054, will give the light of a candle for an hour, by consuming 200 cubic inches; will, after two days, give the same light by consuming 215 cubic inches per hour; and after fou lays, by consuming 240 cubic inches in the like time. With coal gas the deteriora tion appears to be more rapid. When newly prepared, if it affords the light of a candle with a consumption of 400 cubic inches per hour, it will not give the same light after' being kept two days, except with a consumption of 430 inches; and after four days, of 460. Oil gas three weeks old has become so much impaired in quality that 600 inches of it were required. per hour to furnish the light of a candle. All light gas should be used therefore as soon as possible after it is properly purified. Economical consideratio n.-The cost of gas-light depends upon so many local cir blmstances, that no estimate of it can be made of general application; only a feh 860 GAS-LIGHT leading points may be stated. The coals required for heating the retorts used to constitute one half of the quantity required for charging the retorts themselves. When five retorts are heated by one fire, the expenditure for fuel is only one third of that when each retort has a fire. The coke which remains in the retorts constitutes about 60 per cent. of the weight of the original coal; but the volume is increased by the coking in the proportion of 100 to 75. When the coke is used for heating the retorts, about one half of the whole is required. If we estimate the coke by its comparative heating power, it represents 65 per cent. of the coals consumed. One hundred pounds of good coal yield in distillation 10 pounds of ammoniacal liquor, from which sulphate or muriate of ammonia may be made, by saturation with sulphuric or muriatic acid, and evaporation. The liquor ccntains likewise some cyanide of ammonia, which may be converted into Prussian blue by the addition of sulphate of iron, after saturation with muriatic acid. Two hundred pounds of coal afford about 17 pounds of tar. This contains in 100 pounds 26 pounds of coal oil, and 48 pounds of pitch. The tar is sometimes employed as a paint to preserve wood and walls from the influence of moisture, but its disagreeable smell limits its use. The coal oil, when rectified by distillation, is extensively employed for dissolving caoutchouc in making the varnish of waterproof cloth, and also for burning in a peculiar kind of lamps under the name of naptha. Oil of turpentine, however, is often sold and used for this purpose, by the same name. If the coal oil be mixed with its volume of water, and the mixture be made to boil in a kettle, the mingled vapors when passed through a perforated nozzle may be kindled, and employed as a powerful means of artificial heat. The water is not decomposed, but it serves by its vapor to expand the bulk of the volatile oil, and to make it thereby come into contact with a larger volume of atmospherical air, so as to burn without smoke, under a boiler or any other vessel. The pitch may be decomposed into a light-gas. The relative cost of light from coal gas and oil gas may be estimated as one to six at least. Rosin gas is cheaper than oil gas. See ROSIN. I shall conclude this article with a summary of the comparative expense of different modes of illumination, and some statistical tables. One pound of tallow will last 40 hours in six mould candles burned in succession, and costs 8d.; a gallon of oil, capable of affording the light of 15 candles, for 40 hours, costs 5s.; being therefore - of the price of mould candles, and -6 of the price of dips. The cost of wax is about 3- times that of tallow; and coal gas, as sold at the rate of 9s. for 1000 cubic feet, will be one sixth the price of mould candles; for 500 cubic inches of coal gas give a light equal to the above candle for an hour; therefore 40 X 500 - 20,000 cubic inches = 11'57 cubic feet, worth lid., which multiplied by 6 gives 71d., the average price of mould candles per pound. The author of the article Gas-light in the Encyclopedia Britannica, observes, in refel ence to the economy of this mode of illumination, that while the price of coal, in conszquence of the abundant and regular supply of that article, is liable to little fluctuation, the cost of wax, tallow, and oil, on account of the more precarious nature of the sources from which they are obtained, varies exceedingly in different seasons. " Assuming that a pound of tallow candles, which last when burned in succession forty hours, costs ninepence" (seven-pence halfpenny is the average price), " that a gallon of oil, yielding the light of 600 candies for an hour, costs two shillings" (five shillings is the lowest price oi' a gallon of such oil as a gentleman would choose to burL in his lamp), " that the expense of the light from wax is three times as great as from tallow, and that a thousand cubic feet of coal gas cost nine shillings;" he concludes the relative cost to be for the same quantity of light,-from wax, 100; tallow, 25; oil, 5; and coal-gas, 3. I conceive the estimate given above to be much nearer the truth; when referred to wax called 100, it becomes, for tallow, 28-6; oil, 14'3; coal-gas, 4-76. Gas-lighting has received a marvellous development in London. In the year 1834, the number of gas lamps in this city was 168,000, which consumed daily about 4,200,000 cubic feet of gas. For the purpose of generating this gas, more than 200,000 chaldrons, or 10,800,000 cubic feet of coals were required. For the following valuable statistical details upon gas-light, my readers are indebted to Joseph Hedley, Esq., engineer, of the Alliance Gas Works, Dublin; a gentleman who to a sound knowledge of chemistry, joins such mechanical talent and indefatigable diligence, as qualify him to corduct with success any great undertaking committed to his care. He has long endeavored to induce the directors of the London gas-works to employ a better coal, and generate a more richly carbureted gas, which in much smaller quantity would give as brilliant a light, without heating the apartments unpleasantly, as their highly hydrogenated gas now does. Were his judicious views adopted, coal gas would soon supersede oil, and even wax candles, for illuminatirg prn fate mansions. GAS-LIGHT. 861 Copy of a paper laid before a Committee of the House of Commons, showing not only the relative values of the Gases produced at the undermentioned places, but showing in like manner the relative economy of Gas, as produced at the different places, over canles. By Joseph Hedley, Esq. esN.. tiiiiii|... n|| =- - ~. _~ owfhePreexperiments 3pre - t s i';~ a were made. | V! ha Equal to uCandles. Cubic Feet. C. s. L. s. d. PerCen. L. s. d. Birmingham;' Staffordsire ngham 2572 1-22 2704 10 0 1 7 0 9 1 4 7'541 two Companies, Stockport - - 3-254 *85 1489 10 0 0 14 11 121 0 13 0 539 Liverpool Old Manchester - 3060.-825 1536 8 0 0 12 3 114 0 10 10 *534 Lirpool OId P2-369 1 1 2646 100 1 6 5 61 1 4 9 -462 Liverpool New sLiverpool Ne 4-408.9 1164 10 0 0 11 8 64 0 9 10'580 Bradford - 2-190 12 3123 90 1 8 1 121 1 46 -420 Leeds - - 2970 -855 1644 8 0 0 13 2 6T 0 12 4 530 Sheffield - - 2434 1-04 2440 8 0 0 19 6 6 0 18 3 466 Leicester - - 2435 11 2575 7 6 0 19 3 15 0 16 5 528 Nottingham - 1-645 1-3 4200 9 0 1 17 9 15 1 113 *424 Derby. - 1937 1-2 3521 10 0 1 15 4 15 1 100 0 448 Preston - - 2136 1-15 3069 10 0 1 10 8 15 1 62 -419 none London - 2-083 - 1-13 3092 10 0 1 10 11 allowed. 1 10 11 -412 * 100 lbs. of candle es are estimated to burn 5700 hours. The candles cost 31.. 6d. t The Liverpool Old Company have since resorted to the use of Cannel coal, and consequently very nearly assimilate to the Liverpool New Company in illuminating power. MEMORANDUM.-It will not fail to be observed that in deducing the comparative value between candles and as by these experiments, the single jet (and in every iinstance of course, it was the same) has been the medium. This, however, though decidedly the most correct way of making the comparative estimate of the illuminating power of the several gases, is highly disadvantageous in the economical comparison, inasmuch as gas burnt in a properly regulated argand burner, with its proper sized glass, air aperture, and sufficient number of holes, gives an advantage in favor of gas consumed in an argand, over a jet burner, of from 30 to 40 per cent. At the same time it must not be overlooked, that in many situations where great light is not required, it will be found far more economical to adopt th e use of single jets, which, by means of swing brackets and light elegant shades, become splendid substitutes for candles, in banking establishments, offices, libraries, &c. &c. VOTE.-In Glasgow, Edinburgh, Dundee, Perlh, and the Scotch towns generally, the Parrot or Scotch Cannel coal is used; in illurinaating power and specific gravity the gas produced is equal to that from the beest 2escription of Cannel coal in England. The price per 10j3 cubic feet ranges abou; I)., with from 5 to 30 per cent. off for discounts, leaving the net price about 9,s to i b equal in the above table to 100 lbs. of candles. Epitome of Experiments made in Gad pr:d ucse from different qualities of Coal, and consumed in different kinds of Burners: Tried at the Sheffield Gas Light Ccmpany's Works, and laid before a Committee of the House of Commons. By Joseph Hediey, Esq. Q-.. b Date Description Species otf En w j. t, _" e! E, ~ ~ a-. ~i 1835. of Burner. Coal. | l | 1_ried at S I i_.. 1_.. Cubic Cubic IMay IInches Feet. Inches Candles. Feet L. S. d. L. s. d. | 8 Single Jet Deep Pit -410 75 1 4 2-36 2415 0 19 341 9 Ditto Mortormley'450 74 -95 4 2-434 2224 0 17 94 9 Ditto Can'iel -660 614'7 4 3-54 1127 0 9 0 3 2 Argand 4 0 1 2 1 8 | 1os Deep Pit 410 34 3-3 31 1153 1631 0 13 0 1 9 Ditto Mortormley -450 33 3.1 3I 12-24 1443 0 11 61 1 Ditto 9 Ditto Cannel 31 15 85 935 0 7 5~J' _ -______________ ________- --------- 862 GAS-LIGHT. Copy of Experiments made at the Alliance Gas Company's Works in Dublin, during the past year 1837. By Joseph Hedley, Esq. Results of experiments on the qualities of various coals for the production of gas; its value in illuminating power; produce of coke, and quality; and other particulars important in gas-making:1st Experiment, Saturday, May 27, 1837.-Deane coal (Cumberland), 2 cwts. of 112 lbs. each (or 224 lbs.) produced 970 cubic feet of gas; 4 bushels of coke of middling quality; specific gravity of the gas, 475. Consumed in a single-jet burner, flame 4 inches high, 1-4-ths cubic feet per hour; distance from. shadow 76 inches, or 2-3 mould candles. Average quantity of gas made from the charge (6 hours) 4-33 cubic feet per lb., or 9,700 cubic feet per ton of 20 cwts. Increase of coke over coal in measure, not quite'30 per cent. Loss in weight between coal, coke, and breize 56 lbs., converted into gas, tar, ammonia, &c. 2d Experiment, May 28.-Carlisle coal (Blenkinsopp). 224 lbs. produced 1010 cubic feet of gas, 4 bushels of coke of good quality though small; increase of coke over coal in measure not quite 30 per cent. Loss in weight, same as foregoing experiment. Average quantity of gas made from the charge (6 hours) 4-5 cubic feet per lb. or 10,080 per ton. Illuminating power of the Gas. Consumed per hour, Distance.Equal Specific single jet. from candle. to candles. gravity. feet. inches. At the end of the first hour - 1IU 70 2-72 -475 Ditto ditto with 20-hole 25 23 47 argand burner - 5 21-33 -475 When charge nearly off - - 14 85 184'442 When charge quite off, with 20- 10 hole argand burner - - t 1 3d Experiment, May 29.-Carlisle coal (Blenkinsopp). 112 lbs. produced 556 cubic feet of gas. Other products, loss of weight, &c., same proportion as foregoing experiment. Average quantity of gas made from the charge (6 hours) 4-96 cubic feet per lb., or 11,120 per ton. In this experiment the quantity of gas generated every hour was ascertained; the illuminating power, the specific gravity, and the quantity of gas consumed by the single jet with a flame 4 inches high, was triodl at the end of each hour, with the respective gases generated at each hour; and the ioilo7ring is a table of results. RESULTS. Consumed hour. dd }~~per hour, e Distance of Illuminating Hour. Gas produced. per single jet, Specific gravity. candle from power equal to 4 inches high. shadow. mould candles. cubic feet. cubic feet. inches. ist. 150 -or 1 15t *534 70 2-72 or P150!2d. 120 11 -495 75 2-36 3d. 95 12 -344 75 1 2-36 4th. 95 15 -311 80 2-08 5th. 80 17 -270 85 1-81 6th. 16 29 -200 10C not one Total 556 or 92k or 2 feet 9 inches. ___ Average of the above gas, 6-hour charge. 92- 16-lOths, nearly -359 81 2?3 Average of the above gas at 4-hour charge. 115 121-l0ths, -421 75 2-36 Production of gas in 6 hours 556 feet, or at he rate of 11,120 cubic feet per ton. Ditto in 4 hours 460 feet, or at the rate of 9,200 ditto GAS-LIGHT. 863 The relative value of these productions of gas is as follows, viz.: 1,120 at 16-lOths per hour nearly (or 1-5916 accurately), and equal to 203 caudles; the 11,120 feet would be equal to and last as long as 1597 candles, or 2664. lbs. of candles. 9200 at 12.-l0ths per hour (or 1-2375 accurately), and equal to 236 candles; the 9200 feet would be equal to 1949 candles, or 3245 lbs. candles. Now 2661 lbs. of mould candles, at 7s. 6d. per dozen lbs., will cost 81. 6s. 4Qd., whilst 3245 lbs. of do. do. at 7s. 6d. per do. do. 101. 3s. Showing 6he value of 4-hour charges over 6-hour charges; and of 9,200 cubic feel over 11,120 cubic feet. Note -9500 cubit feet of Wigan cannel coal gas are equal in iiluminating power to 859 1-6tli lbs cf canlies. which at 7s. 6d. per dozen lbs. will cost 251. 10s. 51d. It is also found that any burner with superior gas will consume only about half the quantity it would do with common gas. 4th Experiment, May 30th.-Cannel and Cardiff coal mixed 2 and, together 112 lbs., produced 460 feet of gas; 2 bushels of coke of good quality; increase of coke over coal in measure, about 30 per cent.; loss in weight, 41 lbs.; coke weighed 71 lbs., no breize. Average quantity of gas made from the * irge (4 hours), 4-1 cubic feet per lb., or 9'200 per ton. Illuminating power.-At the end of the first hour. Candles. Cubic feet. Distance of candle from 73 or 249 Consumed per hour, single 12-lOtllr 73 or 2'-49 42-10ts. shadow - - - et, 4 inches high - At end of 2d hour, do. 70 or 2-72 Do. do. do. 11 -lOths. At end of 3d hour. This gas very indifferent. Average of the three - 70 or 2-72 Do. do. do. 11O-l0ths. Specific gravity 3'44; 5 feet per hour, with a 20-hole argand burner, equal to 14'66 candles. 5th Experiment, May 31st.-Carlisle coal, 112 lbs. produced 410 feet of gas; other products, same as in former experiments with this coal, but heat very low. Illuminating power and produce of gas. ( Average of this gas: specific gravity, 540; ( st hour 120 cubic feet |distance of candle from shadow, 55 inches, 2. 2 100 or 4'4 candles consumed per single jet, 4 t. 3d 90 9-lOths of a cubic fot per hour. 20-hole 4th 100 argand burner, 4 fret per hour, equal to 21-33 candles. It is possible, from the superior quality of this gas, that a little of the cannel gas made for a particular purpose, may have got intermixed with it in "he experimental gasholder and apparatus. A variety of other experiments were tried on different 4ualities of coal, and mixtures of ditto, too tedious to insert here, though extremely valuable, and all tending to show the superior value of gas produced at short over long charges; and also showing the importance and value of coal producing gas of the highest illuminating power; among which the cannel coal procured in Lancashire, Yorkshire, and some other counties of England and Wales, and the Parrot or splent coal of Scotland, stand pre-eminent. Note.-In all the foregoing experiments the same single-jet burner was used; its flame in all instances exactly 4 inches high. The coal when drawn from the retort was slaked with wa, a-, and after allowing some short time to drying, was weighed. A TABLE of the number of hours Gas s burnt in each month, quarter, and year. an. jJj ^,^ i ~ I l 1.~ Time of Burning..a _'.. a | e o'clock. From dusk to 6 -- 2 31 62 80 65 33 4 - - - - 2 173 102 277 - 7 - 14 22 62 92 111 96 61 31 4 - 4 36 265 188 493 1 - 8 - 40 52 93 122 1-12 127 89 62 28 4 - 32 92 357 278 759. - 9 13 71 82 124 152 173 158 117 93 58 29 8 95 166 449 368 1078 - 10 44 102112 155 182 204 189 145 124 88 60 38 186 258 541 458 1443 Aci - 1 75 133 142 186 212 235 220 173 155 118 Vt 68 277 350 633 548 1808 a - 12 106 164 172 217 242 266 251 201 186 148 122 98 368 442 725 638 2173 All night - 217 307 345 421 473 527 512 411 382 295 243 195 732 869 1421 1305 4327 a a Morning from 4 - 16 48 80 110 137 137 98 71 28 2 - 30 64 327 306 727 28 5 - - 18 49 80 106 106 70 40 3 - - 3 18 235 216 472 v 6 - - - 18 50 5 75 42 9 143 14 6 269 ~ 7 - - - 20 44 44 14 - -- - 64 58 122.!_._. ____-__ _ __ ____ _ ____ L._- J.j 864 GAS-LIGHT Copy of a Paper submitted to a Committee of the House of Commons in the Session of 1337, of England; and procured by actual Survey and tot~-a No.of Name of th Price of coal, Ma- Quan- Public Price Name of the and' m e Cok Sellmo terial tity or Description paid per Who ltgs Place where Price of Gas per Meter, Description madefrom alto d Street Aoum n, p 1 De crisont lowd Leciption;Price of sal to usedS| Gas Wrk and Discounts allowed. deiered pe a T o Coke. heat per Ton Lamps Size or Sort. for and repun. Ton. oa. Retorts. of Coal. sup- Iitto plied. Cu.ft L. s. d. Birminrham 10s. per meter cub. feet. Lump coal 6,500 32 2s. Id per Slack. About 490 Batswinge. 110 0 Corrspany, and Gas Comn- Discounts from WV.est bushels, quarter 5 cwt. 460 20 provides psta, pany. 101. to 301. a 2 ~ Bromwich delivered, of slack, 0 ervice &S, e. 305. to 501. 5 c pits, risen or about at 6s. 50l. to 755.S 71 7 nuch of late. 3d. per per ton, 7S5. to 1005/."10 r 1837,1 Is. lOd. bushel. per 1001. & upwards 15 o- cent. Birmingham 10s. permetercub. feet. From West 6,500 24 bush. 2s. 10d. Slack. 5 cwt. 1,500?etswings. &uerage Ditto. and Staf- Discounts as above. Bromwich but larger per sack and of slack, 18 0 fordshire. pits, 1837, measure of 8 Tar. at 4s. 9s. 3d. than Bir- bushels. 25 per rnineham. ent. Macclesfield. 10s. per meter cub. feet. Common, 8s. 6,720 12 cwt. 10s. Coke. No 220 Ditto. 2 12 0 Company. Discounts average 1834. per ton. account 001. 751. 5 kept. 751. = 1001. 7{,1001. 2-5 1251. 10 1251. S1505. 120. 150z. 4 1755. 15' 1751., 2001. 171 c 2001.&upwards20 Stockport. 10s. permeter cub. feet. Coal lOs. 6d. 7,800 7 cwt. 6s. 8d. Coal, Ditto. 230 Ditto C 0 Comrs. providel Disco'ntssame as Mac- cannel 19s.6d. per ton. coke, Itca. lamps & posts. clesfield. Macclesfield about half and and tar. 2 00 Company's discounts taken from half used. 1837. service light, Stockport card. Average 15s. repair, ceans 1834. and extinguish. Manchester. 10s. per m.cub.ft. 1834. 15s. 2d. 9,500 14 cwt. Ditto. Coke. 4,2-3ds 2,35 Single jets 1 2 0 Comrnissioer 9s. and 8s. - 1837. average. cwt. and flat 2 5 of police. Discounts Oldham - flames, 501. 1005. 2. Water- a about half 1005. 1 1501. 5. ate ~ and half. 1505. 0 2U0. 7; Wigan 2005. 2 2251. 10 S Mixed,1834. 2255. 3 2501. 121 1 250/. ~ 3005. 15 3005. 4005. 171 4005. & upwards 20 Liverp'l Old 10s.permetercub.feet. 7s.3d.per ton 8,200 11i cwt. 8s.. 4d. Slack, 6S cwt. 1,700 Batswintgs. 4 10 0 Company Copany, Discounts of 112 lbs.per por ton of 7s. 3d. 30 1 jet, 2 5 0 light, clean, pu t834. 105. &i under 505. 2J cwt. Ors- 112 Ib. per ton. 2 - 213 out, and repair lbS. to 1005. 5 0 kirk or Wig- per cwt. 3 - 32 9 1001. to 2001. 7 h an slack. 4 - 3 13 1 S000. and upwards 10. Ditto, ditto, In 1835, this Company icsortedtothe use of cannel coal similar to the L iverpool New G as and Coal Compa nY, producing liverpool 10s. permetercub. feet. 18s. allcannel 9,500 13 cwt. 7s. 6d. Coke 5J cwt. Only a Argands. 4 0 0 ommiSSionera lew aGasa snd Discounts same as Liv- Wigan. per ton. and few. Coke, 1833. erpool Old Comp'ny. slack. Grndfordl, 9s. per metercubic feet 8s.6d.perton. 8,000 13 cwt. 12s. Coke. 8i cwt. 2O Batswings 2 12 Company light, 10?4. to large consumers. 3 sorts used per ton., repair, &c. Discounts average. 201. to 30 5 Slack 5s. 6d. 30, to 40 71 Low moor 405. to 60 10 8s. O10d. 601. to 80 12i. Catherine 8CI. to 100 15 7 slack Bs. 100o. & upwards 20 Small Consumers,,Os. per meter cub. feet. and 5 per cent. oft' from 105. to 2,0. Leads,.834. 8s. per metercuoi feet. 8s. per ton 6,500 1 cwt..7 Sd. D9tto 5 cwt. 517 D ks. I 12 6 Commissioners, Discounts averags. per ton. except extin21 per cent. 151. 2-3ds. com at guishing, for 5' on half- 301. 7s. whicl Comp'ny 71 yearly 505, 1-3d cannel pay Ws..10d per 10o payments. 1005. 10s. lamp. Sheffield, Ss. per meter cubic feet. 7s.9d. pertson 8,000 1 cwt. IOs. Ditto j cwt. 600 Ditto I 1 0 Company 1835. Disc'nts same as Leeds. average. of saleable Dor ton. provide lamp, 3 sorts used, coke. cit n, repair, 1, -lOths pui out, &c. cus'cl,at 16s. 8, 3-lOths relslateck. 7o. eilkstone, l0s. Leicester, d. permeerbft 1.. 7,500 4 quarters 10s. pd. Coke, About 4 4 Ditto 18 6 Company lignht 1837. Disc'nts on half-yearly average, or Ss. 8d. tar, ol. 1-3d of put out, ad rental, not exceeding Derbyshire per qr. coke. clean 10l., 5 per cent. soft coal. 105.'so 901. 71 20l. o. 3015. 10 L305'. 401. 1L i 405. 501. 15 [5 601. t 2 GO. 20 601.&upwards 925 SDerby, 1634. 10s. per meter cub.feet. Same coal 7,000 Ditto. Ditto. Coke. Ditlo. 319 Dlt'o. 2 2 0 Commissionerm Discounts used as at 2 7 0 light, put out, 5 to 5 per cent. Leicester. Nottingham, 98. per meter cubic feet. Ditto. 7,000 Ditto. Ditto. Ditto Ditto. 200 Ditto. 0 Commissioner 1834. Discounts as above. light, clean, repair, oc. London, 1834, 10.. permetercub. feet. 17s. average. 8,500 26 bush. 12*. per Ditto. 3 bush. 36,280 Ditto 4 0 0 Caspato light, No discounts. Neh astlf. chaldron. citn, put ou' ba sot. repeir Uitto t. Ditto Ditto. 8,500 Ditto. Ditto. Ditto. Ditto. 80,400 Dit to. 4 0 0 GAS-LIGHT. 865 besng a Synopsiu of the proceedings of the undermentioned principal (;as-Light Establishments Experiments between the Years 1831 and 1837. By Joseph Hedley, Esq. Gas ^ can a9 - too Greatest d a ra *, a.k'o. of Hours, sutued 2. Cc, Quantity of Duration Method Number of a 3.j ) — as instheYear. Lamp e a Lstas made. de=ijevered Charees. cation. Holders. oJ — i -5 5 2938 hoors, 9 pee 40 18 abaut 65s. 8d. perain i e thod e to, mothmit- hossofGasurade. deliveredfee. ad lare in042 heurs. aut S. 6d. p er is the year the wn 7 mots, 4 t 3 12 0 Could not say. 80,000. hurs. Ditto. 3 gas Nt 70 4 Not omitting 5 per Tora fur holders. taket tahen nights Cor hour. year aout. oo. d. Cu millions. 2 nights,or 5feet 3010 18 0 Receives net 48 million s h.... Dry lime. 4, and 2 in'453 72 1,929 1-22 938 os,4 Ditto.D. per 1 6. 6. 4 per i ear the town,2,441.85 ignths,omit- hour. meter cubic feet. orand larges. tin 5 nights new gas for moons. year about 137 nightso- Ditto. 3 18 0 Receives net 85 millions Ditto. Ditto. 6, 6 in 455 1 7042 hours. about 5s. 6d. pe iu the year. the town 7 meter cubic lbet. miles off. 8 monturs, 4 feet 3 6 it 0 Could not say. 00,000. 6 hours. Ditto. 3 gas 534 66 2,295 825 47Not 8 omitti 5 feet, per Total for holders. taken take nights foer hour. year about oon hour. meter cubic feet, millions. 1600 monts. 5 feet 4 6 12 Cold not lear 360,000. Dittours. DiWet and gas 862 75 1,777.. 55 per i the abhts o Total for dry holders. in hour. the manaonsger year 72 retabou t, 4 i 237 nights — 2 millions. 00mi hours., 1000 1000 hours. I feet 6 6 nothing Nearly all by Not 17 500,000. hours. Wet lime. I large 580 5 3,30'82 47 2omitt feet, 5 6 per centreceive Total for holders, and per about 7s. 4d. per year 100 ] ia the hour. meter cubic feet, millions. town. public and 2 private. Nearly all by WOO hours. ifeet 4 4 t1 0 R eeive for public 2360,000. Ditto. Dittanc. 4 gas 466 74 1,726 1-04 -751 I perd private ofts. Total for lare drylime, holdersin hopur. the manaeer. year 740 retorts, ri- all, 4 in more millions. eoldinr c cpally town, 1000 6 cwt. dry. yards off th each. works. reerlts, which meters used. From Ahogust 5 feet 6 not 7 Not suearlyallbficiently ot sufi- 4 hDittours. Wet lime: 3 g lar -580 55,06 9 1 per meter. cientl long as holders, an. hour at work. 1 8 months, & fet e 3 12 6 Receive 8s. per 42,500. [ hours. Dry lime. 4 gas 420 78 1,643'!~ 4 let, omitting7 omittin- per meter cubic feet, Total for holders. I s. 2600 hour. less 5} per cent. yefor hours to 4 o'clock in the morning. 1173 hours. 4 eet o 3 10 LRase for blic 176,000. D hours Ditto. 4 gas 5*448 8 12,453 1- 3 1 from A t p er a nd pate 6. 8d. Total for holders..all s yea hour. er prmeter cubic year 310 oler uyfe 7e. Public, 45s. millions. private, s; metew Lonrs mused 5 to I for private rental. 200hous. 4 Ditto. 2Totaleceiveforpublic for0,000. Ditto. Dittc. 4176 as *466 0 1,561 1-04 4 I1 ndprivate s. ye Total for 1460 holders, per meter cubic year40 and 2 more feet. Public millionest. erectin 3s. 2._d., private 5s. 9.d. Few meters used. From August 5 feet 3 4 1 7 Not sufficiently Total for Ditto. Ditto. 3 gas ~528 74 1,8261 1-1 74 Si 14th to per long, at 7s. 6d. year 18 holders, an8 September hour. millions. Ierectiniia Ist, omitting, [I nights fob [moons, 3000 hours. 11731 ours, Ditto. 4 0 Lose about l?} Ditto. Ditto. Wetlime. 4 gs 448 83 1,453 1~2 928 from Avgusgl nearly per cent. holders. to May. All th year, Ditto. 3 0 Could not learn. Ditto. Ditto. Ditto. -4- 4 go 1,234) 13 I 76 43l7 h ours nearly 42ZT b sers, it4 l~_st 4 2 0 receive for public Total for Ditto. Dit'.o 130 -as'412 so1,56 1- I all thte yea'. per nd privateliT-ht year 1000 lioltfers. llouzl 7s. public, 46. millions. private, 8s. few Longest Nueb, 1 Ditto, 4 6 It 0 Ditto. Total for Ditto Ditto. 17 — as ~ 1 year 1460 hoiers. rillions. Lon= [st ~~~~~~~~~~~~~~~~~~~~~~~~~~~~, t A TABLE showing the rate per Thousand Cubic feet received for any Burner consuming from 2 a Cubic foot to 10 Cubic feet per hour, at any given price per annum, p,rd to the times below stated. By Joseph Hedley, Esq. Farz3y and extravaSingle Jets. 2 Jets. 3 Jets. Small Ar-and. Large Arg-and. gant Burrers. Time of Burning per annum. of hoursT Cu. ftojCu ft. Cu.pr CU. ft. CU ft. Cu. ft. Co. ft Cu ft. Cu. ft Cu. ft. Cu.. ft. Cu. ft.C(?. ft, C.. Cu ft. CX ft. Cu. ft. a 4la 2 21. 3 31 4 41 5.6 7 8 9 10 Fi ron Dusk to 8 o'clock. -....- - 7 25 1700 128 1020 853 731 64 -5139 4268 -3658'3201 2846 2561 2134 -1829 16 -1423 128 dittus o and Sundays 902 2-216 1-478 1-108 887 -739 -633 -554 -4434'3695 *3168 -2771 -2464 -2217 -184'1584 1383 -1232 1108 ditto and frorn6 o'cl kmornings 1050 1-904 127 *952 762 -635'544 -476 381 3174'272'0J 21 9 1527 136 119 1058 0952 ditto and Sundays and from ditto 1172 1.706 1138 83.682 569.47 426.3412 244. 243 2133.1896 1706 1422 1219 1067 0948 0853 9 Welock - - - 1054 1-896 1 4,948 -759 -632 *542 -474'3791'3162'271 -2371 -2108 -1897 -1581 1355 -1185'1054'0948:i ditto and from 6 o'clock mornings 1323 1510 1006'755 604 503 431 378 3022 2519 2158 189:1678'1511 1259 1079 0945 0839 75 10 o'lock1367 142'974 731'585 487 418 36 292 2438 209 1829 1626 1463 1219 1045 0914 0813 0731 ditto and Sundays - 1586 126'84 63 504 42 36 -315 2522 2101 -1802 1576 14 1261 1051 0901 0789 -07 0631 ditto and from 6 o'clock mornings 1636 1-222 814 611 489 407 349 05 2444'2037 1746 1528 1358 1222 1019 0873 0764 0679 0611 ditto and Sundays and fron ditto 1855 1-078 718 539 -431 -359 -308 -29 -2156 1796 -1354 -1347 01198 -1078'0898 -077 *06745 -0599 -0539 11 o'clock 1680 119 -794 595 476 397 -34 *297 -238'1984 17 14S8 -133'119 -0992 -085 -0744 0665 -0595 ditto and Sundays 1951 1-024 -682 -512 -409 -341 *293 -256 -2048 1707 1466 128 11138 01024 00854 70733 064 -0509 *0512 12 o'clock-1993 1' *668 8502 4 334 287'251'2006 1672 1434 1254 1114 -1003 0836 0717'0627 -0557'0502 ditto and Sundays and fron. ditto 2585'772 -514'387'309'257'221'193 1546'1289'1104'0967'0858'0773'0645'0552 -0483 0429'0387 I o'clock- 2306 -866 -578 -434 -347 289 -247 -217'1734 -1445 -1238 -1080 -0962 *0867 -0723 -0619'0542 -0481'0434 ditto and Sundays - - 2681 -746 -498 -373 298'249 213'186 -1492 -1243'1066 -0932'0828 -0746'0621 -0533'0466'0414 -0373 ditto and from 6 o'clock mornings 2575 -776 -518 -388 -31 259 -222 -194 -1552'1294 111 0971 -0862 0776 -0647 -0555 -0485 0431'0388 ditto and Sundays and from ditto 2950 -678 -452 339 271 -226 -193 -169 -1356'113 -0968 -0847 -0754 -0678 -0565 0484 -0424 0377 -0339 _~All night - 4327'~~-462 -308'-231 -185 -154 -132'115 -6924 -077 -066'0578 0515'0462'-0385'033 0289'0257'0231 To use the Table. —Select the hour to which it is agreed the g-as is to burn,-9, 10, 11 o'clock, Sundays, &c., as the case may be, and the description of the burner.-Multiply the decimal number opposite to it by the amount in shillings agreed to be paid per annum, and the product will be the sum received per m. cubic feet for the gas. Example.-Suppose a small argand, which should burn 31 feet per hour, is agreed for till 9 o'clock at 2). per annum. Look along the line of 9 o'clock till you arrive at the column of 34 feet per hour, and you find the number, 271. Multiply this number by 40s. and the result gives 10s. I Od. per m. cubic feet. But suppose instead of keeping to 9 o'clock the party burns till 1 o'clock, Sundays and mornings, and by enlarging the holes or height of flame consumes 8 cubic feet of gas per hour; then you have the number,'0424, which multiplied by 40s., still the price paid, gives Is. 8d. per m. cubic feet only, and so on for any greater or lesser variation of the agreement. * Thn number of hours" includes I of an hour allowed for shutting shops, and 1 hour's extra burning on Saturday nights GAS-LIGHT. 867 TRIALS of, and Experiments on, various Kinds of Coal as regards the Production o Gas from each, and its Quality or Illuminating Power; by Joseph Hedley, Esq., Consuiting Gas Engineer, London. NOTE.-In all the experiments the gas was passed through a governor, on a pressure of 5 10ths of an inch. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17.;1|3 ",. _ Il fa; 20055 co 1' S S Coal.i oEul CO 0, I in t -C 0 c- 0 a0 1 Description of] ~; s h ating i1: ~...1- 3 I 1 11 1 11 to ]'0 O~ * Isch's.-~ 3~ -.0 0: |I 6 WC II2212 7I 121 72 277 23 i 39 7 1 I nch' s 71Cubic Feet. Cubic Fee ~ 1 7 3 50 30 10 2'!' Lismalhag,... j Glasgow Can-] | j... | wcastle coal -18 11 51 6 l 11-1 5 7 5 *444 102 3 29 20 17 1 14 61 I Pelaw, New-n l castle Coal 18 fi 65 16-1 11'1 17.5 56 7.5 -21 100 3 28 20 18 18 18 6 i verpool ditto 19 14 6 16"2 11'1 2'04 4'6 6'5.475 102 3 30 24 18 16 10 4 Neath Coal - 18 16 7 191 12-1. 175 522 7-5 4ti 100 3 26 21 20 14 12 7 j NOTE.-The candle here used was a composition candle, with plaited wick, requiring no snuffing giving at least one third more light than mould tallow candles. Attention to the preceding tabular statement of experiments is important, as exhibiting several very important facts, particularly interesting at this moment to the science of gas-lighting, and now for the first time made public. It will not fail to be observed by these experiments that all the coals produced nearly equal quantities of gas, notwithstanding the variable characters and qualities of the coal. The greatest quantity produced being at the rate of 11P648 cubic feet per ton of 20 cwt., the smallest 11-200 cubic feet. All these experiments were performed with the greatest care, and under precisely similar circumstances as to pressure, manufacture, &c., &c. The time in which the quantity of gas is produced from the several coals varies considerably, and deserves notice, as it most materially affects the economy of production -that coal beingg te mst v ble, which yields or gives out its gas in the shortest time; and particular attention is claimed to this fact. For the more ready reference to the table the columns are numbered. No. 11 exhibits this I lifference, and it wi also be seen by this column that the time varies as.the quality of the coal, the best coal yielding its gas in two hours, and the worst in three hours. Another most important, material, and interesting fact is established by these experi. ments-that the flow of gas is as its density-demonstrated by the variation in the heights of the flames, as shown in column No. 1, being 18 inches in the inferior gases to 22 inches in the superior; while the quantity of gas required to supply these flames is in the inverse ratio of their heights, the losger flame requiring but twelve cubic feet to maintain it, when the shorter flame, from the inferior gas, required sixteen cubic feet. See column No. 2. ttRemarkble as this difference in the heights of the flames and the consumption is It is not so great as the difference caused by the qualiy or illuminating power of the everal gases, shown by columns Nos. 5 and 6; where it will be seen that the consumplion of the best gas per o hour was onl on f a cubic foot, and its light vs equal to 20 cwt., the smallest 11o200 cubic feet. All these experiments were performed with the candles, while that of the worst gas was -2 of a cubic foot, and its lights equal snlr to 17a 5 candles, or nearly, the best to the worst, as 1 to 3.d he next column, No 7, exhibits similar results as to the superir va or e illumin tim power of one gas over another. In this case an argand burner was used. The best gas required only two feet to be equal t ttwelve candles, while the inferior required of thiv te e tbequal to the same. And in column No. 8, in which another and superior argand burner was used, the Iest n ts required only three feet to be equal to twenty-five mould candles, while the nlerior required seven ant d a hafo feet: from this it results that the 7 cubic feet of I 56 ve feet to be equal to the same. 56 868 GAS-LIGHT. inferior gas, to be equal to the 3 feet of good gas, should have given light equal to sixty-two and a half candles, whereas they only gave light equal to twenty-five candles, so great is the difference in the QUALITIES of gas for producing light. Whilst on the subject of the illuminating power and the value of one gas over another, it will not fail to be observed, by the table, that another great difference also exists, caused by the use of particular burners; as, for example, the best gas in column No. 5., where the single jet was used, required seven-tenths of a cubic foot to be equal to three candles, whilst the same gas in column No. 7., where a 20-hole argand burner was used, required only two feet to be equal to twelve candles; and in column No. 8., where a 30-hole argand burner was used, only three feet were required to be equal to twenty-five candles; demonstrating the fact that a great and extraordinary improvement in the quantity of illuminating power is effected by the simple increase or enlargement of the burner, affording, where great light in one position is required, a most extraordinary economy in the use of gas, shown in fact practically by the recent introduction of the celebrated "Bude" light, patented by Mr. Goldsworthy Gurney. TABULAR STATEMENT, deduced from the foregoing Experiments, showing the Cost of Candles to produce as much light as 9,000 Cubic Feet of Gas would afford, being the Product of Onte Ton of Coal. (The candles are moulds, 6 to the pound, 9 inches long, and each candle is calculated to burn 91 hours. Cost of Candles 7id. per pound, or 7s. 6d. per dozen pounds.) Where a Bude Where a single Where a 20-hole Where a 30-hole Burner is used, Candles would cost, to be equivalent to Jet Burner is Argand B,iner Argand Burner according to used. is used. is used. Statement of Company. ~ s. d. ~. d. ~ s. d. ~ s. d. Common coal gas - - - - - 1 1 6 15 15 8 21 18 0 59 2 7 Good do. - - -- - 25 18 4 39 9 6 54 16 7 148 0 9 TABLE, also deduced from, the foregoing, showing the Cost of Gas at the several Prices undermentioned, and equivalent to 100 lbs. of Mould Candles, costirg 31. 2s. 6d. If burnt If btin burnt in in a a 20-hole a 30-hole Description Single Jet Gas would cost at Argand Gas would cost at Argand Gas would coet t ufsups CGliues equal pee thousdsane, prthoouood Buurner, per thousanod of Gas. to 100 ibs. Cobic Feet. Gas eqiual Cubic Feet. Gs equal Cubic Feet. ofMould to o10 Ibs. to 100 Ibs. Coadles. of Candles. of Caudles. Cubic Seot. s... s. 1 9s. Cubic feet.. 5ts. Is. 9s. Cubic Feet. 5s. 7s. 9s s.d. <1.. s, S... &s.. d. Common 2,687 15 18,781 1 12 5 10 1,282 6 5 8 11 11 6 Good - 1,072 54 75 7 712 3 6 4 115 6 4 513 2 7 8 7 47 I have received from Mr. Hedley, an engineer of great eminence and experience, plans and drawings of gas works and of apparatus of the most approved and modern construction, and on the very largest scale as to extent of business or manufacture: also plans and drawings of a gas work on a smaller scale, with its corresponding apparatus. In the first, or large work, purification by wet lime, before described, is used; in the latter, by dry lime. The large work referred to is calculated for and is arranged to contain 400 retorts, 12 wet-lime purifiers, and 2 washers; 12 large double or telescopic gas-holders, capable of storing 1,000,000 cubic feet of gas; and coal stores capable of holding 10,000 tons of coal. The smaller work is calculated for and will contain 40 retorts, 2 dry-lime purifiers, and a wash vessel; 2 gas-holders capable of storing 50,000 cubic feet of gas; and coal stores sufficient for 1000 tons of coal. Fig. 687. is the side elevation (front view) of a gas work capable of containing 400 retorts, and all their dependencies. Fig. 688. is the plan of the retort house, coal stores, tanks, gas-holders, &c., on the largest scale and most approved form, viz., A the retort house, 300 feet long, 56 feet wide; B, retort beds; c, chimney stack; D, flues; E, hydraulic mains; F, coal stores, each 300 feet long, 30 feet wide; a, condensers; H, engine houses; j, wash vessels;' K, purifiers and connections; L, lime store and mixing tub; x, smiths' and fitters' shop; N, refuse lime pits; o, meter houses; p, tar tank; Q, tanks, gasholders, bridges, columns, valves, and connections; n, governors; s, coke stores; r, inlet pipes; v, outlet pipes; w, house and offices; x, stores. GAS-LIGHT. 869 Fig. 689. Transverse section and elevation of a bed of 5 D retorts; A, transverse section; B, elevation. I I 687 ii;11] glill ^^n- rra-s ~~~~~~~~~~~II ~~~~~-t Hf-<45^4iT 870 GAS-LIGHT. i/g. 690. Longitudinal section of a bed of 5 D retorts. Fig. 691. Elevation of an upright air condenser, consisting of 5 chambers, with a series of 10-inch pipes. Fig. 692. Elevation of a double or tilescopic gas-holder, of a modern and approved form, with part of tank. 68 I'; I 688 h, I (I "1^^ I -. 11 0l S11' B3' - ---- -— ~-__~. j GAS-LIGHT. 87i Fig. 693. End elevation and plan of air condenser; A, end elevation; B, plan. Fig. 694. Set of 3 wet-lime purifiers and wash-vessels in elevation and section, with feed-heads, agitators, valves, and connections, raised for the lime liquor to run from one purifier to the next below it, and ultimately into the refuse lime-pits, viz. A, section of wash-vessel; B, section of purifier; c, elevation of purifier. 689 Fig. 695 Front elevation of gas works on a smaller scale, where dry lime is used. Fig. 696. Plan of gas works, consisting of, viz.: A, retort house; B, retort beds; c, chimney stack; D, flue; E, hydraulic main; F, coal store; o, lime store; n, W9sher and purifiers; J, store; K, tar-tank; L, horizontal condenser laid on the ground; M, inlet pipe; N, outlet pipe; o, tanks and gas-holders; P, meter and r' vernor; Q, smith's shop; a, office; s, coke store. T ~ - - -- ~ ~ - - I ^ - --- - ----- II ------------- * ---- - | | | Pl |i | 872 GAS-LIGHT. Fig. 697. Elevations and sections of dry-lime purifiers; A, longitudinal elevation; ditto section; c, transverse elevation; D, ditto section. 691 I am well convinced that a distribution and arrangement of gas-works, combining effectiveness, economy, convenience, and elegance, at all equal to the preceding, have never before met the public eye, in this or any other country. 692 llf l ill [ ( —! In the brief description of the meter given in this Dictionary, I omitted to state, that this most ingenious scientific contrivance for measuriug aeriform or gaseous fluids as they flow through pipes is the invention of Samuel Clegg, Esq., Civil Engineer, of _ GAS-LIGHT. 873 London, Manchester, Liverpool, Birmingham, Chester, Bristol, &c. &c., in all which places he has erected gas-works. To this gentleman's genius and skill the pubiic are mainly indebted for many valuable improvements in the application of gas frou coal to purposes of illumination. 693 694 I(~~* _ B@< — B_ i~~~~~~^S 874 GAS-LIGHT. Brought up in the great engineering establishment of Messrs Boulton and Watt, at Soho, near Birmingham, he became crnnected with Mr. Wm. Murdoch, who most undoubtedly was the author and original: of gas-lighting, as the evidence given before a Committee of the House of Commons n the year 1809 abundantly verified. HP _______. __ I J -I * --- 1 1m GAS-LIGHT. 875 demonstrated that the light produced from gas was superior in economy to all other modes cf artificial illumination; and by that evidence, though so long back as 1809, it will be neen that all the information of the present day was even then known to him, clearly pointed out, and illustrated by his experiments, which strangely contrasted 696 ^| ^ i1 |,,AMRIA xi M CM CC I Ml~~~~~~~~ 876 GAS-LIGHT. I * A 697. %.............. with the statements put forward by the parties then attempting to introduce this mode of lighting into the metropolis. All the ephemeral plans of those parties, have, however, long since disappeared, or nearly all. One, unfortunately, remains, and that a most unlucky one-the unprofitable.manufacture of coke in gas-making-an article worthless in the scale of value, which should never have been sought for. Messrs. Watt and Murdoch predicted that when the parties became incorporated by Parliament, they would resort to their apparatus, notwithstanding their repudiation of it at the time, alleging their own schemes to be so much superior; and they verified this prediction a very few years afterwards by engaging the services of Mr. Clegg, to extricate them from their manifold and egregious errors. He began by introducing the very apparatus of Messrs. Murdoch and Watt, so inconsiderately condemned by them. Mr. Clegg put up the first gas-holder ever erected in London. To Mr. Clegg is due also the introduction of lime for the purification of the gas, without which gas-lighting would to this day have afforded little comfort and economy. The hydraulic main, for separating the gas making from the gas made, valves, lutes, and many other admirable contrivances, are peculiarly due to Mr. Clegg. But the crowning performance of all his inventions, was that for measuring out the gas to the several parties requiring it exactly according to their demands. The manufacture of gas having by this time been so far mechanically perfected as to be brought to our doors, it became at once apparent that some contrivance should be found by the use of which every person might consume as much or as little gas as he pleased, paying only for what he really used, thus making science subservient to fair dealing. Mr. Clegg took out a patent for the gas meter about the year 1814; but great as its merits were, he soon found that serious difficulties remained to be overcome. in inducing parties to support and encourage its use, even where their interests should heve prompted them to adopt it. Mr. Clegg had, however, fortunately associated with him, towards the completion of the apparatus, Mr. Samuel Crosley; and by their joint labours it acquired its present precision. The value of the meter is primarily to the gas companies, next to the public. By its use, the gas companies are enabled to supply gas to all places where light is re. quired, at a rate proportioned to its just value. The public thereby see the economy ifforded by gas over candles, oil, or other material; but they gain also in another most important way-by the use of the meter, gas companies, being duly paid, are enabled to reduce the price of gas, and yet realise ersial profits, thus bringing it within the reach i~~~~~~~_ ~ ~ ~ ~ ~ _ GAS-L: GHT. 877 of a much larger class of the community; and it is a well established fact that in towns where gas is sold by meter, gas companies can and do sell at nearly one half the price they otherwise could do. Reduction of price increases demand; increased demand increases profits; increased profits again enable prices to be reduced; and again, reduced prices increase the demand thus benefiting reciprocally companies and consumers. Notwithstanding, however, all these advantages, there are not wanting persons whc have set up an outcry against the use of the meter, by impugning its accuracy, and accusing the gas companies with fraud in charging by it. It would be idle to follow these parties in their baseless allegations. An action for pirating it was brought and tried in the Court of King's Bench, in which not only the novelty of the machine was fully established, but its accuracy and usefulness proved by the ablest mathematicians, mechanicians, and chemists of the day; and a verdict in its favour obtained. Subsequently very large damages have been given for the infringement-in one case as much as 50001., and in another, in the Court of Chancery, a decree was made referring it to the Master, to take an account of the profits made by the use of the meter; thiis is not yet finally settled, the Master's report finding 6000/. to be due; but this is excepted to by the parties infringing: the Chancellor, however, allowed the exceptions to be argued, only on payment by the infringers of 40001. into court to meet the patentee's law costs. These exceptions have no reference whatever to the question of the accuracy of the meter, but are simply as to whether the advantages of the meter were as great as allowed by the Master. The patent for the meter expired about the year 1828; since that period numerous competitors have commenced making the machine. Mr. Clegg has recently obtained a patent for a dry gas-meter, of which the following are its advantages and construction, es described by the very meritorious inventor:1. Working without water. 2. Working without membranes or valves. 3. Working without requiring the least pressure. 4. Working without interference with the perfect steadiness of the lights. 5. Registering more accurately than any other meter. 6. Occupying only one-tenth of the space of the common meters. 7. Being subject to little or no wear and tear. 8. And being cheaper. Prices.-For plain meters.~ s. d. Three-light meter... 1 1 0 Six-light do..... 2 4 0 Twelve-light do... 3 3 0 The highest numbers will be still cleaper in proportion. Ornamental meters, appearing like handsome time pieces, for halls, living-rooms, corn mittee-rooms, offices, counting-houses, &c., are charged extra, at ten shillings each and up wards, according to pattern. Description of Clegg's patent dry Gas-meter. The two figs. 698,9. are half the full size of the apparatus, and the letters of reference are the same in both. B, B, fig. 698., represents a cylindrical vessel, about three inches and three quarters diameter, and four inches deep, being the dimensions of a meter capable of measuring gas for three burners, called a three-light meter. In this vessel are t\vo glass cylinders F, F, connected together by the bent tube d. The cylinders being perfectly exhausted of air, and half filled with alcohol, are made to vibrate on centres e and e, and are balanced by the weightf. This instrument accurately indicates the excess of heat to which either cylinder may be exposed, upon the principle of Leslie's differential thermometer. C is a hollow brass box, called the hlsater, about four inches long, and half an inch broad, projecting out of the meter about one inch. At a issues a small jet of gas, which, when inflamed, gives motion to the cylinders. The gas enters the meter by the pipe A, and circulates throughout the double case B: having passed round the case B, a portion of it enters the top of the box C, by the pipe D, and passes out again at the bottom by the tube c, into the meter; the rest of the gas enters the body of the meter through holes in the curved faces of the hoods EE, and, after blowing on the glass cylinders, passes to the bmuners by the outlet pipe. To put the meter in action, let the jet a be lighted about an hour before the burners are wanted. In most cases this jet will be lighted all day as a useful flame. The n._____________________, ---------- JV ~-iLVV —--- ---- -------- 878 GAS-LIGHT. role a is so situated on the box C, that whatever be the size of the jet, a fixed ternm perature is given to the box, that temperature depending on the quantity of flame ii _ 69 698 Canf i \ B c yf>_ _ _I__ _ _ _ _ _, \\B 1/ - _~______ ( _____ WHEELWORK contact with the box, and not at all on the length of the jet. The jet being lighted, and the box C thereby heated, the gas which passes through it is raised to the same temperature, and, flowing out at the tube c, impinges on the glass cylinder which happens for the time to be lowest; the heated gas soon raises a vapor in the lower cylinder, the expansion of which drives the liquid into the upper one, until it becomes heavier than the counterpoisef, when the cylinders swing on their centre, the higher one descends, and comes in the line of the current of hot gas, and the lower one ascends; the same motion continues as long as the jet a burns. The same effect on the cylinder is maintained, however the outward temperature may change, by the cold gas, which, issuing from the curved side of the hood EE, impinges on the upper cylinder, and hastens the condensation of the vapor which it contains. The coll gas and the heater vary in temperature with the room, and thus counteract each other. The lighting of the jet a is essential to the action of the meters; in order to insure this, the supply of gas to the burners is made to depend on it in the following manner. The pipe G, by which the gas leaves the meter, is covered by a slide valve, which is opened and shut by the action of the pyrometer g; the pyrometer is in communication with and receives heat from the jet, and opens the valve when hot, closing it again when cold. The speed at which the cylinders vibrate is an index of the quantity of heat communicated to them, and is in exact proportion to the quantity of gas blowing on them through the pipe c and curved side of the hoods EE. The gas passed through the heater is a fixed proportion of the whole gas passing the meter; therefore the number of vibrations of the cylinders is in proportion to the gas consumed. A train of wheel-work, with dials similar to that used in the common meter, registers the vibrations. Simplicity, accuracy, and compactness, are the most remarkable features of this instrument, and the absence of all corrosive agents will insure its durability. GAS-LIGHT. 879 Directions.for fixing and using Clegg's patent dry Gas-meterr. Choose a situation for fixing the meter, where the small jet of flame will be of the greatest use, such as an office-desk or counter, taking care to screw the same firm and level on its base. When the jet at the top of the meter is required to be kept con. stantly burning as a useful flame, press in the brass knob at the front of the meter, and before lighting the burners pull it out; when the small flame is not required, let it be lighted about an hour before you want the burners lighted. Adjust the size of the small flame at pleasure by the screw b. On the back of each meter is marked the number of lights it will supply. The inlet and outlet pipes are marked at the bottom of the meter. The quantity of gas consumed is recorded by the index in the usual way. For testing Clegg's patent dry Gas-meters. Pass the gas through two meters at least, and take the mean. Vary the number of lights at pleasure, not exceeding the number marked on the meter, and when one or two hundred cubic feet of gas have been consumed, compare the indices. These meters are not for measuring small fractional parts; but taking the average for any periodical consumption, are more accurate than any other meter. Mr. Thomas Edge, of Great Peter Street, Westminster, has contrived the following meter, of which drawings are annexed. Fig. 700 is a front view of a three-light meter, the front plate being removed, and some of the parts shown in section 65. 700'A CUBIC FEET a WASTE WATER BOX Fig. 701 is a transverse section of the same. The gas enters at A into the r.:all chamber B, in the bottom of which is a lever valve (part of Mr. Edge's patent improvements), moving upon its axis and attached by the rod to a metal float c, which in the present drawing is buoyant. The object of this arrangement is to intercept the passage of the gas into the meter, unless a sufficient quantity of water is in it, that being necessary to its proper action; the gas then passes through the inverted syphon or tunnel into the convex cover, whence it passes into the chambers of the drum. Another of Mr. Edge's improvements consists in the cutting down of this syphon pipe or tunnel to the proper water level, and connecting the bottom of it to a waste waterbox, into which any surplus water must fall. The importance of this precaution will be seen on investigating the drum, as an excessive height of the water will materially interfere with the measurement, the q-aantity of gas delivered per revolution being considerably less. This, in connexion with the lever valve and float, confines the 580 GAS-LIGHT. variation of the water levels within such narrow limits, that the measurement may be considered perfectly just on all occasions. The last patent by Mr. Edge is for an improves index, which is composed of a series of moving dials, with 10 figures lpoai each, one figure only ap1 pearing of each series at a time. This contrivance is very ingenious, and will no doubt be applied to other machines, where indexes (indices) of quantity are required. Recurring to Mr. Clegg, he is also the inventor of an instrument of great value-appropriately called a " governor." Its purpose is to render -_ l — _.-_ _ ~ equal the height of flame of the several burners in _ I _ —- any house or establishment, and to keep them so,;^ -- -i ~;- jnotwithstanding any, and whatever alteration may be made in the pressure at the works or elsewhere. - - l E -=- T hisThis instrument is perfected, and successfully apI plied, though it is not so generally in use as it ought to be. By the use of this instrument a light A-; STE once set at the height.desired will maintain that WATER height uniformly, and without the least variation - Box tthe whole evening; and continue to do so till altered. Without this instrument, it is necessary to pay attention to the burning of gas-lights, as their heights are frequently affected by the most trifling circumstance, such, for example, as their extinction A=__- ____; at the hour of closing the shops, which makes a sensible difference in the neighborhood. All these works have prodigiously increased in the quantity of gas made and supplied. Since the account in the former edition of this work, large additional manufactories have been erected by new companies, and great additions made by the old ones. There are now in the metropolis alone 15 public gas companies, having among them 23 gas establishments. The quantity of gas manufactured by these 23 gas-works, and supplied to the public was during the past year three thousand one hundred millions of cubic feet of gas; and the coal used to produce this quantity of gas was at the least 400,000 tons! Baked clay retorts are very generally used in Scotland, and found to be most economical as regards wear and tear; in London, however, they are mostly of cast iron. The pressure upon the retorts is caused principally by the use of wet lime, used in London, because the process is less expensive and less cumbersome than dry lime. Wet lime can not be used with clay retorts, owing to this excess of pressure. Merit is due, for enlarging the capacities of double gas-holders, to the late Mr. Joshua Horton, of West Bromwich, near Birmingham; and to Mr. Stephen Hutchinson, engineer of the New London Gas-Works, Vauxhall, where they were first successfully introduced, and manufactured by Ar. Horton. They have now come vary generally into us2 throughout the kingdom. and are manufactured by all gas-holder makers. Separate gas-holders are advisable and advantageous, but they are not generally used, except in Glasgow, Manchester, Birmingham, Shelffield, and a few other places. The annexed drawing represents Mr. Croll's vessels for the purification of gas from ammonia, which is effatied by means of dilute sulphuric acid applied between the condensers with the ordinary lime purifiers. The vessels are made of either wood or iror, and lined with lead; havea wash-plate similar to the wet lime purifiers. The radiating bottom formed of wooden bars, as shown in the drawing, is for the purpose of supporting the wash-plate and distributing the gas. Fig. 702: a, is the inlet pipe; b, the outlet pipe; c, c, the tube with funnel for introducing the sulphuric acid; d, the first purifying vat; e, the second ditto, both lined with lead, and which are filled up to the dotted line with the dilute acid;,f, lhe water supply-pipe; g, g, the discharging cocks. Fig. 703 represents a ground-plan of the vats, each 10 feet in diameter; A, the bottom of the middle; B, the inlet of the gas; C, the outlet of ditto. In commencing the process, these vessels are charged with water and sulphuric acid, in the proportion of seven pounds, or thereabouts, of the latter, to 100 gallons of the former. As the acid is neutralized by the ammonia contained in the gas passing through the vessels, the above proportion, as near as may be, is kept up by a continuous dropping or running of acid regulated according to the quantity of ammon'a contained GAS-LIGHT. 881 in the gas, from a reservoir placed on the top of the saturator. This mode of s applying the acid is continued until the specific gravity of the solution arrives at 11~0, or close jt7 O2 11 d Cd eic ~ L-J ('103 g^J "" g.-s — J to the point of crystallization, after which the supply of acid is discontinued, and the liquor retained in the vessel until neutral, when it is drawn off and evaporated, and yields a pure sulphate of ammonia. This process has been introduced at several of the provincial gas-works, the three stations of the Chartered, the Impqrial, Phoenix. &c., &c. Mr. Croll is also now in treaty with several other companies for its introduction. The produce-sulphate of ammonia-from the process, by the gas-companies using it, now amounts to several tons per week-and it may be here mentioned, as one of the advantages of science, that the ammonia so produced before the adoption of this process passed along with the gas to the consumer, destroying rapidly the main pipes, fittings, and metres, through which it was transmitted, as well as deteriorating the illuminating power of the gas, and producing a choky effect when consumed in close apartments. It is now employed as a manure, and found to be superior in its effects as a fertilizer. as well as comparatively cheaper than any of the other artificial manures; so that whether Mr. C.'s invention be looked upon as affecting improvements in the manufacture of gas, hitherto unknown, or as producing a valuable manure,-the results are alike of the utmost importance. (When Mr. Croll's process is employed before the lime purifiers, dry lime can be used without creating the nuisance hitherto complained of, and a much less quantity is required for this purification.) Mr. Croll has recently patented another invention, connected also with the manufacture of gas, which consists in the combination of clay and iron retorts, so that the heat of the furnace first acts on the clay retorts and then passes to those of iron. The annexed drawing is a transverse section - A is the fireplace. B B are piers of fire-bricks, placed at intervals to form nostrils or flues, and the fire tile resting upon them in conjunction with the front and back wall, form the bed or support of the clay retort 1, and the clay retort 2 is also supported by the front and back brickwork, and a lump, or fire-brick, E, placed midway on the crown of the retort 1. F is a wall which separates the clay retorts 1 and 2, and the iron retorts 1~ and 2~; a space being left between the top of the said wall F, and the under surface of the arch, to allow the fire or heated air to pass freely from the clay to the iron retorts. G G is the bed, and H H is the flue under the iron retort 1~. The retort 2~ is supported by the front wail and pieces or lumps. J, placed at the back and crown of the retort 10, in connexion with the horizontal flue. H is a vertical flue, forming a passage thence into the shaft or chimney. The heat passes from the furnace or fireplace A, through the spaces or nostrils formed by the piers B B, and around the clay retorts 1 and 2, over the wall F, descends between and around the iron retorts and along the flue H, and escapes by the vertical flue into. the chimney. The advantages of this mode of settia retorts are the small quantity of 882 GAS-LIGHT. brickwork necessary for the erections, the increased durability of the retorts, and:he economy in fuel. From adopting this mode of setting a brick lump, it has been foandi that 12 tons of coke will carbonize 100 tons of coal..i' 7O4 El — - I "!~ i t o Iii I I I I I I I I' = II I 7 1 B C L is the chimney stalk, and d is a damper or register plate for regulating the chimney draught. Before dismissing Mr. C(roll's patent improvements, it is proper to state, that the sulphuric acid used for condensing the ammonia should be free from iron, otherwise the s lphuretted hydrogen of the coal gas is apt to give rise to sulphuret of that metal which will blacken the sulphate of ammonia and reduce its value in the market. An occur. rence of this kind was recently brought professionally before me for investiga tion. The sulphuric acid had been made from pyrites. Mr. Kirkham, engineer, obtained a patent, in June, 1837, for an improved mode of removing the carbonaceous incrustation from the internal surfaces of gas retorts. He employs a jet or jets of heated atmospheric air or other gases containinlg oxygen, which he impels with force into the interior of such retorts as have become incrusted in consequence of the decomposition of the coal. The retort is to be kept thoroughly red hot during the application of the proposed jets. An iron pipe, constructed with several GAS-LIGHT. 885 flexible joints, leading from a blowing machine, is bent in such a way as to allow its nozzle end to be introduced within the retort, and directed to any point of its surface. I should suppose that air, even at common temperatures, applied to a retort ignited to the pitch of making gas, would burn away the incrustations; but hot air will, no doubt, be more powerful. Bude-light. - This brilliant mode of illumination has been so called from the name of the resideno3 in Cornwall of Mr. Goldsworthy Gurney, who obtained a patent for it in the year 1838. In its first form it consisted of a common Argand oil flame or lamp of rather narrow circular bore, into the centre of whose wick a jet of oxygen gas was admitted through a tube inserted in the middle of the burner. This contrivance was not, however, new in this country, for a similar lamp, similarly supplied with oxygen gas, was employed by the celebrated Dr. Thomas Young in his lectures at the Royal Institution of Great Britain for the purpose of illuminating a solar microscope, or gas microscope, about 40 years ago, and I had done the same thing in Glasgow in the year 1806 or 1807. When used as a light for lighthouses or for other continuous illumination, it has been found to be too expensive and difficult to manage. It was tried upon a good scale a few years ago both by the Trinity House in Tower Hill, and in one of their lighthouses on the coast, as well as by the House of Commons. The Masters of the Trinity did not find it to be essentially superior for the use of their lighthouses to their old and ordinary plan cf illumination with a number of Argand lamps placed in the focus, or near the focus, of reflecting mirrors. It was, after several expensive trials by them, and in the House of Commons, abandoned by both. In the course of numerous experiments in the Trinity House, Tower Hill, Mr. Gurney had occasion to examine the structure and see the performance of Mr. Fresnel's compound Argand lamps which are used in the French lighthouses, furnished with refracting lenses of peculiar forms which surround these lamps, and transmit their concentrated light in any desired horizontal direction along the surface of the sea. Two of Mr. Fresnel's lamps are placed in the lamp apartment of the Trinity House. Each consists of a series of 4, 5, or 6 concentric wicks in the same plane, supplied with oil from the fountain below by means of a pumping mechanism, as in the well-known Parisian lamps of Carcel and Gagneau. The effect of 4, 5, or 6 concentric flames thus placed in close proximity to each other, with suitable supply of air through the interior of the innermost tube and the interstices between the exterior ones, is, to increase the heat in a very remarkable degree, and by this augmentation of the heat to increase proportionably the light. For it has been long known that a piece of even incombustible matter, such as a lump of brick, intensely heated, sends forth a most brilliant irradiation of light. This fact was applied first to the purpose of illuminating objects by Professor Hare, of Philadelphia, fully 40 years ago. By directing the very feebly luminous flame of the compound jet of hydrogen and oxygen upon a bit of clay, such as one of Wedgwood's pyrometer pieces, a most vivid illumination was sent forth from it as soon as it became intensely heated. More lately, a piece of lime has been used instead of a bit of clay, as it is not so apt to change by the ignition, and affords, therefore, a more durable effect. It is used in our modern gas microscopes. Mr. Gurney suggested the use of lime for the above purpose in a work on chemistry which he published more than twenty years ago. It was afterwards adopted by Mr. Drummond, in order to make signal lights in the trigonometrical survey of the Board of Ordinance, and was therefore cal.?d the Drummond light, though he had no share whatever in the merit of the invention. The structure of the Fresnel lamp would naturally suggest to Mr. Gurney the idea of trying the effect of a similar construction of an Argand gas lamp. But prior tc, the execution of this scheme, he obtained a second patent in the year 1839. for increasing the illuminating power of coal gas by feeding its flame in a common Argand burner with a stream of oxygen. But here a serious difficulty occurred. The stream of oxygen, when admitted into the centre of such a flame, instead of augmenting its qr.antity of light, destroys it almost entirely. This result might have been predicted by a person well versant in the principles of gas illumination, as long ago expounded in Sir Humphry Davy's admirable Researches on Flame. This philosopher demonstrated that the white light of gas-lamps, as also of oil lamps, was due to the vivid ignition of solid particles of carbon evolved by the igneous decomposition of the hydro-carburet, either in the state of gas or vapour; and that if, by any means, these particles were not deposited, but burned more or less completely in the moment or act of their evolution from the hydro-carburet, then the illumination would be more or less impaired. Mr. Gurney, on observing this result, sought to obviate the evil, by charging the coal gas with the vapour of naphtha. Thus a larger supply of hydro-carbaret, and of carbon of course, being obtained, the flame of the naphthalized gas, admitted with advantage the application of oxygen gas, for the increase of its light; on the principle of greater 884 GAS-LIGHT. intensity of ignition, and consequently of light, being produced by the burning of carbon in oxygen than in common air, as had been long known to the chemical world. But an obstruction to the permanent employment of naphthalized gas was experienced by Mr. Gurney, from the deposition of liquid naphtha in the pipes of distribution. He was therefore induced to renounce this project. He then resorted to the use of coal-gas, purified in a peculiar way, and burned in compound Argand lamps, consisting of two or more concentric metallic rings, perforated with rows of holes in their upper surfaces, having intervals between the rings for the admission of a proper quantity of air, the burner being enclosed in a glass chimney at the level of the flame, surmounted by a tall iron chimney. Between these two chimneys, a certain space is left for the admission of air, and to favour draught and ventilation. The intensity and whiteness of the cylinder of light produced by the combustion of coal-gas in this lamp are truly admirable, and form such an improvement in illumination for streets, churches, public rooms and private houses, as to merit the protection of a patent, and the encouragement of the public at large. General Estimate of Sizes, Number of Concentrics, Consumption of Gas, and Comparative Light. e Number of Bude Consump- Height of Argand ze Concentrics. tion per hour. Flame. C o upti on per hour. Inches. Feet. Inches. Inches. 15-hole Argands. Cubic Feet. 2~ 2 10 6 3 5 30 3 2 16 4 3 8 48 39 2 21 6 3 10 60 4 2 26 4 3 12 72 41 2 33 7 3 15 90 5 3 40 0 3 18 108 56 3 43 5 3+ 20 120 6 3 56 4 4 24 144 Laming and Evans's Invention.-The first part of this invention consists of an improvement in retorts for making gas, and for other uses; and in making pots, crucibles, muffles, stoves, fire-bricks and lumps, and other articles of clay, required to stand the action of fire without cracking. The improvement consists in mixing with the fire-clay, which is to enter into the composition of any of the aforesaid articles, about 0-25 per cent. of its weight of asbestos or fibrous silicate of magnesia; the vessels are then to be constructed and burned in the usual manner. The patentees state that they do not confine themselves to any particular forms of the articles, each of which may be made of one or more pieces, as at present; and the proportion of silicate of magnesia may be varied to meet the exigencies of particular cases, its introduction being for the purpose of giving greater tenacity to the materials used, and thus diminishing their tendency to become cracked under the influence of change of temperature. They claim under this head of the invention, the introduction of asbestos or fibrous silicate of magnesia among the materials used for making articles of clay, intended to be submitted to a great heat; and the use of all such articles, made with asbestos or fibrous silicate of magnesia in their composition. Another part of this invention consists in an arrangement of apparatus for making gas from oil, tar, melted pitch, resin, fat, or other analogous material, in conjunction or not with water. The apparatus consists of an iron or clay retort, composed of two horizontal chambers, one above the other, and communicating at the back only. The ends of the chambers are closed by three man-hole doors; two of which are secured over the front end of the chambers; and the third, which is a large door, serves to close the hind ends of both chambers;-the three doors all projecting beyond the brickwork setting of the retort. Upon the upper chamber, near the front end thereof, is an inverted funnel of large diameter, closed by a cover, the edge of which is turned down, and dips into a hydraulic joint, or into a joint filled with metal, fusible at the temperature to which it is exposed, or else it is secured in the same manner as the ordinary man-hole doors. The cover is fitted with a double syphon, furnished with a stop-cock. The eduction-pipe, leading to the hydraulic main, is connected with the front end of the lower chamber of the retort. To use this apparatus, previously raised to the usual temperature, the patentees charge the upper chamber with coke, heaping it somewhat just beneath the funnel, and allowing some pieces to fall over against the large man-hole door at the back, and they charge the lower chamber either with coal or coke. A stream of oil, tar, melted pitch, resin, fat, or other analogous matter, in GAS-LIGHT. 985 conjunction or not with water, is then allowed to fall from the double syphon through the large funnel, on to the red-hot coke beneath; it passes thence, partly as gas and partly as liquid, through the upper chamber to the back of the lower one, along which it next proceeds, chiefly in the state of gas, and escapes, mixed with the gaseous products of the lower chamber, through the eduction pipe into the hydraulic main. When the lower chamber of this apparatus is charged with coal, the liquid should not be permitted to flow from the double syphon, till the coal has had time to give off the greater part of its richer gas, and to become heated throughout; but when coke is used in both chambers, the liquid is admitted from the commencement, and without intermission, until the passages of the gas apparatus need to be opened and cleaned out. The patentees do not claim the making of gas from tar, or any other form of hydrocarbon, or water, by means of red-hot coke, or the combining of any materials affording gas. What they claim is, the combination and arrangement of the apparatus, particularly of the large funnel, with the double chambers, and back and front man-hole oors, for making gas by the decomposition of any suitable hydro-carbon, or water, by bringing it, in a fluid state, into contact with red-hot coke or other suitable material. Another part of the invention consists in elongating the eduction pipes of retorts, used for making gas for illumination, into their interior, and arranging them in lines near their axes. The further ends of these pipes are left open, and they are supported by bearers. Holes should be made along the pipes, but only in sufficient number to permit of the free escape of the gas as it is generated; or a longitudinal slit may be made in the under side of the horizontal pipe, from its further end to near its ascending portion; and this arrangement is preferred, bucause it admits of the passage being cleared out by a proper tool, in the event of its becoming choked. The improvement is applicable to retorts of any material, and of the ordinary forms; but it will be found more easy to charge the retorts, to which this improvement is applied, when they are made large enough to receive a charging-scoop on either side of the horizontal eduction pipes. The object of the improvement is to diminish the contact of a gas with a surface heated high enough to cause it to deposit some portion of its carbon; and thus to produce a richer gas, or a larger quantity of equally rich gas, from a given quantity of coal. The claim made under this head is for the elongation of the eduction-pipes of retorts, used for making gas for illumination, along or near their axes. Another part of the invention consists in a process for obtaining light by means of platinum, heated to whiteness by coal gas or peat gas. It is known, that when water is decomposed, and the resulting hydrogen burnt within a small cage, made of platinum wire or platinum foil, in such a manner as to heat the metal to whiteness, the platinum becomes luminous, and remains so as long as its temperature is maintained; but it is equally well known that hydrogen gas, resulting from the decomposition of water, is not readily obtainable under the generality of circumstances when light is required. The improvement consists in replacing hydrogen gas from water by coal gas (which is to be obtained almost universally, and which answers the purpose) or by peat gas. In carrying out this improvement, it is preferred to burn the gas either by itself, or mixed with atmospheric air, within a platinum wire cylinder, greater in height and diameter and made of coarser material, as the quantity of gas burned within it in a given time is greater,-the only practical rule that it is necessary to give being, that all the metal be placed, with respect to the flame, in the best position for becoming white-hot. The advantages which result firom this part of the invention are, first, with respect to ordinary coal gas that more light is obtained in proportion to the quantity of coal gas consumed, than is the case when platinum is not used; and, secondly, that, by its means, a good light is obtained by the combustion of peat gas, or of coal gas of inferior quality. Under this head, the patentees state, that they neither claim nor restrict themselves to the use of any particular form or dimensions of the platinum apparatus; but what they claim is, the use of coal or peat gas, mixed or not with air, for heating platinum wire or foil to whiteness, and thereby producing light. A previous patent has been obtained by one of the patentees (Mr. Laming), for purifying coal gas by a solution of muriate of iron, mixed with porous materials; and also by muriate of iron, decomposed by lime into chloride of calcium and oxide of iron, and made porous by suitable materials. Now, one part of the present invention consists in combining known processes, so as to obtain the last-named purifying materials. The patentees decompose sulphate of iron, in solution, by its equivalent quantity of chloride of sodium; and, having separated, by known means, the resulting sulphate of soda, they add to the solution of muriate of iron concentrated by evaporation, first, enough dry sawdust, or other suitable matter, to absorb it, and then enough hydrate of limo to decompose it into chloride of calcium and precipitated oxide of iron. Coal gas is purified with this mixture, disposed in dry purifiers; and, afterwards, sulphur, cyanogen, 88b GAS-LIGHT. and muriate of ammonia, are extracted from the used materials by any ordinary processes adapted for that purpose. Sometimes the purifying material is modified in the following manner: an equivalent quantity of ground or granulated sulphate of iron, or chloride of sodium, is mixed with the other of these salts in solution, absorbed into sawdust or other suitable matter; and then an equivalent of hydrate of lime is stirred in. This modified material, after being used in dry purifiers for purifying coal gas, affords by lixiviation a mixed solution of sulphate of soda and muriate of ammonia; sulphur and cyanogen also may be extracted from it, as in the former case. Sometimes the sulphate of iron is replaced by sulphate of copper; and then the resulting oxide, of course, is the oxide of that metal instead of the oxide of iron. The patentees claim, under this head, the combination of processes above described for making a purifying material, containing chloride of calcium, and precipitated oxide of iron or copper; and likewise the composition of the modified material, as described. They also claim the use of both kinds of materials for purifying coal gas. Another part of the invention consists in purifying coal gas by means of a cheap maVterial, made by mixing refuse sulphate of lime or gypsum, in a finely divided state, with sulphate of iron. The sulphate of iron should be either ground fine or granulated, and mixed with sawdust, or other matter, suitable for separating its particles; or it may be merely mixed, in a divided state, with the earthy salt, or absorbed into its mass, or into sawdust, or other porous matter. The gypsum should be previously baked at a red heat, to prevent its tendency to solidify with water. The material, thus prepared, is used in dry purifiers, in the way well understood for purifying by hydrate of lime. For the sulphate of iron other metallic salts may be substituted with similar results; such, for example, as muriate of iron, sulphate or muriate of zinc, sulphate or muriate of manganese, or even sulphate or muriate of copper; but sulphate of iron is preferred. The resulting mass is either used as a manure, or else it is subjected to certain known chemical processes for obtaining from it an ammoniacal salt, or salts, sulphur, and cyanogen. The claim under this head is for the purification of coal gas by the use of sulphate of lime, mixed with any of the metallic salts above named; and the use of the spent purifying material as a manure. Another improvement consists in causing impure coal gas to pass through dry purifiers charged with a porous solid material, which is made by mixing, in about equivalent proportions, hydrated or precipitated oxide of iron, with carbonate of lime, magnesia, carbonate of magnesia, or magnesian limestone, in fine powder, or else burned or slaked, either by themselves, or rendered more pervious to the gas by sawdust, or other suitable matter. A mixture of precipitated oxide of iron and lime answers the same purpose, and was claimed by Mr. Laming, under a former patent. In each of the above cases oxide of copper may be substituted for the oxide of iron. All the several compounds, when they begin to act on the impure gas, purify it from sulphuretted hydrogen and cyanogen; and any one of them, having been once made foul, and afterwards placed in contact with atmospheric air for a few hours, acquires the property of purifying coal gas from ammonia also. The spent materials afford, by processes well known, cyanogen, sulphur, and ammoniacal products. The patentees claim, under this head, the purification of coal gas, by mixtures made as described, whether with hydrated or precipitated oxide of copper or of iron. Another part of the invention consists in a particular way of using chloride of mag. nesium, or sulphate of magnesia, for withdrawing from coal gas ammonia and carbonic acid. Sawdust or other solid matter calculated to expose an extensive surface to the gas, without opposing great resistance to its passage, is caused to absorb a saturated solution of one or both of the above named salts; or those salts may be mixed, singly or together, in a divided and solid state, with sawdust or other suitable matter, in a damp state; and then the mixture is placed in dry purifiers, through which the gas is made to pass in its way from the condensers to the gas-holders. When the gas ceases to be purified from its ammonia, the contents of the purifier are taken out and washed, to obtain an ammoniacal solution; and a new charge of similar purifying materials is introduced into the purifier. The claim made under this head is for the extraction of ammonia and carbonic acid from coal gas, by chloride of magnesium, or sulphate of magnesia and water, diffused through sawdust or other solid matter, capable of exposing an extensive surface of the re-agents to the gas, without materially impeding its passage. A further improvement consists in purifying coal gas by the use of a solid material, containing chloride of magnesium or of calcium, or sulphate of magnesia, mixed with hydrated or precipitated oxide of copper. To make this purifying material, the patentees take sawdust, or other suitable matter, wetted with a strong solution of suitable matter, wetted with a strong solution of muriate or sulphate of copper, or else either of those salts of copper in a finely-divided state, and mixed with moistened i GAS-LIGHT. 887 stawdust or other suitable matter, and they mix therewith enough lime, magnesia, or its carbonate, or magnesian limestone, burned and slaked with water or powdered, to decompose the salt of copper into precipitated oxide of the metal, and a salt of lime or magnesia, or both. Or, instead of making extemporaneously both or either of the salts of magnesia and lime and oxide of copper, they mix sulphate of magnesia or chloride of magnesium or of calcium, ready formed and in a state of mechanical division, or in solution, wvith oxide of copper and sawdust, or other suitable matter. These purifying materials are used in dry purifiers, like hydrate of lime. They can be employed for removing ammonia, carbonic acid, and sulphuretted hydrogen from the gas; or they may be used for the latter impurity without the two former. In the first case, it is found useful to add to them about half an equivalent of fine carbonate of lime, or of carbonate of magnesia, or of both; and in the latter case it is preferred to make either the same addition, or, in lieu thereof, to add about the same quantity of caustic lime or magnesia, or of both of them. When the used material will no longer purify the gas from sulphuretted hydrogen, either it is taken out of the purifier and exposed to the atmosphere, or else a current is directed through it while in that vessel; a vent-hole in the purifier, below the level of the foul purifying matter being open, or not, at the same time, as may be found necessary. The purifying energy of the material is thus restored, and this alternate expenditure and restoration of energy can be repeated a number of times, until the material becomes sufficiently charged with sulphur and with ammoniacal and cyanogen products, or either of them, to render it worth while to extract it or them in any known way. The patentees claim under this head, the purifying coal gas by the repeated use of a solid material, containing sulphate of magnesia, or chloride of magnesium, or calcium, or more than one of those re-agents, in combination with oxide of copper, and mixed or not with lime or magnesia, or both, or either, or both of the carbonates of those earths. The next part of the invention consists in a process for converting the ammoniacal liquor, produced in making gas, or by distilling animal matters, into sulphate of ammonia. By repeatedly using the same portion of hydrated or precipitated oxide of iron or copper, in conjunction with lime, magnesia, carbonate of lime, carbonate of magnesia, or any compound of lime or magnesia, susceptible, under the circumstances in which it is used, of being decomposed by carbonate of ammonia,-for purifying coal gas, with subsequent exposure to atmospheric air, the spent material eventually becomes in great part changed into sulphate of lime or sulphate of magnesia, mixed with oxide of a metal. When this has taken place, the spent material is mixed in a vat for an hour or two, with nearly as much of the ammoniacal liquor as it will decompose; the fluid is next drawn off and filtered; the saturation of any ammonia which it may contain in a volatile state is effected by sulphuric acid; and then it is evaporated to obtain crystals of ammoniacal sulphate. The same process is followed by another good result; for the decomposition of the carbonate of ammonia by the sulphate of lime, or sulphate of magnesia, reproduces in the spent material a carbonate of the earth, which fits it for beginning anew the work of purifying coal gas. The patentees claim the use of the spent materials, above described, for converting solutions of carbonate of ammonia, mixed or not with hydrosulphate of ammonia, inte solutions of ammoniacal sulphate; by which use, also, the sulphate of lime or sulphate of magnesia, in the said mixtures, is changed into carbonate of lime, or carbonate of magnesia. When solid or porous mixtures, containing hydrated or precipitated oxide of iron or copper, or a salt of either of those metals, decomposable into hydro-sulphuret of the metal, are employed to absorb sulphuretted hydrogen from coal gas, and are afterwards brought into contact with atmospheric air, the mixture rapidly absorbs oxygen, and thereby acquires an elevated temperature, greater in proportion as it is free from moisture. In certain cases, when the materials are at first, or become by use, dry to the touch, their temperature during the subsequent absorption of oxygen rises much higher than is desirable. One way of preventing this injurious accession of heat is by communicating humidity to the mixture of materials, at a proper time; and this constitutes another part of the invention. This improvement is put into practice, either by sprinkling the used purifying materials with water, on removing the cover from the vessel, which contains them; or by pipes, properly disposed within the vessel, distributing water over the surface of the materials, without the cover being removed; or by sprinkling the materials with water, after they have been thrown out of the vessel; or lastly, by placing the purifier in communication with a steam-boiler, and directing through the used materials a sufficient quantity of the vapour of water to moisten them and subsequently submitting them to the influence of a current of atmospheric air, also directed through them. The patentees state, that they know it to be necessary that the metallic oxides used for purifying coal gas from sulphuretted hydrogen should be hydrated; that is to say, combined with a certain portion of water in a dry state; but 888 GAS-LIGHT. experience has proved to them, contrary to common opinion, that the said oxides act less'energetically on the sulphuretted hydrogen in the gas, and also that they regain their expended energy less suddenly, when they contain water in a liquid state, than wher they are free from hygrometric water. The patentees do not claim the regeneration of the purifying energy of any spent purifying mixtures, by exposing them to atmospheric air; but what they claim is, the means, above described, for checking the rapidity of the regenerating action, and, consequently, preventing the temperature of the materials from rising to a pernicious height;viz., by wetting them with water, or by condensing steam in their mass, either in or out of the purifier, at any time after they commence to purify the gas, and before they are put in communication with the atmosphere. The patentees have found that mixtures containing hydrated or precipitated oxide of iron, changed into hydro-sulphuret of iron, by purifying coal gas from sulphuretted hydrogen, do not readily re-absorb oxygen, and, consequently, do not readily recover their purifying energy at temperatures below 32~ Fahr. Now, another improvement consists in applying to such used mixtures, during frosty weather, atmospheric air, artificially warmed to about 60~ Fahr.: by the ordinary operations of the "retort house," or in any other convenient manner. The warmed air may be used there, or conducted thence to the purifiers, by suitable pipes, in which a draft is established by any known means. The claim under this head is for the use of air, artificially warmed, for promoting, in cold weather, the regeneration of hydrated oxide of iron, in mixtures which have been used for purifying coal gas from sulphuretted hydrogen,-whether the warmed air be conveyed to the used purifying mixtures, or the latter be carried to the warm air. Another part of the invention consists in the use of phosphate of lime, dissolved in hydrochloric acid, for purifying coal gas, and for decomposing the ammoniacal liquors produced in making gas, and in the distillation of animal matters, and the application of the products as manures. In carrying out the improvement, bones, or other form of phosphate of lime, are dissolved in hydrochloric acid. This solution is prepared for purifying gas by mixing it with sawdust or other suitable solid matter; and thus it is exposed to the impure gas in dry purifiers. To use the solution for decomposing ammoniacal liquors, one of the fluids is added to the other, until the hydro-sulphuric and carboni6 acids combined with the ammonia have escaped. To facilitate the transport of the product, and its application as a manure, it is heated in pans until it becomes dry. The product of the purification of gas is also a good manure, mixed as it is with the sawdust or other absorbent matter used. The patentees claim under this head the'-we of a solution of phosphate of lime in hydrochloric acid,.for purifying coal gas and for saturating ammoniacal solutions; and also the use of the products as manure. Another part of the invention relates to certain processes for obtaining, in an economical manner, one of the re-agents which the patentees use for purifying gas,-namely chloride of calcium. In certain chemical works, hydrochloric acid gas is a residuary product,-not only of no value, but even costly to get rid of without nuisance to the neighbourhood. One of the processes consists in causing hydrochloric acid gas to pass, in a heated state, over r,~ds of lime, or carbonate of lime, in its way from the furnaces, where it is generated, to the condensers, where it would else become absorbed into water. The beds of lime, or carbonate of lime, are formed on the bottom of the ordinary conduits; two conduits being arranged in a line, and worked and discharged alternately. When the lime in one passage has been converted into chloride, the draft through it is diverted into the neighbouring passage by means of dampers arranged for that purpose; and the finished charge is withdrawn through doors made at convenient distances. When this is done, the bed is re-charged with lime or its carbonate, in readiness to receive the current of hydrochloric acid, after it shall have saturated the lime in the second conduit. When this saturation is completed, the dampers are reversed, so as to divert the acid gas again into the first conduit, while the charge of the second is being withdrawn, preparatory to re-charging it a second time; and so on continually. By the second process, hydrochloric acid is obtained in a concentrated state, preparatory to its saturation in a fluid form by lime or its carbonate, or to its application to other uses. This process is carried on with only one conduit leading from the furnaces where the hydrochloric acid is generated. Tile conduit is lined with hard glazed bricks, or tiles, or sandstone; and its bottom is so constructed, that any fluid formed within it shall escape by a pipe adjusted to its lowest part. Along this conduit a number of porous earthenware vessels are arranged in a line or lines, standing on its floor, and built into its arch or cover up to their necks. These vessels are filled with water, and made to communicate, by means of syphons, with one another, and with a reservoir of water placed with its highest part on the same level as the mouths of the earthenware vessels. By well-known arrangements, the water is kept at a constant level GAS-LIGHT. &89 in the reservoir, and consequently at a constant level in the earthenware vessels which communicate with it. The consequences of this arrangement are, that the water contained in the vessels within the heated conduit is speedily raised to a temperature of 212~ F.; that the gaseous contents of the conduit are reduced to that temperature, of nearly so,-and that the water which exudes from the porous earthenware absorbs as much hydrochloric acid gas as it can combine with. Now, as strong hydrochloric acid is condensable at a temperature above 212~ Fahr.; and as the vapour of water is not condensable at that temperature, the strong acid flows down the outsides of the porous vessels and runs in a stream to the most depending part of the passage, where it escapes by the pipe placed for that purpose. By treating the acid so obtained with lime or its carbonate, chloride of calcium or muriate of lime is obtained, with hardly any cost for evaporation. The patentees claim, under this head, making chloride of calcium, by causing the hydrochloric acid gas, which results from the decomposition of common salt by sulphuric acid, to act on lime or carbonate of lime in its passage from the furnace where the decomposition is effected; and also the collecting of concentrated hydrochloric acid, for making chloride of calcium or other purposes, by condensing hydrochloric acid gas in water by means of earthen vessels built into a conduit or flue, conducting from furnaces in which chloride of sodium is decomposed by sulphuric acid, and containing water kept at about 212~ Fahr. by the heated products of the said furnaces. The next part of the invention is a new way of using certain forms of carbon for purifying coal gas and obtaining ammonia therefrom. It consists in alternately causing the material to absorb impurities from the gas, and to discharge them under the influence either of heat or of a current of air, or steam directed through the purifying material. In carrying out this improvement, a dry lime purifier, or other convenient vessel, is filled with animal charcoal in coarse powder, and impure coal gas is directed through it, until it no longer issues from the vessel pure. The gas is then sent in another direction, and a current of steam or air, heated or otherwise, is passed through the foul material; the volatile products being received into any desirable acid or other substance calculated to fix the ammonia, or else the ammonia, combined with carbonic and hydro-sulphuric acids, is condensed by water, or by the abstracting of heat, in any suitable apparatus. If steam be used, it brings away nearly the whole of the ammonia, but it damps the purifying material, which then needs to be dried by a current of hot air or otherwise; and if air be used, in the first instance, to bring away the ammonia, part of it becomes sulphate of that base, and must be removed by washing. In addition to, or without the introduction of air or steam among the purifying material, it may be heated by steam or hot water contained in a jacket around the vessel, or in pipes within it; or the foul material may be removed from the purifier and heated to about 2120 Fahr. in any suitable close vessel. Coke, wood, charcoal, or peat charcoal may be substituted for animal charcoal, in the process above described, but with inferior results. The patentees do not claim the exclusive use of any form of carbon for absorbing the impurities of coal gas; their claim being for the means above described, for making coke and charcoal repeatedly useful f6r purifying coal gas, and for obtaining its ammonia by their agency. Another part of the invention consists of certain processes by which prussiate of potash, prussiate of soda, and prussiate of ammonia, are obtained from prussiate of lime. With respect to prussiate of potash, the process is to mix well together equivalent quantities of prussiate of lime and sulphate of potash, or carbonate of potash, previously dissolved in separate portions of water; and then, after subsidence of the sulphate or carbonate of lime which is formed, to evaporate and crystallize the clear solution. The prussiates of soda and of ammonia are made in like manner, by substituting the sulphates or carbonates of the respective bases for the sulphate or carbonate of potash. The claim under this head is for the manufacture of the prussiates of potash, soda, and ammonia, by decomposing solutions of the sulphates or carbonates of those bases by solutions of prussiate of lime. Another improvement consists in a process for obtaining carbonic acid gas for converting the hydrosulphate of ammonia in gas liquor into carbonate of ammonia, and for other useful purposes to which carbonic acid gas is applicable. It is known that hydrosulphate of ammonia is decomposable by carbonic acid, and that hydrosulphate of ammonia exists in gas liquor. To change it into carbonate of ammonia,the patentees proceed as follows:They make a mixture of deutoxide of copper and charcoal, or other form of carbon, in fine powder, in the proportion of twelve parts, by weight, of the former to one part of the latter, and introduce the mixture into a retort, made red hot, and furnished with an eduction pipe which passes through cold water and finally enters into gas liquor. The formation of carbonic acid gas soon takes place, by the union of the carbon with the oxygen of the metal: and this gas, combining with the base of the hydrosulphate of ammonia, combined in the gas liquor, converts it into carbonate, causing hydrosulphuric 890 GAS-LIGHT. acid to escape. When the carbonic acid ceases to come away, nearly all the carbon will have disappeared from the retort, and the copper which it contains become reduced to the metallic state. The charge is then drawn and left to cool, while a second charge, of similar materials, is being worked off; during which time the copper re-absorbs oxygen from the air, and becomes again deutoxide of copper, which may then be used anew with fresh carbon. The patentees claim making carbonic acid gas for converting hydrosulphate of ammonia into carbonate of ammonia, and for all other purposes in the arts, by exposing a proper mixture of deutoxide of copper and carbon in powder to a red heat in suitable vessels. The last part of this invention is a process for consilidating peat to be used in furnishing gas or charcoal, or for feul. The process is as follows:-The peat, without being previously dried, is treated with water in a mill in a way similar to that in which chalk is treated for the manufacture of whitening, and which is well understood. The resulting liquor is made to pass through a strainer of wire-work (fine enough to prevent the passage of the large fibres) into tanks or backs, cut in the earth, or built upon the surface of the ground if necessary; where it is left to deposit the finer parts of the peat. When this is effected, the supernatent liquor is run off from the deposit, and the magma taken out from the tanks or backs and dried, either by the air, by the sun, or on arches of brick or other absorbent material, heated by flues underneath. The patentees claim under this head the separation of the grosser from the finer parts of the peat, and the consolidation of the latter by the process above described. ~ Gas-light, Purification of. The purification of coal gas has lately received one of those important improvements, which constitute an era in the practical application of science to the arts. From the commencement of the manufacture of gas up to a very recent period, the only agent in use for the removal of the impurities of coal-gas was the hydrate of lime. The impurities in question are, as is well known, carbonic acid and sulphuretted hydrogen united to ammonia, and held in the gas more by a principle of diffusion than from their own proper volatility. Hence mere condensation by cold, or the application of water, unless both of these are employed to an injurious excess, will not combine with or precipitate the bicarbonate and hydrosulphate of ammonia present in impure coal gas. The hydrate of lime, however, readily decomposes both of these salts, with the production of carbonate and hydrosulphate of lime and the liberation of free ammonia, the greater part of which may subsequently be removed by the use of a dilute acid, or the application of cold water in an apparatus similar to the " cascade chemique" of Clement Desormes. Thus, then, it was possible by lime to remove the whole, or at least nearly the whole, of the impurities of coal-gas, and as we have before stated, this, up to within a very recent date, was the general practice whenever coal-gas was manufactured. But the use of lime in this way entailed many and serious dis advantages in a sanitary point of view, to obviate or rather to diminish which considerable outlay was incurred in large towns, for it is a property of the hydrosulphate of lime to be decomposed with singular rapidity by carbonic acid, and as the atmosphere, more especially in crowded localities, always contains a notable proportion of this latter gas, it follows that the hydrosulphate of lime begins to decompose the moment it comes in con. tact with the air, and, consequently, an intolerable nuisance and pestilential effluvium were thus originated, not only in the neighbourhood of the gas-works themselves, but also in those localities to which this gas-lime refuse happened to be transported; of which a lamentable illustration occurred not long ago in Pimlico, where a sewer had been covered over by this kind of refuse; and though three or four years had intervened between the deposition of this matter and the accident we now relate, yet no less than five healthy individuals were struck dead, as if by lightning, on entering the sewer beneath the spot where the refuse lime had been placed. With so terrific a proof of the deleterious action of the hydrosulphate of lime, even after many years had elapsed, it becomes superfluous to dwell upon the necessity which existed for discontinuing the formation of this poisonous substance, and, fortunately, science has stepped in at the eleventh hour to the relief of the public. About the year 1847, a Mr. Laming, of Paris, took out a patent for the employment of various metallic oxides in lieu of lime for the purification of gas, which oxides were used at the same time or in combination with muriate of lime. The effect of this arrangement was two-fold, for as we have seen that the impurities to be taken away consist of ammonia, carbonic acid, and sulphuretted hydrogen, then by the use of muriate of lime, Mr. Laming was able to remove the carbonic acid and ammonia, whilst by the metallic oxide he removed the sulphuretted hydrogen; producing in the first case muriate of ammonia and carbonate of lime, and in the second a metallic sulphuret and water. The oxides patented were those of manganese, iron, zinc, and lead; but there was this insuperable difficulty connected with their employment, that as they could be formed only by the decomposition of a metallic salt and its equivalent GAS-LIGHT. 891 of lime, they necessarily cost, for an equal amount of work done, the whole value of the lime plus that of the metallic salt. The expense of purification by this plan, therefore, stood as an insurmountable barrier to its introduction, though the peculiar defect of lime was entirely got rid of in the use of the metallic oxide, as this did not suffer decomposition by atmospheric carbonic acid, and therefore evolved no sulphuretted hydrogen. Nevertheless, the process languished, and threatened to die out on the score of cost. Mr. Laming's first essays with this patent seem to have been made almost entirely with the oxides of manganese and lead, and oxide of iron does not appear to have been employed or tried on a large scale until about three years ago, when, in conjunction with Mr. F. J. Evans, of the Chartered Gas Works, it was put in use by Mr. Laming at Westminster. The success of the experiment was complete as to purification, but the question of expense could only be decided by a few consecutive trials, and therefore, fresh materials were sent for this purpose, whilst the old, or as it was called "spent" material was cast on one side. During the progress of the ensuing experiments it was, however, observed by Mr. Evans, that this spent material, consisting as it did of black sulphuret of iron, rapidly regained its original red colour, and looked like oxide of iron. This induced him to give it snother trial in the purifier, when, to his astonishment, he discovered that its purifying power was completely restored, and that, in fact, it might be used over and over again, 10, 15, or 20 times, or even more in succession, nothing being required to restore its power but a few hours' exposure to the air. From that moment the practical employment of oxide of iron in the purification of coalgas became un fait accompli; for the question of expense was altogether done away with by a material which, though costly in the first instance, soon ceased to be so from repeated and continuous usage without additional outlay. And it is here worthy of remark, that oxide of iron is the only oxide yet discovered which fully answers this purpose, for the sulphurets of manganese, zinc, and lead, do not become reconverted into oxides by simple exposure at ordinary temperatures to the action of the air. And as oxide of iron is contained in the blood of all animals, it opens out an interesting question in physiology, how far this gas purification process may be analogous to that of the blood, through the agency of the pulmonary system. We shall now, however, merely give a condensed view of the oxide of iron method, as.practised at the Westminster and other gas works, without offering more than a few brief theoretical remarks by way of explanation. Impure coal-gas, as it leaves the condenser, contains about two per cent. in bulk of carbonic acid, and one per cent. of sulphuretted hydrogen, with a quantity of ammonia, generally insufficient to saturate these two acids, though this varies much with the variations of the weather and the state of the condenser. For the most part, however, the amount of ammonia is equal to the carbonic acid, and in this case the new process is perfect; but if the ammonia be less than will saturate the carbonic acid, then the excess of this acid remains in the gas, and to this extent the coal-gas may be said to be impure. Taking the normal condition of gas as it quits the condenser, it is first made to traverse a quantity of sawdust, saturated with a very strong solution of muriate of lime. Here double decomposition goes on, accompanied by the formation of carbonate of lime and muriate of ammonia, and the gas becomes deprived of its carbonic acid and ammonia, consequently it now contains only sulphuretted hydrogen; and when the muriate of lime in the sawdust is totally decomposed, the muriate of ammonia which it then contains is dissolved out by lixiviation, and crystallised as a marketable product. The impure gas is next transmitted through a mixture of the hydrated peroxide of iron and sawdust, damped with a solution of muriate of lime, by which the whole of the sulphuretted hydrogen is absorbed, and also any traces of carbonate of ammonia which may have escaped the first purifier. In this way the peroxide of iron is reduced to the state of protoxide, with the formation of water and deposition of half an atom of sulphur, whilst the protoxide of iron as it is produced reacts upon the remaining sulphuretted hydrogen, and yields a hydrated proto-sulphuret of iron of a black colour, so that the resulting products are water, sulphur, and hydrated protosulphate of iron. So soon, however, as these are exposed to the air, the iron of the protosulphuret combines with oxygen and liberates free sulphur, whilst it nevertheless retains the water of combination belonging to the protosulphuret, thus generating a mixture of hydrated and anhydrous peroxide of iron; and as it is the former of these alone which is useful in purification, there is after each renewal a slight loss of power, and this slowly increasing ultimately renders the whole mass inefficacious after from 18 to 20 exposures. At the same time the fiee sulphur in the material goes on augmenting, and at last a period arrives in which the mixture becomes pyrophoric, and it is almost impossible to prevent it from catching fire. The effect of the muriate of lime is te diminish this tendency; but this gives rise to the presence of carbonate of lime, as we have seen above, and when much carbonate of lime has made its appearance, then the disposition of the sulphur to form sulphuric acid is increased by the readiness for its absorption by the carbonate of lime, and therefore the proneness to inflammation is 892 GAS-LIGHT. again manifested; so that in practice a small specimen of this material is seldom usec more than twenty times in succession before it is removed from the gas works. It is. however, now very far from being valueless, as it not only contains a vast amount of free sulphur, but also of ferrocyanic acid; a product scarcely to have been expected in a commercial sense. Nevertheless, it is found that one tol of Newcastle coals gives off in distillation sufficient cyanogen to produce from 5 to 8 lbs. of Prussian blue with the hydrated oxide of iron; and it is part of the process now carried on by Mr. Laming at Mill Wall, to extract this ferrocyanic acid from the spent material, and convert it into prussiate of potash or Prussian blue at pleasure. The great advantage of this invention is not therefore confined to its sanitary details, but extends into the merit of having discovered a new and fertile source for the production of an article of great commercial value, and rendered both useful and profitable that which was previously a pestilential waste threatening to interfere very seriously with the progress of gas manufacturing.Mr. L. Thompson. Lowe and Evans's Improvements. On the 20th January, 1852, a patent was granted to George Lowe, of Finsbury-circus, in the city of London, civil engineer, and Frederick John Evans, of Horseferry Road, in the city of Westminster, civil engineer, for improvements in the manufacture of gas for the purpose of illumination, and of improvements in the purification of gas. The first part of this invention refers to certain means of enriching or improving the quality of gases, so as to render them fit for the purposes of illumination. In carrying out this improved manufacture of gas, the patentees pass gas, obtained from any of the sources hereinafter specified, through heated retorts containing cannel coal, coal, lignite, resin, pitch, tar, oil, retinite, or other substance or substances capable of yielding carburetted hydrogen gas: by which means such a combination of rich and poor gases may be produced as will be exactly suited to the purposes of illumination. For this purpose, it is proposed to use retorts open at both ends, as shown in the drawing given in fig. 705.,'which represents a longitudinal vertical section of the apparatus employed in carrying out this part of the invention. Only one retort is exhibited; but 705 a similar arrangement of retorts may be adopted to that in general use in gas-works. c a is the retort, set in a suitable furnace for heating the same; and b, b are mouth-pieces and lids, fitted to both ends of the retorts. c is the pipe for carrying off the gaseous pro. i ducts generated in the retort; and d, is a pipe By_ ~_ 4 _e for introducing into the retort the gas which b -'|| eI > -ta/ - b is intended to combine with the gaseous pro. jp.....-L H~ ducts of the substances under distillation in _~ -- ---. g % the retort. As soon as the retort is charged with coal or other carbonaceous matter, a cock e, in the pipe d, is opened, which allows the gas to flow into the retort; and it then passes I: ______ E7in the direction of the arrows, and mingles with the gas that is evolved from the carbonaceous matters contained in the retort: whereby a compound gas is formed, possessing a much higher illuminating power than could have been obtained had the combination taken place after instead of at the time of the generation of the gas in the retort a. The gas, which is brought to the retort by means of the pipe d, may be forced into the retort, so as to overcome the internal pressure put on the retort by means of the hydraulic main; or, instead thereof, an exhauster may be applied to draw off the gas from the retort. Should tar, oil, resin (previously melted), or any liquid hydrocarbon be employed for the generation of the gas, it is to be run into the retort in the way generally adopted for making oil or resin gas. The sources from which the patentees propose to obtain inflammable gases, to be applied as above indicated, are wood, sawdust in a damp or dry state, spent tanner's bark, and other like substances capable of yielding an inflammable gas. These substances must be put into a red-hot retort, and distilled like coal. The resulting gases may be either purified at once, or passed directly to the retort containing the coal or other carbonaceous materials. As a general rule, however, these gases are preferred to be stored in gas-holders for use; as, in that case, a more uniform and constant supply to the coal retort may be relied on. Another source of inflammable gas is from coal of an inferior description, or from peat. These substances having been distilled in a retort, the resulting gas can be then employed as above indicated. It is also proposed to conduct carbonic oxide gas into retorts containing carbonaceous matters under distillation. This gas the patentees obtain from carbonic acid, by passing the latter gas (which may be obtained from any GAS-LIGHT. 893 convenient source) through a retort or furnace containing red or white hot ca ke. Or, they utilize a portion of the gases generated in furnaces, by collecting these gases and converting the carbonic acid they contain into carbonic oxide, by passing them through a retort or furnace, as described for treating carbonic acid; or the gases may be conducted directly into retorts, wherein carburetted hydrogen is being generated, for the purpose of effecting the desired combination. From the foregoing description, it will be understood, that the object of this part of the invention is to obtain gas of a uniform quality,-that is, possessing a definite amount of illuminating power. Now, it is well known that if the gas be too rich in carbon it will burn with a dull flame, and give off a large amount of smoke; and that, if deficient in carbon, it will burn with a blue flame, and possess very little illuminating power. It is therefore proposed to mix the rich and poor gases, obtained as above described, in such proportions as will be needful to produce a highly illuminating quality of gas. As the proportions will depend entirely on the quality of the gases to be combined, no rule can be laid down for the amount of the gas required to be passed into the retorts, wherein the distillation is proceeding. The mode, however, in which the gas burns, on issuing from the retort, will be a sufficient test for the workmen in attendance. The second part of this invention refers to the purification of coal-gas from sulphuretted hydrogen; and consists in effecting this operation by the use of what has been considered by chemists to be the ferrate of potash, but what is now found to be a peroxide of iron in a peculiar state, and such as results from the employment of the following means:-First the patentees heat together peroxide of iron and caustic potash or soda to a dull red heat, by which a kind of ferrate or ferrite of potash or soda is produced; and when this substance is washed in water, it undergoes decomposition, with the reproduction of caustic potash or soda (which remains in solution), and the precipitation of peroxide of iron in the state fit for the purification of gas. All or any of the peroxides of iron may be used for the above purposes, and will, by its means, become useful for purifying gas, though previously inert; and the solution of potash or soda, when evaporated to dryness, may be again and again employed upon fresh portions of peroxide of iron, so as to communicate to them the peculiar property desired. Or peroxide of iron may be heated with a smaller quantity of caustic potash or soda, and a portion of common salt, in order to economize the potash or soda: the heat in this case should be, as before, a dull red; and the same measures must be adopted for recovering the potash or soda and common salt, which may be used over and over again with fresh portions of peroxide of iron. Or the patentees heat the common hydrated peroxide of iron, to about 6000 Fahr.,-taking care that the heat never reaches a bright red; and in this way they obtain a peroxide of iron, having the requisite properties. Or they heat in the same way, and with the same precautions, such of the native ochres or ferruginous compounds as will, after such treatment, become rapidly black upon being subjected to the action of a stream of sulphuretted hydrogen. A quantity of peroxide of iron, fit for purifying gas, having been procured, by any of the means thus indicated, the oxide is next to be mixed with sawdust or other convenient material, and damped slightly with water; and the mixture is then to be spread in a dry lime purifier, and used in the way adopted with hydrate of lime; or it may be mixed with water, and run into a wet lime purifier, and used in the way adopted with regard to lime when employed in this kind of apparatus. In both cases it will be necessary, after the peroxide of iron has ceased to act upon the gas, to expose it to the air, by which its energies are renewed, so that it may be again and again used for the purification of gas. With the dry lime purifier, simple exposure is all that is required. With the wet lime purifier, the mixture must be run out and left at rest for some time; then, when the fluid has entirely separated from the solid part, it may be allowed to escape; and as the solid portion dries, its power will become renewed: after which it may be mixed with water and employed as before. The renewal of the peroxide of iron, in both these cases, is known by its changing from black to red or deep brown. Another part of the invention relates to the use of the sulphite and bisulphite of lead for the removal of the sulphuretted hydrogen from coal-gas. These substances are to be employed singly or together, mixed with water, in a wet lime purifier, exactly as is practised with regard to lime. When they cease to purify the gas, the mixture is run out of the purifier; and after the water has been removed by subsidence and decantation, or by a filter, the residue is dried and burned, so as to make sulphurous acid, which is employed in the manufacture of fresh sulphite or biaulphite of lead, or in the production of sulphuric acid. The matter which remains, after this burning process, is carefully roasted, and thus converted into oxide of lead or litharge, from which sulphite or bisulphite of lead may be again produced. The patentees claim the combining of gases which possess different degrees of illuminating power, by the introduction of gas, obtained in any of the ways above indicated into retorts or vessels containing carbonaceous matters under distillation. They also 894 GELATINE. claim, as their improvements in the purification of gas, First,-the use of anhydrous per. oxide of iron prepared as above described;. and, Secondly,-the use of sulphite and bisulphite of lead, for the removal of sulphuretted hydrogen from coal-gas.-Newton's Journal. We are indebted to Mr. Thomas G. Barlow, an eminent engineer, for a vast body of information on coal-gas, contained in his excellent Journal of Gas Lighting, commenced on the 10th of February, 1849, and continued in monthly numbers ever since. His first number presented a list of the London Gas Companies, and the value of their shares at the Stock Exchange, to which we have added the ruling rates in the present year. Paid up. Name. January, 1848. January, 1849. September, 1852. ~. ~ ~ ~ ~ ~ ~ 25 Commercial -- - 25 to 26 25 to 26 30'to 32 150 City of London - - - -285 —290 240 —245 124 -126 50 Chartered - -- 58- 59 48- 49 36 - 37 50 Equitable - - - - - 8- 39 33- 35 25 - 26 50 Imperial - ----- 80- 84 62- 64 75 - 80 50 Independent - - 60- 62 46 -- 47 50 London (Vauxhall) - 10- 20 2 - 3 50 Ditto (preference) - - - -20- 30 15 - 18 49 Phoenix ------- 35 to 361 28- 30 26 - 27 90 Ratcliff - - - 78- 80 72- 74 60 - 65 25 South Metropolitan - - - 28 - 30 21- 23 20 - 22 GENERAL SUMMARY. For lighting London and its suburbs with gas, there are - 18 public gas works. 12 do. companies. 2,800,0001. capital employed in works, pipes, tanks, gas-holders, apparatus, 450,0001. yearly revenue derived. 134,300 private burners supplied to about 40,000 consumers. 30,400 public or street do. N. B. about 2650 of these are in the city of London. 380 lamplighters employed. 176 gas-holders; several of them double ones, capable of storing 5,500,000 cubic feet. 890 tons of coal used in the retorts on the shortest day, in 24 hours. 7,120,000 cubic feet of gas used in the longest night, 24th December. About 2500 persons are employed in the metropolis alone, in this branch of manufacture. Between 1822 and 1827 the quantity nearly doubled itself, and that in 5 years. Between 1827 and 1837 it doubled itself again. The consumption of coals of all kinds for the supply of gas to the metropolis during the year ending June, 1852, is almost exactly 408,000 tons, which on an average would yield about 4,000 millions of cubic feet of gas. GAS-HOLDER; a vessel for containing and preserving gas, of which various forms are described by chemical writers. GASOMETER, means properly a measurer of gas, though it is employed often tc denote a recipient of gas of any kind. See the article GAs-LIGHT. GAUZE WIRE CLOTH, is a textile fabric, either plane or tweeled, made ot brass, iron, or copper wire, of very various degrees of fineness and openness of textures Its chief uses are for sieves and safety lamps. GAY-LUSSITE, is a white mineral of a vitreous fracture, which crystallizes in oblique rhomboidal prisms; specific gravity from 1-93 to 1-95; scratches gypsum, but is scratched by calcspar; affords water by calcination; it consists of carbonic acid 28-66; soda, 20-44; lime, 17-70; water, 32-20; clay, 1-00. It is in fact, by my analysis, a hydrated soda-carbonate of lime in atomic proportions. This mineral occurs abundantly in insulated crystals, disseminated through the bed of clay which covers the vrao, or native sesquicarbonate of soda, at Lagunilla in Columbia. GELATINE; (Eng. and Fr.; Gallert, Leim, Germ.) is an animal product which is never found in the humours, but it may be obtained by boiling with water the soft and solid parts; as the muscles, the skin, the cartilages, bones, ligaments, tendons, and membranes. Isinglass consists almost entirely of gelatine. This substance is very soluble in boiling water; the solution forms a tremulous mass of jelly when it cools. Cold water has little action upon gelatine. Alcohol and tannin (tannic acid, see GALL-NUTS) precipitate gelatine from its solution; the former by abstracting the water, the latter by combining with the substance itself into an insoluble compound, of the nature of'eather No other acid, except the tannic, and no alkali, possesses the property of precipitating GELATINE. 895 gelatine. But chlorine and certain salts render its solution more or less turbid; as the nitrate and bi-chloride of mercury, the proto-chloride of tin, and a few others. Sulphuric acid converts a solution of gelatine at a boiling heat into sugar. See LIGNEOUS FIBRE. Gelatine consists of carbon, 47-88; hydrogen, 7'91; oxygen, 27-21. See GLUE and ISINGLASS. This substance is produced by boiling the skin of animals in water, which in its crude but solid state is called glue, and when a tremulous semi-liquid, size. The latter preparation is greatly used by the paper-makers, and was much improved by the following process, for which Mr. William Rattray obtained a patent in May, 1838. The parings and scrows of skins are steeped in water till they begin to putrefy; they are then washed repeatedly in fresh water with the aid of stampers, afterwards subjected, in wooden or leaden vessels, to the action of water strongly impregnated with sulphurous acid for from 12 to 24 hours; they are now drained, washed with stampers in cold water, and next washed with water of the temperature of 120~ F., which is poured upon them and run off very soon to complete their purification. The scrows are finally converted into size, by digestion in water of 120~ for 24 hours; and the solution is made perfectly fine by being strained through several thicknesses of woollen cloth. They must be exhausted of their gelatinous substance, by repeated digestions in the warm water. The claim is for the sulphurous acid which, while it cleanses, acts as an antiseptic.Newton's Journal, xiv. 173. A fine gelatine for culinary uses, as a substitute for isinglass, is prepared by Mr. Nelson's patent, dated March, 1839. After washing the Darings, &c., of skin, he scores their surfaces, and then digests them in a dilute caustic soda lye during ten days. They are next placed in an air-tight vat, lined with cement, kept at a temperature of 70~ Fahr.; then washed in a revolving cylinder apparatus with plenty of cold water, and afterwards exposed to the fumes of burning sulphur (sulphurous acid) in a wooden chamber. They are now squeezed to expel the moisture, and finally converted into soluble gelatine, by water in earthen vessels, enclosed in steam cases. The fluid gelatine is purified by straining it at a temperature of 100~ or 120~ Fahr. I have examined this patent gelatine, and found it to be remarkably good, and capable of forming a fine calf's-foot jelly. Very recently a very beautiful sparkling gelatine has been prepared under a patent granted to Messrs. J. and G. Cox, of Edinburgh. By their process the substance is rendered perfectly pure, while it possesses a gelatinizing force superior even to isinglass. It makes a splendid calves'-feet jelly and a milk-white blanc-mange. The patentees also prepare a semi-solid gelatine, resembling jujubes, which readily dissolves in warm water, as also in the mouth, and may be employed to make an extemporaneous jelly. The gelatine of bones may be extracted best by the combined action of steam and a current of water trickling over their crushed fragments in a properly constructed apparatus. When the gelatine is to be used as an alimentary article, the bones ought to be quite fresh, well preserved in brine, or to be dried strongly by a stove. Bones are best crushed by passing them between grooved iron rolls. The cast-iron cylinders in which they are to be steamed, should be three times greater in length than in diameter. To obtain 1000 rations of gelatinous soup daily a charge of four cylinders is required; each being 3J feet long, by 14 inches wide, capable of A. -. B M'7i06 tWt IB D 896 GELATINE. holding 0O lbs. of bones. These will yield each hour about 20 gallons of a strong ielly, and will require nearly 1 gallon of water in the form of steam, and 5 gallons 3f water to be passed through them in the liquid state. The 5 quarts of jelly produced hourly by each cylinder, proceeds from the 1 quart of steam-water and 4 quarts of percolating water. The boiler should furnish steam of about 223~:Fahr., at a pressure of about 4 lbs. on:the square inch. In fig. 706: A, B, C, D, represents a vertical section of the cylinder; G, H, I, K, a section of the basket or cage, as filled wyith the bruised hones, inclosed in the cylinde; r, c, c, the pipe which conducts the steam down to the bottom of the cylinder; L, h a pipe for introducing water into the interior; x, a stopcock for regulating the quantity of water (according to the force of the steam pressure within the apparatus), which should be 3~ quarts per hour; N is a tube of tin plate fitting tightly into the part s of the pipe L; it is shut at E, and perforated below with a hole; it is inserted in its place, after the cage full of bones has been introduced. Fig. 707. is ar 707 h h elevation of the apparatus. A, B, c, D, represent the four cylinders, raised about 20 inches above the floor, and fixed in their seats by screws; h A, are the lids, g, tubulures or valves in the lids; i, ring junction of the lid; p, a thermometer cageful of bones in and out. Fig. 708. is an end view of the apparatus; a, the main steam-pipe; ea, bc cc,, branches that conduct that g, tubulures o r va steam to the bottom of the cylinder; o, the stopo tackle for raising the cage; s, stopcock; a, small o \ s gutter; m, main conduit; b, cistern of reception. When a strong and pure jelly is wished for, KE.. M'..the cylinder charged with the bones is to be wrapped in blanket stuff; and whenever the grease ceases to drop, the stopcock which admits the cold water is to be shut, as also that at the bottom of the cylinder, which is to be opened only....... \ at the end of every hour, and so little as to let *708 i the gelatinous solution run out, without allow ing any of the steam to escape with it. _-:b ^ b Butchers' meat contains on an average in 100 pounds, 24 of dry flesh, 56 of water, and 20 of bones. These 20 pounds can furnish 6 pounds ] ) l> ~of alimentary substance in a dry state; whence it appears that, by the above means, one fourth more nutritious matter can be obtained than is usually got. I am aware that a keen dispute has been carried on for some time in Paris, bef,, li|i| i~i~ tween the partisans and adversaries of gelatine 6iii bl|lrl - l las an article of food. It is probable that both | li~ - ~ parties have pushed their arguments too far. Calf's-foot jelly is still deemed a nutritious irticle by the medical men of this country, at least, though it is not to be trusted GERHARDT'S ACETIC ACID. 897 to alone, but should have a due admixture or interchange of fibrine, albumine, caseum, &c. GEMS, are precious stones, which, by their colour, limpidity, lustre, brilliant polish, purity, and rarity, are sought after as objects of dress and decoration. They form the principal part of the crown jewels of kings, not only from their beauty, but because they are supposed to comprise the greatest value in the smallest bulk; for a diamond, no larger than a nut or an acorn, may be the representative sign of the territorial value of a whole country, the equivalent in commercial exchange of a hundred fortunes acquired by severe toils and privations. Among these beautiful minerals mankind have agreed in forming a select class, to which the title of gems or jewels has been appropriated; while the term precious stone is more particularly given to substances which often occur under a more considerable volume than fine stones ever do. Diamonds, sapphires, emeralds, rubies, topazes, hyacinths, and chrysoberyls, are reckoned the most valuable gems. Crystalline quartz, pellucid, opalescent or of various hues, amethyst, lapis lazuli, malachite, jasper, agate, &c., are ranked in the much more numerous and inferior class of ornamental stones. These distinctions are not founded upon any strict philosophical principle, but are regulated by a conventional agreement, not very well defined; for it is impossible to subject these creatures of fashion and taste to the rigid subdivisions of science. We have only to consider the value currently attached to them, and take care not to confound two stones of the same colour, but which may be very differently prized by the virtuoso. Since it usually happens that the true gems are in a cut and polished state, or even set in gold or silver, we are thereby unable to apply to them the criteria of mineralogical and chemical science. The cutting of the stone has removed or masked its crystalline character, and circumstances rarely permit the phenomena of double or single refraction to be observed; while the test by the blowpipe is inadmissable. Hence the only scientific resources that remain are the trial by electricity, which is often inconclusive; the degree of hardness, a criterion requiring great experience in the person who employs it; and, lastly, the proof by specific gravity, unquestionably one of the surest means of distinguishing the really fine gems from ornamental stones of similar colour. This proof can be applied only to a stone that is not set; but the richer gems are usually dismounted when offered for sale. This character of specific gravity may be applied by any person of common intelligence, with the aid of a small hydrostatic balance. If, for example, a stone of a fine crimson-red colour, be offered for sale, as an oriental ruby, the purchaser must ascertain if it be not a Siberian tourmaline, or ruby spinel. Supposing its weight in air to be 100 grains, if he finds it reduced to 69 grains, when weighed in water, he concludes that its bulk is equal to that of 31 grains of water, which is its loss of weight. Now, a real sapphire which weighs 100 grains in air, would have weighed 76-6 in water; a spinel ruby of 100 grains would have weighed 72-2 in water, and a Siberian tourmaline of 100 grains would have weighed only 69 grains in water. The quality of the stone in question is, therefore, determined beyond all dispute, and the purchaser may be thus protected from fraud. The sard of the English jewellers (Sardoine, French) is a stone of the nature of agate, having an orange colour more or less deep, and passing by insensible shades into yellow, reddish, and brown; whence it has been agreed to unite under this denomination all the agates whose colour verges upon brown. It should be remarked, however, that the sard presents, in its interior and in the middle of its ground, concentric zones, or small nebulosities, which are not to be seen in the red cornelian, properly so called. The ancients certainly knew our sard, since they have left us a great many of them engraved, but they seem to have associated under the title sarda both the sardoine of the French, and our cornelians and calcedonies. Pliny says that the sarda came from the neighbourhood of a city of that name in Lydia, and from the environs of Babylon. Among the engraved sards which exist in the collection of antiques in the Bibliothbque Royale of Paris, there is an Apollo remarkable for its fine colour and great size. When the stone forms a part of the agate-onyx, it is called sardonyx. For further details upon Gems, and the art of cutting and engraving them, see LAPIDARY. GEOGNOSY, means a knowledge of the structure of the earth: GEOLoGY, a description of the same. The discussion of this subject does not come within the province of this Dictionary. GERHARDT'S ANHYDROUS ACETIC ACID. Mix perfectly dry fused acetate of potash with about half its Weight of chloride of benzoyle, and applying a gentle heat, a limpid liquid distils over, which after being rectified has a constant boiling point of 2-'79 Fahr., is heavier than water, with which it does not mix till after it has been agitated with it for some time. It dissolves at once in hot water, forming $'98 GIN. a hydrated acetic acid. Its composition agrees perfectly with the atomic numbers See ACID, ACETIC. GERMAN SILVER. See the latter end of the article COPPER. GERMINATION; (Eng. and Fr.; Das Keimen, Germ.) is the first sprouting of a seed after it is sown, or when, after steeping, it is spread upon the malt floor. See BEER. GIG MACHINES, are rotatory drums, mounted with thistles or wire teeth for teazling cloth. See WOOLLEX MANUFACTURE. GILDING (Dorure, Fr.; Vergoldung, Germ.); is the art of coating surfaces with a thin film of gold. For a full discussion of this subject, see GOLD. Mr. Elkington, gilt toy maker, obtained a patent, in June, 1836, for gilding copper, brass, &c., by means of potash or soda combined with carbonic acid, and with a solution of gold. Dissolve, says he, 5 oz. troy of fine gold in 52 oz. avoirdupois of nitro-muriatic acid of the following proportions; viz. 21 oz. of pure nitric acid, of spec. grav. 1'45, 17 oz. of pure muriatic acid, of spec. grav. 1'15; with 14 oz. of distilled water. The gold being put into the mixture of acids and water, they are to be heated in a glass or other convenient vessel till the gold is dissolved; and it is usual to continue the application of heat after this is effected, until a reddish or yellowish vapour ceases to rise. The clear liquid is to be carefully poured off from any sediment which generally appears and results from a small portion of silver, which is generally found in alloy with gold. The clear liquid is to be placed in a suitable vessel of stone; pottery ware is preferred. Add to the solution of gold 4 gallons of distilled water, and 20 pounds of bicaroonate of potash of the best quality; let the whole boil moderately for two hours, the mixture will then be ready for use. The articles to be gilded having been first perfectly cleaned from scale or grease, they aie tc be suspended on wires, conveniently for a workman to dip them in the liquid, which is kept boiling. The time required for gilding any particular article will depend on circumstances, partly on the quantity of gold remaining in the liquid, and partly on the size and weight of the article; but a little practice will readily give sufficient guidance to the workman. Supposing the articles desired to be gilded be brass or copper buttons, or small articles for gilt toys, or ornaments of dress, s;.:.h as ear-rings or bracelets, a considerable number of which may be strung on a hoop, -i bended piece of copper or brass wire, and dipped into the vessel containing the boiling liq ud above described, and moved therein, the requisite gilding will be generally obtained in from a few seconds to a minute; this is when the liquid is in the condition above described, and depending on the quality of the gilding desired; but if the liquid has been used some time, the quantity of gold will be lessened, which will vary the time of operating to produce a given effect, or the color required, all which will quickly be observed by the workman; and by noting the appearance of the articles from time to time, he will know when the desired object is obtained, though it is desirable to avoid as much as possible taking the articles out of the liquid. When the operation is completed, the workman perfectly washes the articles so gilded with clean water; they may then be submitted to the usual process of coloring. If the articles be cast figures of animals, or otherwise of considerable weight, compared with the articles above mentioned, the time required to perform the process will be greater. In case it is desired to produce what is called a dead appearance, it may be performed by several processes: the one usually employed is to dead the articles in the process of cleaning, as practised by brass-founders and other trades; it is produced by an acid, prepared for that purpose, sold by the makers under the term "deading aquafortis," which is well understood. It may also be produced by a weak solution of nitrate of mercury, applied to the articles previous to the gilding process, as is practised in the process of gilding with mercury, previous to spreading the amalgam, but generally a much weaker solution; or the articles having been gilded may be dipped in a solution of nitrate of mercury, and submitted to heat to expel the same, as is practised in the usual process of gilding. It is desirable to remark, that much of the beauty of the result depends on the well cleaning of the articles, and it is better to clean them by the ordinary processes, and at once pass them into the liquid to be gilded. See Go.D, towards the end. GIN, or Geneva, from Genievre (juniper), is a kind of ardent spirits manufactured in Holland, and hence called Hollands gin in this country, to distinguish it from British gin. The materials employed in the distilleries of Schiedam, are two parts of unmalted rye from Riga, weighing about 54 lbs. per bushel, and one part of rralted bigg, weighing about 37 lbs. per bushel. The mash tun, which serves also as the fermenting:un, has a capacity of nearly 700 gallons, being about five feet in diameter at the mouth, GLASS. 899 rather narrower at the bottom, and 4~ feet deep; the stirring apparatus is an oblong rectangular iron grid made fast to the end of a wooden pole. About a barrel, = 36 gallons of water, at a temperature of fiom 162~ to 168~ (the former heat being best for the most highly dried rye), are put into the mash tun for every 1} cwt. of meal, after which the malt is introduced and stirred, and lastly the rye is added. Powerful agitation is given to the magma till it becomes quite uniform; a process which a vigorous workman piques himself upon executing in the course of a few minutes. The mouth of the tun is immediately covered over with canvas, and further secured by a close wooden lid, to confine the heat; it is left in this state for two hours. The contents being then stirred up once more, the transparent spent wash of a preceding mashing is first added, and next as much cold water as will reduce the temperature of the whole to about 85~ F. The best Flanders yeast, which had been brought, for the sake of carriage, to a doughy consistence by pressure, is now introduced to the amount of < no pound for every 100 gallons of the mashed materials. The gravity of the fresh wort is usually from 33 to 38 lbs. per Dicas' hydrometer; and the fermentation is carried on from 48 to 60 hours, at the end of which time the attenuation is from 7 to 4 lbs., that is, the specific gravity of the supernatant wash is from 1'007 to 1-004. The distillers are induced, by the scarcity of beer-barm in Holland, to skim off a quantity of the yeast from the fermenting tuns, and to sell it to the bakers, whereby they obstruct materially the production of spirit, though they probably improve its quality, by preventing its impregnation with yeasty particles; an unpleasant result which seldom fails to take place in the whiskey distilleries of the United Kingdom. On the third day after the fermenting tun is set, the wash containing the grains is transferred to the still, and converted into low wines. To every 100 gallons of this liquor, two pounds of juniper berries, from 3 to 5 years old, being added along with about one quarter of a pound of salt, the whole are put into the low wine still, and the fine Holland spirit is drawn off by a gentle and well-regulated heat, till the magma becomes exhausted; the first and the last products being mixed together; whereby a spirit, 2 to 3 per cent. above our hydrometer proof, is obtained, possessing the peculiar fine aroma of gin. The quantity of spirit varies from 18 to 21 gallons per quarter of grain; this large product being partly due to the employment of the spent wash of the preceding fermentation; an addition which contributes at the same time to improve the flavour. For the above instructive details of the manufacture of genuine Hollands, I am indebted to Robert More, Esq., formerly of Underwood, distiller, who, after studying the art at Schiedam, tried to introduce that spirit into general consumption in this country, but found the palates of our gin-drinkers too much corrupted to relish se pure a beverage. GINGER BEER. Boil 65 gallons of river water, 1- cwt. of the best loaf sugar, and') Ibs. of the best race ginger, bruised, half an hour; then add the whites of 10 eggs, beaten to a froth with 2 ounces of dissolved isinglass. Stir it well in, and boil 20 minutes longer, skimming it the whole time. Then add the thin rinds of 50 lemons, boiling them 10 minutes more. Cut 28 lbs. of good Malaga raisins in half, take away the stones and stalks, and put them, with the juice of the lemon, strained, into the hogshead. Strain the hot liquor into a cooler, and when it has stood two hours and is settled, draw it off the lees, clear, and put it into the cask; filter the thick and fill up with it. Leave the bung out, and when at the proper temperature, stir 3 quarts of thick fresh ale yeast well into it; put on the bung lightly, and let it ferment 6 or 7 days, filling up with liquor as it ferments over. When the fermentation has ceased, pour in 6 quarts of French brandy, and 8 ounces of the best isinglass, dissolved in a gallon of the wine; then secure the bung effectually, and paste paper over it, &c. Keep it 2 years in a cool cellar, then bottle it, using the best corks, and sealing them; and when it is 4 years old commence using it. GINNING, is the name of the operation by which the filaments of cotton are separable from the seeds. See COTTON MANUFACTURE. GLANCE COAL, or anthracite, of which there are two varieties, the slaty and the conchoidal. See ANTHRACITE and PITCOAL. GLASS (Verre, Fr.; Glas, Germ.); is a transparent solid formed by the fusion of siliceous and alkaline matter. It was known to the Phoenicians, and constituted for a long time an exclusive manufacture of that people, in consequence of its ingredients, natron, sand, and fuel, abounding upon their coasts. It is probable that the more ancient Egyptians were unacquainted with glass, for we find no mention of it in the writings of Moses. But according to Pliny and Strabo, the glass works of Sidon and Alexandria were famous in their times, and produced beautiful articles, which were cut, engraved, gilt, and stained of the most brilliant colours, in imitation of precious stones. The Romans employed glass for various purposes; and have left specimens in Herculaneum of window-glass, which must have been blown by methods analogous to 58 900 GLASS. the moaem The Phoenician processes seem to have been learned by the Crusaders, and transferred to Venice in the 13th century, where they were long held secret, and formed a lucrative commercial monopoly. Soon after the middle of the 17th century, Colbert enriched France with the blown mirror glass manufacture. Chance undoubtedly had a principal share in the invention of this curious fabrication, but there were circumstances in the most ancient arts likely to lead to it; such as the fusing and vitrifying heats required for the formation of pottery, and for the extraction of metals from their ores. Pliny ascribes the origin of glass to the following accident. A merchant ship laden with natron being driven upon the coast at the mouth of the river Belus, in tempestuous weather, the crew were compelled to cook their victuals ashore, and having placed lumps of the natron upon the sand, as supports to the kettles, found to their surprise masses of transparent stone among the cinders. The sand of this small stream of Galilee, which runs from the foot of Mount Carmel, was in consequence supposed to possess a peculiar virtue for making glass, and continued for ages to be sought after and exported to distant countries for this purpose. Agricola, the oldest author who has written technically upon glass, describes furnaces and processes closely resembling those employed at the present day. Neri, Kunckel, Henckel, Pott, Achard, and some other chemists, have since then composed treatises upon the subject; but Neri, Bosc, Antic, Loysel, and Allut, in the Encyclopedie Methodique, are the best of the older authorities. The window-glass manufacture was first begun in England in 1557, in Crutched Friars, London; and fine articles of flint-glass were soon afterwards made in the Savoy House, Strand. In 1635 the art received a great improvement from Sir Robert Mansell, by the use of coal fuel instead of wood. The first sheets of blown glass for looking-glasses and coach windows were made in 1673 at Lambeth, by Venetian artisans employed under the patronage of the Duke of Buckingham. The casting of mirror-plates was commenced in France about the year 1688, by Abraham Thevart; an invention which gave rise soon afterwards to the establishment of the celebrated works of St. Gobain, which continued for nearly a century the sole place where this highly-prized object of luxury was well made. In cheapness, if not in excellence, the French mirror-plate has been for some time rivalled by the English. The analysis of modern chemists, which will be detailed in the course of this article, and the light thrown upon the manufacture of glass in general by the accurate means now possessed of purifying its several ingredients, would have brought the art long since to the highest state of perfection in this country, but for the vexatious interference and obstructions of our excise laws. The researches of Berzelius having removed all doubts concerning the aciu character of silica, the general composition of glass presents now no difficulty of conception. This substance consists of one or more salts, which are silicates with bases of potash, soda, lime, oxide of iron, alumina, or oxide of lead; in any of which compounds we can substitute one of these bases for another, provided that one alkaline base be left. Silica in its turn may be replaced by the boracic acid, without causing the glass to lose its principal characters. Under the title glass are therefore comprehended various substances fusible at a high temperature. solid at ordinary temperatlures, brilliant, generally more or less transparent, and always brittle. The following chemical distribution of glasses has been proposed. 1. Soluble glass; a simple silicate of potash or soda; or both of these alkalis. 2. Bohemian or crown glass; silicate of potash and lime. 3. Common window and mirror glass silicate of soda and lime; sometimes also of potash. 4. Bottle glass; silicate of soda, lime, alumina and iron. 5. Ordinary crystal glass; silicate of potash and lead. 6. Flint glass; silicate of potash and lead; richer in lead than the preceding. 7. Strass; silicate of potash and lead; still richer in lead. S. Enamel; silicate and stannate or antimoniate of potash or soda, and lead. The glasses which contain several bases are liable to suffer different changes when they are melted or cooled slowly. The silica is divided among these bases, forming new compounds in definite proportions, which by crystallizing separate from each other, so that the general mixture of the ingredients which constitute the glass is destroyed. It becomes then very hard, fibrous, opaque, much less fusible, a better conductor of electricity and of heat; forming what Reaumur styled devitrified glass; and what is called after him Reaumur's porcelain. This altered glass can always be produced in a more or less perfect state, by melting the glass and allowing it to cool very slowly; or merely by heating it to the softening pitch, and keeping it at this heat for- some time. The process succeeds best with the most complex vitreous compounds, such as bottle glass; next with ordinary window glass; and lastly with glass of potash and lead. This property ought to be kept constantly in view in manufacturing glass. It slows GLASS-MAKING. 901 why in making bottles we should fashion them as quickly as possible with the aid of a mould and reheat them as seldom as may be absolutely necessary. If it be often heated and cooled, the glass loses its ductility, becomes refractory, and exhibits a multitude ol stony granulations throughout its substance. When coarse glass is worked at the enamel ler's lamp, it is apt to change its nature in the same way, if the workman be not quick and expert at his business. From these facts we perceive the importance of making a careful choice of the glass intended to be worked in considerable masses, such as the large object glasses of telescopes; as their annealing requires a very slow process of refrigeration, which is apt to cause devitrified specks and clouds. For such purposes, therefore, no other species of glass is well adapted except that with basis of potash and lead; or that with basis of potash and lime. These two form the best flint glass, and crown glass; and they should be exclusively employed for the construction of the object glasses of achromatic telescopes. Crystal glass is rapidly corroded by the sulphate of ammonia at a heat of 600~ Fahr. The following is an account of the exports of British manufacture:Quantities. Declared Value. 1851. 1852. 1851. 1852. Flint glass ------ cwts. 23,870 25,755 ~106,500 ~110,519 Window glass - - - cwts. 15,517 16,460 20,077 22,234 Bottles, green or common - cwts. 296,065 325,804 162,843 172,880 Plate glass - - - - - - value - - - 18,335 20,929 Imports and exports of Glass of Foreign and Colonial produce in the years ending respectively 5th January, 1851 and 1852:Window glass, not exceeding a of an inch thick, and shades and cylinders: imports, 21,015 cwts. and 12,358 cwts.; exports, 11,604 cwts. and 2,059 cwts.; duty on imports, 1,6561. and 1,8771. All glass exceeding I of an inch thick, all silvered or polished glass of whatever thickness: imports, 122,394 sq. ft. and 173,935 sq. ft.; exports, 32,388 sq. ft. and 36,550 sq. ft.; duty received, 1,8451. and 2,8411. White flint glass goods (except bottles) not cut, engraved, or otherwise ornamented: imports, 95,240 lbs. and 102,002 lbs.; exports, 70,660 lbs. and 66,738 Ibs.; duty received, 1011. and 1081. All flint cut glass, flint coloured glass, and fancy ornamental glass: imports, 880,981 lbs. and 682,011 lbs.; exports, 187,209 lbs. and 166,948 lbs.; duty received, 5,5421. and 4,4541. GLASS-MAKING, general principles of. Glass may be defined in technical phraseology, to be a transparent homogeneous compound formed by the fusion of silica with oxides of the alkaline, earthy, or common metals. It is usually colourless, and then resembles rock crystal, but is occasionally stained by accident or design with coloured metallic oxides. At common temperatures it is hard and brittle, in thick pieces; in thin plates or threads, flexible and elastic; sonorous when struck; fracture conchoidal, and of that peculiar lustre called vitreous; at a red heat, becoming soft, ductile and plastic. Besides glass properly so called, other bodies are capable of entering into vitreous fusion, as phosphoric acid, boracic acid, arsenic acid, as also certain metallic oxides, as of lead, and antimony, and several chlorides; some of which are denominated glasses. Impure and opaque vitriform masses are called slag- such are the production of blast iron furnaces and many metallurgic operations. Silica, formerly styled the earth of flints, which constitutes the basis of all commercial glass, is infusible by itself in the strongest fire of our furnaces; but its vitreous fusion is easily effected by a competent addition of potash or soda, either alone or mixed with lime or litharge. The silica, which may be regarded as belonging to the class of acids, combines at the heat of fusion with these bases, into saline compounds; and hence glass may be viewed as a silicate of certain oxides, in which the acid and the bases exist in equivalent proportions. Were these proportions, or the quantities of the bases which silica requires for its saturation at the melting point, exactly ascertained, we might readily determine beforehand the best proportions of materials for the glass manufacture. But as this is far from being the case, and as it is, moreover, not improbable that the capacity of saturation of the silica varies with the temperature, and that the properties of glass also vary with the bases, we must, in the present state of our knowledge, regulate the proportions rather by practice than by theory, though the latter may throw an indirect light upon the subject. For example, a good colourless glass has been found by analysis to consist of 72 parts of silica, 13 parts of potash, and 10 parts of lime, in 95 parts. If we reduce these numbers to the equivalent ratios, we shall have the following results; taking the atomic weights as given by Berzelius. 902 G-LASS-MAKING. 1 atom potash = 590 14.67 1 lime 356 8'84 3 silica 1722 42-79 71'49 2 silica 1155 28-70) 3823 95-00 This glass would therefore have been probably better compounded with the just atomic proportions, to which it nearly approaches, viz. 71-49 silica, 14-67 potash, and 8-84 lime, instead of those given above as its actual constituents. The proportions in which silica unites with the alkaline and other oxydes are modified by the temperature as above stated; the lower the heat, the less silica will enter into the glass, and the more of the base will in general be required. If a glass which contains an excess of alkali be exposed to a much higher temperature than that of its formation, a portion of the base will be set free to act upon the materials of the earthen pot, or to be dissipated in fumes, until such a silicate remains as to constitute a permanent glass corresponding to that temperature. Hence the same mixture of vitrifiable materials will yield very different results, according to the heats in which it is fused and worked in the glass-house; and therefore the composition should always be referrible to the going of the furnace. When a species of glass which at a high temperature formed a transparent combination with a considerable quantity of lime, is kept for some time in fusion at a lower temperature, a portion of the lime unites with the silica into another combination of a semi-vitreous or even of a stony aspect, so as to spoil the transparency of the glass altogether. There is probably a supersilicate and a sub-silicate formed in such cases; the latter being much the more fusible of the two compounds. The Reaumur's porcelain produced by exposing bottle glass to a red heat for 24 hours, is an example of this species of vitreous change, in which new affinities are exercised at a lower temperature. An excess of silica, caused by the volatilization of alkaline matter with too strong firing, will bring on similar appearances. The specific gravity of glass varies from 2-3 to 3'6. That of least specific gravity consists of merely silica and potash fused together; that with lime is somewhat denser, and with oxyde of lead denser still. Plate glass made from silica, soda, and lime, has a speci. fic gravity which varies from 2'50 to 2'6; crystal or flint glass from 3'0 to 3-6. The power of glass to resist the action of water, alkalis, acids, air, and light, is in general the greater, the higher the temperature employed in its manufacture, the smaller the proportion of its fluxes, and the more exact the equivalent ratios of its constituents. When glass contains too much alkali, it is partially soluble in water. Most crystal glass is affected by having water boiled in it for a considerable time; but crown glass being poorer in alkali, and containing no lead, resists that action much longer, and is therefore better adapted to chemical operations. The affinity of glass for water, or its hygrometric attraction, is also proportional to the quantity of alkali which it contains. Irr general also potash glass is more apt to become damp than soda glass, agreeably to the respective hygrometric properties of these two alkalis, and also to the smaller proportion of soda than of potash requisite to form glass. Air and light operate upon glass probably by their oxydizing property. Blhish or greenish colored glasses become by exposure colorless, in consequence undoubtedly of the peroxydizement of the iron, to whose protoxyde they owe their tint; other glasses become purple red from the peroxydizement of the manganese. The glasses which contain lead, suffer another kind of change in the air, if sulphureted hydrogen be present; the oxyde of lead is converted into a sulphuret, with the effect of rendering the surface of the glass opaque and iridescent. The more lead is in the glass, the quicker does this iridescence supervene. By boiling concentrated sulphuric acid in a glass vessel, or upon glass, we can ascertain its power of resisting ordinary menstrua. Good glass will remain smooth and transparent; bad glass will become rough and dim. The brittleness of unannealed glass by change of temperature is sometimes very great. I have known a thick vessel to fly by vicissitudes of the atmosphere alone. This defect may be corrected by slowly heating the vessel in salt water or oil to the highest pitch consistent with the nature of these liquids, and letting it cool very slowly. Within the limits of that range of heat, it will, in consequence of this treatment, bear alternations of temperature without cracking as before. It has been said that glass made front silica and alkalis alone will not resist the action:of water but that the addition of a little lime is necessary for this effect. In general 100 parts of quartzose sand require 33 parts of dry carbonate of soda for their vitrification, and 45 parts of dry carbonate of potash. But to make unchangeable alkaline glass, especially with potash, a smaller quantity of this than the above should be used, with a very violent heat. A small proportion of lime increases the density, hardness, and lustre of glass; and it aids-in decomposing the alkaline sulphates and muriates always present mn the pearlash of commerce. From 7 to 20 parts of dry slaked lime have been added;:fr 100 of silica, with advantge, it is said, in some German glass manufactories. where L ----; —---------------------------- ---- ^ GLASS-MAKING. 903 the alkaline matter is soda; for potash does not assimilate well with the calcareous earth. In many glass works on the Continent, sulphate of soda is the form ander which alkaline matter is introduced into glass. This salt requires the addition of 8 per cent. of charcoal to decompose and dissipate its acid; a result which takes place at a high heat, without the addition of any lime. 88 pounds of quartz-sand, 44 pounds of dry glauber salt and 3 pounds of charcoal, properly mixed ant fused, afford a limpid, fluent, and workable glass; with the addition of 17 pounds of lime these materials fuse more readily into a plastic mass. If less carbon be added, the fusion becomes more tedious. The two following formulae afford good glauber salt glass. 1. 2. Sand - 100 60-2 Calcined sulphate of soda - - 50 26-8 Lime - 20 10-8 Charcoal - - - 265 2-1 The first mixture has been proved in the looking-glass manufactory of Nethaus near Vienna, and the second by the experiments of Kirn. The fusion of the first requires 13, of the second 21 hours. The bluish green tinge which these otherwise beautifil and brilliant glasses possess, is not removeable by the ordinary means, such as manganese or arsenic, which decolor alkaline glass. When the sulphate of soda and charcoal are used in smaller proportions, the glass becomes more colorless. The tinge is no doubt owing to the sulphur combining with the oxyde of sodium, in some such way as in the pigment ultramarine. By a proper addition of galena (the native sulphuret of lead), to glauber salt and quartz sand, without charcoal, it is said a tolerably good crystal glass may be formed. The sulphuric acid of the salt is probably converted by the reaction of the sulphuret of lead into sulphurous acid gas, which is disengaged. One atom of sulphuret of lead = 1495-67, is requisite to decompose 3 atoms of sulphate of soda = 2676. It is stated, on good authority, that a good colorless glass may be obtained by using glauber salt without charcoal, as by the following formula. Quartz-sand - 100 pounds Calcined glauber salt - - 24 Lime - -- 20 Cullet of'soda glass - - 12 The melting heat must be continued for 262 hours. A small quantity of the sand is reserved to be thrown in towards the conclusion of the process, in order to facilitate the expulsion of air bubbles. The above mixture will bear to be blanched by the addition of manganese and arsenic. The decomposition of the salt is in this case effected by the lime, with wii'ch the sulphuric acid first combines, is then converted into sulphurous acid, and dissipated. Glass made in this way was found by analysis to consist of 79 parts of silica, 12 lime, and 9-6 soda, without any trace of gypsum or sulphuric acid. Glauber salt is partially volatilized by the heat of the furnace, and acts upon the arch of the oven and the tops of the pots. This is best prevented by introducing at first into the pots the whole of the salt mixed with the charcoal, the lime, and one fourth part of the sand; fusing this mixture at a moderate heat, and adding gradually afterwards the remainder of the sand, increasing the temperature at the same time. If we put in the whole ingredients together, as is done with potash glass, the sand and lime soon fall to the bottom, while the salt rises to the surface, and the combination becomes difficult and unequal. Sulphate of potash acts in the same way as sulphate of soda. Muriate of soda also, according to Kirn, may be used as a glass flux with advantage. The most suitable proportions are 4 parts of potash, 2 of common salt, and 3 of lime, agreeably to the following compositions:i. 2. Quartz-sand -. 60-0 75-1 Calcined carbonate of potash - - 178 19-1 Common salt - - - - 8-9 9-5 Lime - - - - 13-3 14-3 For No. 1., the melting heat must be 10 hours, which turns out a very pure, solid, good glass; for No. 2., 23 hours of the furnace are required. Instead of the potash, glauber salt may be substituted; the proportions being then 19'1 glauber salt, 9'5 muriate of soda, 14-3 lime, 75-1 sand, and 1-3 charcoal The oxide of lead is an essential constituent of the denser glasses, and may be regarded as replacing the lime, so as to form with the quartz-sand a silicate of lead. It assimilates be.t with purified pearl ash, on account of the freedom of this alkali from iron, which is iresent in most sodas. 904 GLASS. Its atomic constitution may be represented as follows:Computation. Analysis. Siiicic acid - - - - - - 5 atoms = 2877- 59-19 59-20 Oxide of lead - - - 1 = 1394-5 28-68 28.20 Potash- - -- - 1 = 590'0 12-13 9-00 Oxides of iron and an nganese - - 1'40 [.____________ __4861-5 100-00 100'00 The above analysis by Berthier relates to a specimen of the best English crystal glass, perfectly colourless and free from air-bubbles. Tllis kind of glass may however take several different proportions of potash and silica to the oxide of lead. The composition of mirror-plate, as made on the Continent, is as follows:White quartz-sand - - - 300 pounds Dry carbonate of soda - - - - - 100 Lime slaked in the air - - - - - 43 Cullet, or old glass - - - 300 The manganese should not exceed one-half per cent. of the weight of soda. Optical glass requires to be made with very peculiar care. It is of two different kinds; namely, crown glass and flint glass. The latter contains a considerable proportion of lead, in order to give it an increased dispersive power upon the rays of light, in proportion to its mean refractive power. Optical crown glass should be perfectly limpid, and have so little colour, that a pretty thick piece of it may give no appreciable tinge to the rays of light. It should be exempt from strim or veins as well as air-bubbles, and have not the slightest degree of milkiness. It should moreover preserve these qualities when worked in considerable quantities. Potash is preferable to soda for making optical crown glass, because the latter alkali is apt to make a glass which devitrifies and becomes opalescent, by long exposure to heat in the annealing process. A simple potash silicate would be free from this defect, but it would be too attractive of moisture, and apt to decompose eventually by the humidity of the atmosphere. It should therefore contain a small quantity of lime, and as little potash as suffices for making a perfect glass at a pretty high temperature. It is probably owing to the high heats used in the English crown glass works, and the moderate quantity of alkali (soda) which is employed, that our crown glass has been found to answer so well for optical purposes. The following recipe for crown glass is excellent:5 atoms of silica (2 ) - - - - 80 1 carbonate of soda - - - - - 54 5 silica - - 80 1 carbonate of lime - - - - - 50 1 atom of carbonate of baryta - - - 98 5 atoms of silica - - - - - Silicates of lime and baryta per se, or even combined, are very refractory; but they vitrify well along with a third silicate, such as that of soda, or potash. PRACTICAL DETAILS OF THE MANUFACTURE OF GLASS. The Venetians were the first in modern times who attained to any degree of excellence in the art of working glass, but the French became eventually so zealous of rivalling them, particularly in the construction of mirrors, that a decree was issued by the court of France, declaring not only that the manufacture of glass should not derogate from the dignity of a nobleman, but that nobles alone should be masters of glass-works. Within the last 30 or forty years, Great Britain has made rapid advances in this important art, and at the present day her pre-eminence in every department hardly admits of dispute. There are five different species of glass, each requiring a peculiar mode of fabrication, and peculiar materials: 1. The coarsest and simplest form of this manufacture is bottle glass. 2. Next to it in cheapness of material may be ranked broad or spread windowu glass. An improved article of this kind is now made near Birmingham, under the name of British or German plate. 3. Crown glass comes next, or window glass, formed in large circular plates or discs. This glass is peculiar to Great Britain. 4. Flint glass, crystal glass, or glass of lead. 5. Plate or fine mirror glass. The materials of every kind of glass are vitrified in pots made of a pure refractory lay; the best kind of which is a species of shale or slate clay dug out of the coal-formation near Stourbridge. It contains hardly any lime or iron, and consists of silica and alumina in nearly equal proportions. The masses are carefully picked, brushed, and ground under edge iron wheels of considerable weight, and sifted through sieves GLASS-MAKING. 903 having 20 meshes in the square inch. This powder is moistened with watel (best hotand kneaded by the feet or a loam-mill into a uniform smooth paste. A large body of this dough should be made up at a time, and laid by in a damp cellar to ripen. Previously to working it into shapes, it should be mixed with about a fourth of its weight of cement of old pots, ground to powder. This mixture is sufficiently plastic, and being less contractile by heat, forms more solid and durable vessels. Glass-house pots have the figure of a truncated cone, with the narrow end undermost; those for bottle and window-glass being open at top, about 30 inches diameter at bottom, 40 inches at the mouth, and 40 inches deep; but the flint-glass pots are ccvered in at top with a dome-cap, having a mouth at the side, by which the materials are introduced, and the glass is extracted. Bottle and crown-house pots are from 3 to 4 inches thick; those for flint-houses are an inch thinner, and of proportionally smaller cai' city. The well-mixed and kneaded dough is first worked upon a board intc I cake for the bottom; over this the sides are raised, by laying on its edges rolls of clay above each other with much manual labor, and careful condensation. The clay is made into lumps, is equalized, and slapped much in the same way as for making POTTERY. The pots thus fashioned must be dried very prudently, first in the atmospheric temperature, and finally in a stove floor, which usually borrows its heat directly from the glass-house. Before setting the pots in the furnace, they are annealed during 4 or 5 days, at a red heat, in a small reverberatory vault, made on purpose. When completely annealed, they are transferred with the utmost expedition into their seat in the fire, by means of powerful tongs supported on the axle of an iron-wheel carriage frame, and terminating in a long lever for raising them and swinging them round. The pot-setting is a desperate service, and when unskilfully conducted without due mechanical aids, is the forlorn hope of the glass-founder.-Quceque ipse miserrima vidi. The celebrated chemist, Dr. Irvine, caught his last illness by assisting imprudently at this formidable operation. The working breast of the hot furnace must be laid bare so as to open a breach for the extraction of the faulty pot, and the insertion of the fresh one, both in a state of bright incandescence. It is frightful to witness the eyes ane fuming visages of the workmen, with the blackening and smoking of their scorched wool' len clothes, exposed so long to the direct radiations of the flame. A light mask and sack dress coated with tinfoil, would protect both their faces and persons from any annoyance, at a very cheap rate. The glass-houses are usually built in the form of a cone, from 60 to 100 feet high, and from 50 to 80 feet in diameter at the base. The furnace is constructed in the centre of the area, above an arched or groined gallery which extends across the whole space, and terminates without the walls, in large folding doors. This cavern must be sufficiently high to allow laborers to wheel out the cinders in their barrows. The middle of the vaulted top is left open in the building, and is covered over with the grate-bars of the furnace. 1. Bottle glass.-The bottle-house and its furnace resemble nearlyfig. 505. The furnace is usually an oblong square chamber, built of large fire-bricks, and arched over with fire-stone, a silicious grit of excellent quality extracted from the coal measures of Newcastle. This furnace stands in the middle of the area; and has its base divided into three compartmc.ts. The central space is occupied by the grate-bars; and on either side is the platform or fire-brick siege (seat), raised about 12 inches above the level of the ribs upon which the pots rest. Each siege is about 3 feet broad. In the sides of the furnace, semi-circular holes of about a foot diameter are left opposite to, and a little above the top of, each pot, called working holes, by which the workmen shovel in the materials, and take out the plastic glass. At each angle of the furnace there is likewise a hole of about the same size, which communicates with the calcining furnace of a cylindrical form, dome-shaped at top. The flame that escapes from the founding or pot-furnace is thus economically brought to reverberate on the raw materials of the bottle-glass, so as to dissipate their carbonaceous or volatile impurities, and convert them into a frit. A bottle-house has generally eight other furnaces or fire-arches; of which six are used for annealing the bottles after they are blown, and two for annealing the pots, before setting them in the furnace. The laws of this country till lately prohibited the use for making common bottles of any fine materials. Nothing but the common river sand, and soap-boilers' waste, was allowed. About 3 parts of waste, consisting of the insoluble residuum of kelp, mixed with lime and a'ittle saline substance, were used for 1 part of sand. This waste was first of all calcined in two of the fire arches or reverberatories reserved for that purpose, called the coarse arches, where it was kept at a red heat, with occasional stirring, from 24 to 30 hours, being the period of a journey or journee, in which the materials could be melted and worked into bottles. The roasted soap-waste was then withdrawn, under the name of ashes, from its arch, coarsely ground, and mixed with its proper proportion of sand. This mixture was now put into the fine arch, and calcined during the working jour. ney, which extended to 10 or 12 hours. Whenever the pots were worked out, that fril 906 GLASS-MAKING. was immediately transferred into them in its ignited state, and the founding procest proceed(d with such despatch that this first charge of materials was completely melted down in 6 hours, so that the pots might admit to be filled up again with the second charge of frit, which was founded in 4 hours more. The heat was briskly continued, and in the course of from 12 to 18 hours, according to the size of the pots, the quality of the fuel, and the draught of the furnace, the vitrification was complete. Before blowing the bottles, however, the glass must be left to settle, and to cool down to the blowing consistency, by shutting the cave doors and feeding holes, so as to exclude the air from the fire-grate and the bottom of the hearth. The glass or metal becomes more dense, and by its subsidence throws up the foreign lighter earthy and saline matters in the form of a scum on the surface, which is removed with skimming irons. The furnace is now charged with coal, to enable it to afford a working heat for 4 or 5 hours, at the end of which time more fuel is cautiously added, to preserve adequate heat for finishing the journey. It is hardly possible to convey in words alone a correct idea of the manipulations necessary to the formation of a wine bottle; but as the manufacturers make no mystery of this matter, any person may have an opportunity of inspecting the operation. Six people are employed at this task; one, called a gatherer, dips the end of an iron tube, about five feet long, previously made red-hot, into the pot of melted metal, turns the rod round so as to surround it with glass, lifts it out to cool a little, and then dips and turns it round again; and so in succession till a ball is formed on its end sufficient to make the required bottle. He then hands it to the blower, who rolls the plastic lump of glass on a smooth stone or cast-iron plate, till he brings it to the very end of the tube; he next introduces the pear-shaped ball into an open brass or cast-iron mould, shuts this together by pressing a pedal with his foot, and holding his tube vertically, blows through it, so as to expand the cooling glass into the form of the mould. Whenever he takes his foot from the pedal-lever, the mould spontaneously opens out into two halves, and falls asunder by its bottom hinge. He then lifts the bottle up at the end of the rod, and transfers it to the finisher, who, touching the glass tube at the end of the pipe with a cold iron, cracks off the bottle smoothly at its mouth-ring. The finished bottles are immediately piled up in the hot annealing arch, where they are afterwards allowed to cool slowly for 24 hours at least. See BOTTLE MOULD. 2. Broad or spread window-glass.-This kind of glass is called inferior window-glass, in this country, because coarse in texture, of a wavy wrinkled surface, and very cheap, but on the Continent spread window-glass, being made with more care, is much better than ours, though still far inferior in transparency and polish to crown glass, which has, therefore, nearly superseded its use among us. But Messrs. Chance and Hartley, of West Bromwich near Birmingham, have of late years mounted a spread-glass work, where they make British sheet glass, upon the best principles, and turn out an article quite equal, if not superior, to anything of the kind made either in France or Belgium. Their materials are those used in the crown-glass manufacture. The vitrifying mixture is fritted for 20 or 30 hours in a reverberatory arch, with considerable stirring and puddling with long-handled shovels and rakes; and the frit is then transferred by shovels, while red hot, to the melting pots to be founded. When the glass is rightly vitrified, settled, and brought to a working heat, it is lifted out by iron tubes, as will be described under the article CROWN GLASS, blown into pears, which being elongated into cylinders, are cracked up along one side, parallel to the axis, by touching them with a cold iron dipped in water, and are then opened out into sheets. Glass cylinders are spread in France, and at West Bromwich, on a bed of smooth stone Paris-plaster, or laid on the bottom of a reverberatory arch; the cylinder being placed on its side horizontally, with the cracked line uppermost, gradually opens out, and flattens on the hearth. At one time, thick plates were thus prepared for subsequent polishing into mirrors; but the glass was never of very good quality; and this mode of making mirror-plate has accordingly been generally abandoned. The spreading furnace or oven is that in which cylinders are expanded into tables or plates. It ought to be maintained at a brisk red heat, to facilitate the softening of the glass. The oven is placed in immediate connexion with the annealing arch, so that the tables may be readily and safely transferred from the former to the latter. Sometimes the cylinders are spread in a large muffle furnace, in order to protect them from being tarnished by sulphureous and carbonaceous fumes. Fig. 709 represents a ground plan of both the spreading and annealing furnace; fig. 710 is an oblong profile in the direction of the dotted line x x,fig. 709. a is the fire-place; b b the canals or flues through which the flame rises into both furnaces; c the spreading furnace, upon whose sole is the spreading slab. d is the cooling and annealing oven; e e iron bars which extend obliquely across the annealing arch, and serve for resting the glass tables against, during the cooling. f f the channel dlong which the previously cracked cylinders are slid, so as to be gradually warmed; GLASS-MAKING. 907 g Ihe opening Tn the spreading furnace, for enabling the workmen to regulate the nro ~~~~709~~710 OC-1.,, Ike... hi ~, _,,,.t U: x ij cess; h a door in the annealing arch, for introducing the tools requisite for raising ua and removing the tables. In forming glass-plates by the extension of a cylinder into a plane, the workman first blows the lump of glass into the shape of an oblong pear, the length of which must be nearly equal to the length of the intended plate, and its diameter such, that the circumference, when developed, will be equal to the breadth of the plate. He now rests the blowing iron on a stool or iron bar, while an assistant, with a pointed iron, pierces a hole into the extreme end of the pear, in the line of the blowing-pipe. This opening is then enlarged, by introducing the blade of a pair of spring-tongs, while the glass is turned round; and by skilful management, the end of the pear is eventually opened out into a cylindrical mouth. The workman next mounts upon a stool, and holds the blowing-iron perpendicularly. The blown cylinder is now cracked off. a punto rod of iron having been previously stuck to its one end, to form a spindle for working the other by. This rod has a flat disc on its end, or three prongs, which being dipped in melted glass, are applied to the mouth of the cylinder. By this as a handle, the glass cone is carried to the fire, and the narrow end being heated, is next opened by spring tongs, and former into a cylinder of the same size as the other end. The cylinder, thus equalized, is next cracked or slit down in its side with a pair of shears, laid on a smooth copper plate, detached from the iron rod, spread out by heat into a plane surface, and finally annealed. This series of transformations is represented infig. 711, at A, B, c, D, E, F, G, H. Figs. 712 and 713 represent a Bohemian furnace in which excellent white window dass is founded. Fig. 712 is a longitudinal section of the glass and annealing furnace. Fig. 713 is the ground plan. a is the ash-pit vaulted under the sole of the furnace; the fire-place itself is divided into three compartments; with a middle slab at d, which is hollowed in the centre, for collecting any split glass, and two hearth tiles or slabs b b. c c A'711 )D'712 /,s 7l are the draught or air holes; e e are Pi /2 > - 133 t 7 arches upon which the bearing slabs v /4lljN r,,S18 t A/ W f f partly rest. In the middle between these arches, the flame strikes s~~~~B ~{ gJ,U //'////~ } / upwards upon the pots g g, placed B /' 1 as closely together as possible, for n'\.v l"~, -^fee7X2^ economy of room. h is the breast U ll|. "-~_ _wall of the furnace; i,fig. 713, the opening through which the pots are H 1' 713 introduced; it is bricked up as soon as they are set. k k, is the base of the cone or dome of the furnace; io Flt ~ JT ^ I1, the working orifices, which ALf it mi ^^fi^^^^^^^y^ ^1 are made larger or smaller accordI|0I~Ii~ II I I ft',, ing to the size of the glass articles to be made. m is the flue which II~ I leads to the annealing stove n, with 1~I H:1 I "I::~~~~~ ^^^an arched door. Exterior to this, Ij 1I Mthere is usually a drying kiln not shown in the figure; and there are adjoining stoves called arches, for drying and annealing the new pots before they are set. The cooling or annealing arch, or leer, is often built independent of the glass-house furnace, is then heated by a separate fire-place, and constructed like a very long reverberatory furnace. See COPPER. The leer pans or trays of sheet-iron, are laid upon its bottom in an oblong series, and hooked to each other. 3. Crown-glass.-The crown-glass house with its furnace is represented in fig. 714, where the blowing operation is shown on the one side of the figure, and the flashing on the other. The furnace is usually constructed to receive 4 or 6 pots, of such dimen. sions as to make about a ton of glass each at a time. There are, however, several sub 908 GLASS-MAKING. sidiary furnaces to a crown-house. 1. A reverberatory furnace or calcar, for zalcining o fritting the materials; 2. a t.ow rf.^^^^^ \\ 9 S\\\\\ing furnace, for blowing the peat714 / - \ \\\\shaped balls, made at the pot. holes, into large globes; 3. a l, l /g t Ad flashing furnace, and bottoming l Aid X WtY hole for communicating a softening heat, in expanding the globe into a circular plate; 4. the /B E their a eannealing arch for the finished I' /11_^~ ftf/ & ft/ i stables; 5. the reverberatory oven er - H!for annealing the pots prior to their being set upon the founding siege. woIoden l^ ^^^^^ ^ be The materials of crown glass used to be, fine sand, by measure 6IP'T^^~ fhTh5 parts, or by weight 10; ground Iit nce when.t t kelp by measure 11 parts, or by weight Ib'6; but instead of kelp, soda ash is now generally employed. From 6 to 8 cwts. of sand, lime, and soda-ash, mixed together in wooden boxes with a shovel, are thrown on the sole of a large reverberatory, such as is represented in the article COPPER. Here the mixture is well worked together, with iron paddles, flat shovels, and rakes with long handles; the area of this furnace being about 6 feet square, and the height 2 feet. The heat soon brings the materials to a pasty consistence, when they must be diligently turned over, to favor the dissipation of the carbon, sulphur, and other volatile matters of the kelp or soda ash, and to incorporate the fixed ingredients uniformly with the sand. Towards the end of three hours, the fire is considerably raised, and when the fourth hour has expired, the fritting operation is finished. The mass is now shovelled or raked out into shallow cast-iron square cases, smoothed down, and divided, before it hardens by cooling, into square lumps, by cross sections with the spade. These frit-bricks are afterwards piled up in a large apartment for use; and have been supposed to improve with age, by the efflorescence of their saline constituents into carbonate of soda on their surface. The founding-pots are filled up with these blocks of frit, and the furnace is powerfully urged by opening all the subterranean passages to its grate, and closing all the doors and windows of the glass-house itself. After 8 or 10 hours the vitrification has made such progress, and the blocks first introduced are so far melted down, that another charge of frit can be thrown in, and thus the pot is fed with frit till the proper quantity is used. In about 16 hours the vitrification of the frit has taken place, and a considerable quantity, amounting often to the cwt. of liquid saline matter, floats over the glass. This salt is carefully skimmed off into iron pots with long ladles. It is called Sandiver or Glass-gall, and consists usually of muriate of soda, with a little sulphate. The pot is now ready for receiving the topping of cullet, which is broken pieces of window glass, to the amount of 3 or 4 cwts. This is shovelled in at short intervals; and as its pressure forces up the residuary saline matter, this is removed; for were it allowed to remain, the body of the glass would be materially deteriorated. The heat is still continued for several hours till the glass is perfect, and the extrication of gas called the boil, which accompanies the fusion of crown glass, has nearly terminated, when the fire is abated, by shutting up the lower vault doors and every avenue to the grate, in order that the glass may settle fine. At the end of about 40 hours altogether, the fire being slightly raised by adding some coals, and opening the doors, the glass is carefully skimmed, and the working of the pots commences. Before describing it, however, we may state that the marginal figure'715 shows the'715 base of the crown-house cone, with the four open pots in two ranges on opposite sides of the furnace, sitting on their raised ~~WE~i~~r^^ 11 sieges, at each side of the grate. At one I^ ~ ~ ~ t..-.1:.....side of the base the door of the vault is. "h*-**-shown, and its course is marked by the dotted lines. Detailed description of the crown-glass furnace,figs. 716, 717.-It is an oblong square, built in the centre of a brick cone, large enough to contain within it, two or three pots at each side of the grate room, which is either divided as shown in the plan, or runs the whole length of the furnace, as the manufacturer chooses. Fig. 717is a ground plan, and fig. 716 a fiont elevation, of a six-Dot furnace. 1, 2, 3,fig. 717, are the working holes .GLASS-MAKING. 909 for the purposes of ventilation, of putting in the materials, and of taking out tl e metal to be wrought. 4, 5, 6, 7, are pipe holes for warming the pipes before beginning to wori with them. 8, 9, 10, are foot holes for mending the pots and sieges. 11 is a barofiro for binding the furnace, and keeping it from swelling. 716 l1., II.. 6l I 0.:.....:_il>rcg 717 rhe arch is of an elliptic form; though a barrel arch, that is, an arch shaped like the lalf of a barrel cut longwise through the centre, is sometimes used. But this soon gives way when used in the manufacture of crown glass, although it does very well in the clayfurnace used for bottle houses. The best stone for building furnaces is fire-stone, from Coxgreen in the neighborhood of Newcastle. Its quality is a close grit, and it contains a greater quantity of talc than the common fire-stone, which seems to be the chief reason of its resisting the fire better. The great danger in building furnaces is, lest the cement at the top should give way with the excessive heat, and by dropping into the pots, spoil the metal. The top should therefore be built with stones only, as loose as they can hold together after the centres are removed, and without any cement whatever. The stones expand and come quite close together when annealing; an operation which takes from eight to fourteen days at rnost. There is thus less risk of any thing dropping from the roof of the furnace. The inside of the square of the furnace is built either of Stourbridge fire-clay annealed, or the Newcastle fire-stone, to the thickness of sixteen inches. The outside is built of common brick about nine inches in thickness. The furnace is thrown over an ash-pit, or cave, as it is called, which admits the atmospheric air, and promotes the combustion of the furnace. This cave is built of stone until it comes beneath the grate room, when it is formed of fire-brick. The abutments are useful for binding and keeping the furnace together, and are built of masonry. The furnaces are stoutly clasped with iron all round, to keep them tight. In four-pot furnaces.his is unnecessary, provided there be four good abutments. Fig. 718 is an elevation of the flashing furnace. The outside is built 6f common brick, the inside of fire-brick, and the mouth or nose of Stourbridge fire-clay. Fig. 719 is the annealing kiln. It is built of common brick, except round the grate room, where fire-brick is used. Few tools are needed for blowing and flashing crown-glass. The requisite ball of plastic glass is gathered, in successive layers as for bottles, on the end of an iron tube, and rolled into a pear-shape, on a cast-iron plate; the workman taking care that the ail blown into its cavity is surrounded with an equal body of glass, and if he perceives any side to be thicker than another, he corrects the inequality by rolling it on the sloping ron table called marver, (marbre). He now heats the bulb in the fire, and rolls it so a 910 GLASS-MAKING. to form the glass upon the end of the tube, and by a dexterous s ing or two ht iengthens it, as shown in I, fig. 720. To extend the neck of that pear, he next rolls i over a smooth iron rod, turned round in a horizontal direction, into the shape K, fig. 720. By further expansion at the blowing-furnace, he now brings it tc the shape., repre. sented in fig. 720. 719 1 K L 72C This spheroid having become cool and somewhat ti i next carried to the bottomin This spheroid having become cool and somewhat stiff, is next carried to the bottoming hole (like fig. 718), to be exposed to the action of flame. A slight wall erected before one half of this hole, screens the workman from the heat, but leaves room for the globe to pass between it and the posteriorwall. The blowing-pipe is made to rest a little way fronr the neck of the globe, on a hook fixed in the front wall; and thus may be made easily to re. volve on its axis, and by giving centrifugal force to the globe, while the bottom of it, or part opposite to the pipe, is softened by the heat, it soon assumes the form exhibited in M, fig. 720. In this state the flattened globe is removed from the fire, and its rod being rested on the casher box covered with coal cinders, another workman now applies the end of a solid iron rod tipped with melted glass, called a punto, to the nipple or prominence in the middle; and thus attaches it to the centre of the globe, while the first workman cracks off the globe by touching its tubular neck with an iron chisel dipped in cold water. The workman having thereby taken possession of the globe by its bottom or knobbed pole attached to his punty rod, he now carries it to another circular opening, where he exposes it to the action of moderate flame with regular rotation, and thus slowly heats the thick projecting remains of the former neck, and opens it slightly out, as shown at N, in fig. 120. He next hands it to the flasher, who, resting the iron rod in a hook placed near the side of the orifice A, fig. 718, wheels it rapidly round opposite to a powerful flame, till it assumes first the figure o, and finally that of a flat circular table. The flasher then walks off with the table, keeping up a slight rotation as he moves along, and when it is sufficiently cool, he turns down his rod into a vertical position, and lays the table flat on a dry block of fire-clay, or bed of sand, when an assistant nips it off from the punto with a pair of long iron shears, or cracks it off with a toucl of cold iron. The loose table or plate is lastly lifted up horizontally on a double prongec. iron fork, introduced into the annealing arch fig. 719 and raised on edge; an assistant with a long-kneed fork preventing it from falling too rapidly backwards. In this arch a great many tables of glass are piled up in iron frames, and slowly cooled from a heat of about 600~ to 100~ F., which takes about 24 hours; when they are removed. A circular plate or table of about 5 feet diameter weighs on an average 9 pounds. 4. Flint glass.-This kind of glass is so called because originally made with calcined flints, as the silicious ingredient. The materials at present employed in this country for the finest flint glass or crystal, are first, Lynn sand, calcined, sifted, and washed; second, an oxyde of lead, either red lead or litharge; and third, pearlash. The pearlash of commerce must however be purified by digesting it in a very little hot water, which dissolves the carbonate of potash, and leaves the foreign salts, chiefly sulphate of potash, muriate of potash, and muriate of soda. The solution of the carbonate being allowed to cool and become clear in lead pans, is then run off into a shallow iron boiler, and evaporated to dryness. Nitre is generally added as a fourth ingredient of the body of the glass; and it serves to correct any imperfections which might arise from accidental combustible particles, or from the lead being not duly oxydized. The above four substances constitute the main articles; to which we may add arsenic and manganese, introduced in very small quantities, to purify the color and clear up the transparency of the glass. The black oxyde of manganese, when used in such quantity only as to peroxydize the iron of the sand, simply removes the green tinge caused by the iron; but if more mangan se be added than accomplishes that purpose, it will give a purple tinge to the glass; and in fact, most manufacturers prefer to have an excess rather than a defect of manganese, since cut glass has its brilliancy increased by a faint lilach hue. The arsenic is supposed to counteract the injury arising from excess of man. zane.-e. but is itself very apt on the other hand to communicate some Jegree of opalescence GLASS-MAKING. 911 oi at least, to impair the lustre of the glass. When too much manganese has beer added, the purple tinge may indeed be removed by any carbonaceous matter, as by thrusting a wooden rod down into the liquid glass; but this cannot be done with good effect in practice, since the final purple tinge is not decided till the glass is perfectly formed, and then the introduction of charcoal would destroy the uniformity of the whole contents of the pot. The raw materials of flint glass are always mixed with about a third or a fourth of their weight of broken crystal of like quality; this mixture is thrown into the po: with a shovel; and more is added whenever the preceding portions by melting subside; the object being to obtain a pot full of glass, to facilitate the skimming off the impurities 721 and sandiver. The mouth of the pot is now shut, by applying clay-lute rcund the stopper, with the exception of a small orifice below, for the escape of../ /X ~ \\\. \~' l the liquid saline matter. Flint glass / /il~ A of\ ag D1X it requires about 48 hours for its complete I(// /^^,^ @ NT W vl) % v|l ^vitrification, though the materials be 1/ g//// 2 Al W i X v more fusible than those of crown glass; in consequence of the contents of the pot being partially screened by its cover I from the action of the fire, as also from 1 nn l the lower intensity of the heat. Fig. 721 represents a flint glass 4ffl ull thouse for 6 pots, with the arch or leer' $ 0 I -- M 0 lon one side for annealing the crystal ware. In fig. 722, the base of the cone is seen, and the glass pots in situ 1 A on their platform ranged round the central fire grate. The dotted line denotes the contour of the furnace,fig. 721. Whenever the glass appears fine, and is freed from its air bubbles, which it usually is in about 36 hours, the /-_ —M~-^ heat is suffered to fall a little by closing 722 the bottom valves, &c., that the pot may settle; but prior to working the -— /-i —- metal the heat is somewhat raised again. - L ---- - I It would be useless to describe the manual operations of fashioning the various articles of the flint-glass manufacture, because they are indefinitely varied to suit the conveniences and caprices of human society. Every different flint-house has a peculiar proportion of glass materials. The following have been offered as good practical mixtures. 1. Fine white sand - 300 parts, Red lead or litharge - 200 Refined pearlashes - - - - - 80 Nitre - - -- 20 Arsenic and manganese, a minute quantity. In my opinion, the proportion of lead is too great in the above recipe, which is given on the authority of Mr. James Geddes, of Leith. The glass made with it would be probably yellowish and dull. 2. Fine sand.- - 50'5 Litharge - -- - - - - 27-2 Refined pearlashes (carbonate of potash, with 5 per cent. of water) 17'5 Nitre - - 4-8 100'0 To these quantities from 30 to 50 parts of broken glass or cullet are added; with about a two-thousandth part of manganese, and a three-thousandth part of arsenic. But man. ganese varies so extremely in its purity, and contains often so much oxyde of iron, tha nothing can be predicated as to its quantity previously to trial. M. Payen, an eminent manufacturing chemist in France, says that the composition of crystal does not deviate much from the following proportions:Wood fire. Coal fire Silicious sand -3 3 Minium - - - 2 24 Carbonate of potash - - - - 1 912 GLASS-MAKING. I conceive that this glass contains too much lead and potash. Such a mixture will prc duce a dull metal, very attractive of moisture; defects to which the French crown-glas also is subject. The flint-glass leer for annealing glass, is an arched gallery or large flue, about 36 feel -ong, 3 feet high, 4 wide; having as floor raised above 2 feet above the ground of the glass-house. The hot air and smoke of a fire-place at one end pass along this gallery, and are discharged by a chimney 8 or 10 feet short of the other end. On the floor of the vault, large iron trays are laid and hooked to each other in a series, which are drawn from the fire end towards the other by a chain, wound about a cylinder by a winch-handle proiecting through the side. The flint-glass articles are placed in their hot state into the tray next the fire, which is moved onwards to a cooler station whenever it is filled, and an empty tray is set in its place. Thus, in the course of about 20 hours, the glass advances to the cool end thoroughly annealed. Besides colorless transparent glass, which forms the most important part of this manufacture, various colored glasses are made to suit the taste of the public. The taste at Paris was lately for opaline crystal; which may be prepared 1t adding to the above composition (No. 2) phosphate of lime, or well burnt bone ash ir. fine powder, washed and dried. The article must be as uniform in thickness as possible, and speedily worked into shape, with a moderate heat. Oxyde of tin, putty, was formerly used for making opalescent glass, but the lustre of the body was always impaired by its means. Crystal vessels have been made recently of which the inner surface is colorless, and all the external facets colored. Such works are easily executed. The end of the blowingrod must be dipped first in the pot containing colorless glass, to form a bulb of a certain size, which being cooled a little is then dipped for an instant into the pot of colored glass. The two layers are associated without intermixture; and when the article is finished in its form, it is white within and colored without. Fluted lines, somewhat deeply cut, pass through the colored coat, and enter the colorless one; so that when they cross, their ends alone are colored. For some time past, likewise, various crystal articles have been exhibited in the market with colored enamel-figures on their surface, or with white incrustations of a silvery lustre in their interior. The former are prepared by placing the enamel object in the brass mould, at the place where it is sought to be attached. The bulb of glass being put into the mould, and blown while very hot, the small plate of enamel gets cemented to the surface. For making the white argentine incrustations, small figures are prepared with an impalpable powder of dry porcelain paste, cemented into a solid by means of a little gypsum plaster. When these pieces are thoroughly dried, they are laid on the glass while it is red hot, and a large patch of very liquid glass is placed above it, so as to encase it and form one body with the whole. In this way the incrustation is completely enclosed; and the polished surface of the crystal, which scarcely touches it, gives a brilliant aspect, pleasing to the eye. A uniform flint-glass, free from strioe, or wreath, is much in demand for the optician. It would appear that such an article was much more commonly made by the English manufa:turers many years ago, than at present; and that in improving the brilliancy of crystal-glass they have injured its fitness for constructing optical lenses, which depends not so much on its whiteness and lustre as on the layers of different densities being parallel to each other. The oxyde of lead existing in certain parts of a potful of glass in greater proportion than in other parts, increases the density unequally in the same mass, so that the adjoining strata are often very different in this respect. Even a potful of pretty uniform glass, when it stands some time liquid, becomes eventually unequable by the subsidence of the denser portions; so that strim and gelatinous appearances begin to manifest themselves, and the glass becomes of little value. Glass allowed to cool slowly in mass in the pot is particularly full of wreath; and if quickly refrigerated, that is, in two or three hours, it is apt to split into a multitude of minute splinters, of which no use can be made. For optical purposes, the glass must be taken out in its liquid state, being gathered on the end of the iron rod from the central portion of a recently skimmed pot, after the upper layers have been worked off in general articles. M. Guinand, of Brennets near Geneva, appears to have hit upon processes that furnished almost certainly pieces of flint-glass capable of forming good lenses of remarkable dimensions, even of 11 inches diameter; of adequate density and transparency, and nearly free from strice. M. Cauchoix, the eminent French optician, says, that out of ten object glasses, 4 inches in diameter, made with M. Guinand's flint glass, eight or nine turned out very good, while out of an equal number of object glasses made of the flint glass of the English and French manufactories, only one, or two at most, were found serviceable. The means by which M. Guinand arrived at these results have not been published. He has lately died, and it is not known whether his son be in possession of its secret. GLASS-MAKING. 913 An achromatic object glass for telescopes and microscopes consists of at least two lenses; the one made with glass of lead, or flint-glass, and the other with crown-glass; the fobmer possessing a power of dispersing the colored rays relatively to its mean refrac. tive power, much greater than the latter; upon which principle the achromatism of the image is produced, by reuniting the different colored rays into one focus. Flint-glass to be fit for this delicate purpose must be perfectly homogeneous, or of uniform density throughout its substance, and free from wavy veins or wreaths; for every such inequality would occasion a corresponding inequality in the refracticn and dispersion of the light; like what is perceived in looking through a thick and thin solution of gum-arabic imperfectly mixed. Three plans have been prescribed for obtaining homogeneous pieces of optical glass: 1. to lift a mass of it in large ladles, and let it cool in them; 2. to pour it out from the pots into moulds; 3. to allow it to cool in the pots, and afterwards to cut it off in horizontal strata. The last method, which is the most plausible, seldom affords pieces of uniform density, unless peculiar precautions have been adopted to settle the flint glass in uniform strata; because its materials are of such unequal density, the oxyde of lead having a specific gravity of 8, and silica of 2'7, that they are apt to stand at irregular heights in the pots. One main cause of these inequalities lies in the construction of the furnace, whereby the bottom of the pot is usually much less heated than the upper part. In a plate glass furnace the temperature of the top of the pot has been found to be 130~ Wedgew., while that of the bottom was only 1100, constituting a difference of no less than 2610~ F. The necessary consequence is that the denser particles which subside to the bottom, during the fusion of the materials, and after the first extrication of the gases, must remain there, not being duly agitated by the expansive force of caloric, acting from below upwards. The preparation of the best optical glass is now made a great mystery by one or two proficients. The following suggestions, deduced from a consideration of principles, may probably lead to some improvements, if judiciously applied. The great object is to counteract the tendency of the glass of lead to distribute itself into strata of different densities; which may be effected either by mechanical agitation or by applying the greatest heat to the bottom of the pot. But however homogeneous the glass may be thereby made, its subsequent separation into strata of different densities must be prevented by rapid cooling and solidification. As the deeper the pots, the greater is the chance of unequal specific gravity in their contents, it would be advisable to make them wider and shallower than those in use for making ordinary glass. The intermixture may be effected either by lading the glass out of one pot into another in the furnace, and back again, with copper ladles, or by stirring it up with a rouser, then allowing it to settle for a short time, till it becomes clear and free from air bubbles. The pot may now be removed from the furnace, in order to solidify its contents in their homogeneous state; after which the glass may be broken in pieces, and be perfected by subjecting it to a second fusion; or. what is easier and quicker, we may form suitable discs of glass without breaking down the potful, by lifting it out in flat copper ladles with iron shanks, and transferring the lumps after a little while into the annealing leer. 723 To render a potful of glass homogeneous by agitation, is a more difficult task, as an iron rod would discolor it, and a copper rod would be apt to melt. An iron rod sheathed in laminated platinum would answer well, but for its expense. A stone-ware tube supported within by a rod of iron, might also be employed for the purpose in careful hands; the stirring being repeated several times, till at last the glass is suffered to stiffen a little by decrease of temperature. It must then be allowed to settle and cool, after which the pot, being of small dimensions, may be drawn out of the fire. 2. The second method of producing the desired uniformity of mixture, consists in applying a greater heat to the bottom than to the upper part of the melting pot. Fig. 723 repre(C.^~ B^ sents in section a furnace contrived to effect this object. It is cylindrical, and of a diameter no greater than to allow the O! A l - flames to play round the pot, containing from three to four cwts. of vitreous materials. A is the pot, resting upon the k=i o>-L arched grid b a, built of fire-bricks, whose apertures are wide..-.-.-l.. enough to let the flames rise freely, and strike the bottom and d__t' sides of the vessel. From 1- to 2 feet under that arch, the fuel grate c d is placed. B c are the two working openings 7i..... ] i~ l for introducing the materials, and inspecting the progress of,-' --',~ the fusion; they must be closed with fire-tiles and luted with fire-clay at the beginning of the process. At the back of the furnace, opposite the mouth 914 GLASS-MAKING. of the fire-place there is a door-way, which is bricked up, except upon occasion of putting in and taking out the pot. The draught is regulated by means of a slide-plate upon the mouth of the ash-pit f. The pot being heated to the proper pitch, some purified pearlash, mixed with fully twice its weight of colorless quartz sand, is to be thrown into it, and after the complete fusion of this mixture, the remaining part of the sand along with the oxyde of lead (fine litharge) is to be strown upon the surface. These silicious parlicles in their Jescent serve tb extricate the air from the mass. Whenever the whole is fused, the heat must be strongly urged, to ensure a complete uniformity of combination by the internal motions of the particles. As soon as the glass has been found, by making test vials, to be perfectly fine, the fire must be withdrawn, the two working holes must be opened, as well as the mouths of-the fire-place and ash-pit, to admit free ingress to cooling currents of air, so as to congeal the liquid mass as quickly as possible; a condition essential to the uniformity of the glass. It may be worth while to stir it a little with the pottery rod at the commencement of the cooling process. The solidified glass may be afterwards detached by a hammer in conchoidal discs, which, after chipping off their edges, are to be placed in proper porcelain or stone-ware dishes, and exposed to a softening heat, in order to give them a lenticular shape. Great care must be taken that the heat thus applied by the muffle furnace be very equable, for otherwise wreaths might be very readily reproduced in the discs. A small oven, upon the plan of a baker's, is best fitted for this purpose, which being heated to dull redness, and then extinguished, is ready to soften and afterwards anneal the conchoidal pieces. Guinand's dense optical flint glass, of specific gravity 3'616, consists, by analysis, of oxyde of lead, 43-05; silica, 44-3; and potash, 11'75; but requires for its formation the following ingredients: 100 pounds of ground quartz; 100 pounds of fine red lead; 35 pounds of purified potash; and from 2 to 4 pounds of saltpetre. As this species of glass is injured by an excess of potash, it should be compounded with rather a defect of it, and melted by a proportionably higher or longer heat. A good optical glass has been made in Germany with 7 parts of pure red lead, 3 parts of finely ground quartz, and 2 parts of calcined borax. 5. Plate glass. This, like English crown-glass, has a soda flux; whereas flint-glass requires potash, and is never of good quality when made with soda. We shall distribute our account of this manufacture under two heads. 1. The different furnaces and principal machines, without whose knowledge it would be impossible to understand the several processes of a plate-glass factory. 2. The materials which enter into the composition of this kind of glass, and the series of operations which they undergo; devoting our chief attention to the changes and improvements which long experience, enlightened by modern chemistry, has introduced into the great manufactory of Saint-Gobin, in France, under the direction of M. Tassaert. It may however be remarked, that the English plate-glass manufacture derives peculiar advantages from the excellence of its grinding and polishing machinery. The clay for making the bricks and pots should be free from lime and iron, and very refractory. It is mixed with the powder of old pots passed through a silk sieve. If the clay be very plastic it will bear its own weight of the powder, but if shorter in quality, it will take only three fifths. But before mingling it with the cement of old pots, it must be dried, bruised, then picked, ground, and finally elutriated by agitation with water, decantation through a hair sieve, and subsidence. The clay fluid after passing the sieve is called slip (coulis). The furnace is built of dry bricks, cemented with slip, and has at each of its four angles a peculiar annealing arch, which communicates with the furnace interiorly, and thence derives sufficient heat to effect in part, if not wholly, the annealing of the pots, which are always deposited there a long time before they are used. Three of these arches, exclusively appropriated to this purpose, are called pot-arches. The fourth is called the arch of the materials, because it serves for drying them before they are founded. Each arch has, moreover, a principal opening called the throat, another called bonnard, by the French workmen, through which fire may be kindled in the arch itself, when it waS thought to be necessary for the annealing of the pots; a practice now abandoned. The duration of a furnace is commonly a year, or at most 14 months; that of the arches is 30 years or upwards, as they are not exposed to so strong a heat. In the manufacture of plate-glass two sorts of crucibles are employed, called the pots and the basins (cuvettes). The first serve for containing the materials to be founded, and for keeping them a long time in the melted state. The cuvettes receive the melted glass after it is refined, and decant it out on the table to be rolled into a plate. Three pots hold liquid glass for six small basins, or for three large ones, the latter being employed for making mirrors of great dimensions, that is, 100 inches long and up GLASS-MAKING. 915 wa-dso Vurnaces have been lately constructed with 6 pots, and 12 cuvettes, 8 of which are small, and 4 large; and cuvettes of three sizes are made, called small, middling, and large. The small are perfect cubes, the middling and the large ones are oblong parallel opipeds. Towards the middle of their height, a notch or groove, two or three inches broad, and an inch deep, is left, called the girdle of the cuvette, by which part they are grasped with the tongs, or rather are clamped in the iron frame. This frame goes round the four sides of the small cuvettes, and may be placed indifferently upon all their sides; in the other cuvettes, the girdle extends only over the two large sides, because they cannot be turned up. See m T,fig. 724, p. 918. The pot is an inverted truncated cone, like a crown glass pot. It is about 30 inches high, and from 30 to 32 inches wide, including its thickness. There are only a few inches of difference between the diameter of the top and that of the bottom. The bottom is 3 inches thick, and the body turns gradually thinner till it is an inch at the mouth of the pot. The large building or factory, of which the melting furnace occupies the middle space, is called the halle in French. At Ravenhead in Lancashire it is called the foundry, and is of magnificent dimensions, being probably the largest apartment under one roof in Great Britain, since its length is 339 feet, and its breadth 155. The famous halle of St. Gobin is 174 feet by 120. Along the two side walls of the halle, which are solidly constructed of hewn stone, there are openings like those of common ovens. These ovens. destined for the annealing of the newly cast plates, bear the name of carquaises. Their soles are raised two feet and a half above the level of the ground, in order to bring them into the same horizontal plane with the casting tables. Their length, amounting sometimes to 30 feet, and their breadth to 20, are required in order to accommodate 6, 8, or even 10 plates of glass, alongside of each other. The front aperture is called the throat, and the back door the little throat (gueulette). The carquaise is heated by means of a fire-place of a square form called a tisar, which extends along its side. The founding or melting furnace is a square brick building laid on solid foundations, being from 8 to 10 feet in each of its fronts, and rising inside into a vault or crown about 10 feet high. At each angle of this square, a small oven or arch is constructed, likewise vaulted within, and communicating with the melting furnace by square flues, called lunettes, through which it receives a powerful heat, though much inferior to that round the pots. The arches are so distributed as that two of the exterior sides of the furnace stand wholly free, while the two other sides, on which the arches encroach, offer a free space of only three feet. In this interjacent space, two principal openings of the furnace, of equal size in each side, are left in the building. These are called tunnels. They are destined for the introduction of the pots and the fuel. On looking through the tunnels into the inside of the furnace, we perceive to the right hand and the left, along the twofree sides, two low platforms or sieges, at least 30 inches in height and breadth. See figs. 715, 17. These sieges (seats) being intended to support the pots and the cuvettes filled with heavy materials, are terminated by a slope, which ensures the solidity of the fire-clay mound. The slopes of the two sieges extend towards the middle of the furnace so near as to leave a space of only from 6 to 10 inches between them for the hearth. The end of this is perforated with a hole sufficiently large to give passage to the liquid glass of a broken pot, while the rest is preserved by lading it from the mouth into the adjoining cuvette. In the two large parallel sides of the furnace, other apertures are left much smaller than the tunnels, which are called ouvreaux (peep holes). The lower ones, or the ouvreaux en bas, called cuvetle openings, because, being allotted to the admission of these vessels, they are exactly on a level with the surface of the sieges, and with the floor of the halle. Plates of cast-iron form the thresholds of these openings, and facilitate the ingress and egress of the cuvettes. The apertures are arched at top, with hewn stone like the tunnels, and are 18 inches wide when the cuvettes are 16 inches broad. The upper and smaller apertures, or the higher ouvreaux called the lading holes, because they serve for transvasing the liquid glass, are three in number, and are placed 31 or 32 inches above the surface of the sieges. As the pots are only 30 inches high, it becomes easy to work through these openings either in the pots or the cuvettes. The pots stand opposite to the two pillars which separate the openings, so that a space is left between them for one or more cuvettes according to the size of the latter. It is obvious that if the tunnels and ouvreaux were left open, the furnace would not draw or take the requisite founding heat. Hence the openings are shut by means of fire-tiles. These are put in their places, and removed by means of two holes left in them, in correspondence with the two prongs of a large iron fork supported by. an axle and two iron wheels, and terminated by two handles which the workmen lay hold of when they wish to move the tile. The closing of the tunnel is more complex. WThen it is shut or ready for the firing 59 916 GLASS-MAKING. the aperture appears built up with bricks and mortar from the top of the arch to the middle of the tunnel. The remainder of the door-way is closed; 1. on the two sides down to the bottom, by a small upright wall, likewise of bricks, and 8 inches broad, called walls of the glaye; 2. by an assemblage of pieces called pieces of the glaye, because the whole of the closure of the tunnel bears the name of glaye. The upper hole, 4 inches square, is called the tisar, through which billets of wood are tossed into the fire. Fuel is also introduced into the posterior openings. The fire is always kept up on the hearth of the tunnel, which is, on this account, 4 inches higher than the furnacehearth, in order that the glass which may accidentally fall down on it, and which does not flow off by the bottom hole, may not impede the combustion. Should a body of glass, however, at any time obstruct the grate, it must be removed with rakes, by opening the tunnel and dismounting the fire-tile stoppers of the glaye. Formerly wood fuel alone was employed for heating the melting-furnaces of the mirror-plate manufactory of Saint Gobin; but within these few years, the Director of the works makes use with nearly equal advantage of pit-coal. In the same establishment, two melting furnaces may be seen, one of which is fixed with wood, and- the other with coals, without any difference being perceptible in the quality of the glass furnished by either. It is not true, as has been stated, that the introduction of pit-coal has made it necessary to work with covered pots in order to avoid the discoloration of the materials, or that more alkali was required to compensate for the diminished heat in the covered pots. They are not now covered when pit-coal is used, and the same success is obtained as heretofore by leaving the materials two or three hours longer in the pots and the cuvettes. The construction of the furnaces in which coal is burned, is the same as that with wood, with slight modifications. Instead of the close bottomed hearth of the wood furnace, there is an iron grate in the coal-hearth through which the air enters, and the waste ashes descend. When billets of wood were used as fuel, they were well dried beforehand, by being placed a few days on a frame-work of wood called the wheel, placed two feet above the furnace and its arches, and supported on four pillars at some distance from the angles of the building. Composition of plate-glass.-This is not made now, as formerly, by random trials. The progress of chemistry, the discovery of a good process for the manufacture of soda from sea salt, which furnishes a pure alkali of uniform power, and the certain methods of ascertaining its purity, have rendered this department of glass-making almost entirely new, in France. At Saint Gobin no alkali is employed at present except artificial crystals of soda, prepared at the manufactory of Chauny, subsidiary to that establishment. Leaden chambers are also erected there for the production of sulphuric acid from sulphur. The first crop of soda crystals is reserved for the plate-glass manufacture, the other crystals and the mother-water salts are sold to the makers of inferior glass. At the mirror-plate works of Ravenhead, near St. Helen's in Lancashire, soda crystals, from the decomposition of the sulphate of soda by chalk and coal, have been also tried, but without equal success as at Saint Gobin; the failure being unquestionably due to the impurity of the alkali. Hence, in the English establishment the soda is obtained by treating sea-salt with pearl-ash, whence carbonate of soda and muriate of potash result. The latter salt is crystallized out of the mingled solution, by evaporation at a moderate heat, for the carbonate of soda does not readily crystallize till the temperature of the solution falls below 60~ Fahr. When the muriate of potash is thus removed, the alkaline carbonate is evaporated to dryness. Long experience at Saint Gobin has proved that one part of dry carbonate of soda is adequate to vitrify perfectly three parts of fine silicious sand, as that of the mound of Aumont near Senlis, of Alum Bay in the Isle of Wight, or of Lynn in Norfolk. It is also known that the degree of heat has a great influence upon the vitrification, and that increase of temperature will compensate for a certain deficiency of alkali; for it is certain that a very strong fire always dissipates a good deal of the soda, and yet the glass is not less beautiful. The most perfect mirror-plate has constantly afforded to M. Vauquelin in analysis, a portion of soda inferior to what had been employed in its formation. Hence, it has become the practice to add for every 100 parts of cullet or broken plate that is mixed with the glass composition, one part of alkali, to make up for the loss that the old glass must have experienced. To the above mentioned proportions of sand and alkali independently of the cullet which may be used, dry slaked lime carefully sifted is to be added to the amount of one seventh of the sand; or the proportion will be, sand 7 cwts.; quicklime 1 cwt.; dry carbonate of soda 2 cwts. and 37.bs.; besides cullet. The lime improves the quality of the glass; rendering it less brittle and less liable to change. The preceding quantities ~f materials, suitably blended, have been uniformly found to afford most advantageous results. The practice formerly was to dry that mixture as soon as it was made, in the -_______ -, GLASS-MAKING. 917 arch for the materials, but it has been ascertained that this step may be dispensed with. and the small portion of humidity present is dissipated almost instantly after they are thrown into the furnace. The coat of glaze previously applied to the inside of the pot, prevents the moisture from doing them any harm. For this reason, when the demand for glass at Saint-Gobin is very great, the materials are neither fritted nor even dried, but shovelled directly into the pot; this is called founding raw. Six workmen are employed in shovelling-in the materials either fritted or otherwise, for the sake of expedition, and to prevent the furnace getting cooled. One third of the mixture is introduced at first; whenever this is melted, the second third is thrown in, and then the last. These three stages are called the first, second, and third fusion or founding. According to the ancient practice, the founding and refining were both executed in the pots, and it was not till the glass was refined, that it was laded into the cuvettes, where it remained only 3 hours, the time necessary for the disengagement a' the ail bubbles introduced by the transvasion, and for giving the metal the proper consistence for casting. At present, the period requisite for founding and refining, is equally divided between the pots and the cuvettes. The materials are left 16 hours in the pots, and as many in the cuvettes; so that in 82 hours the glass is ready to be'cast. During the last two or three hours, the fireman or tiseur ceases to add fuel; all the openings are shut, and the glass is allowed to assume the requisite fluidity; an operation called stopping the glass, or performing the ceremony. The transfer of the glass into the cuvettes, is called lading, (trejetage). Before this is done, the cuvettes are cleared out, that is, the glass remaining on their bottom is removed, and the ashes of the firing. They are lifted red hot out of the furnace by the method presently to be described, and placed on an iron plate, near a tub filled with water. The workmen, by means of iron paddles 6 feet long, flattened at one end and hammered to an edge, scoop out the fluid glass expeditiously, and throw it into water; the cuvettes are now returned to the furnace, and a few minutes afterwards the lading begins. Ill this operation, ladles of wrought iron are employed, furnished with long handles, which are plunged into the pots through the upper openings or lading holes, and immediately transfer their charge of glass into the buckets. Each workman dips his ladle only three times, and empties its contents into the cuvette. By these three immersions (whence the term trejeter is derived), the large iron spoon is heated so much that when plunged into a tub full of water, it makes a noise like the roaring of a lion, which may be heard to a very great distance. The founding, refining, and ceremony, being finished, they next try whether the glass be ready for casting. With this view, the end of a rod is dipped into the bucket, which is called drawing the glass; the portion taken up being allowed to run off, naturally assumes a pear-shape, from the appearance of which, they can judge if the consistence be proper, and if any air bubbles remain. If all be right, the cuvettes are taken out of the furnace, and conveyed to the part of the halle where their contents are to be poured out. This process requires peculiar instruments and manipulations. Casting.-While the glass is refining, that is, coming to its highest point of perfection, preparation is made for the most important process, the casting of the plate, whose success crowns all the preliminary labors and cares. The oven or carquaise destined to receive and anneal the plate is now heated by its small fire or tisar, to such a pitch that its sole may have the same temperature as that of the plates, being nearly red-hot at the moment of their being introduced. An unequal degree of heat in the carquaise would cause breakage of the glass. The casting table is then rolled towards the front door or throat, by means of levers, and its surface is brought exactly to the level of the sole of the oven. The table T, fig. 724, is a mass of bronze, or now preferably cast iron, about 10 feet long, 5 feet broad, and from 6 to 7 inches thick, supported by a frame of carpentry, which rests on three cast iron wheels. At the end of the table opposite to that next to the front of the oven, is a very strong frame of timber-work, called the puppet or standard, upon which the bronze roller which spreads the glass is laid, before and after the casting. This is 5 feet long by 1 foot in diameter; it is thick in the metal but hollow in the axis. The same roller can serve only for two plates at one casting, when another is put in its place, and the first is laid aside to cool; for otherwise the hot roller would at a third casting make the plate expand unequally, and cause it to crack. When the rollers are not in action, they are laid aside in strong wooden trestles, like those employed by sawyers. On the two sides of the table in the line of its length, are two parallel bars of bronze, t, t, destined to support the roller during its passage from end to end; the thickness of these bars determines that of the plate. The table being thus arranged, a crane is had recourse to for lifting the cuvette, and keeping it suspended, till it be emptied upon the table. This raising and suspension are effected by means of an iron gib, furnished with pulleys, held horizontally, and which turns with them. 918 GLASS-MAUIUNG. The tongs T, fig. "24, are made of four iron bars, bent into a square frame in their middle, for embracing the bucket. Four chains proceeding from the corners of the frame v are united at their other ends into a ring which fits into the hook of the crane, 724 Things bEing thus arranged, all the workmen of the foundry co-operate in the manipulations of the casting. Two of them fetch, and place quickly in front of one of the lower openings, the small cuvette-carriage, which bears a forked bar of iron, having two prongs corresponding to the two holes left in the fire-tile door. This fork, mounted on the axle of two cast-iron wheels, extends at its other end into two branches terminated by handles, by which the workmen move the fork, lift out the tile stopper, and set it down against the outer wall of the furnace. The instant these men retire, two others push forward into the opening the extremity of the tongs-carriage, so as to seize the bucket by the girdle, or rather to clamp it. At the same time, a third workman is busy with an iron pinch or long chisel, detaching the bucket from its seat, to which it often adheres by some spilt glass; whenever it is free, he withdraws it from the furnace. Two powerful branches of iron united by a bolt, like two scissor blades, which open, come together, and join by a quadrant near the other end, form the tongs-carriage, which is mounted upon two wheels like a truck. The same description will apply almost wholly to the iron-plate carriage, on which the bucket is laid the moment it is taken out of the furnace; the only difference in its construction is, that on the bent iron bars which form the tail or lower steps of this carriage (in place of the tongs) is permanently fastened an iron plate, on which the bucket is placed and carried for the casting. Whenever the cuvette is set upon its carriage, it must be rapidly wheeled to its station n.ear the crane. The tongs T above described are now applied to the girdle, and are then hooked upon the crane by the suspension chains. In this position the bucket is skimmed by means of a copper tool called a sabre, because it has nearly the shape of that weapon. Every portion of the matter removed by the sabre is thrown into a copper ladle (poche de gamin), which is emptied from time to time into a cistern of water. After being skimmed, the bucket is lifted up, and brushed very clean on its sides and bottom; then by the double handles of the suspension-tongs it is swung round to the table, where it is seized by the workmen appointed to turn it over; the roller having been previously laid on its ruler-bars, near the end of the table which is in contact with the annealing oven. The cuvette-men begin to pour out towards the right extremity E of the roller, and terminate when it has arrived at the left extremity D. While preparing to do so, and at the instant of casting, two men place within the ruler-bar on each side, that is, between the bar and the liquid glass, two iron instruments called hands, m, m, m, m, which prevent the glass from spreading beyond the rulers, while another draws along the table the wiping bar c, c, wrapped in linen, to remove dust, or any small objects which may interpose between the table and the liquid glass. Whenever the melted glass is poured out, two men spread it over the table, guiding the roller slowly and steadily along, beyond the limits of the glass, and then run it smartly into the wooden standard prepared for its reception, in place of the trestles v, v. The empty bucket, while still red-hot, is hung again upon the crane, set on its plateiron carriage, freed from its tongs, and replaced in the furnace, to be speedily cleared out anew, and charged with fresh fluid fiom the pots. If while the roller glides along, the two workmen who stand by with picking tools, perceive tears in the matter in ad. vance of the roller, and can dexterously snatch them out, they are suitably rewarded, according to the spot where the blemish lay, whether in the centre, where it would have proved most detrimental, or near the edge. These tears proceed usually from GLASS-MAKING 919 small portions of semi-vitrified matter which fall from the vault of the furnace, and from their density occupy the bottom of the cuvettes. While the plate is still red-hot and ductile, about 2 inches of its end opposite to the carquaise door is turned up with a tool; this portion is called the head of the mirror; against the outside of this head, the shovel, in the shape of a rake without teeth, is applied, with which the plate is eventually pushed into the oven, while two other workmen press upon the upper part of the head with a wooden pole, eight feet long, to preserve the plate in its horizontal position, and prevent its being warped. The plate is now left for a few moments near the throat of the carquaise, to give it solidity; after which it is pushed farther in by means of a very long iron tool, whose extremity is forked like the letter y, and hence bears that name; and is thereby arranged in the most suitable spot for allowing other plates to be introduced. However numerous the manipulations executed from the moment of withdrawing the cuvette from the furnace, till the cast-plate is pushed into the annealing oven, I have seen them all performed in less than five minutes; such silence, order, regularity, and despatch prevail in the establishment of Saint-Gobin. When all the plates of the same casting have been placed in the carquaise, it is sealed up, that is to say, all its orifices are closed with sheets of iron, surrounded and made tight with plastic loam. With this precaution, the cooling goes on slowly and equably in every part, for no cooling-current can have access to the interior cf the oven. After they are perfectly cooled, the plates are carefully withdrawn one after another, seeping them all the while in a horizontal position, till they are entirely out of the carquaise. As soon as each plate is taken out, one set of workmen lower quickly and steadily the edge which they hold, while another set raise the opposite edge, till the glass be placed upright on two cushions stuffed with straw, and covered with canvass. In this vertical position they pass through, beneath the lower edge of the plate, three girths or straps each four feet long, thickened with leather in their middle, and ending in wooden handles; so that one embraces the middle of the plate, and the other two, the ends. The workmen, six in number, now seize the handles of the straps, lift up the glass closely to their bodies, and convey it with a regular step to the warehouse. Here the head of the plate is first cut off with a diamond square, and then the whole is attentively examined, in reference to its defects and imperfections, to determine the sections which must be made of it, and the eventual size of the pieces. The pairings and small cuttings detachec are set aside, in order to be ground and mixed with the raw materials of another glass-pot. The apartment in which the roughing-down and smoothing of the plates is performed, is furnished with a considerable number of stone tables truly hewn and placed apart like billiard tables, in a horizontal position, about 2 feet above the ground. They are rectangular, and of different sizes proportional to the dimensions of the plates, which they ought always to exceed a little. These tables are supported either on stone pillars or wooden frames, and are surrounded.with a wooden board whose upper edge stands somewhat below their level, and leaves in the space between it and the stone all round an interval of 3 or 4 inches, of which we shall presently see the use. A cast plate, unless formed on a table quite new, has always one of its faces, the one next the table, rougher than the other; and with this face the roughing-down begins. With this view, the smoother face is cemented on the stone table with Paris-plaster. But often, instead of one plate, several are cemented alongside of each other, those of the same thickness being carefully selected. They then take one or more crude plates of about one third or one fourth the surface of the plate fixed to the table, and fix it on them with liquid gypsum to the large base of a quadrangular truncated pyramid of stone, of a weight proportioned to its extent, or about a pound to the square inch. This pyramidal muller, if small sized, bears at each of its angles of the upper face a peg or ball, which the grinders lay hold of in working it; but when of greater dimension, there is adapted to it horizontally a wheel of slight construction, 8 or 10 feet in diameter, whose circumference is made of wood rounded so as to be seized with the hand. The upper plate is now rubbed over the lower ones, with moistened sand applied between. This operation is however performed by machinery. The under plate being fixed or imbedded in stucco, on a solid table, the upper one likewise imbedded by the same cement in a cast-iron frame, has a motion of circumrotation given to it closely resembling that communicated by the human hand and arm, moist sand being supplied between them. While an eccentric mechanism imparts this double rotatory movement to the upper plate round its own centre, and of that centre round a point in the lower plate, this plate, placed on a moveable platform, changes its position by a slow horizonta, motion, both in the direction of its length and its breadth. By this ingenious contrivance, which pervades the whole of the grinding and polishing machinery, a remark-. able regularity of friction and truth of surface is produced. When the plates are sutfiriently worked on one face, they are reversed in the frames, and worked together or _________________________________^______________________________ 920 GLASS-MAKhING;;he ather. The Paris plaster is usually colored red, in order to show any defects in the glass. The smoothing of the r!ates is effected on the same principles by the use of moist emery washed to successive degrees of fineness, for the successive stages of the operation; and the polishing process is performed by rubbers of hat-felt and a thin paste of colcothal and water. The colcothar, called also crocus, is red oxyde of iron prepared by the ignition of copperas, with grinding and elutriation of the residuum. The last part or the polishing process is performed by hand. This is managed by females, who slide one plate over another, while a little moistened putty of tin finely levigated is thrown between. Large mirror-plates are now the indispensable ornaments of every large and sumptuous apartment; they diffuse lustre and gayety round them, by reflecting the rays of light in a thousand lines, and by multiplying indefinitely the images of objects placed between op. posite parallel planes. The silvering of plane mirrors consists in applying a layer of tin-foil alloyed with mercury to their posterior surface. The workshop for executing this operation is provided with a great many smooth tables of fine freestone or marble, truly levelled, having round their contour a rising ledge, within which there is a gutter or groove which terminates by a slight slope in a spout at one of the corners. These tables rest upon an axis of wood or iron which runs along the middle of their length; so that they may be inclined easily into an angle with the horizon of 12 or 13 degrees, by means of a hand-screw fixed below. They are also furnished with brushes, with glass rules, with rolls of woollen stuff, several pieces of flannel, and a great many weights of stone or cast-iron. The glass-tinner, standing towards one angle of his table, sweeps and wipes its surface with the greatest care, along the whole surface to be occupied by the mirror-plate; then taking a sheet of tin-foil adapted to his purpose, he spreads it on the table, and applies it closely with a brush, which removes any folds or wrinkles. The table being horizontal, he pours over the tin a small quantity of quicksilver, and spreads it with a roll of woollen stuff; so that the tin-foil is penetrated and apparently dissolved by the mercury. Placing now two rules, to the right and to the left, on the borders of the sheet, he pours on the middle a quantity of mercury sufficient to form everywhere a layer about the thickness of a crown piece; then removing with a linen rag the oxyde or other impurities, he applies to it the edge of a sheet of paper, and advances it about half an inch. Meanwhile another workman is occupied in drying very nicely the surface of the glass that is to be silvered, and then hands it to the master workman, who, laying it flat, places its anterior edge first on the table, and then on the slip of paper; now pushing the glass forwards, he takes care to slide it along so that neither air nor any coat of oxyde on the mercury can remain beneath the plate. When this has reached its position, he fixes it there by a wveight applied on its side, and gives the table a gentle slope, to run off all the loose quicksilver by the gutter and spout. At the end of five minutes he covers the mirror with a piece of flannel, and loads it with a great many weights which are left upon it for twenty-four hours, under a gradually increased inclination of the table. By this time the plate is ready to be taken off the marble table, and laid on a wooden one sloped like a reading desk, with its under edge resting on the ground, while the upper is raised successively to different elevations by means of a cord passing over a pulley in the ceiling of the room. Thus the mirror has its slope graduated from day to day, till it finally arrives at a vertical position. About a month is required for draining out the superfluous mercury from large mirrors; and from 18 to 20 days from those of moderate size. The sheets of tin-foil being always somewhat larger than the glass plate, their edges must be paired smooth off, before the plate is lifted off the marble table. Process for silvering concave mirrors.-Having prepared some very fine Paris plaster by passing it through a silk sieve, and some a little coarser passed through hair-cloth, the first is to be made into a creamy liquor with water, and after smearing the concave surface of the glass with a film of olive oil, the fine plaster is to be poured into it, and spread by turning about, till a layer of plaster be formed about a tenth of an inch thick. The second or coarse plaster, being now made into a thin paste, poured over the first, and moved about, readily incorporates with it, in its imperfectly hardened state. Thus an exact mould is obtained of the concave surface of the glass, which lies about three quarters of an inch thick upon it, but is not allowed to rise above its outer edge. The mould, being perfectly dried, must be marked with a point of coincidence on the glass, in order to permit of its being exactly replaced in the same position, after it has been lifted out. The mould is now removed, and a round sheet of tin-foil is applied to it, so large that an inch of its edge may project beyond the plaster all round; this border being necessary for fixing the tin to the contour of the mould by pellets of white wax softened a little with some Venice turpentine. Before fixing the tin-foil, however, it must be properly spread over the mould, so as to remove every wrinkle; which the GLASS-MAKING. 921 tliancy of the foil easily admits of, by uniform and well-directed pressure wih t!e Sngers. The glass being placed in the hollow bed of a tight sack filled with fine sand, set in a well-jointed box, capable of retaining quicksilver, its concave surface must be dusted with sifted wood-ashes, or Spanish white contained in a small cotton bag, and then well wiped with clean linen rags, to free it from all adhering impurity, and particularly the moisture of the breath. The concavity must be now filled with quicksilver to the very lip, and the mould, being dipped a little way into it, is withdrawn, and the adhering mercury is spread over the tin with a soft flannel roll, so as to amalgamate and brighten its whole surface, taking every precaution against breathing on it. Whcnever this brightening seems complete, the mould is to be immersed, not vertically, but one edge at first, and thus obliquely downwards till the centres coincide; the mercury meanwhile being slowly displaced, and the mark on the mould being brought finally into coincidence with the mark on the glass. The mould is now left to operate by its own weight, in expelling the superfluous mercury, which runs out upon the sand-bag and thence into a groove in the bottom of the box, whence it overflows by a spout into a leather bag of reception. After half an hour's repose, the whole is cautiously inverted, to drain Afl the quicksilver more completely. For this purpose, a box like the first is provided with a central support rising an inch above its edges; the upper surface of the support being nearly equal in diameter to that of the mould. Two workmen are required to execute the following operation. Each steadies the mould with the one hand, and raises the box with the other, taking care not to let the mould be deranged, which they rest on the (convex) support of the second box. Before inverting the first apparatus, however, the reception bag must be removed, for fear of spilling its mercury. The redundant quicksilver now drains off; and if the weight of the sandbag is not thought sufficient, supplementary weights are added at pleasure. The whole is left in this position for two or three days. Before separating the mirror from its mould, the border of tinfoil, fixed to it with wax, must be pared off with a knife. Then the weight and sandbag being removed, the glass is lifted up with its interior coating of tinamalgam. For silvering a convex surface.-A concave plaster mould is made on the convex glass, and their points of coincidence are defined by marks. This mould is to be lined with tinfoil, with the precautions above described; and the tin surface being first brightened with a little mercury, the mould is then filled with the liquid metal. The glass is to be well cleaned, and immersed in the quicksilver bath, which will expel the greater part of the metal. A sandbag is now to be laid on the glass, and the whole is to be inverted as in the former case on a support; when weights are to be applied to the mould, and the mercury is left to drain off for several days. If the glass be of large dimensions, 30 or 40 inches, for example, another method is adopted. A circular frame or hollow ring of wood or iron is prepared, of twice the diameter of the mirror, supported on three feet. A circular piece of new linen cloth of close texture is cut out, of equal diameter to the ring, which is hemmed stoutly at the border, and furnished round the edge with a row of small holes, for lacing the cloth to the ring, so as to leave no folds in it, but without bracing it so tightly as to deprive it of the elasticity necessary for making it into a mould. This apparatus being set horizontally, a leaf of tinfoil is spread over it, of sufficient size to cover the surface of the glass; the tin is first brightened with mercury, and then as much of the liquid metal is poured on as a plane mirror requires. The convex glass, well cleaned, is now set down on the cloth, and its own weight, joined to some additional weights, gradually presses down the cloth. and causes it to assume the form of the glass which thus comes into close contact witls the tin submersed under the quicksilver. The redundant quicksilver is afterwards drained off by inversion, as in common cases. The following recipe has been given for silvering the inside of glass globes. Melt in an iron ladle or a crucible, equal parts of tin and lead, adding to the fused alloy one part of bruised bismuth. Stir the mixture well, and pour into it as it cools, two parts of dry mercury; agitating anew and skimming off the drossy film from the surface of the amalgam. The inside of the glass globe, being freed from all adhering dust and humidity, is to be gently heated, while a little of the semi-fluid amalgam is introduced. The liquidity being increased by the slight degree of heat, the metallic coating is applied to all the points of the glass, by turning round the globe in every direction, but so slowly as to favor the adhesion of the alloy. This silvering is not so substantial as that of plane mirrors: but the form of the vessel, whether a globe, an ovoid, or a cylinder, conceals or palliates the defects by counter reflection from the opposite surfaces. Colored Glasses and Artificial Gems.-The general vitreous body preferred by Fontanieu in his treatise on this subject, which he calls the Mayence base, is prepared in the following manner. Eight ounces of pure rock-crystal or flint in powder, mixed with 24 ounces of salt of tartar, are baked and left to cool. This is afterwards poured 922 GLASS-MAKING. into a basin of hot water, and treated with dilute nitric acid till it ceases to effervesce. when the frit is to be washed till the water comes off tasteless. The frit is now dried and mixed with 12 ounces of fine white lead, and the mixture is to be levigated and elutriated with a little distilled water. An ounce of calcined borax is to be added to about 12 ounces of the preceding mixture in a dry state, the whole rubbed together in a porce lain mortar, then melted in a clean crucible, and poured out into cold water. This vitreous matter must be dried, and melted a second and a third time, always in a new crucible, and after each melting poured into cold water as at first, taking care to separate the lead that may be revived. To the last glass ground to powder, five drachms of nitre are to be added, and the mixture being melted for the last time, a mass of crystal will be found in the crucible with a beautiful lustre. The diamond is well imitated by this Mayence base. Another very fine white crystal may be obtained, according to M. Fontanieu, from eight ounces of white lead, two ounces of powdered borax, half a grain of manganese, and three ounces of rock-crystal, treated as above. The colors of artificial gems are obtained from metallic oxydes. The oriental topaz is prepared by adding oxyde of antimony to the base; the amethyst from manganese, with a little purple precipitate of Cassius; the beryl from antimony and a very little cobalt; yellow artificial diamond and opal from horn-silver (chloride of silver); blue stone from cobalt. See PASTES and PIGMENTS VITRIFIABLE. The following are recipes for making the different kinds of glass. 1. Bottle glass.-l11 pounds of dry glauber salts; 12 pounds of soaper salts; a half bushel of waste soap ashes; 56 pounds of sand; 22 pounds of glass skimmings; I cwt. of green broken glass; 25 pounds of basalt. This mixture affords a dark green glass. 2. Yellow or white sand, 100 parts; kelp, 30 to 40; lixiviated wood ashes, from 160 to 170 parts; fresh wood ashes, 30 to 40 parts; potter's clay, 80 to 100 parts; cullet or broken glass, 100. If basalt be used, the proportion of kelp may be diminished. In two bottle-glass houses in the neighborhood of Valenciennes, an unknown ingredient, sold by a Belgian, was employed, which he called spar. This was discovered by chemical analysis to be sulphate of baryta. The glass-makers observed that the bottles which contained some of this substance were denser, more homogeneous, more fusible, and worked more kindly, than those formed of the common materials. When one prime equivalent of the silicate of baryta = 123, is mixed with three primes of the silicate of soda = (3 X 77-6) 232-8, and exposed in a proper furnace, vitrification readily ensues, and the glass may be worked a little under a cherry red heat, with as much ease as a glass of lead, and has nearly the same lustre. Since the ordinary run of glass-makers are not familiar with atomic proportions, they should have recourse to a scientific chemist, to guide them in using such a proportion of sulphate of baryta as may suit their other vitreous ingredients; for an excess or defect of any of them will injure the quality of the glass. 3. Green window glass, or broad glass.-11 pounds of dry glauber salts; 10 pounds of soaper salts; half a bushel of lixiviated soap waste; 50 pounds of sand; 22 pounds of glass pot skimmings; 1 cwt. of broken green glass. 4. Crown glass.-300 parts of fine sand; 200 of good soda ash; 33 of lime; fiom 250 to 300 of broken glass; 60 of white sand; 30 of purified potash; 15 of saltpetre (1 of borax); 2 of arsenious acid. 5. Nearly white table glass.-20 pounds of potashes; 11 pounds of dry glauber salts, 16 of soaper salt; 55 of sand; 140 of cullet of the same kind. Another.-100 of sand; 235 of kelp; 60 of wood ashes; 1 of manganese; 100 of broken glass. 6. White table glass.-40 pounds of potashes; 11 of chalk; 76 of sand; X of manga nese; 95 of white cullet. Another.-50 of purified potashes; 100 of sand; 20 of chalk; and 2 of saltpetre. Bohemian table or plate glass is made with 63 parts of quartz; 26 of purified pot ashes; 11 of sifted slaked lime, and some cullet. 7. Crystal glass.-60 parts of purified potashes; 120 of sand; 24 of chalk; 2 of salt petre; 2 of arsenious acid; - of manganese. Another.-70 of purified pearlashes, 120 of white sand; 10 of saltpetre; 2 of arse nious acid; - of manganese. A third.-67 of sand; 23 of purified pearlashes; 10 of sifted slaked lime; l of man ganese; (5 to 8 of red lead). A fourth.-120 of white sand; 50 of red lead; 40 of purified pearlash; 20 of salt petre; ^ of manganese. A fifth.-120 of white sand; 40 of pearlash purified; 35 of led lead; 13 of saltpetre l of manganese. A sixth.-30 of the finest sand; 20 of red lead; 8 of pearlash purified; 2 of salt tctre; a little arsenious acid and manganese. GLASS-CUTTING. 923 A seventh. — 100 of sand; 45 of red lead; 35 of purified pearlashes; 1 of manganese; of arsenious acid. 8. Plate giass.-Very white sand 300 parts; dry purified soda 100 parts; carbonate of lime 43 parts; manganese 1; cullet 300. Another.-Finest sand 720; purified soda 450; quicklime 80 parts; saltpetrre 25 parts; cullet 425. A little borax has also been prescribed; much of it communicates an exfoliating property to glass. Tabular view of the composition of several kinds of Glass. No. 1. No. 2. Nio. 3. No. 4. No. 5. No. 6. No. 7. No. 8. No. 9. Silica - - 71-7 69-2 62-8 692 60-4 53-55 59-2 51-93 42-5 Soda - - 2-5 3-0 3-0 S. pot. Lime - - 10-3 7-6 12-5 13-0 20-7 29-22 0-5 Alumina - i 0-4 1-2 3-6 10-4 6-01 1-8 Magnesia - 2-0 ) 0-6 0-6 Oxyde of iron 0-3 0-5 2.6 1-6 3-8 5-74 0-4 - manganese 0-2 ) 1-0 -lead - 28-2 33-28 43-5 Baryta - 0 9 No. 1 is a very beautiful white wine glass of Neuwelt in Bohemia. No. 2. Glass tubes, much more fusible than common wine glasses. No. 3. Crown glass of Bohemia. No. 4. Green glass, for medicinal vials and retorts. No. 5. Flask glass of St. Etienne, for which some heavy spar is used. No. 6. Glass of Sevres. No. 7. London glass employed for chemical and physical purposes. No. 8. English flint glass. No. 9. Guinand's flint glass. The manufacture of Glass beads at Murano near Venice, is most ingeniously simple. Tubes of glass of every color are drawn out to great lengths in a gallery adjoining the glass-house pots, in the same way as the more moderate lengths of thermombter and barometer tubes are drawn in our glass-houses. These tubes are chopped into very smal. pieces of nearly uniform length on the upright edge of a fixed chisel. These elementary cylinders, being then put in a heap into a mixture of fine sand and wood ashes, are stirred about with an iron spatula till their cavities get filled. This curious mixture is now transferred to an iron pan suspended over a moderate fire and continually stirred about as before, whereby the cylindrical bits assume a smooth rounded form; so that when removed from the fire and cleared out in the bore, they constitute beads, which are packed in casks, and exported in prodigious quantities to almost every country, especially to Africa and Spain. GLASS CUTTING AND GRINDING, for common and optical purposes. By this nechanical process the surface of glass may be modified into almost any ornamental or iseful form. 1. The grinding of crystal ware. This kind of glass is best adapted to receive polished facets, both on account of its relative softness, and its higher refractive power, which gives lustre to its surface. The cutting shop should be a spacious long apa.tment, furnished with numerous sky-lights, having the grinding and polishing lathes arranged right under them, which are set in motion by a steam-engine or water-wheel at 725 one end of the building. A shaft is fixed as usual J E in gallowses alone the ceiling; and from the pulleys a D I " of the shaft, bands descend to turn the different:y-^t <- I l Jhlathes, by passing round the driving pulleys near C The turning lathe tuis of the simplest construction. Fig. 725, D is an iron spindle with two well-turned prolongations, running in the iron puppets a a, 11 S B. 1 between two concave bushes of tin or type metal, | 1 Ii _ which may be pressed more or less'together by the thumb-screws shown in the figure. These two A L....-......... puppets are made fast to the wooden support a, - which is attached by a strong screw and bolt to the ongitudinal beam of the workshop A. E is the fast and loose pulley for putting the 924 GLASS-CUTTING. athe into and out of gear with the driving shaft. The projecting end of the spindle l; furnished with a hollow head-piece, into which the rod c is pushed tight. This rod car. ries the cutting or grinding disc plate. For heavy work, this rod is fixed into the head by a screw. When a conical fit is preferred, the cone is covered with lead to increase the friction. Upon projecting rods or spindles of that kind the different discs for cutting the glass are made fast. Some of these are made of fine sandstone or polishing slate, from 8 to 10 inches in diameter, and from 4 to 2 inch thick. They must be carefully turned and polished at the lathe, not only upon their rounded but upon their flat face, in order to grind and polish in their turn the flat and curved surfaces of glass vessels. Other discs of the same diameter, but only 4 of an inch thick, are made of cast tin truly turned, and serve for polishing the vessels previously ground; a third set consist of sheet iron from 1 to i an inch thick, and 12 inches in diameter, and are destined to cut grooves in glass by the aid of sand and water. Small discs of well-hammered copper from 1 to 3 inches in diameter, whose circumference is sometimes flat, and sometimes concave or convex, serve to make all sorts of delineations upon glass by means of emery and oil. Lastly, there are rods of copper or brass furnished with small hemispheres from -1 to 1 of an inch in diameter, to excavate round hollows in glass. Wooden discs are also employed for polishing, made of white wood cut across the grain, as also of cork. The cutting of deep indentations, and of grooves, is usually performed by the iron disc, with sand and water, which are allowed constantly to trickle down from a wooden hopper placed right over it, and furnished with a wooden stopple or plug at the apex, to regulate by its greater or less looseness the flow of the grinding materials. The same effect may be produced by using buckets as shown in fig. 726. The G 726 sand which is contained in the bucket F, above the lathe, has a spigot and faucet inserted near its bottom, and is supplied with a stream of F 2SFFA~ water from the stopcock in the vessel G, which, together running down the inclined board, are conducted to the periphery of the disc as shown in the figure, to whose lowest point the glass vessel is applied with pressure by the hand. The sand and water are afterwards collected in 5J the tub H. Finer markings, which are to remain without lustre, are made with the small copper discs, emery, and oil. The polishing is effected by the edge of the tin disc, which is from time to time moistened with putty (white oxyde of tin) and water. The wooden disc is also employed for this purpose with putty, colcothar, or washed tripoli. For fine delineations, the glass is first traced over with some colored varnish, to guide the hand of the cutter. In grinding and facetting crystal glass, the deep grooves are first cut, for example the cross lines, with the iron disc and rounded edge, by means of sand and water. That disc is one sixth of an inch thick and 12 inches in diameter. With another iron disc about half an inch thick, and more or less in diameter, according to the curvature of the surface, the grooves may be widened. These roughly cut parts must be next smoothed down with the sandstone disc and water, and then polished with the wooden disc about half an inch thick, to whose edge the workman applies, from time to time, a bag of fine linen containing some ground pumice moistened with water. When the cork or wooden disc edged with hat felt is used for polishing, putty or colcothar is applied to it. The above several processes in a large manufactory, are usually committed to several workmen on the principle of the division of labor, so that each may become expert in his department. 2. The grinding of optical glasses.-The glasses intended for optical purposes, being spherically ground, are called lenses; and are used either as simple magnifiers and spectacles, or for telescopes and microscopes. The curvature is always a portion of a sphere, and either convex or concave. This form ensures the convergence or divergence of the rays of light that pass through them, as the polishing does the brightness of the image. The grinding of the lenses is performed in brass moulds, either concave or convex, formed to the same curvature as that desired in the lenses; and may be worked either by hand or by machinery. A gauge is first cut out out of brass or copper plate to suit the curvature of the lens, the circular arc being traced by a pair of compasses. In this way both a convex and concave circular gauge are obtained. To these gauges the brass moulds are turned. Sometimes, also, lead moulds are used. After the two moulds are made, they are ground face to face with fine emery. The piece of glass is now roughed into a circular form by a pair of pincers, leaving It a little larger than the finished lens ought to be, and then smoothed round upon the stone disc, or in an old mould with emery and water, and is next made fast to a hold. fast. This consists of a round brass plate having a screw in its back; and is somewhat smaller in diameter than the lens, and two thirds as thick. This as'turned concave upon GLASS-CUTTING. 925 the lathe, and then attached to the piece of glass by drops of pitch applied to severa, points of its surface, taking care, while the pitch is warm, that the centre of the glass coincides with the centre of the brass plate. This serves not merely as a holdfast, by enabling a person to seize its edge with the fingers, but it prevents the glass from bending by the necessary pressure in grinding. The glass must now be ground with coarse emery upon its appropriate mould, whetheconvex or concave, the emery being all the time kept moist with water. To prevent the neat of the hand from affecting the glass, a rod for holding the brass plate is screwed to its back. For every six turns of circular motion, it must receive two or three rubs across the diameter in different directions, and so on alternately. The middle point of the glass must never pass beyond the edge of the mould; nor should strong pressure be at any time applied. Whenever the glass has assumed the shape of the mould, and touches ii in every point, the coarse emery must be washed away, finer be substituted in its place, and the grinding be continued as before, till all the scratches disappear, and a uniform dead surface be produced. A commencement of polishing is now to be given with pumice stone powder. During all this time the convex mould should be occasionally worked in the concave, in order that both may preserve their correspondence of shape between them. After the one surface has been thus finished, the glass must be turned over, and treated in the same way upon the other side. Both surfaces are now to be polished. With this view equal parts of pitch and rosin must be melted together, and strained through a cloth to separate all impurities. The concave mould is next to be heated, and covered with that mixture in a fluid state to the thickness uniformly of one quarter of an inch.,The cold convex mould is now to be pressed down into the yielding pitch, its surface being quite clean and dry, in order to give the pitch the exact form of the ground lens; and both are to be plunged into cold water till they be chilled. This pitch impression is now the mould upon which the glass is to be polished, according to the methods above described, with finely washed colcothar and water, till the surface become perfectly clear and brilliant. To prevent the pitch from changing its figure by the friction, cross lines must be cut in it about ^ an inch asunder, and 1-12th of an inch broad and deep. These grooves remove all the superfluous parts of the polishing powder, and tend to preserve the polishing surface of the pitch clean and unaltered. No additional colcothar after the first is required in this par' of the process; but only a drop of water from time to time. The pitch gets warm as the polishing advances, and renders the friction more laborious from the adhesion between the surfaces. No interruption must now be suffered in the work, nor must either water or colcothar be added; but should the pitch become too adhesive, it must be merely breathed upon, till the polish be complete. The nearer the lens is brought to a true and fine surface in the first grinding, the better and more easy does the polishing become. It should never be submitted to this process with any scratches perceptible in it, even when examined by a magnifier. As to small lenses and spectacle eyes, several are ground and polished together in a mould about 6 inches in diameter, made fast to a stiffening plate of brass or iron of a shape corresponding with the mould. The pieces of glass are affixed by means of drops of pitch, as above described, to the mould, close to each other, and are then all treated as if they formed but one large lens. Plane glasses are ground upon a surface of pitch rendered plane by the pressure of a piece of plate glass upon it in its softened state. Lenses are also ground and polished by means of machinery, into the details of which the limits of this work will not allow me to enter. GLAss IN THE EXHIBITION. —So far as may be inferred, from the analysis of ordinary" commercial samples of window-glass, this substance has not only a very variable composition, but, worse than this, is out of all keeping with anything like definite proportion. That it should be full of strice, and, therefore, refract the rays of light equally, as it does, so as to produce the most hideous appearances of distortion, is a mere natural consequence of its mechanical composition, which might, and must one day, be corrected; but that whole nations should have come to view this defect as an unavoidable peculiarity, is precisely one of those surprising facts which demonstrate the influence of habit over the powers of the mind, and show how easily human reason can reconcile itself to the most gross inconsistencies. If window-glass had one uniform atomic composition, the tendency to form these strife would nowhere exist in excess; and, therefore, their production would diminish as the skill of the workmen increased; but, with the present variable compound, the glass stretches unequally in different parts, by an equal application of force, and, in spite of human skill, presents a result alternately thick or thin, as accident determines. That these strime have not the same composition as the parts surrounding them is very obvious, from the circumstance that, if striated glass be cut to an uniform thickness, and polished on both sides, the optical defects remain but little changed, and bccasionally they are found to be increased. Again it is known, that the more complex the composition of any glass may be, the greater the liability to this striated 926 GLASS. structure,-of which flint glass offers an opposite illustration. for here, in addition to the ordinary components of glass, the silicate of lead is superadded. Now the speziii gravity of silicate of lead is very high compared with that of silicate of soda, potash, or lime; hence, unless employed in the exact quantity to form a chemical combination with the other silicates, a mere mechanical mixture is produced of very different densities throughout; and the product, under the action of light, displays, permanently, that peculiar fugitive appearance, seen when syrup and water, or alcohol and water, are mixed together: that is to say, a series of curved lines are formed, by the unequal refraction of the two fluids, which entirely disappear, so soon as perfect admixture has taken place, but which remain in the case of flint glass, from the utter impossibility or affecting the necessary union between its various parts. Although, however, this cannot be done mechanicallyv vet, in a chemical way, nature performs such operations with ease and unerring fidelity. The French chemist, Berthier, long ago proved that many neutral salts combine together by fusion in atomic proportions, and form new, anc definite compounds. Thus, carbonate of potash and carbonate of soda when mixed, atom for atom, unite and produce a compound more easy of fusion than the most fusible of the two:-similarly, either of these carbonates will act with carbonate of baryta or stronchia, and again, flour-spar and sulphate of lime, two remarkably infusible substances, when mixed, melt readily, at a low red heat, into a fluid as mobile and transparent as water. It is useless to multiply examples of this kind, for thousands exist; and the alkaline and earthy silicates form no exception to this almost universal rule. A mixture of silicate of potash and silicate of soda, will, if in atomic ratios, fuse much more readily than either of them alone. But now, let us imagine an attempt to fuse these two bodies together, in any other proportion than that in whicl they are naturally disposed to combine;-say that the silicate of soda is in excessthen the silicate of potash would unite with exactly sufficient of the silicate of soda to produce the extremely fusible compound above spoken of: whilst the less easily fusible silicate of soda, added in excess, would form a kind of network throughout the mass. It may be said, that a higher heat would overcome this difficulty, by thoroughly hquifying the silicate of soda; and this is really the plan now used with that view; but, independent of the fact, that the mixed silicate of potash and soda would also undergo a corresponding liquefaction, and, therefore, favour the separation of the silicate of soda; yet, as chemical union is impossible, from the very conditions of the experiment, even the most perfect mechanical mixture, under the greatest advantages of fluidity, would never generate a homogeneous body. The strife might, indeed, be diminished in size; but this would imply a corresponding increase in their number; and, if carried very far, complete opacity would result from such an endeavour to subvert the laws of nature. The power of the workmen to remedy this defect is therefore limited to the capability of modifying its more salient features; he can neither remove nor destroy it. What we have here illustrated by the simplest of all assumptions, gathers and accumurates into a formidable evil, when several silicates are fused together, having considerable differences of specific weight. Thus, in the case of flint glass before alluded to, there are generally three, and sometimes five, of these silicates fused together, into, probably, one of the most antagonistic compounds that could be conceived, refracting and dispersing the ray of light in fifty different directions, and demonstrating the unfriendly nature of its coerced union, by flying in pieces from the most trivial applications of heat or violence. Yet in flint-glass we are not surpassed, nor indeed equalled, by any other nation; and so thoroughly has this beautiful substance become associated with our industrial reputation, that the name, flint-glas, has been adopted into several continental languages. Nevertheless, it cannot be doubted that a wide field of improvement is open in this quarter, and that some more solid foundation is needed by our manufacturers in this line, than the prestige of a name, or the force of capital. In our concluding remarks we shall point out the direction in which improvement is practicable; and at present it may not be uninteresting to examine the contents of the Great Exhibition in respect to this kind of glass. The display of goods by Messrs. Apsley, Pellatt and Co., is alone sufficient to exhaust the entire subject of flint-glass; and the mere inquirer into this branch of manufacture need go no farther to get a perfect conception of the wonders that can be achieved by the manipulation of this material. The coup d'ceil is certainly most beautiful; but, supported as it is and nultiplied by the rival exhibitions of Messrs. Osler, Harris, Bacchus, Powell, Lloyd and Summerfield, and a host of others, the effect is positively dazzling and gorgeous. At a distance sufficient to cover the faults of refraction, not even the diamond itself has a more pleasing appear ance; and indeed, the glass koh-i-noor of Mr. Pellatt, displayed in the gallery, might be substituted for the real gem, shown in the main avenue, without the least risk of detection on the part of the million, or any great loss of brilliancy to the most practised eye,o( perfect is the imitation. Is it not then to be deplored, that science has had no hand it i I~~__ ^ GLASS. 92T mingling its constituents together? But we must turn from this glittering assortment and descend to a lower level, where we shall find Great Britain in disgrace, and suffering severely from comparison with a rival inferior in capital and natural resources, but conscious of power through the aid of real knowledge, and triumphantly asserting a claim to supremacy in the very perfection of the glass-maker's art. The plate-glass of France casts that of England far into the shade. The productions of St. Gobain stand alone in the Exhibition; they have no competitors; and we are in a condition to prove that chemistry has done this. Tlhe plate-glass of Montlucon, too, adds to the defeat. In examining the refractive aberrations of a mirror, the spectator will find his task facilitated by standing so that the rays Gf light from any geometrically shaped body fall upon the glass, at an angle of 25~; when, of course, they will be reflected towards his eye at the same angle. Now gazing intently on the figure in question-and which, in the Exhibition, may be one of the parallelograms formed by the rafters of the roof, let him gently move his head from one side to the other. If the glass be of English manufacture, he will immediately perceive a tumultuous movement in the lines of the figure, as if this were subjected to an undulatory action,-the lines, before straight and parallel, become crooked and con-rgent in places, and minute objects lose entirely their outline and definition. In the case of the St. Gobain glass, shown in the French department, nothing of this kind takes place. As it can serve no good purpose to dwell upon each individual example of imperfection, we refrain from entering further into the comparative merits of the British exhibitors. They are all surpassed by the French makers, both in respect to uniformity of composition and fineness of polish. The St. Gobain Company having had Cle good sense to place a number of small samples of their glass for the acceptance of those visitors who may feel an interest in the manufacture, we have selected and analyzed one of these little squares, and shall presently detail the result; but our object in alluding to them here is, that glass-makers themselves may procure one of these specimens and contrast it with a like morsel of English plate-glass. If the two be laid side by side upon any moderately light-coloured ground, and a distant object, as a chimney for ex ample, be subjected to reflection, it will be found, that whilst the French glass gives a clear sharp outline, the English reflects either two or more images in a hazy and imperfect manner. There is no getting over this fact; and therefore improvement is imperative. The mode of making plate-glass being, so to say, identical in the two countries, the difference here remarked can arise from nothing elke than a difference in composition. In France, as in England, the ingredients are mixed with some care, and introduced into a crucible, heated by a powerful furnace. These ingredients are sand or silica, carbonate of soda, and carbonate of lime, with perhaps a little ground felspar in some cases. The carbonate of soda is first attacked by the silica, and its carbonic acid driven off, whilst the remaining silica and carbonate of lime becomes imbedded in the vitrifying mass. As the heat increases, a more perfect fusion takes place; and then the carbonic acid of the carbonate of lime makes its way through the fused materials by which they are mechanically mingled together during the effervescence, which is technically termed the "boil;" and, provided no after separation ensues from the process of " settling," the whole crucible or "pot' of glass will have a uniform composition, But, as we have seen, this depends altogether upon the relative proportion of the materials towards each other, for an excess of either one or other of the bases will destroy the homogeneous character of the whole, and introduce a plexus of strieN. Now the plate-glass of St. Gobain is almost exactly an atomic compound, and consists of one atom of the trisilicate of soda and one atom of the trisilicate of lime, with a small per-centage of alumina. The union is therefore coizplete; and when it is remembered that the celebrated French chemist, Gay Lussac, was reg.uarly employed as an adviser to this company, and that his son, M. Jules Lussac, retains that appointment to this day, it is not very surprising that our manufacturers are defeated in the article of plate-glass. Science must ever take the lead of prejudice and custom. The examination of English plate-glass fully corroborates the general result deduced fiom the action of light. There is no approach to an atomic arrangement. The principal constituent is trisilicate of soda, but variable quantities of lime, alumina, and even magnesia, exist in it. Potash is sometimes present, and oxide of iron is invariably so; but in not one single instance, out of 17 samples examined with great care, could so much as a surmise of the doctrine of combining proportions be gathered from the result of the analyses. Similarly fruitless was a research instituted upon flintglass, both British and foreign. Of 35 samples analyzed, no satisfactory evidence could be adduced to favour the opinion that science had been a helpmate to industry, or was at all concerned in this branch of manufacture. There are, however, some points of vast interest associated with the practical working out of this matter. Potash is known to give a more brilliant and harder glass than soda, and alumina seems to tend in the same direction. The Bohemian glass, so celebrated throughout Europe, is a glass of this description, and contains silicate of alumina, silicate of lime, and silicate of 39*d28 ~ GLASS. potash, bu; not in chemical proportions. This glass is therefore striated, as may be seen by examining that in the Austrian department; but it seems to permit of a more perfect decoration by metallic oxides than can be developed in glass of lime and soda. This very probably depends upon the alumina contained in it. From some singmlal oversight, the use of carbonate of baryta has not yet found its way into the composition of glass, though we can scarcely conceive a more hopeful material. This substance may be had in large quantity in the North of England, of great purity, and at a merely nominal cost as compared with its value for such a purpose as glass-making That it would fuse readily with a due amount of soda, and give "a boil" as well as chalk, there can be no doubt; whilst its great density will certainly improve the refractive power of the resulting product, and thus rival the brilliancy of lead or flintglass, without imparting that softness and liability to receive scratches which are so objectionable in the latter variety. One difficulty may perhaps reside in the want of information concerning the quantity to be employed. But this is easily adjusted; for it has been demonstrated that, during vitrification, the silicic acid unites to bases in the proportion of three atoms to one: consequently three atoms, or 138 parts, will always require one atom of each base. Therefore, this weight of good dry sand may be set against 54 of dry carbonate of soda, 70 of carbonate of potash, 50 of pure marble or chalk, 99 of carbonate of baryta, and 112 of oxide of lead or litharge. Suppose, then, that the object is to employ carbonate of baryta for the first time, here 6 atoms or 276 parts of sand, 1 atom or 54 parts of dry carbonate of soda, and 1 atom or 99 parts of carbonate of baryta, may be mixed and fused together with every prospect of obtaining a good result; or 9 atoms of silica, 1 of carbonate of potash, 1 of carbonate of soda, and 1 of carbonate of baryta, might be tried without fear of failure. Again, in the case of flint-glass, 112 of litharge, 54 of soda, and 276 of sand, would probably succeed, or an additional atom of trisilicate of potash might be used. For many years past, M. Dumas, now, perhaps, the first chemist in France, has been in the habit of demonstrating to his pupils that glass of all kinds, when properly made, must necessarily be an atomic compound; and yet we scarcely expect to find a single British glassmaker who will admit that his art is susceptible of such decisive and beautiful simpli. fication. To assist as far as we can in the attainment of this end, we shall proceed to describe a simple means for the analysis of glass, which will enable any person, possessed of even very trifling chemical skill, to determine the composition of any given sample of glass in a comparatively short time. From the nature of the material, it becomes necessary to divide the analysis into two distinct portions; one of which has for its object the estimation of its alkaline ingredients, the other that of the earthy, metallic, and siliceous matters. Having heated a sufficient quantity of the sample in question to dull redness, it must be suddenly thrown, whilst still hot, into a basin containing cold water. In this way it becomes cracked and flawed in all directions, so as to favour its reduction into powder. When dry it must, therefore, be carefully ground in an agate or steel mortar, until it has the appearance of fine flour. Nor is it a matter of indifference whether this takes place in contact with water or not; for glass, in this extreme state of comminution, readily gives up a part of its alkali to water; and hence, if ground in the presence of that fluid, the resulting analysis would prove incorrect. But we will suppose that a quantity of finely powdered glass has been obtained as above indicated, and the amount of its alkali is desired; then weigh out 100 grains of the glass, and carefully mix with it 200 grains of pure fluor spar in a similarly powdered condition. Place the mixture in a platinum or leaden vessel, and pour over it 500 grains of strofng sulphuric acid,stirring the whole well together with a silver spoon; but taking care not to remove any portion of the materials. Next, apply a heat of about 212~ Fahr.; and as the process draws to a conclusion, this may be raised as high as 300~. When all evolution of gaseous fumes has ceased, water may be poured on the residuary mass to the extent of four or five ounces, and the mixture thrown on a filter. After the clear fluid las passed through, a little more water must be added to the filter, so as to wash out the whole of the soluble matter; these washings being joined to the original clear fluid, which consists of sulphate of soda or potash, or both, with a quantity of sulphate of lime, and perhaps also of magnesia and alumina. To this an excess of carbonate of ammonia must now be added, to admit of the separation of the earthy salts being effected by filtration. The clear solution is next boiled down to dryness, and the residue is heated red-hot for a minute or two. This residue is the soda or potash, or both, formerly contained in 100 grains of the glass, but now united to sulphuric acid. Having ascertained its weight, the relative proportions of potash and soda may be found by testing its content of sulphuric acid with a barytic solution, and calculating the result by the well-known Archimedean equation; or by dissolving the mixed salt in a small quantity of water, and, after adding an excess of tartaric acid, leaving the whole for a few hours covered up in a cool place. Almost the whole of the potash will separate ir GLASS. 929 this way as bitartrate of potash. The quantity of alkali may be determined from the atomic constitution of the alkaline salts. Thus, supposing the dry residue altogether composed of sulphate of soda, then as 72 grains of it indicate 32 of pure soda, the result may be obtained by the rule of proportion. The amount of alkali being known, another portion of the powdered glass must be employed for ascertaining the remainder of the ingredients. That is to say, 100 grains of the sample must be mixed with 200 grains of pure potash, and the whole fused together in a silver crucible, at a red heat, until perfect liquefaction ensues, when the crucible and its contents may be withdrawn from the fire, and, as soon as cool enough, boiled in half-a-pint of pure water, so as thoroughly to dissolve the fused mass from the crucible. An excess of nitric acid being poured into the solution, the mixture is then evaporated to dryness, by which means the silicic acid is rendered insoluble; consequently, on the application of water, this remains, and may be dried and weighed, whilst the lime, alumina, and lead of the glass may be separated from the soluble portion by the addition, first, of sulphuretted hydrogen, which separates the lead, then of ammonia, which throws down the alumina, and, next, by pouring in carbonate of ammonia, which precipitates the lime as a carbonate. Thus, therefore, the alkaline matters are found by one process, and the silica, earthy, and metallic constituents by another, both of which may be conducted at the same time. It has been recommended to employ carbonate of baryta in the analysis of glass; but the high temperature required with this substance dissipates a portion of the alkaline components, and thus leads to serious errors. Even mere fusion in a glass furnace expels soda from glass, and renders it more and more infusible; but this expulsion is much favoured by the presence of baryta. The above method of analyzing glass is, therefore, to be preferred to the baryta plan, by individuals not habitually engaged in manipulative chemistry. Until manufacturers adopt the custom of examining every specimen of glass they make, the chances of improvement are extremely limited; for success one day is constantly followed by failure in another, without any means of checking or controlling the manufacture. It is generally said that the best glass is made during cold weather, as at this time the furnaces give most heat, from the increased activity of the draught, through the augmented barometrical pressure. The assertion itself is most likely true; but the explanation of its cause leaves much to be elucidated, even if a higher heat prevails at the period in question. Admitting the beneficial agency of a high temperature, or "sharp fire," as it is termed, this perhaps depends upon the sudden fusion of the materials before the carbonic acid of either of the carbonates has had time to escape; consequently, a much more active " boil" and thorough intermixture must occur under such circumstances than where this gas has been suffered to pass off in great part before fusion. This, however, would only diminish the individual size of the strive by multiplying their number; and such glass must, even under the most favourable circumstances, suffer greatly by comparison with that of St. Gobain. Nor can improvement be hoped for until, as in France, in this particular case, science is linked hand in hand with manufacturing industry. Since the grand discovery made by Dalton, that Nature works in definite proportions, there can be no excuse for continuing to follow the doctrine of chance, with its occasional successes and frequent failures-the alternations of hope and despair. The laws which regulate the entire universe are not more immutable than those which tend to unite silica and soda in equivalent proportions. It is, therefore, simply futile to battle with such a power; for even when success seems on the point of attainment, we find Nature reasserting her dominion, and stamping those works of man which have been pursued in defiance of her laws with the indelible impress of imperfection and error. That glass of all kinds may be made in this country quite equal to that of St. Gobain, is saying no more than that Nature's laws are universal. But, remembering the great facilities we possess as a glass manufacturing nation, the attainment even of such a result is but a sorry flight of ambition. We are placed in a position which demands from us something more than mediocrity or successful competition, as no nation in the world possesses the same amount of natural advantages. In fuel, in soda, in sand, in chalk, in litharge, we are naturally rich to overflowing. Our capital and commerce give us the command of every market; our manufacturers need only ask and have. So long as a miserable fiscal impost sat like an incubus upon the back of the glass-making interest, inferiority was unavoidable; but the humiliating aspect of the British plate glass throughout the Great Exhibition is scarcely palliated by this excise reminiscence; and we refrain from terming it a national disgrace only under a belief that already improvement has begun, which will thrust these specimens into the oblivious records of the past. AN ACHROMATIC TELESCOPE of gigantic dimensions and powers, which is now being constructed for the Rev. Mr. Craig, Vicar of Leamington, under the superintendence of W. Cravatt, Esq. F.R.S., has been the occasion of the manufacture of some admirable 930 GLASS. optical flint object glasses at the great works of Messrs. Chance, of Birmingham. It is 24 inches in diameter, and is perfectly clear and homogeneous in structure. The crown glass lens, of like size, is of plate glass, cast by the Thames Plate-glass Company. The total length of the telescope in use will be 85 feet, but the real focal length of the lens is much less, being probably about 76 feet. A quarter of an inch letter can be read with this telescope, even in its imperfect state, at the distance of half a mile. It promises to be as powerful as Lord Rosse's colossal reflector, and it is mounted, in its observatory, on Wandsworth Common on such mechanical principles, as to be moveable in any direction with the slightest touch of the finger, while it can be directed to objects at 80~ of elevation above the horizen. The weight of the tube is 3 tons; it is quite inflexible and free from tremor or vibration. The chain by which the tube is lowered or raised, is capable of raising a weight of 13 tons. A gentle touch on the wheel of the iron railway, on which it moves, lifts 20 cwt. GLASS FROM ALKALINE SULPHATES. Messrs. Balmain and Parnell have patented a process for making glass from alkaline sulphates, in which they first make a silicate by igniting sulphate of soda with sand and charcoal powder, for example, so as to contain from about 12 to 20 per cent. of alkali. To make a silicate of about 20 per cent. of soda, they mix 3 cwt. of sand, 2 cwt. of dry sulphate of soda in fine powder, and from 16 to 18 lbs. of finely ground charcoal, and heat the mixture to whiteness in a furnace. As the silicate falls from the furnace it is received into a vessel of water, which renders it more easy to grind, and by dissolving the excess of sulphate, presents that substance in a convenient form for being recovered. To make a silicate of soda of 12 per cent. of soda, 3 parts of sand and 1 pait of sulphate of soda are mixed, and the mixture is heated, with occasional stirring, in the furnace. By exposure to a low red heat for from 6 to 10 hours, a perfect silicate of soda will be formed. A silicate of potash of 26 per cent. is made by heating 3j cwt. of sand, 2~ cwt. of sulphate of potash, and 18 pounds of charcoal. Sometimes both a sulphate and carbonate of a base are used together; and sometimes two bases are used to make a double silicate. In all cases, chemical equivalents are observed; a single equivalent of charcoal to one of sulphate. To make a double silicate of soda and barytes, either of the following mixtures may be used:No. 1., 273 parts of sand, 72 sulphate of soda, 117 sulphate of barytes, and 12 charcoal. No. 2., 273 sand, 72 sulphate of soda, 99 carbonate of barytes, and 6 charcoal. A flow of sulphate indicates want of charcoal, and a brown colour in the result an excess of charcoal; but both of these accidents may be produced by too low a heat in the furnace. The highest working temperature is a fair white heat. The addition of 5 or 10 per cent. of common salt aids the fluxing, and is not hurtful to the result. The sulphate should be in fine powder. The patentees also use a sulphuret or hyposulphite as a decomposing agent for the sulphates instead of charcoal. Half an equivalent proportion of sulphuret, or a single equivalent of hyposulphite, should be used in the place of each equivalent of the charcoal; as, for example, 20 parts of sulphuret of sodium for 6 parts of charcoal. These decompositions and combinations are effected by means of a peculiar reverberatory furnace, with two inclined beds or flues through which the fire passes and plays.NVewton's Journal, xxxv. 223. The duties payable in the United Kingdom, upon the different descriptions of glase are, for:~ s. d. Window glass, any kind, not exceeding - inch thickness - - - - 0 3 6 per cwt. All glass exceeding g inch thickness, and all silvered or polished glass, superficial measure: - - - - Not exceeding 9 square feet - - 0 0 3 per square foot Exceeding 9 and not 14 square feet - 0 0 6 - 14,, 36,, - 0 07 - - 36 and upwards - -0 0 9 Painted or ornamented - - 0 0 9 per superficial foot. All white flint glass bottles, not cut, engraved, or otherwise ornamented, and beads and bugles - - - - - 0 0 per lb. Wine glasses, tumblers, and all other white flint glass goods not cut, engraved, or otherwise ornamented - - - -0 0 1 All flint cut glass, flint coloured glass, and fancy ornamental glass - - - 0 0 2 per lb. GLASS (BOHEMIAN). 931 ~ s. d. Bottles of glass covered with wicker (not being flint or cut glass), or of green or common glass - 0 0 9 per cwt. Unenumerated, and old broken glass - - 0 3 6 per cwt. GLASS, AUSTRIAN. M. Peligot states that the hard glass of Bohemia is composed of 100 parts of silica, 12 parts of quicklime, and only 28 parts of carbonate of potash. These proportions give a glass quite unmanageable in ordinary furnaces; but the addition of a comparatively small quantity of boracic acid is capable of determining fusion, and the result is a glass having all the requisite limpidity at a high temperature and possessing at the same time a great brilliancy and hardness. GLASS, BOHEMIAN. Glasses are silicates which must contain at least 50 per cent. of silica; the more there is of it, the more perfect, unalterable, hard, and infusible is the glass. The hardest, most beautiful, and most perfect glass, is found in nature in the state of pure silica in rock crystal. To render silica fusible, certain fluxes must be added: these fluxes are potassa, soda, lime, and oxide of lead. Silica fuses very well with the alkalis, but the resulting glat is rapidly changed by absorbing moisture from the air. To prevent this alteration, it is always necessary, in the manufacture of glass, to introduce a certain quantity of lime or of oxide of lead. In the following table is given the analyses of a certain number of Bohemian glasses, which will indicate their composition with precision. (1.) (2.) (3.) (4.) (5.) (6.) (7.) I (8.) l Silica- --- - 1-6 717 69-4 62-8 75-9 78-85 70- 57 Potassa -—. — 11-0 12-7 11 8 22-1 - 55 20- 25Soda - - ---- 23 - - 17 5 12-05 Lime - - ---- 10- 10-3 9-2 125 3-8 5-6 4- 12-5 Magnesia - - - - 2'3 Alumina - - - - 22 0-4 9-6 2-6 2-8 3'5 5' 3. I Oxide of Iron - - - 39 0-3 -- 0-6 1-3 I Oxide of Manganese - 0-2 0.2 - 0-4 0-4 1012 I 98-1 100 100 100- 100-5 100- 99-2 (1.) Bohemian glass from Neufeld, (M. Grus); its composition is represented, nearly, by the formula, Ca S5 4+ (Al F) S5 + (K Mg Mn) S5. (The reader will remember, that these are mineralogical, and not chemical, symbols' since the letters signify the oxides, or acids, and not the elementary bases, as they would in chemistry.-Trans.) (2.) A fine table glass from Neuwelt (M. Berthier); it is exceedingly beautiful, and is prepared, according to M. Perdonnet, with a mixture of 100 quartz, 50 caustic lime, 75 carbonate of potassa, and a very small quantity of nitre, arsenious acid, and oxide of manganese. The presence of arsenic cannot be detected by analysis. The composition of this glass is expressed by the formula C S6 + (K N) S 6. (3.) Old Bohemian glass, (M. Dumas); its formula is (Al C K) S4. (4.) Crown glass of German manufacture, (M. Dumas); its composition is expressed by the formula (K C) S 4. (5.) Glass for mirrors, (M. Dumas); it is represented by the formula (N Al C) S 6. (6.) Another glass for mirrors, (M. Dumas); its formula lies between B S 5 and B S6. (7.) White table glass, from Silberberg near Gratzen; its composition is exactly expressed by the formula, 2 (K Ca) S5 + (Al F) S5. (8.) Mirror glass from New-Hurkenthal, for the manufacture of cast mirrors. It shows a greenish tint in section, and softens at a gentle heat. Its composition is nearly represented by the formula (Al F) S3 + 6 (K C M) S3, or more simply (K C Al) S3. Properties of Glass, Transparence, Colourlessness.-Transparence and colourlessness are the first properties of glass: to obtain them, the materials must be employed extremely pure, and the least possible flux added; an excess of potassa gives the glass a greenish tint; soda and its salts give it a yellow tint, and lime renders it milky. A very small quantity of the sulphate of potassa, or soda, gives it a yellowish, or blackish, brown green; iron colours it strongly bottle green; and an excess of the manganese employed to remove the coloration due to the oxide of iron, gives it a bluish tint, which becomes a decided violet by the action of the solar light. If the minium employed in 60 932 GLOVE MANUFACTURE. the manufacture of crystal contains a little copper, which very often happens, the crystal takes a slight emerald green tint; this, however, is not to be feared in Bohemia, where there is but a single establishment which makes lead glass. Charcoal colours glass of a topaz yellow, more r: less dark, and sometimes reaching a purple, so that it is impossible to obtain a perfectly colourless glass in furnaces which smoke, or in those which are heated by turf, lignite, or bituminous coal; and in these cases it is necessary to employ covered crucibles, as is done in the manufactory of crystal at Choisy-le-Roi; it is also necessary on this account, when in the fabrication of glass the alkaline carbonates are replaced by sulphate of soda, to add in the crucible a little (about -)) less of carbon than would be necessary to reduce the sulphate completely, and even thus but common glass is obtained by this process, since the slight excess of sulphate of soda, which must be left, gives a blackish brown tint. Hardness, Elasticity.-The Bohemian glass is, within certain limits, perfectly elastic. and very sonorous; when well made, it is sufficiently hard to strike fire with steel, and is scratched with difficulty. The lead glasses, on the other hand, have but little hardness, and less in proportion as they contain more oxide of lead; besides which they rapidly lose their brilliancy by use. Fusibility, Cooling, Annealing, Devitrificatios.-All glass is more or less fusible; when it is softened by the action of heat, it may be worked with the greatest ease, and may be drawn out into threads as fine as those of the cocoon of the silkworm. Glass, when it is submitted to rapid cooling, becomes very fragile, and presents several very remarkable phenomena, among which I will cite as an example Prince Rupert's drops. Glass supports variations of temperatures better in proportion as it has been more slowly cooled; thus, when it has been but slightly annealed, or not at all, its fragility may be considerably diminished by annealing it in water, or better, in boiling oil. All glass exposed during a longer or shorter time to a heat sufficiently elevated, loses its transparency, and becomes extremely hard, and much less brittle than before. There takes place a phenomenon precisely similar to that which we see taking place every day, by the slow cooling of the slags of our smelting furnaces, and especially in volcanic lavas. Glass with a soda base is more fusible and less hard than that whose base is potassa. Density.-Below is given the density of several glasses without lead:Old Bohemian glass (Dumas) - -.. 2-396 Bohemian bottle glass - - - 3-782 do. window glass - - - - - - 2-642 Fine glass, called Bohemian crystal - - - - 2'892 Mirror glass of Cherbourg, (Dumas) - -.- 2-506 do. St. Gobain - - - - - - 2488 do. Newhaus 1812, (Scholz) -. - 2551 do. do. 1830. - - - 2.653 Action of Atmospheric and Chemical Agents.-The harder and more infusible a glass is, the less is it alterable by the action of atmospheric and chemical agents, with the exception of hydrofluoric acid. Glass which is too alkaline attracts gradually the moisture of the air and loses its lustre and polish. Many glasses are perceptibly attacked by a prolonged boiling with water, and afortiori by acid and alkaline solutions; thus, the bottle glass is frequently attacked by the tartar which is found in the wine. According to Guyton Morveau all glass which is attacked by prolonged boiling with concentrated solutions of alum, common salt, sulphuric acid, or potassa, is of bad quality. The silica which is employed in Bohemia in the manufacture of glass, is obtained by calcining crystalline quartz, and afterwards pounding it while dry. When the quartz has been heated to a cherry-red, it is withdrawn from the fire, and thrown immediately into cold water. Almost all the Bohemian glass is a potash glass, because soda and its salts give to glass a sensible yellowish tint. The limestone which is used is as white as Carrara marble. The clay employed for the crucibles is very white, and consists of silica 45-8, alumina 40-4, and water 13-8O. GLAUBER SALT is the old name of sulphate of soda. GLAZES. See POTTERY. GLAZIER, is the workman who cuts plates, or panes of glass, with the diamond, and fastens them by means of putty in frames or window casements. See DIAMOND, for an explanation of its glass-cutting property. GLOVE MANUFACTURE. In February, 1822, Mr. James Winter of Stoke tnder-Hambdon, in the county of Somerset, obtained a patent for an improvement upon GLOVE-SEWING. 933 a former patent machine of his for sewing and 728 dA pointing leather gloves. Fig. 727 represents a pedestal, upon which the instrument called 8a/ b 1 732 the Jaws is to be placed. Fig. 728 shows the af d arcf " Ag Jaws, which instead of opening ana closing by Ita — 1 // \\ a circular movement upon a joint as described Ut e ~ ~ % in the former specification, are now made to MayL pkR790m9 Rago open and shut by a parallel horizontal movef --- n |Rnu a ment, effected by a slide and screw; a a is the 7271'733 fixed jaw, made of one piece, on the under L/ 0 A 0~ ~ side of which is a tenon, to be inserted into the top of the pedestal. By means of this tenon the jaws may be readily removed, and 0 another similar pair of jaws placed in their stead, which affords the advantage of expediting the operation by enabling one person to prepare the work whilst another is sewing; b b is'E731 the moveable jaw, made of one piece. The E[ I xtwo jaws being placed together in the manner shown atfig. 728, the moveable jaw traverses l E4~ =backwards and forwards upon two guide-bars, c, which are made to pass through holes exW =actly fitted to them, in the lower parts of the jaws. At the upper parts of the jaws are /'?729 what are called the indexes, d d, which are / (^~ t/// npressed tightly together by a spring, shown at fig. 729, and intended to be introduced between the perpendicular ribs of the jaws at e. At f is a thumbscrew, passing through the ribs for the purpose of tightening the jaws, and holding the leather fast between the indexes while being sewn; this screw, however, will seldom, if ever, be necessary if the spring is sufficiently strong; g is an eye or ring fixed to the moveable jaw, through which the end of a lever, h, in fig. 727 passes; this lever is connected by a spring to a treadle, i, at the base of the pedestal, and by the pressure of the right foot upon this treadle, the moveable jaw is withdrawn; so that the person employed in sewing may shift the leather, and place another part of the glove between the jaws. The pieces called indexes are connected to the upper part of the jaws, by screws passing through elongated holes which render them capable of adjustment. The patentee states, that in addition to the index described in his former patent, which is applicable to what is called round-seam sewing only, and which permits the leather tc expand but in one direction when the needle is passed through it, namely, upwards, he now makes two indexes of different construction, one of which he calls the receding index, and the other the longitudinally grooved index. Fig.'730 represents an end view, and fig. 731 a top view of the receding index, which is particularly adapted for what ire called "drawn sewing, and prick-seam sewing;" this index, instead of biting to the top, is so rounded off in the inside from the bottom of the cross grooves, as to permit the needles, by being passed backwards and forwards, to carry the silk thread on each side of the leather without passing over it. Fig. 732 represents an end view of the longitudinally grooved index, partly open, to show the section of the grooves more distinctly; andfig. 733 represents an inside view of one side of the same index, in which the longitudinal groove is shown passing from k to 1. This inaex is more particularly adapted to round seam sewing, and permits the leather to expand in every direction when the needle is passed through it, by which the leather is less strained, and the sewing consequently rendei ed much stronger. It is obvious that the parallel horizontal movement may be effected by other mechanical means besides those adopted here, and the chief novelty claimed with respect to that movement, is its application to the purpose of carrying the index used in sewing and pointing leather gloves. Importation of leather gloves for home consumption; and amount of duty in 1836. 1837. 1836. 1837. 1,461,769. 1,221,350. ~27,558. ~22,923. GLOVE-SEWING. The following simple and ingenious apparatus, invented by an Englishman, has been employed extensively in Paris, and has enabled its proprietors to realize a handsome fortune. The French complain that "it has inundated the world with gloves, made of excellent quality, at 30 per cent. under their former wholesale 934 GLUE. prices." The instrument is | \ 7Tv\734 shown in profile ready for ac -t..................... tion infig. 734. It resembles an iron vice, having the upper ~73f5 \ / | //; \\ ~portion of each jaw made of'735 ~\ I f /J ] 1 brass, and tipped with a kind of comb of the same metal. The teeth of this comb, only one twelfth of an inch long, are perfectly regular and equal. l —- 5 - - Change combs are provided for | - -i- _ _A different styles of work. The'730G 3 vice A A is made fast to the edge of the bench or table n, | 0 ^ I [~-l A of the proper height, by a -I \ —-g'j thumb-screw c, armed with a SL t cramp which lays hold of the iOJ ~ wood. Of the two jaws composing the machine, the one D is made fast to the foot A A, but the other E is moveable upon the solid base of the machine, by means of a hinge at the point F. At i I is shown how the upper brass portion is adjusted to the lower part made of iron; the two being secured to each other by two stout screws. The comb, seen separately in fig.'736, is made fast to the upper end of each jaw, by the three screws n n n. Fig. 735 is a front view of the jaw mounted with its comb, to illustrate its construction. The lever K corresponds by the stout iron wire L, with a pedal pressed by the needlewoman's foot, whenever she wishes to separate the two jaws, in order to insert between. them the parallel edges of leather to be sewed. The instant she lifts her foot, the two jaws join by the force of the spring G, which pushes the moveable jaw E against the stationary one D. The spring is made fast to the frame of the vice by the screw H. After putting the double edge to be sewed in its place, the woman passes her needle successively through all the teeth of the comb, and is sure of making a regular seam in every direction, provided she is careful to make the needle graze along the bottom of the notches. As soon as this piece is sewed, she presses down the pedal with her toes, whereby the jaws start asunder, allowing her to introduce a new seam, and so in quick succession. The comb may have any desired shape, straight or curved; and the teeth may be larger or smaller, according to the kind of work to be done. With this view, the combs might be changed as occasion requires; but it is more economical to have sets of vices ready mounted with combs of every requisite size and form. GLUCINA (Glucine, Fr.; Berryllerde, Germ.), is one of the primitive earths, originally discovered by Vauquelin, in the beryl and emerald. It may be extracted from either of these minerals, by treating their powder successively with potash, with water, and with muriatic acid. The solution by the latter, being evaporated to dryness, is to be digested with water, and filtered. On pouring carbonate of ammonia in excess into the liquid, we form soluble muriate of ammonia, with insoluble carbonates of lime, chrome, and iron, as also carbonate of glucina, which may be dissolved out from the rest by an excess of carbonate of ammonia. When the liquid is filtered anew, the glucina passes through, and may be precipitated in the state of a carbonate by boiling the liquid, which expels the excess of ammonia. By washing, drying, and calcining the carbonate, pure glucina is obtained. It is a white insipid powder, infusible in the heat of a smith's forge, insoluble in water, but soluble in caustic potash and soda; as also, especially when it is a hydrate, in carbonate of ammonia. It has a metallic base called glucinum, of'which 100 parts combine with 45-252 of oxygen to form the earth. It is too rare to be susceptible of application in manufactures. GLUCOSE. The name given to grape and starch sugar by M. Dumas. GLUE (Colle forte, Fr.; Leim, Tischlerleim, Germ.) is the chemical substance gelatine in a dry state. The preparation and preservation of the skin and other animal matters employed in the manufacture of glue, constitute a peculiar branch of industry. Those who exercise it should study to prevent the fermentation of the substances, and to diminish the cost of carriage by depriving them of as much water as can conveniently be done. They may then be put in preparation by macerating them in milk of lime, renewed three or four times in the course of a fortnight or three weeks. This process's performed in large tanks of masonry. They are next taken out with all the adhering.ime, and laid in a layer, 2 or 3 inches thick, to drain and dry, upon a sloping pavement, where they are turned over by prongs two or three times a day. The action of the GLUE. 935 lime dissolves the blood and certain soft parts, attacks the epidermis, and disposes the gelatinous matter to dissolve more readily. When the cleansed matters are dried, they may be packed in sacks or hogsheads, and transported to the glue manufactory at any distance. The principal substances of which glue is made are the parings of ox and other thick hides, which form the strongest article, the refuse of the leather dresser; both afford from 45 to 55 per cent. of glue. The tendons, and many other offals of slaughter-houses, also afford materials, though of an inferior quality, for the purpose. The refuse of tanneries, such as the ears of oxen, calves, sheep, &c., are better articles; but parings of parchment, old gloves, and, in fact, animal skin in every form, uncombined with tannin, may be made into glue. The manufacturer who receives these materials is generally careful to ensure their purification by subjecting them to a weak lime steep, and rinsing them by exposure in baskets to a stream of water. They are lastly drained upon a sloping surface, as above described, and well turned over till the quicklime gets mild by absorption of carbonic acid; for, in its caustic state, it would damage the glue at the heat of boiling water. It is not necessary, however, to dry them before they are put into the boiler, because they dissolve faster in their soft and tumefied state. The boiler is made of copper, rather shallow in proportion to its area, with a uniform flat bottom, equably exposed all over to the flame of the fire. Above the true bottom there is a false one of copper or iron, pierced with holes, and standing upon feet 3 or 4 inches high; which serves to sustain the animal matters, and prevent them from being injured by the fire. The copper being filled to two-thirds of its height with soft water,:s then heaped up with the bulky animal substances, so high as to surmount its brim. But soon after the ebullition begins they sink down, and, in a few hours, get entirely immersed in the liquid. They should be stirred about from time to time, and well pressed down towards the false bottom, while a steady but gentle boil is maintained. The solution must be drawn off in successive portions; a method which fractions the products, or subdivides them into articles of various value, gradually decreasing from the first portion drawn off to the last. It has been ascertained by careful experiments that gelatine gets altered over the fire very soon after it is dissolved, and it ought therefore to be drawn off whenever it is sufficiently fluid and strong for forming a clear gelatinous mass on cooling capable of being cut into moderately firm slices by the wire. This point is commonly determined by filling half an egg-shell with the liquor, and exposing it to the air to cool. The jelly ought to get very consistent in the course of a few minutes; if not so, the boiling must be persisted in a little longer. When this term is attained, the fire is smothered up, and the contents of the boiler are left to settle for a quarter of an hour. The stop-cock being partially turned, all the thin gelatinous liquor is run off into a deep boiler, immersed in a warm water bath, so that it may continue hot and fluid for several hours. At the end of this time the supernatant clear liquid is to be drawn off into congealing boxes, as will be presently explained. The grounds, or undissolved matters in the boiler, are to be again supplied with a quantity of boiling water from an adjoining copper, and are to be once more subjected to the action of the fire, till the contents assume the appearance of dissolved jelly, and afford a fresh quantity of strong glue liquor, by the stop-cock. The grounds should be subjected a third time to this operation, after which they may be put into a bag, and squeezed in a press to leave nothing unextracted. The latter solutions are usually too weak to form glue directly, but they may be strengthened by boiling with a portion of fresh skin-parings. Fig. 737. represents a convenient apparatus for the boiling of skins into glue, in which there are three coppers upon three different levels; the uppermost being acted upon by the waste heat of the chimney, provides warm water in the most economical way; the second contains the crude materials, with water for dissolving them; and the third receives the solution to be settled. The last vessel is double, with water contained between the outer and inner one; and discharges its contents by a stop-cock into buckets for filling the gelatinizing wooden boxes. The last made solution has about one-fivehundredth part of alum in powder usually added to it. with'proper agitation, after which it is left to settle for several hours. The three successive boils furnish three different qualities of glue. Flanders or Dutch glue, long much esteemed on the Continent, was made in the manner above described, but at two boils, from animal offals well washed and soaked, so as to need less boiling. The liquor being drawn off thinner, was therefore less coloured, and being made into thinner plates was very transparent. The above two boils gave two qualities of glue. By the English practice, the whole of the-animal matter is brought into solution at once, and the liquor being drawn off, hot water is poured on the residuum, and made to boil on i' for some time, when the liquor thus obtained is merely used instead of water 936 GLUE upon a fresh quantity of glue materials. The first drawn off liquor is kept hot in a settling copper for five hours, and then the clear solution is drawn off into the boxes. These boxes are made of deal, of a square form, but a little narrower at bottom than at top. When very regular cakes of glue are wished for, cross grooves of the desired square form are cut in the bottom of the box. The liquid glue is poured into the boxes placed very level, through funnels furnished with filter cloths, till it stands at the brim of each. The apartment in which this is done ought to be as cool and dry as possible, to favour the solidification of the glue, and should be floored with stone flags kept very clean, so, that if any glue run through the seams, it may be recovered. At the end of 12 or 18 hours, or usually in the morning if the boxes have been filled over-night, the glue is sufficiently firm for the nets, and they are at this time removed to an upper story, mounted with ventilating windows to admit the air from all quarters. Here the boxes are inverted upon a moistened table, so that the gelatinous cake thus turned out will not adhere to its surface; usually the moist blade of a long knife is insinuated round the sides of the boxes beforehand, to loosen the glue. The mass is first divided into horizontal layers by a brass wire stretched in a frame, like that of a bow-saw, and guided by rulers which are placed at distances corresponding to the desired thickness of the cake of glue. The lines formed by the grooves in the bottom of the box define the superficial area of each cake, where it is to be cut with a moist knife. The gelatinous layers thus formed, must be dexterously lifted, and immediately laid upon nets stretched in wooden frames, till each frame be filled. These frames are set over each other at distances of about three inches, being supported by small wooden pegs, stuck into mortise holes in an upright, fixed round the room; so that the air may have perfectly free access on every side. The cakes must moreover be turned upside down upon the nets twice or thrice every day, which is readily managed, as each frame may be slid out like a drawer upon the pegs at its two sides. The drying of the glue is the most precarious part of the manufacture. The least disturbance of the weather may injure the glue during the two or three first days of its exposure; should the temperature of the air rise considerably, the gelatine may turn so soft as to become unshapely, and even to run through the meshes upon the pieces below, or it may get attached to the strings that surround them, so as not to be separable without plunging the net into boiling water. If frost supervene, the water may freeze and form numerous cracks in the cakes. Such pieces must be immediately re-melted and re-formed. A slight fog even produces upon glue newly exposed a serious deterioration; the damp condensed upon its surface occasioning a general mouldiness. A thunderstorm sometimes destroys the coagulating power in the whole lamine at once; or causes the glue to turn on the nets, in the language of the manufacturer. A wind too dry or too hot may cause it to dry so quickly, as to prevent it from contracting tc its proper size without numerous cracks and fissures. In this predicament, the closing of all the flaps of the windows is the only means of abating the mischief. On these accounts it is of importance to select the most temperate season of the year, such as spring and autumn, for the glue manufacture. After the glue is dried upon the nets it may still preserve too much flexibility, or softness at least, to be saleable; in which case it must be dried in a stove by artificial heat. This aid is peculiarly requisite in a humid climate, like that of Great Britain. When sufficiently dry it next receives a gloss, by being dipped cake by cake in ho, GLUTEN. 937 water, and then rubbed with a brush also moistened in hot water; after which the glue is arranged upon a hurdle, and transferred to the stove room, if the weather be not sufficiently hot. One day of proper drought will make it ready for being packed up in casks. The pale-colored, hard, and solid article, possessing a brilliant fracture, which is made from the parings of ox-hides by the first process, is the best and most cohesive, and is most suitable for joiners, cabinet-makers, painters, &c. But many workmen are influenced by such ignorant prejudices, that they still prefer a dark-colored article, with somewhat of a fetid odor, indicative of its impurity and bad preparation, the result of bad materials and too long exposure to the boiling heat. There is a good deal of glue made in France from bones, freed from the phosphate of lime by muriatic acid. This is a poor article, possessing little cohesive force. It dissolves almost entirely in cold water, which is the best criterion of its imperfection. Glue should merely soften in cold water, and the more considerably it swells, the better, generally speaking, it is. Some manufacturers prefer a brass to a copper pan for boiling glue, and insist much on skimming it as it boils; but the apparatus I have represented renders skimming of little consequence. For use, glue should be broken into small pieces, put along with some water into a vessel, allowed to soak for some hours, and subjected to the heat of a boil-:ng-water bath, but not boiled itself. The surrounding hot water keeps it long in a fit state [or joiners, cabinet-makers, &c. Water containing only one hundredth part of good glue, forms a tremulous solid. When the solution, however, is heated and cooled several times, it loses the property of gelatinizing, even though it be enclosed in a vessel hermetically sealed. Isinglass or fishglue undergoes the same change. Common glue is not soluble in alcohol, but is precipitated in a white, coherent, elastic mass, when its watery solution is treated with that fluid. By transmitting chlorine gas through a warm solution of glue a combination is very readily effected, and a viscid mass is obtained like that thrown down by alcohol. A little chlorine suffices to precipitate the whole of the glue. Concentrated sulphuric acid makes glue undergo remarkable changes; during which are produced, sugar of gelatine, leucine, an animal matter, &c. Nitric acid, with the aid of heat, converts glue into malic acid, oxalic acid, a fat analogous to suet, and into tannin; so that, in this way, one piece of skin may be made to tan another. When the mixture of glue and nitric acid is much evaporated, a detonation at last takes place. Strong acetic acid renders glue first soft and transparent, and then dissolves it. Though the solution does not gelatinize, it preserves the property of gluing surfaces together when it dries. Liquid glue dissolves a considerable quantity of lime, and also of the phosphate of lime recently precipitated. Accordingly glue is sometimes contaminated with that salt. Tannin both natural and artificial combines with glue; and with such effect, that one part of glue dissolved in 5000 parts of water affords a sensible precipitate with the infusion of nutgalls. Tannin unites with glue in several proportions, which are to each other as the numbers 1, I, and 2; one compound consists of 100 glue and 89 tannin; another of 100 glue and 60 tannin; and a third of 100 glue and 120 tannin. These two substances cannot be afterwards separated from each other by any known chemical process. Glue may be freed from the foreign animal matters generally present in it, by softening it in cold water, washing it with the same several times till it no longer gives out any color, then bruising it with the hand, and suspending it in a linen bag beneath the surface of a large quantity of water at 60~ F. In this case, the water loaded with the soluble impurities of the glue gradually sinks to the bottom of the vessel, while the pure glue remains in.he bag sturrounded with water. If this softened glue be heated to 92~ without adding water, it will liquefy; and if we heat it to 122~, and filter it, some albifminous and other impurities will remain on the filter, while a colorless solution of glue will pass through. Experiments have not yet explained how gelatine'; formed from skin by ebullition. It is a change somewhat analogous to that of starch into gum and sugar, and takes place without any appreciable disengagement of gas, and even in close vessels. Gelatine, says Berzelius, does not exist in the living body, but several animal tissues, such as skin, cartilages, hartshorn, tendons, the serous membranes, and bones, are susceptible of being converted into it. GLUTEN (Colle Vegetale, Fr.; Kleber, Germ.) was first extracted by Beccaria from wheat flour, and was long regarded as a proximate principle of plants, till Einhof, Taddei, and Berzelius succeeded in showing that it may be resolved by means of alcohol into three different substances, one of which resembles closely animal albumine, and has been called Zymome, or vegetable albumine; another has been called Gliadine; and a third, Mucine. The mode of separating gluten from the other constituents of wheat flour has oeen described towards the end of the article BREAD. Gluten, when dried in the air or a stove, diminishes greatly in size, becomes hard, brit 938 GLYCERINE. brittle, glistening, and of a'deep yellow colour. It is insoluble in ether, in fat and essential oils, and nearly so in water. Alcohol and acetic acid cause gluten to swell and make a sort of milky solution. Dilute acids and alkaline lyes dissolve gluten. Its ultimate constituents are not determined, but azote is one of them, and accordingly when moist gluten is left to ferment, it exhales the smell of old cheese. Some years since, M. E. M. Martin, of Vervins, proposed to extract the starch without injuring the gluten, which then becomes available for alimentary purposes. His process is a mechanical one (resembling that long practised in laboratories for procuring gluten), and consists in washing wheat flour, made into a paste, with water, either by the hand or machinery. The gluten thus obtained is susceptible of numerous useful applications for alimentary purposes. Mixed with wheat flour, in the proportions of 30 parts of flour, 10 of fresh gluten, and 7 of water, it has been employed to produce a superior sort of macaroni, vermicelli, and other kinds of Italian pastes; and MM. VYron freres, of Paris, have made with it a new sort of paste, which they have termed granulated gluten (gluten granule). Mr. I. P. Gentile, of the Habertonford works, near Totness, in Devonshire, has for some time past been engaged in the manufacture of gluten for alimentary purposes, and placed in the Exhibition samples of several dietetical substances made with gluten: such as macaroni, vermicelli, a sort of gluten chocolate, and a kind of meal biscuit powder. Madame St. Etienne, the wife of Mr. Gentile's foreman, also placed in the Exhibition a very complete collection of alimentary preparations, made with gluten. To the same category belongs Mr. Bullock's Semola, of which he has given an account in the Lancet of December 15, 1849, and March 9, 1850. It is, in fact, wheat gluten made into a paste with wheat flour, and granulated. In all the above preparations, the gluten employed is that extracted from wheat by a mechanical process (hand working), as practised by M. E. M. Martin. Messrs. Orlando Jones and Co., manufacturers of rice starch, also placed in the Exhibition a specimen of rice gluten. But, as it is extracted from rice by a solution of caustic soda, and precipitated from its alkaline solution by an acid, it is obvious that it must have suffered deterioration, and be less proper for alimentary purposes than gluten extracted from the grain by a mechanical process. We hail with much satisfaction these attempts to introduce into use, as alimentary substances, preparations of gluten. No one has hitherto succeeded in making in England macaroni and vermicelli equal to the Italian pastes; for, although the Englishmade article presented a tolerably good appearance, it failed in cooking, either running into a mass, or falling to pieces; whereas it should simply expand and retain its form, even after long boiling. With Mr. Gentile's gluten it is to be hoped that good pastes may be made, even with English wheat. Hitherto, hundreds of tons of a most valuable and important article of food have been annually lost, and the prevention of this by the economic application of the gluten deserves, therefore, every encouragement. By mixing gluten with wheat flour, Mr. Gentile prepares what he calls gluten flour, containing 42 per cent., or four times the normal quantity of gluten. This preparation is susceptible of several very useful applications. It yields a very nutritious and digestible gluten biscuit; mixed with cocoa it forms an agreeable and nutritious gluten chocolate; and mixed with beef or mutton it furnishes a highly-condensed nutritive food. Bread made with gluten flour might be advantageously employed by diabetic patients as a substitute for Bouchardat's gluten bread. GLYCERINE, is a sweet substance which may be extracted from fatty substances. If we take equal parts of olive oil and finely-ground litharge, put them into a basin with a little water, set this on a sand bath moderately heated, and stir the mixture constantly, with the occasional addition of hot water to replace what is lost by evaporation, we shall obtain, in a short time, a soap or plaster of lead. After having added more water to this, we remove the vessel from the fire, decant the liquor, filter it, pass sulphuretted hydrogen through it to separate the lead, then filter afresh, and concentrate the liquor as much as possible without burning upon the sand-bath. What remains must be finally evaporated within the receiver of the air-pump. Glycerine thus prepared is a transparent liquid, without colour or smell, and of a syrupy consistence. It has a very sweet taste. Its specific gravity is 1-27 at the temperature of 60~. When thrown upon burning coals, it takes fire and burns like an oil. Water combines with it in almost all proportions; alcohol dissolves it readily; nitric acid converts it into oxalic acid; and according to Vogel, sulphuric acid transforms it into sugar, in the same way as it does starch. Ferment or yeast does not affect it in any degree. Its constituents are, carbon 40, hydrogen 9, oxygen 51, in 100. The employment of glycerine as an application in the treatment of deafness, and also fr other purposes as a medicinal agent, has given rise to enquiries on the subject, on GOLD. 939 which account a few practical remarks may probably be interesting to some of our: eaders. Glycerine is one of the products of the saponification of fat oils. It is produced in large quantities in the soap manufactories in a very impure state, being contaminated with saline and empyreumatic matters, and having a very strong disagreeable odour. In order to obtain glycerine from this source, the residuary liquors are evaporated and treated with alcohol, which dissolves out the glycerine. The alcohol having been separated by evaporation, the glycerine is diluted with water, and boiled with animal charcoal. This process must be repeated several times, or until the result is sufficiently free from smell. It is, however, extremely difficult to obtain pure glycerine from this source, on account of the nature and condition of the ingredients usually employed in making soap, which it is almost impossible to deprive of rancid odour. The best method of obtaining glycerine for medicinal purposes is to evaporate the water used in making emplastrum plumbi. When the oil employed is fresh, and the process is carefully conducted, the result is easily made fit for use, and is almost without odour. Any lead with which it may be contaminated is separated by passing a stream of sulphuretted hydrogen through it when in a dilute state. The excess of gas escapes during the process of evaporation. If requisite, it may be ooiled with animal charcoal, filtered, and evaporated. The specific gravity, when reduced to the proper consistence, is 1-27. It is now about twelve months since an announcement appeared in the medical journals, respecting a new cure for deafness, discovered by Mr. Yearsley. The remedy was reported to be perfectly simple, remarkably safe and very effectual. Several papers ny Mr. Yearsley appeared in the Lancet during July and August, 1848; and from the statements therein contained, it appeared that the novelty consisted in the insertion of a piece of moistened cotton wool into the ear in a particular manner. In answer to the intimation that he "had not so fully described the modus operandi as to enable others to adopt it with more than a mere chance of success," Mr. Yearsley observes " in answer, I have only to say, that the experience of several years has taught me that It is impossible to convey to others, in words, such explicit directions as shall enable them to manipulate with any degree of certainty. In fact, it was on this account that I have so long held back from publishing any account of the remarkable fact J had observed in my practice." GNEISS, is the name of one of the great mountain formations, being reckoned the oldest of the stratified rocks. It is composed of the same substances as granite, viz. quartz, mica, and felspar. In gneiss, however, they are not in granular crystals, but in scales, so as to give the mass a slaty structure. It abounds in metallic treasures. GOLD. (Eng. and Germ.; Or, Fr.) This metal is distinguished by its splendid yellow colour; its great density = 19'3 compared to water 1-0; its fusibility at the S2d degree of Wedgewood's pyrometer; its pre-eminent ductility and malleability, whence it can be beat into leaves only 1-282,000th of an inch thick; and its insolubility in any acid menstruum, except the mixture of muriatic and nitric acids, styled by the alchemists aqua regia, because gold was deemed by them to be the king of metals. Gold is found only in. the metallic state, sometimes crystallized in the cube, and its derivative forms. It occurs also in threads of various sizes, twisted and interlaced into a chain of minute octahedral crystals; as also in spangles or roundish grains, which when of a certain magnitude are called pepitas. The small grains are not fragments broken from a greater mass; but they show by their flattened ovoid shape and their rounded outline that this is their original state. The spec. grav. of native gold varies from 13'3 to 17 7. Humboldt states that the largest pepita known was one found in Peru weighing about 12 kilogrammes (261 lbs. avoird.); but masses have been quoted in th- province of Quito which weighed nearly four times as much. Another ore of gold is the alloy with silver, or argental gold, the electrum of Pliny, so called fiom its amber shade. It seems to be a definite compound, containing in 100 parts, 64 of gold and 36 of silver. The mineral formations in which this metal occurs are the crystalline primitive rocks, the compact transition rocks, the trachytic and trap rocks, and alluvial grounds. It never predominates to such a degree as to constitute veins by itself. It is either disseminated, and as it were impasted in stony masses, or spread out in thin plates or grains on their surface, or, lastly, implanted in their cavities, under the shape of fila. ments or crystallized twigs. The minerals composing the veins are either quartz, calcspar, or sulphate of baryta. The ores that accompany the gold in these veins are chiefly iron pyrites, copper pyrites, galena, blende, and mispickel (arsenical pyrites). In the ores called auriferous pyrites, this metal occurs either in a visible or invisible form, and though invisible in the fresh pyrites becomes visible by its decomposition; as the hydrated oxide of con allows the native gold particles to shine forth on their reddish. 940 GOLD orown ground, even when tne precious metal may constitute only the five mn.lionth part of its weight, as at Rammelsberg in the Hartz. In that state it has bhen extracted with )rofit; most frequently by amalgamation with mercury, proving that the gold was in the native state, and not in that of a sulphuret. Gold exists among the primitive strata, disseminated in small grains, spangles, and crystals. Brazil affords a remarkable example of this species of gold mine. Beds of granular quartz, or micaceous specular iron, in the Sierra of Cocaes, 12 leagues beyond Villa Rica, which form a portion of a mica-slate district, include a great quantity o(' native gold in spangles, which in this ferruginous rock replace mica. Gold has never been observed in any secondary formation, but pretty abundantly in its true and primary locality among the trap rocks of igneous origin; implanted on the sides of the fissures, or disseminated in the veins. The auriferous ores of Hungary and Transylvania, composed of tellurium, silver pyrites or sulphuret of silver, and native gold, lie in masses or powerful veins in a rock of trachyte, or in a decomposed feldspar subordinate to it. Such is the locality of the gold ore of K6nigsberg, of Telkebanya, between Eperies and Tokay in Hungary, anc probably that of the gold ores of Kapnick, Felsobanya, &c., in Transylvania; an arrange. menent nearly the same with what occurs in Equatorial America. The auriferous veins of Guanaxuato, of Real del Monte, of Villalpando, are similar to those of Schemnitz in Hungary, as to magnitude, relative position, the nature of the ores they include, and of the rocks they traverse. These districts have impressed all mineralogists with the evidences of the action of volcanic fire. Breislak and Hacquet have described the gold mines of Transylvania as situated in the crater of an ancient volcano. It is certain that the trachytes which form the principal portions of the rocks including gold, are now almost universally regarded as of igneous or volcanic origin. It would seem, however, that the primary source of the gpld is not in these rocks, but rather in the sienites and greenstone porphyries below them, which in Hungary and Transylvania are rich in great auriferous deposites; for gold has never been found in'he trachyte of the Euganean mountains, of the mountains of the Vicentin, of those )f Auvergne; all of which are superposed upon granite rocks, barren in metal. Finally, if it be true that the ancients worked mines of gold in the island of Ischia, it would be another example, and a very remarkable one, of the presence of this metal in:rachytes of an origin evidently volcanic. Gold is, however, much more common in the alluvial grounds than among the primi-.ive and pyrogenous rocks just described. It is found disseminated under the form of spangles, in the silicious, argillaceous, and ferruginous sands of certain plains and rivers, especially in their re-entering angles, at the season of low water, and after storms ano temporary floods. It has been supposed that the gold found in the beds of rivers had been torn out by the waters from the veins and primitive rocks, which they traverse. Some have even searched, but in vain, at the source of auriferous streams, for the native bed of this precious metal. The gold in them belongs, however, to the grounds washed by the waters as they glide along. This opinion, suggested at first by Delius, and supported by Deborn, Guettard, Robitant, Balbo, &c., is founded upon just observations. 1. The soil of these plains contains, frequently, at a certain depth and in several spots, spangles of gold, separable by washing. 2. The beds of the auriferous rivers and streamlets contain more gold after storms of rain upon the plains than in any other circumstances. 3. It happens almost always that gold is found among the sands of rivers only in a very circumscribed space; on ascending these rivers their sands cease to afford gold; though did this metal come from the rocks above, it should be found more abundantly near the source of the rivers. Thus it is known that the Orco contains no gold except from Pont to its junction with the Po. The Ticino affords gold only below the Lago Maggiore, and consequently far from the primitive mountains, after traversing a lake, where its course is slackened, and into which whatsoever it carried down from these mountains must have been deposited. The Rhine gives more go.a near Strasburg than near Basle, though the latter be much closer to the mountains. The sands of the Danube do not contain a grain of gold, while this river runs in a mountainous region; that is, from the frontiers of the bishopric ot Passau to Efferding; but its sands become auriferous in the p ains below. The same thing is true of the Ems; the sands of the upper portion of this river, as it flows among the mountains of Styria, include no gold; but from its entrance into the plain at Steyer, till its embouchure in the Danube, its sands become auriferous., and are even rich enough to be washed with profit. The greater part of the auriferous sands, in Europe, Asia, Africa, and America are black or red, and consequently ferruginous; a remarkable circumstance in the geological position of alluvial gold. M. Napione supposes that the gold of these ferruginous grounds is due to the decomposition of auriferous pyrites. The auriferous sand occurring in Hungarp almost always in the neighborhood of the beds of lignites. GOLD. 911 and the petrified wood covered with gold grains, found buried at a depth of 55 yards ir clay, in the mine of Vorospatak near Abrabanya in Transylvania, might lead us to presume that the epoch of the formation of the auriferous alluvia is not remote from that of the lignites. The same association of gold ore and fossil wood occurs in South America, at Moco. Near the village of Lloro, have been discovered at a depth of 2C feet, large trunks of petrified trees, surrounded with fragments of trap rocks interspersed with spangles of gold and platinum. But the alluvial soil affords likewise all the characters of the basaltic rocks; thus in France, the Ceze and the Gardon, auriferous rivers, where they afford most gold, flow over ground apparently derived from the destruction of the trap rocks, which occur in situ higher up the country. This fact had struck Reaumur, and this celebrated observer had remarked that the sand which more immediately accompanies the gold spangles in most rivers, and particularly in the Rhone and the Rhine, is composed, like that of Ceylon and Expailly, of black protoxyde of iron and small grains of rubies, corindon, hyacinth, &c. Titanium has been observed more recently. It has, lastly, been remarked that the gold of alluvial formations is purer than that extracted from rocks. Principal Gold Mines. Spain anciently possessed mines of gold in regular veins, especially in the province of Asturias; but the richness of the American mines has made them to be neglected. The Tagus, and some other streams of that country, were said to roll over golden sands. France contains no workable gold mines; but it presents in several of its rivers auriferous sands. There are some gold mines in Piedmont; particularly the veins of auriferous pyrites of Macugnagna, at the foot of Monte Rosa, lying in a mountain of gneiss; and although they do not contain 10 or 11 grains of gold in a hundred weight, they have long defrayed the expense of working them. On the southern slope of the Pennine Alps, from the Simplon and Monte Rosa to the valley of Aoste, several auriferous districts and rivers occur. Such are the torrent Evenson, which has afforded much gold by washing; the Orco, in its passage from the Pont to the Po; the reddish grounds over which this little river runs for several miles, and the hills in the neighborhood of Chivasso, contain gold spangles in considerable quantity. In the county of Wicklow, in Ireland, a quartzose and ferruginous sand was discovered not long ago, containing many particles of gold, with pepitas or solid pieces, one of which weighed 22 ounces. No less than 1000 ounces of gold were collected. There are auriferous sands in some rivers of Switzerland, as the Reuss and the Aar. In Germany no mine of gold is worked, except in the territory of Salzburg, amid the chain of mountains which separates the Tyrol and Carinthia. The mines of Hungary and Transylvania are the only gold mines of any importance in Europe; they are remarkable for their position, the peculiar metals that accompany them, and their product, estimated at about 1430 pounds avoird. annually. The principal ones are in Hungary. 1. Those of Konigsberg. The native gold is disseminated in ores of sulphuret of silver, which occur in small masses and in veins in a decomposing feldspar rock, amid a conglomerate of pumice, constituting a portion of the trachytic formation. 2. Those of Borson, Schemnitz. And, 3. of Felsobanya; ores also of auriferous sulphuret of silver, occur in veins of sienite and greenstone porphyry. 4. Those of Telke. banya, to the south of Kaschau, are in a deposite of auriferous pyrites amid trap rocks of the most recent formation. In Transylvania the gold mines occur in veins often of great magnitude, 6, 8, and sometimes 40 yards thick. These veins have no side plates or wall stones, but abut without intermediate gangues at the primitive rock. They consist of carious quartz, ferriferous limestone heavy spar, fluor spar, and sulphuret of silver. The mine of Kapnik deserves notice, where the gold is associated with orpiment, and that of Vcrospatak in granite rocks; those of Offenbanya, Zalatna, and Nagy-Ag, where it is associated with tellu rium The las is in a sienitic rock on the limits of the trachyte. In Sweaen, the mine of Edelfors in Smoland may be mentioned, where the gold occurs native and in auriferous pyrites; the veins are a brown quartz, in a mountain of foliated hornstone. In Siberia, native gold occurs in a hornstone at Schlangenberg or Zmeof, an.l at Zmeino-garsk in the Altai mountains, accompanied with many other ores. The gold mine of Berezof in the Oural mountains has been long known, consisting of partially decomposed auriferous pyrites, disseminated in a vein of greasy quartz. About 1S20, a very rich deposit of native gold was discovered on the eastErn side of the Oural mountains, disseminated at some yards depth in an argillaceous loam, and accompanied with the debris of rocks which usually compose the auriferous alluvial soils, as greenstone, serpentine, protoxide of iron, corundum, &c. The rivers of this district possess auriferous sands. The product of the gold mines of the Oural, in 1845, was 11,808 pounds 942 GOLD. avoirdupois, and in 1846, 11,327 pounds; that of Siberia, in 1845, 37,57 pounds, and in 1846, 48,863 pounds. In these accounts the pood has been reckoned at 36 lbs. It is believed that in 1847 and 1849 the yield was still larger, but it must since have materially fallen off, as it is stated in Erman's Archives that the yield in 1851 will not exceed 20,000 pounds troy. In Asia, and especially in its southern districtss there are many mines, streams, rivers, and wastes, which contain this metal. The Pactolus, a small river of Lydia, rolled over such golden sands, that it was supposed to constitute the origin of the wealth of Crcesus. But these deposits are now poor and forgotten. Japan, Formosa, Ceylon, Java, Sumatra, Borneo, the Philippines, and some other islands of the Indian Archipelago, are rich in gold mines. Those of Borneo are worked by the Chinese in an alluvial soil on the western coast, at the foot of a chain of volcanic mountains. Little or no gold comes into Europe from Asia, because its servile inhabitants place their fortune in treasure, and love to hoard up that precious metal. Numerous gold mines occur on the two slopes of the chain of the Cailas mountains in the Oundes, a province of Little Thibet. The gold lies in quartz veins which traverse a very crumbling reddish granite. Africa was, with Spain, the source of the greater portion of the gold possessed by the ancients. The gold which Africa still brings into the market is always in dust, showing that the metal is obtained by washing the alluvial soils. None of it is collected in the north of that continent; three or four districts only are remarkable for the quantity of gold they produce. The first mines are those of Kordofan, between Darfour and Abyssinia. The negroes transport the gold in quills of the ostrich or vulture. These mines seem to have been known to the ancients, who considered Ethiopia to abound in gold. Herodotus relates that the king of that country exhibited to the ambassadors of Cambyses all their prisoners bound with golden chains. The second and chief exploitation of gold dust is to the south of the great desert of Zaara, in the western part of Africa, from the mouth of the Senegal to the Cape of Palms. The gold occurs in spangles, chiefly near the surface of the earth, in the bed of rivulets, and always in a ferruginous earth. In some places the negroes dig wells.n the sQil to a depth of about 40 feet, unsupported by any props. They do not follow any vein; nor do they construct a gallery. By repeated washings they separate the gold from the earthy matters. The same district furnishes also the greater part of what is carried to Morocco Fez, and Algiers, by the caravans which go from Timbuctoo on the Niger, across the great desert of Zaara. The gold which arrives by Sennaar at Cairo and Alexandria comes from the same quarter. From Mungo Park's description, it appears that the gold spangles are found usually in a ferruginous small gravel, buried under rolled pebbles. The third spot in Africa where gold is collected is on the south-east coast, between the twenty-fifth and the twenty-second degree of south latitude, opposite to Madagascar, in the country of Sofala. Some persons think that this was the kingdom of Ophir, whence Solomon obtained his gold. In modern times, the richest gold mines are found in South America. It occurs there principally in spangles among the alluvial earths, and in the beds of rivers; more rarely in veins. See Calfornia, infra. There is little gold in the northern part of America. In 1810, a mass of alluvial gold, weighing 28 pounds, was found in the gravel pits of the creeks of Rockhole, district of Lebanon, in North Carolina. Previously to the important discoveries in California, Brazil, Choco, and Chili, were the regions which furnished most gold. The only contributor of Chilian objects to the Great Exhibition was one who forwarded a lump of gold ore weighing S cwt., which was brought up from a deep mine on the back of a miner, from a depth of 45 yards beneath the surface. The gold of Mexico is in a great measure contained in the argentiferous veins, so numerous in that country, whose principal localities are mentioned under the article SILVER. The silver of the argentiferous ores of Guanaxuato contains one 360th of its weight of gold; the annual product of the mines being valued at from 2640 to 3300 pounds avoirdupois. Oaxaco contains the only auriferous veins exploited as gold mines in Mexico; they traverse the rocks of gneiss and mica slate. All the rivers of the province of Caracas, to ten degrees north of the line, flow over golden sands. Peru is not rich in gold ores. In the provinces of Huailas and Pataz, this metal s mined in veins of greasy quartz, variegated with red ferruginous spots, which traverse primitive rocks. The mines called pacos de oro, consist of ores of iron and copper oxides, oontaining a great quantity of gold i 1 GOLD. 94S All the gold furnished by New Grenada (New Columbia) is the product of washings established in alluvial grounds. The gold exists in spangles and in grains, disseminated among fragments of greenstone and porphyry. At Choco, along with the gold and platinum, hyacinths, zircons, and titanium occur. There has been found, as already stated, in the auriferous localities, large trunks of petrified trees. The gold of Antioquia is 20 carats fine, that of Choco 21, and the largest lump or pepita of gold weighed about 271 pounds avoirdupois. The gold of Chili also occurs in alluvial formations. Brazil does not contain any gold mine, properly so called; for the veins containing the metal are seldom worked. It is in the sands of the Mandi, a branch of the Rio-Dolce, at Catapreta, that the auriferous ferruginous sands were first discovered in 1682. Since then they have been found almost everywhere at the foot of the immense chain of mountains, which runs nearly parallel with the coast, from the 5th degree south to the 30th. It is particularly near Villa Rica, in the environs of the village Cocaes, that the numerous washings for gold are established. The pepitas occur in different forms, often adhering to micaceous specular iron. But in the province of Minas Geraes, the gold occurs also in veins, in beds, and in grains, disseminated among the alluvial loams. It has been estimated in annual product, by several authors, at about 2800 pounds avoirdupois of fine metal. We thus see that almost all the gold brought into the market comes from alluvial lands, and is extracted by washing. The gold coin of the ancients was made chiefly out of alluvial gold, for in these early times the metallurgic arts were not sufficiently advanced to enable them to purify it. The gold dust from Bambouk in Africa is of 221 carats fine, and some from Morocco is even 23. The gold of Giron, in New Grenada, is of 231 carats; being the purest from America. "For those who traffick in gold," says Humboldt, "it is sufficient to learn the place where the metal has been collected, to know its title." Californian Gold Mines.-The accident which first revealed the golden treasures of the soil of California is thus related by a writer of Article VII. of the Quarterly Review, for September, 1852. Captain Suter, the first white man who had established himself in the district where the Americanos joins the Sacramento, having erected a saw-mill on the former river, whose tail race turned out to be too narrow, took out the wheel, and let the water run freely off. A great body of earth having been carried away by the torrent, laid bare many shining yellow spangles, and on examination, Mr. Marshall, his surveyor, picked up several little lumps of gold. He and Captain Suter then commenced a search together and gathered an ounce of the ore from the sand without any difficulty; and with his knife the captain picked out a lump of an ounce and a half from the rock. A Kentuckian workman employed at the mill had espied their supposed secret discovery, and when after a short absence the gentlemen returned, he showed them a handful of the glittering dust. The captain hired a gang of fifty Indians, and set them to work. The news spread, but the announcement of the discovery was received with incredulity beyond the immediate neighbourhood. But presently when large and continuous imports of gold from San Francisco placed the matter beyond doubt, there ensued such a stir in the States, as even in that go-a-head region is wholly without parallel: numbers of every age and of every variety of occupation pushed for the land of promise. Many were accompanied by their families, and most under the excitement of the hour overlooked their physical unfitness, and their inability to procure necessaries The waters of the Humboldt, from their head to their " sink," a space of nearly 300 miles, are in the dry season strongly impregnated with alkali: and it was here that they first began to faint. Some died from thirst, others from ague, others fell beneath the burdens they attempted to carry when their last animal dropped into the putrid marsh, which grew thicker at every step. Beyond the "sink" the diminished bands had to encounter sixty or seventy miles of desert, where not a blade of herbage grew, and not a drop of pure water could be procured; and those who pushed safely through this ordeal had still to ascend the icy slopes of Sierra Nevada, when the rigours of winter were added to all other difficulties. At different points, one being almost in sight of the golden land, overwearied groups had formed encampments, in case perhaps some help might reach them. It is to the credit of the settlers that on hearing this, they strained their resources to the utmost to afford relief. Yet when all was done, a sick, destitute, most wretched horde of stragglers, was all that remained of the multitude, who, full of hope and spirits, had commenced the prairie journey. Enterprise and energy have now overcome or smoothed the worst difficulties of the route. A great central railroad has been projected, and will probably at no distant time be formed. To this time, the stream of life flowing into California has kept continually increasing. Upwards of 20,000 souls, and about 50,000 animals, forming a scattered train of about 700 miles in length, passed Fort Kearney in the month of May last. In this multitude 944 GOLD. the strangest contrasts were seen; ladies on spirited steeds, in full Bloomer costume, or in the more modest equestrian habit to which we are accustomed, and men gallantly mounted with Kossuth hat and plume, swept by the humble pedlar driving ass or mule, and toil-worn women, leading their children by the hand. Some had their little stock of provisions strapped on their backs; others trusted to hand-carts and wheelbarrows. " The journey would be pleasant," writes one of the company, " but for the vast number of graves along the road. There are about 80 graves to 100 miles so far; that is new ones, the old ones are nearly obliterated, and their places no longer known by man." This passage depicts well the recklessness with which in the States life is squandered in the pursuit of gain. By sea, the arrivals are even more numerous; upwards of 10,000 landed at the port of San Francisco in May, and about an equal number in June. In the first six months of the year 10,000 Chinamen had arrived to claim part in the golden harvest; 400 more followed in the first fortnight of July, and eighteen women, in the costume of the Celestial Empire, had come infrom Hong Kong. The population of California was about 200,000 at the commencement of the present year; it will be 300,000 by its close. Already the sea-board of California is brought within a month's passage of England; and its exports now amount in value to one fourth the exports of the United Kingdom. The produce of California up to the 10th of January, 1851, is stated by Mr. Scheer at about 62 millions sterling; but these figures taken from a gold circular published at San Francisco must be much too high. From 35 to 40 millions would probably be nearer the mark. 17,339,5441. is the amount for last year, as carefully computed by Mr. Birkmyre. See Times, May 21. The exports this year are known to have been during the three first months, 3,900,000 dollars more than those of the three corresponding months of the preceding year, 1851. Report of Deposits of Goldfrom California, at the several United States Mints, dollars. in 1848 - 44,177 1849 - - - - - 6,147,509 1850 - - - - 36,074,062 1851 - - - 55,938,232 Hussey & Co.'s Circular, San Francisco, July 30, 1852. Australian Gold 1Mines.-The discovery of a great gold field in Australia to the westward of Bathurst, about 150 miles trom Sydney, was officially made known in Great Britain, by a despatch from Sir C. A. Fitzroy to Earl Grey, on the 18th September, 1851, many persons with a tin dish having obtained from one to two ounces per day. On the 25th of May, he writes that lumps have been obtained varying in weight from an ounce to four pounds. On the 29th May, he writes that gold has been found in abundance, that people of every class are proceeding to the locality, that the field is rich, and from the geological formation of the country of immense area. By assay the gold was found to consist of 91.1 of that metal and about 8.333 of silver, with a little base metal; or of 22 carats in fineness. July 17th, a mass of gold weighing 106 pounds was found imbedded in the quartz matrix, about 53 miles from Bathurst' and much more, justifying the anticipations formed of the vast richness and extent of the gold field in this colony. This magnificent treasure, the property of Dr. Kerr, surpasses the largest mass found in California, which was 28 pounds; and that in Russia, which was 70 pounds, now in the museum at Petersburg. One party of six persons got at the same time 4001. in ten days, by means of a quicksilver machine; and a party of three, who were unsuccessful for seven days, obtained in five days more, 200 ounces. A royalty of 10 per cent. was ordered to be paid on gold in matrix if found in Crown lands, and 5 per cent. if found in private property. Four armed men travel in the carriage that conveys the gold from the diggings to Sydney, accompanied by two armed constables, in general weekly, or oftener if required. The licence fee is 30s. a month. August 19th, 1851, the Governor Sir C. Fitzroy reports to Earl Grey, that gold to the value of 70,0001. had been already collected; and on the 21st, that 3,614 ozs. had that morning arrived at Sydney from Bathurst, worth upwards of 12,6001. August 25th, 1851, Lieutenant Governor C. J. Latrobe announced to Earl Grey from Melbourne, the discovery of large deposits of gold in that district of the colony. In a second Parliamentary blue book, issued February 3, 1852, it is stated that 79,340 ounces of gold, worth 257,8551. 7s. had been previously forwarded to England; and that the gold fields of the colony of Victoria rival, if they do not exceed in value, the first discovered gold fields of New South Wales; the total value being now 300,0001.; and a little time afterwards about half a million sterling. Mr. E. Hargraves, commissioner for Crown lands, announces from Bathurst, that no part of California which he had seen has prodluced gold so generally and to such an extent as Summerhill Creek, the Turon ________________ _ ^ _, __ ____ _ ___, -- --- GOLD. 945 River and its tributaries. A letter from Sir J. F. W. Herschel, Bart., dated Royal Mint, London, February 7th, 1852, says, "it is believed that in California, gold to the value of 18 millions sterling had been found during each of the two last years; and prior to the discovery of that gold region, the whole annual produce throughout the world was sup posed to be only about one-fifth of that amount. Taking the actual amount shipped from Melbourne to the end of March last, and allowing for the quantity supposed to be at the diggings, and waiting shipment, it would appear that about 700,000 ounces had been raised in Victoria. At 31. per oz. this would be worth 2,100,0001. The licences up to the same date were 49,386; equivalent to 421. 10s. as the average monthly earnings of each licensed digger. The amount raised in New South Wales to the end of March may be taken at 320,000 ounces, and the value at 960,0001.; being at the rate of 311. 3s. monthly per individual; probably about 11. daily for each digger. Australia will soon be supplied with silver coin. The shipments on board (September 13) are understood to amount to 2,000,0001. and estimating the additional sum taken out by emigrants, it is probable that the value of the total quantity exported equals that of the gold received. The diggers must be largely benefited by these shipments of coin, as the gold, which in London would realize 41. per oz., has not always brought them 31. The gold fields discovered in Australia stretch over 1000 miles, in a south-westerly direction from Moreton district'to Ballarat. Up to the first week in June last, it is certain from the actual exports, that the total gold raised in Australia must have amounted in value to 4,000,0001. sterling; and the produce was still on the increase. The number of diggers at present hardly reaches 20,000. It seems moderate to assume that 50,000 labourers will be scattered over the Australian gold fields before the end of the present year; and taking their earnings at only 201. per month, we shall have a yield then of 12,000,0001. yearly. Mr. Birkmyre supposes that in 1846 there were raised from,North and South America - -- 1,301,500 Russia. — 3,414,427 Austria - - - 282,750 Piedmont, Spain, and North Germany - - - 20,696 Africa - - - - 203,900 Borneo - - - - 305,90Q Ava, Malacca and other countries - - 317,519 ~ 5,846 692 This total is exclusive of China and Japan. Metallurgic treatment of gold.-The gold found in the sands of rivers, or in auriferous soils, needs not be subjected to any metallurgic process, properly speaking. The Orpaillers separate it from the sands, by washing them first upon inclined tables, sometimes covered with a cloth, and then by hand in wooden bowls of a particular form. Amalgamation is employed to carry off from the sand the minuter particles of gold they may contain. The people called Bohemians, Cigans, or Tehinganes, who wash the auriferous sands in Hungary, employ a plank with 24 transverse grooves cut in its surface. They hold this plank in an inclined position, and put the sand to be washed in the first groove; they then throw water on it, when the gold mixed with a little sand collects usually towards the lowest furrow. They remove this mixture into a flat wooden basin, and by a peculiar sleight of hand, separate the gold entirely from the sand. The richest of the auriferous ores consist of the native gold quite visible, disseminated in a: gangue, but the veins are seldom continuous for any length. The other ores are auriferous metallic sulphurets, such as sulphurets of copper, silver, arsenic, &c., and particularly iron. The stony ores are first ground In the stamping mill, and then washed in hand-basins, or on wooden tables. The auriferous sulphurets are much more common, but much poorer than the former ores; some contain only one 200,000th part of gold, and yet they may be worked with advantage, when treated with skill and economy. The gold of these ores is separated by two different processes; namely, by fusion and amalgamation. The auriferous metallic sulphurets are first roasted; then melted into mattes, which are roasted anew; next fused with lead, whence an auriferous lead s 6btained, which may be refined by the process of cupellation. When the gold ores are very rich, they are melted directly with lead, without preliminary calcination or fusion. These processes are, however, little practised, because they are less econonical and certain than amalgamation, especially when the gold ores are very poor. If these ores consist of copper pyrites, and if their treatment has been pushed to the point 946 GOLD. of obtaining auriferons rose c/Jpper, or even black copper including gold, the precious metal cannot be separated by the process of liquation, because the gold, having more affinity for copper than for lead, can be but partially run off by the latter metal. For these reasons the process of amalgamation is far preferable. This process being the same for silver, I shall reserve its description for this metal. The rich ores in which the native gold is apparent, and merely disseminated in a stony gangue, are directly triturated with quicksilver, without any preparatory operation. As to the poor ores, in which the gold seems lost amid a great mass of iron, sulphuret of copper, &c., they are subjected to a roasting before being amalgamated. This process seems requisite to lay bare the gold enveloped in the sulphurets. The quicksilver with which the ore is now ground, seizes the whole of its gold, in however small quantity this metal may be present. The gold procured by the refining process with lead, is free from copper and lead, but it may contain iron, tin, or silver. It cannot be separated from iron and tin without great difficulty and expense, if the proportion of gold be too small to admit of the employ ment of muriatic acid. By cupellation with lead, gold may be deprived of any antimony united with it. Tin gives gold a remarkable hardness and brittleness; a piece of gold, exposed for some time over a bath of red hot tin, becomes brittle. The same thing happens more readily over antimony, from the volatility of this metal. A two thousandth part of antimony, bismuth, or lead, destroys the ductility of gold. The tin may be got rid of by throwing some corrosive sublimate or nitre into a crucible, containing the melted alloy. By the first agent, perchloride of tin is volatilized; by the second, stannate of potash forms, which is carried off in the resulting alkaline scoriae. Gold treated by the process of amalgamation, contains commonly nothing but a little silver. The silver is dissolved out by nitric acid, which leaves the gold untouched; but to make this parting with success and economy on the great scale, several precautions must be observed. If the gold do not contain fully two thirds of its weight of silver, this metal, being thoroughly enveloped by the gold, is partially screened from the action of the acid. Whenever, therefore, it is known by a trial on a small scale, that the silver is much below this proportion, we must bring the alloy of gold and silver to that standard by adding the re. quisite quantity of the latter metal. This process is called quartation. This alloy is then granulated or laminated; and from twice to thrice its weight of sulphuric or nitric acid is to be boiled upon it; and when it is judged that the solution has been pushed as far as possible by this first acid, it is decanted, and new acid is poured on. Lastly, after having washed the gold, some sulphuric acid is to be boiled over it, which carries off a two or three thousandth part of silver, which nitric acid alone could not dissolve. Thus perfectly pure gold is obtained. The silver held in solution by the sulphuric or nitric acid is precipitated in the metallic state by copper, or in the state of chloride by sea-salt. See PARTING. Not only has the ratio between the value of gold and silver varied much in different ages of the world; but the ratio between these metals and the commodities they represent has undergone variations, owing to the circumstances in which their mines have been successively placed; since they have always poured a greater quantity of the metals into the market than has been absorbed by use. This quantity has greatly increased since the discovery of America, a period of little more than 300 years. The mines of that continent, rich, numerous, and easily worked, by augmenting the mass of gold and silver, necessarily lessened the value of these metals compared with that of the objects of commerce represented by them, so that everything else being equal, there is now required for purchasing the same quantity of commodities, much more gold or silver than was necessary in the reign of Henry VII., before the discovery of America. This productiveness of the American mines has had an influence on those of the ancient continent; many of whose silver and gold mines have been abandoned, not because the veins or auriferous sands are less rich than they were, but because their product no longer represents the value of human labor, and of the goods to be furnished in return for their exploitation. In the 3d vol. of the Mining Journal, p. 331, we have the following statement as to the produce of the precious metals.-" In 40 years, from 1790 to 1830, Mexico produced 6,436,4531. worth of gold, and 139,818,0321. of silver. Chili, 2,768,4881. of gold, and 1,822,9241. of silver. Buenos Ayres, 4,024,8951. of gold, and 27,182,6731. of silver. Russia, 3,703,7431. of gold, and 1,502,9811. of silver. Total, 1880 millions sterling, or 47 millions per annum. The following table shows what proportion the product of the mines of America bears to that of the mines of the ancient continent. GOLD. 947 Table of the Quantities of Gold which?nay be considered as having been brought into the European Market, every Year on an.Average, from 1790 to 1802. Continents. Gold. ANCIENT CONTINENT. lbs. Avoir. Asia: - - - Siberia - -. 3740 Africa -- -.3300 Europe: Hungary -. 1430 Salzbourg: -. 165 Austrian States - Hartz and Hessia - Saxony - Norway - -. 165 Sweden France Spain, &c, Total of the Ancient Continent - - 8800 NEW CONTINENT. North America - - - -. 2860 South America- - - - Spanish dominions - - - 22,000 Brazil - - - - 15,400 Total of the New Continent - - 40,260 The mines of America have sent into Europe three and a half times more gold, and twelve times more silver, than those of the ancient continent. The total quantity of silver was to that of gold in the ratio of 55 to 1; a very different ratio from that which holds really in the value of these two metals, which is in Europe as 1 to 15. This difference depends upon several causes, which cannot be investigated here at length; but it may be stated that gold, by its rarity and price, being much less employed in the arts than silver, the demand for it is also much less; and this cause is sufficient to lower its price much beneath what it would have been, if it had followed the ratio of its quantity compared to that of silver. Thus also bismuth, tin, &c., though much rarer than silver, are, nevertheless, very inferior in price to it. Before the discovery of America, the value of gold was not so distant from that of silver, because since that era silver has been distributed in Europe in a far greater proportion than gold. In Asia the proportion is now actually only 1 to 11 or 12; the product of the gold mines in that quarter, being not so much below that of the silver mines as in the rest of the world. The total annual production of Gold at present has been estimated as follows. From the ancient Spanish colonies of America - - - 10,400 kilogrammeb Brazil- 600 Europe and Asiatic Russia - - 6,200 The Indian Archipelago - 4,700 Africa - --- 14,000? 35,900=36 tons nearly without taking into account the quantity of gold now extracted from silver. Gold has less affinity for oxygen than any other metal. When alone, it cannot be oxydized by any degree of heat with contact of air, although in combination with other oxydized bodies, it may pass into the state of an oxyde, and be even vitrified. The pur. ple smoke into which gold leaf is converted by an electric discharge is not an oxyde, tbr it is equally formed when the discharge is made through it in hydrogen gas. There are two oxydes of gold; the first or protoxyde is a green powder, which may be obtained by pouring, in the cold, a solution of potash into a solution of the metallic chloride. It is not durable, but soon changes in the menstruum into metallic gold, 61 948 GOLD. and peroxyde. Its constituents are 96-13 metal, and 3-87 oxygen. The peroxyde is best prepared by adding magnesia to a solution of the metallic chloride; washing the precipi. tate with water till this no longer takes a yellow tint from muriatic acid; then digesting strong nitric acid upon the residuum, which removes the magnesia, and leaves the per. jxyde in the form of a black or dark brown powder, which seems to partake more of the properties of a metallic acid than a base. It contains 10'77 per cent. of oxygen. For the curious combination of gold and tin, called the PURPLE PRECIPITATE OF CASSIUS, see this article, and PIGMENTS VITRIFIABLE. Gold beating.-This is the art of reducing gold to extremely thin leaves, by beating with a hammer. The processes employed for this purpose may be applied to other metals, as silver, platinum, and copper. Under tin, zinc, &c., we shall mention such modifications of the processes as these metals require to reduce them o thin leaves. The Romans used to gild the ceilings and walls of their apartments; and Pliny tells us, that from an ounce of gold forming a plate of 4 fingers square, about 600 leaves of the same area were hammered. At the present day, a piece of gold is extended so as to cover a space 651,590 times greater than its primary surface when cast. The gold employed in this art ought to be of the finest standard. Alloy hardens gold, and renders it less malleable; so that the fraudulent tradesman who should attempt to debase the gold, would expose himself to much greater loss in the operations, than he could derive of profit from the alloy. Four principal operations constitute the art of gold beating. 1. The casting of the gold ingots. 2. The hammering. 3. The lamination; and 4, the beating. 1. The gold is melted in a crucible along with a little borax. When it has become,iquid enough, it is poured out into the ingot-moulds previously heated, and greased on the inside. The ingot is taken out and annealed in hot ashes, which both soften it and free it from grease. The moulds are made of cast iron, with a somewhat concave internal surface, to compensate for the greater contraction of the central parts of the metal in cooling than the edges. The ingots weigh about 2 ounces each, and are | of an inch broad. 2. The forging.-When the ingot is cold, the French gold-beaters hammer it out on a mass of steel 4 inches long and 3 broad. The hammer for this purpose is called the forging hammer. It weighs about 3 pounds, with a head at one end and a wedge at the other, the head presenting a square face of 11 inches. Its handle is 6 inches long. The workman reduces the ingot to the thickness of 1 of an inch at most; and during this operation he anneals it whenever its substance becomes hard and apt to crack. The English gold-beaters omit this process of hammering. 3. The lamination.-The rollers employed for this purpose should be of a most perfectly cylindrical figure, a polished surface, and so powerful as not to bend or yield in the operation. The ultimate excellence of the gold leaf depends very much on the precision with which the riband is extended in the rolling press. The laminating machine represented under the article MINT, is an excellent pattern for this purpose. The gold-beater desires to have a riband of such thinness that a square inch of it will weigh 6} grains. Frequent annealings are requisite during the lamination. 4. Beating.-The riband of gold being thus prepared uniform, the gold-beater cuts it with shears into small squares of an inch each, having previously divided it with compasses, so that the pieces may be of as equal weight as possible. These squares are piled over each other in parcels of 150, with a piece of fine calf-skin vellum interposed between each, and about 20 extra vellums at the top and bottom. These vellum leaves are about 4 inches square, on whose centre lie the gold laminm of an inch square. This packet is kept together by being thrust into a case of strong parchment open at the ends, so as to form a belt or band, whose open sides are covered in by a second case drawn over the packet at right angles to the first. Thus the packet becomes sufficiently compact to bear beating with a hammer of 15 or 16 pounds weight, having a circular face nearly 4 inches diameter, and somewhat convex, whereby it strikes the centre of the packet most forcibly, and thus squeezes out the plates laterally. The beating is performed on a very strong bench or stool framed to receive a heavy block of marble, about 9 inches square on the surface, enclosed upon every side by woodwork, except the front where a leather apron is attached, which the workman lays before him to preserve any fragments of gold that may fall out of the packet. The hammer is short-handled, and is managed by the workman with one hand; who strikes fairly on the middle of the packet, frequently turning it over to beat both sides alike; a feat dexterously done in the interval of two strokes, so as not to lose a blow. The packet is occasionally bent or rolled between the hands, to loosen the leaves and secure the ready extension of the gold; or it is taken to pieces to examine the gold, and to shift the central leaves te the outside, and vice versa, that every thing may be equalized. Whenever the gold plates have extended, under this treatment, to nearly the size of the vellum,.hey are removed from the packet, and cu into four equal squares by a knife. Thev GOLD. 949 are thus reduced to nearly the same size as at first, and are again made up into packets and enclosed as before, with this difference, that skins prepared from ox-gut are now interposed between each gold leaf instead of vellum. The second course of beating is performed with a smaller hammer, about 10 pounds in weight, and is continued till the leaves are extended to the size of the skins. During this period the packet must be often folded, to render the gold as loose as possible between the membranes; otherwise the leaves are easily chafed and broken. They are once more spread on a cushion, and subdivided into four square pieces by means of two pieces of cane cut to very sharp edges, and fixed down transversely on a board. This rectangular cross being applied on each leaf, with slight pressure, divides it into four equal portions. These are next made up into a third packet of convenient thickness, and finally hammered out to the area of fine gold leaf, whose average size is from 3 to 31 inches square. The leaves will now have obtained an area 192 times greater than the plates before the hammering begun. As these were originally an inch square, and 75 of them weighed an ounce (- 6- X 75 = 487)), the surface of the finished leaves will be 192 X 75 = 14,400 square inches, or 100 square feet per ounce troy. This is by no means the ultimate degree of attenuation, for an ounce may be hammered so as to cover 160 square feet; but the waste incident in this case, from the number of broken leaves, and the increase and nicety of the labor, make this an unprofitable refinement; while the gilder finds such thin leaves to make less durable and satisfactory work. The finished leaves of gold are put up in small books made of single leaves of soft paper, rubbed over with red chalk to prevent adhesion between them. Before putting the leaves in these books, however, they nre lifted one by one with a delicate piir of pincers out of the finishing packet, and spread out on a leather cushion by blowing them flat down. They are then cut to one size, by a sharp-edge square moulding of cane, glued on a flat board. When this square-framed edge is pressed upon the gold, it cuts it to the desired size and shape. Each book commonly contains 25 gold leaves. I shall now describe some peculiarities of the French practice of gold beating. The workman cuts the laminated ribands of an inch broad into portions an inch and a half long. These are called quartiers. He takes 24 of them, which he places exactly over each other, so as to form a thickness of about an inch, the riband being. of a line, or 1~ of an inch thick; and he beats them together on the steel slab with the round face (panne) of the hammer, so as to stretch them truly out into the square form. He begins by extending the substance towards the edges, thereafter advancing towards the middle; he then does as much on the other side, and finally hammers the centre. By repeating this mode of beating as often as necessary, he reduces at once all the quartiers (squares) of the same packet, till none of them is thicker than a leaf of gray paper, and of the size of a square of 2 inches each side. When the quartiers are brought to this state, the workman takes 56 of them, which he piles over each other, and with which he forms the first packet (caucher) in the manner already described; only two leaves of vellum are interposed between each gold leaf. The empty leaves of vellum at the top and bottom of the packet are called emplures. They are 4 inches square, as well as the parchment pieces. The packet thus prepared forms a rectangular parallelopiped; it is enclosed in two sheaths, composed each of several leaves of parchment applied to each, and glued at the wo sides, forming a bag open at either end. The block of black marble is a foot square at top, and 18 inches deep, and is framed is above described. The hammer used for beating the first packet is called the flat, Dr the enlarging hammer; its head is round, about 5 inches in diameter, and very slightly convex. It is 6 inches high, and tapers grad-ally from its head to the other extremity, which gives it the form of a hexagonal truncated pyramid. It weighs 14 or 15 pounds. The French gold-beaters employ, besides this hammer, three others of the same fqrm; namely, 1. The commencing hammer, which weighs 6 or 7 pounds, has a head 4 inches in diameter, and is more convex than the former. 2. The spreading hammer (marteau a chasser); its head is two inches diameter, more convex than the last, and weighs only 4 or 5 pounds. 3. The finishing hammer; it weighs 12 or 13 pounds, has a head four inches diameter, and is the most convex of all. The beating processes do not differ essentially from the English described above. The vellum is rubbed over with fine calcined Paris plaster, with a hare's foot. The skin of the gold-beater is a pellicle separated from the outer surface of ox-gut; but before being employed for this purpose, it must undergo two preparations. 1. It is sweated, in order to expel any grease it may contain. With this view, each piece of membrane is placed between two leaves of white paper; several of these pairs are piled over each other, and struck strongly with a hammer, which drives the grease from the gut into the paper. 2. A body is givonO to the pieces of gut; that is, they are moistened with ac infusion 950 GOLD. 3f cinnamon, nutmeg, and other warm and aromatic ingredients, in order to preserve them; an operation repeated after they have been dried in the air. When the leaves of skin are dry, they are put in a press, and are now ready for ase. After the parchment, vellum, and gut membrane have been a good deal hammered, they become unfit for work, till they are restored to proper flexibility, by being placed leaf by leaf between leaves of white paper, moistened sometimes with vinegar, at others with white wine. They are left in this predicament for 3 or 4 hours, under compression of a plank loaded with weights. When they have imbibed the proper humidity, they are put between leaves of parchment 12 inches square, and beat in that situation for a whole day. They are then rubbed over with fine calcined gypsum, as the vellum was originally. The gut-skin is apt to contract damp in standing, and is therefore dried before being used. The average thickness of common gold leaf is 1-i- of an inch. The art of Gilding.-This art consists in covering bodies with a thin coat of gold; which may be done either by mechanical or chemical means. The mechanical mode is the application of gold leaf or gold powder to various surfaces, and their fixation by various means. Thus gold may be applied to wood, plaster, pasteboard, leather; and to metals, such as silver, copper, iron, tin, and bronze; so that gilding, generally speaking, includes several arts, exercised by very different classes of tradesmen. I. Mechanical Gilding.-Oil gilding is the first method under this head, as oil is the fluid most generally used in the operation of this mechanical art. The following process has been much extolled at Paris. 1. A coat of impression is to be given first of all, namely, a coat of white lead paint, made with drying linseed oil, containing very little oil of turpentine. 2. Calcined ceruse is to be ground very well with unboiled linseed oil, and tempered with essence of turpentine, in proportion as it is laid on. Three or four coats of this'ard tint are to be applied evenly and dryly on the ornaments and the parts which are to be most carefully gilded. 3. The Gold color is then to be smoothly applied. This is merely the dregs of the ~olors, ground and tempered with oil, which remain in the little dish in which painters Jlean their brushes. This substance is extremely rich and gluey; after being ground 1p, and passed through fine linen cloth, it forms the ground for gold leaf. 4. When the gold color is dry enough to catch hold of the leaf gold, this is spread on.he cushion, cut into pieces, and carefully applied with the palette knife, pressed down with cotton, and in the small ornaments with a fine brush. 5. If the gildings be for outside exposure, as balconies, gratings, statues, &c., they must not be varnished, as simple oil gilding stands better; for when it is varnished, a bright sun-beam, acting after heavy rain, gives the gilding a jagged appearance. When the objects are inside ones, a coat of spirit varnish may be passed over the gold leaf, then a glow from the gilder's chafing dish may be given, and finally a coat of oil varnish. The workman who causes the chafing dish to glide in front of the varnished surface, must avoid stopping for an instant opposite any point, otherwise he would cause the varnish to boil and blister. This heat brings out the whole transparency of the varnish and lustre of the gold. Oil Gilding is employed, with varnish polish, upon equipages, mirror-frames, and other furniture. The following method is employed by eminent gilders at Paris. 1. White lead, with half its weight of yellow ochre, and a little litharge, are separately ground very fine; and the whole is then tempered with linseed oil, thinned with essence of turpentine, and applied in an evenly coat, called impression. 2. When this coat is quite dry, several coats of the hard tint are given, even so many as 10 or 12, should the surface require it, for smoothing and filling up the pores. These coats are given daily, leaving them to dry in the interval in a warm sunny exposure. 3. When the work is perfectly dry, it is first softened down with pumice stone and water, afterwards with worsted cloth and very finely powdered pumice, till the hard tint give no reflection, and be smooth as glass. 4. With a camel's hair brush, there must be given lightly and with a gentle heat, from 4 to 5 coats at least, and even sometimes double that number, of fine lac varnish. 5. When these are dry, the grounds of the panels and the sculptures must be first polished with shave-grass (de la prle); and next with putty of tin and tripoli, tempered with water, appled with woollen cloth; by which the varnish is polished till it shines like a mirror. 6. The work thus polished is carried into a hot place, free from dust, where it receives very lightly and smoothly a thin coat of gold color, muih softened down. This coat is passed over it with a clean soft brush, and the thinner it is the better. 7. Whenever the gold color is dry enough to take the gold, which is known by laying:he back of the hand on a corner of the frame work, the gilding is begun and finished as usual. 8. The gold is smoothed off with a very soft brush, one of camel's hair, for example )f three fingers' breadth; after which it is left to dry for several days. GOLD. 951 9. It is then varnished with a spirit of wine varnish; which is treated with the chafing dish as above described. 10. When this varnish is dry, two or three coats of cepal or oil varnish are applied, at intervals of two days. 11. Finally, the panels are polished with a worsted cloth, imbued with tripoli and water, and lustre is given by friction with the palm of the hand, previously softened with a little olive oil, taking care not to rub off the gold. In this country, burnished gilding is practised by first giving a ground of size whiting, in several successive coats; next applying gilding size; and then the gold leaf, which is burnished down with agate, or a dog's tooth. Gilding in distemper of the French, is the same as our burnished gilding. Their process seems to be very elaborate, and the best consists of 17 operations; each of them said to be essential. 1. Encollage, or the glue coat. To a decoction of wormwood and garlic in water, strained through a cloth, a little common salt and some vinegar are added. This composition, as being destructive of worms in wood, is mixed with as much good glue; and the mixture is spread in a hot state, with a brush of boar's hair. When plaster or marble is to be gilded, the salt must be left out of the above composition, as it is apt to attract humidity in damp places, and to come out as a white powder on the gilding. But the salt is indispensable for wood. The first glue coating is made thinner than the second. 2. White preparation. This consists in covering the above surface with 8, 10, or 12 coats of Spanish white, mixed up with strong size, each well worked on with the brush, and in some measure incorporated with the preceding coat, to prevent their peeling off in scales. 3. Stopping up the pores, with thick whiting and glue, and smoothing the surface with dog-skin. 4. Polishing the surface with pumice-stone and very cold water. 5. Reparation; in which a skilful artist retouches the whole. 6. Cleansing; with a damp linen rag, and then a soft sponge. 7. Preler. This is rubbing with horse's tail (shave-grass) the parts to be yellowed, in order to make them softer. 8. Yellowing. With this view yellow ochre is carefully ground in water, and mixed with transparent colorless size. The thinner part of this mixture is applied hot over the white surface with a fine brush, which gives it a fine yellow hue. 9. Ungraining consists in rubbing the whole work with shave-grass, to remove any granular appearance. 10. Coat of assiette; trencher coat. This is the composition on which the gold is to be laid. It is composed of Armenian bole, 1 pound; bloodstone (hematite), 2 ounces; and as much galena; each separately ground in water. The whole are then mixed together, and ground up with about a spoonful of olive oil. The assiette well made and applied gives beauty to the gilding. The assiette is tempered with a white sheep-skin glue, very clear and well strained. This mixture is heated and applied in three successive coats, with a very fine long-haired brush. 11. Rubbing, with a piece of dry, clean linen cloth; except the parts to be burnished, which are to receive other two coats of assiette tempered with glue. 12. Gilding. The surface, being damped with cold water (iced in summer), has then the gold leaf applied to it. The hollow grounds must always be gilded before the prominent parts. Water is dexterously applied by a soft brush, immediately behind the gold leaf, before laying it down, which makes it lie smoother. Any excess of water is then removed with a dry brush. 13. Burnishing with bloodstone. 14. Deadening. This consists in passing a thin coat of glue, slightly warmed, over the parts that are not to be burnished. 15. Mending; that is, moistening any broken points with a brush, and applying bits of gold leaf to them. 16. The vermeil coat. Vermeil is a liquid which gives lustre and fire to the gold; and makes it resemble or moulu. It is composed as follows: 2 ounces of annotto, 1 ounce of gamboge, 1 ounce of vermilion, half an ounce of dragon's blood, 2 ounces of salt of tartar, and 18 grains of saffron, are boiled in a litre (2 pints English) of water, over a slow fire, till the liquid be reduced to a fourth. The whole is then passed through a silk or muslin sieve. A little of this is made to glide lightly over the gold, with a very soft brush. 17. Repassage is passing over the dead surfaces a second coat of deadening glue, which must be hotter than the first. This finishes the work, and gives it strength. Leaf gilding, on paper or vellum, is done by giving them a coat of gum water or fine size, applying the gold leaf ere the surfaces be hard dry, and burnishing with agate. ____________________ _ _ ______________ 952 GOLD. Gold lettering, on bound books, is given without size, by la:'ing the gold leaf on tht leather, and imprinting it with hot brass types. The edges of the leaves of books are gilded while they are in the press, where they have been cut smooth, by applying a solution of isinglass in spirits, and laying on the gold when the edges are in a proper state of dryness. The French workmen employ a ground of Armenian bole, mixed with powdered sugar-candy, by means of white of egg. This ground is laid very thin upon the edges, after fine size or gum water has been applied; and when the ground is dry it is rubbed smooth with a wet rag, which moistens it sufficiently to take the gold. Japanner's gilding is done by sprinkling or daubing with wash leather, some gold powler, over an oil sized surface, mixed with oil of turpentine. This gives the appearance of frosted gold. The gold powder may be obtained, either by precipitating gold from its solution in aqua regia by a solution of pure sulphate of iron, or by evaporating away the mercury from some gold amalgam. TI. Chemical gilding, or the application of gold by chemical affinity to mttallic sur faces. A compound of copper with one seventh of brass is the best metal for gilding on; copper by itself being too soft and dark colored. Ordinary brass, however, answers very well. We shall describe the process of wash gilding, with M. D'Arcet's late improvements, now generally adopted in Paris. Wash gilding consists in applying evenly an amalgam of gold to the surface of a copper alloy, and dissipating the mercury with heat, so as to leave the gold film fixed. The surface is afterwards burnished or deadened at pleasure. The gold ought to be quite pure, and laminated to facilitate its combination with the mercury; which should also be pure. Preparation of the amalgam. After weighing the fine gold, the workman puts it in a crucible, and as soon as this becomes faintly red, he pours in the requisite quantity of mercury; which is about 8 to 1 of gold. He stirs up the mixture with an iron rod, bent hookwise at the end, leaving the crucible on the fire till he perceives that all the gold is dissolved. He then pours the amalgam into a small earthen dish containing water, washes it with care, and squeezes out of it with his fingers all the running mercury that he can. The amalgam that now remains on the sloping sides of the vessel is so pasty as to preserve the impression of the fingers. When this is squeezed in a shamoy leather bag it gives up much mercury; and remains an amalgam, consisting of about 33 of mercury, and 57 of gold, in 100 parts. The mercury which passes through the bag, under the pressure of the fingers, holds a good deal of gold in solution; and is employed in making fresh amalgam. Preparation of the mercurial solution. The amalgam of gold is applied to brass, through the intervention of pure nitric acid, holding in solution a little mercury. 100 parts of mercury, and 110 parts by weight of pure nitric acid, specific gravity 1-33, are to be put into a glass matrass. On the application of a gentle heat the mercury dissolves with the disengagement of fumes of nitrous gas, which must be allowed to escape into the chimney. This solution is to be diluted with about 25 times its weight of pure water, and bottled up for use. 1. annealing.-The workman anneals the piece of bronze after it has come out of the hands of the turner and engraver. He sets it among burning charcoal, or rather peats, which have a more equal and lively flame; covering it quite up, so that it may be oxydized as little as possible, and taking care that the thin parts of the piece do not become hotter than the thicker. This operation is done in a dark room, and when he sees the piece of a cherry red color, he removes the fuel from about it, lifts it out with long tongs, and sets it to cool slowly in the air. 2. The decapage.-The object of this process is to clear the surface from the coat or oxyde which may have formed upon it. The piece is plunged into a bucket filled with extremely dilute sulphuric acid; it is left there long enough to allow the coat of oxyde to be dissolved, or at least loosened; and it is then rubbed with a hard brush. When the piece becomes perfectly bright, it is washed and dried. Its surface may however be still a little variegated; and the piece is therefore dipped in nitric acid, specific gravity 1'33, and afterwards rubbed with a long-haired brush. The addition of a little common salt to the dilute sulphuric acid would probably save the use of nitric acid, which is so apt to produce a new coat of oxyde. It is finally made quite dry (after washing in pure water), by being rubbed well with tanners' dry bark, saw-dust, or bran. The surface should now appear somewhat de-polished; for when it is very smooth, the gold does not adhere so well. application of the amalgam.-The gilder's scratck-brush or pencil, made with fine brass wire, is to be dipped into the solution of nitrate of mercury, and is then to be drawn over a lump of gold amalgam, laid on the sloping side of an earthen vessel, after which it is to be applied to the surface of the brass. This process is to be GOLD. 953 repeated, dipping the brush into tne solution, and drawing it over the ama-gam, till the whole surface to be gilded is coated with its just proportion of gold. The piece is then washed in a body of water, dried, and put'to the fire to volatilize the mercury. If one coat of gilding be insufficient, the piece is washed over anew with ai algam, and the operation recommenced till the work prove satisfactory. 4. Volatilization of the mercury.-Whenever the piece is well coated with amalgam, the gilder exposes it to glowing charcoal, turning it about, and heating it by degrees to the proper point; he then withdraws it from the fire, lifts it with long pincers, and, seizing it in his left hand, protected by a stuffed glove, he turns it over in every direction, rubbing and striking it all the while with a long-haired brush, in order to equalize the amalgam. He now restores the piece to the fire, and treats it in the same way till the mercury be entirely volatilized, which he recognises by the hissing sound of a drop of water let fall on it. During this time he repairs the defective spots, taking care to volatilize the mercury very slowly. The piece, when thoroughly coated with gold, is washed, and scrubbed well with a brush in water acidulated with vinegar. if the piece is to have some parts burnished, and others dead, the parts to be burnished are covered with a mixture of Spanish white, bruised sugar-candy, and gum dissolved in water. This operation is called in French epargner (protecting). When the gilder has protected the burnished points, he dries the piece, and carries the heat high enough to expel the little mercury which might still remain on it. He then plunges it, while still a little hot, in water acidulated with sulphuric acid, washes it, dries it, and gives it the burnish. 5. The burnish is given by rubbing the piece with burnishers of hematite (bloodstone). The workman dips his burnisher in water sharpened with vinegar, and rubs the piece always in the same direction backwards and forwards, till it exhibits a fine polish, and a complete metallic lustre. He then washes it in cold water, dries it with fine linen cloth, and concludes the operation by drying it slowly on a grating placed above a chafing dish of burning charcoal. 6. The deadening is given as follows. The piece, covered with the protection on those parts that are to be burnished, is attached with an iron wire to the end of an iron rod, and is heated strongly so as to give a brown hue to the epargne by its partial carbon-. ization. The gilded piece assumes thus a fine tint of gold; and is next coated over with a mixture of sea salt, nitre, and alum, fused in the water of crystallization of the latter salt. The piece is now restored to the fire, and heated till the saline crust which covers it becomes homogeneous, nearly transparent, and enters into true fusion. It is then taken from the fire and suddenly plunged into cold water, which separates the saline crust, carrying away even the coat of epargne. The piece is lastly passed through very weak nitric acid, washed in a great body of water, and dried by exposure eithler to the air, over a drying stove, or with clean linen cloths. 7. Of or-moulu color.-When it is desired to put a piece of gilded bronze into ormoulu color, it must be less scrubbed with the scratch-brush than usual, and made to come back again by heating it more strongly than if it were to be deadened, and allowing it then to cool a little. The or-moulu coloring is a mixture of hematite, alum, and sea salt. This mixture is to be thinned with vinegar, and applied with a brush so as to cover the gilded brass, with reserve of the burnished parts. The piece is then put on glowing coals, urged a little by the bellows, and allowed to heat till the color begins to blacken. The piece ought to be so hot that water sprinkled on it may cause a hissing noise. It is then taken from the fire, plunged into cold water, washed, and next rubbed with a brush dipped in vinegar, if the piece be smooth, but if it be chased, weak nitric acid mus: be used. In either case, it must be finally washed in a body of pure water, and dried over a gentle fire. 8. Of red gold color. —To give this hue, the piece, after being coated with amalgam and heated, is in this hot state to be suspended by an iron wire, and tempered with the composition known under the name of gilder's wax; made with yellow wax, red ochre, verdigris, and alum. In this state it is presented to the flame of a wood fire, is heated strongly, and the combustion of its coating is favored by throwing some drops of the wax mixture into the burning fuel. It is now turned round and round over the fire, so that the flame may act equally. When all the wax of the coloring is burned away, and when the flame is extinguished, the piece is to be plunged in water, washed, and scrubbed with the scratch-brush and pure vinegar. If the color is not beautiful, and quite equal in shade, the piece is coated with verdigris dissolved in vinegar, dried over a gentle fire, plunged in water, and scrubbed with pure vinegar, or even with a little weak nitric acid if the piece exhibit too dark a Irae. It is now washed, burnished, washed anew, wiped with linen cloth, and finally dried over a gentle fire. The following is the outline of a complete gilding factory, as now fitted up at Paris. Fig..732. Front elevation and plan of a complete gilding workshop. 964 GOLD. P Fainace cir appel, or draught, serving at the same time to heat the deadening pan (poelon au mat)'38 _ A t W C. iii D i.. y_ I m I - r. Ashpit of this furnace. N. Chimney of this furnace constructed of bricks, as far as the contraction of tie great chimney s of the forge, and which is terminated by a summit pipe rising 2 or 3 yards above this contraction. B. Forge for annealing the pieces of bronze; for drying the gilded pieces, &c. c. Chimney of communication between the annealing forge B, and the space D below the forge. This chimney serves to carry the noxious fumes into the great vent of the factory. u. Bucket for the brightening operation. A. Forge for passing the amalgam over the piece. R. Shelf for the brushing operations E E. Coal cellarets. o. Forge for the deadening process. G. Furnace for the same. M. An opening into the furnace of appev, oy which vapors may be let off from any ope ration by taking out the plug at M. r. Cask in which the pieces of gilded brass are plunged for the deadening process. The vapors rising thence are carried up the general chimney. J J. Casement with glass panes, which serves to contract the opening of the hearths, without obstructing the view. The casement may be rendered moveable to admit larger objects. H H. Curtains of coarse cotton cloth, for closing at pleasure, in whole or part, one or several of the forges or hearths, and for quickening the current of air in the places where the curtains are not drawn, Q. Opening above the draught furnace, which serves for the heating of the poelon au mat (deadening pan). Gilding on polished iron and steel. -If a nearly neutral solution of gold in muriatic acid be mixed with sulphuric ether, and agitated, the ether will take up the gold, and float above the denser acid. When this auriferous ether is applied by a hair pencil to brightly polished iron or steel, the ether flies off, and the gold adheres. It must be fixed by polishing with the burnisher. This gilding is not very rich or durable. In fact, the affinity between gold and iron is feeble, compared to that between gold and copper or silver. But polished iron, steel, and copper, may be gilded with heat, by gold leaf. They are first heated till the iron takes a bluish tint, and till the copper has attained tc like temperature; a first coat of gold leat is now applied, which is pressed gently GRADUATOR. 955 lown with a burnisher, and then exposed to a gentle heat. Several leaves either single or double are thus applied in succession, and the last is burnished down cold. Cold gilding.-Sixty grains of fine gold and 12 of rose copper are to be dissolved in two ounces of aqua regia. When the solution is completed, it is to be dropped on clean linen rags, of such bulk as to absorb all the liquid. They are then dried, and burned into ashes. These ashes contain the gold in powder. When a piece is to be gilded, after subjecting it to the preliminary operations of softening or annealing and brightening, it is rubbed with a moistened cork, dipped in the above powder, till the surface seems to be sufficiently gilded. Large works are thereafter burnished with pieces of hematite, and small ones with steel burnishers, along with soap water. In gilding small articles, as buttons, with amalgam, a portion of this is taken equivalent to the work to be done, and some nitrate of mercury solution is added to it in a wooden trough; the whole articles are now put in, and well worked about with a hard brush, till their surfaces are equably coated. They are then washed, dried, and put altogether into an iron frying-pan, and heated till the mercury begins to fly off, when they are turned out into a cap, in which they are tossed and well stirred about with a painter's brush. The operation must be repeated several times for a strong gilding. The surfaces are finally brightened by brushing them along with small beer or ale grounds. Gold wire is formed by drawing a cylindrical rod of the metal, as pure as may be, through a series of holes punched in an iron plate, diminishing progressively in size. The gold, as it is drawn through, becomes hardened by the operation, and requires frequent annealing. Gold thread, or spun gold, is a flatted silver-gilt wire, wrapped or laid over a thread of yellow silk, by twisting with a wheel and iron bobbins. By the aid of a mechanism like the Braiding Machine, a number of threads may thus be twisted at once by one master wheel. The principal nicety consists in so regulating the movements that the successive volutions of the flatted wire on each thread may just touch one another, and form a continuous covering. The French silver for gilding is said to be alloyed with 5 or 6 pennyweights, and ours with 12 pennyweights of copper in the pound troy. The gold is applied in leaves of greater or less thickness, according to the quality of the gilt wire. The smallest proportion formerly allowed in this country by act of parliament, was 100 grains of gold to one pound, or 5760 grains of silver; but more or less may now be used. The silver rod is encased in the gold leaf, and the compound cylinder is then drawn into round wire down to a certain size, which is afterwards flatted in a rolling mill such as is described under MINT. The liquor employed by goldsmiths to bring out a rich color upon the surface of their trinkets, is made by dissolving 1 part of sea salt, 1 part of alum, 2 parts of nitre, in 3 or 4 of water. This pickle or sauce, as it is called, takes up not only the copper alloy, but a notable quantity of gold; the total amount of which in the Austrian empire, has been estimated annually at 47,000 francs. To recover this gold, the liquor is diluted with at least twice its bulk of boiling water; and a solution of very pure green sulphate of iron is poured into it. The precipitate of gold is washed upon a filter, dried, and purified by melting in a crucible along with a mixture of equal parts of nitre and borax. Gold refining.-The following process has been patented as a foreign invention by Mr. W. E. Newton in January, 1851. It consists, 1., in reducing argentiferous or any other gold bullion to a granulated, or spongy, or disintegrated molecular condition by fusion therewith of zinc, or some other metal baser than silver, and the subsequent removal of the zinc by dilute sulphuric or other acid; that is, the reducing of the gold bullion to a state to allow of the removal by acids of the silver and other impurities contained therein, so as to fit it for coinage and other purposes without quartation with silver or any other intermediate process. And 2., in pulverizing by grinding or concussion gold bullion, rendered brittle by union with lead, solder, or other suitable metal, the silver and other impurities being removed by acids in this as in the preceding case, and recovered from the acid solution by any of the known chemical means. This operation, if properly conducted, will produce fine ductile gold in a state of great purity; that is, containing from 98'5 to 99'5 per cent. of pure gold. GONG-GONG; or tam-tam of the Chinese; a kind of cymbal made of a copper alloy, described towards the end of the article COPPER. GONIOMETER, is the name of a little instrument made either on mechanical or optical principles, for measuring the angles of crystals. It is indispensable to the mine ralogist. GRADUATOR, called by its contriver M. Wagenmann, Essigbilder, which means, in German, vinegar-maker, is represented in fig. 739. It is an oaken tut, 5J feet high, BJ feet wide at top, and 3 at bottom, set upon wooden beams, which raise its bcttom 956 GRAUWACKE. about 14 inches from the floor. At a distance of 15 inches above the bottom, the tub is pierced with a horizontal row 739 of 8 equidistant round holes, of an inch in diameter. At 5 inches beneath the mouth of the tub, a thick beech wood hoop is made fast to the inner surface, which supports a circular oaken shelf, leaving a space round its edge of l1 inches, which is stuffed water-tight with hemp or tow. In this shelf, 400 holes at least must be bored, about i of an inch in diameter, and 1- inches apart; and each of these must be loosely filled with a piece of packthread, or cotton..........t d I wick, which serves to filter the liquid slowly downwards. /,,'"' ]_In the same shelf there are likewise four larger holes of 1 - inches diameter, and 18 inches apart, each of which receives air-tight a glass tube 3 or 4 inches long, having its ends projecting above and below the shelf. These tubes serve to allow the air that enters by the 8 circumferential holes, to circulate freely through the graduator. The mouth of the tube is covered with a wooden lid, in whose middle is a hole for the insertion of a funnel, when the liquor of acetification requires to be introduced. One inch above the bottom, a hole is bored for receiving a syphon-formed discharge pipe, whose upper curvature stands one inch below the level of the holes in the side of the tub, to prevent the liquor from rising so high as to overflow through them. The syphon is so bent as to retain a body of liquor 12 inches deep above the bottom of the tub, and to allow the ex cess only to escape into the subjacent receiver. In the upper part of the graduator, but under the shelf, the bulb of a thermometer is inserted through the side, some way into the interior, having a scale exteriorly. The whole capacity of the cask from the bottom up to within one inch of the perforated shelf, is to be filled with thin shavings of beech wood, grape stalks, or birch twigs, previously imbued with vinegar. The manner of using this simple apparatus is described under ACETIC ACID. GRANITE is a compound rock, essentially composed of quartz, feldspar, and mica, each in granular crystals. It constitutes the lowest of the geological formations, and therefore has been supposed to serve as a base to all the rest. It is the most durable material for building, as many of the ancient Egyptian monuments testify. The obelisk in the place of Saint Jean de Lateran at Rome, which was quarried at Syene, under the reign of Zetus; king of Thebes, 1300 years before the Christian era; and the one in the place of Saint Pierre, also at Rome, consecrated to the Sun by a son.f Sesostris, have resisted the weather for fully 3000 years. On the other hand there are many granites, especially those in which feldspar predominates, which crack and crumble down in the course of a few years. In the same mountain, or even in the same quarry, granites of very different qualities as to soundness and durability occur. Some of the granites of Cornwall and Limousin readily resolve themselves into a white kaolin or argillaceous matter, from which pottery and porcelain are made. Granite, when some time dug out of the quarry, becomes refractory, and difficult to cut. When this rock is intended to be worked it should be kept under water; and that variety ought to be selected which contains least feldspar, and in which the quartz or gray crystals predominate. GRANULATION is the process by which metals are reduced to minute grains. It is effected by pouring them, in a melted state, through an iron cullender pierced with small holes, into a body of water; or directly upon a bundle of twigs immersed in water. In this way copper is granulated into bean shot, and silver alloys are granulated preparatory to PARTING; which see. GRAPHITE (Plombagi7e,Fr.; Reissblei, Germ.) is a mineral substance of a lead or iron gray color, a metallic lustre, soft to the touch, and staining the fingers with a lead gray hue. Spec. grav. 2-08 to 2-45. It is easily scratched, or cut with a steel edge, and displays the metallic lustre in its interior. Burns with great difficulty in the outward flame of the blow-pipe. It consists of carbon in a peculiar state of aggregation, with an extremely minute and apparently accidental impregnation of iron. Graphite, called also plumbago and black lead, occurs in gneiss, mica slate, and their subordinate clay slates and lime stones; in the form of masses, veins, and kidney-shaped disseminated pieces; as also in the transition slate, as at Borrodale in Cumberland, where the most precious deposite exists, both in reference to extent and quality, for making pencils. It has been found also among the coal strata, as near Cumnock in Ayrshire. This substance is employed for counteracting fiiction between rubbing surfaces of wood or metal, for making crucibles and portable furnaces, for giving a gloss to the surface of cast iron, &c. See PLUMBAGO, for some remarks concerning the Cumberland mine. GRAUWACKE, or GREYWACKE, is a rock formation, composed of pieces of quartz, flinty slate, feldspar, and clay slate, cemented by a clay-slate basis; the pieces varying in -ze from small grains to a hen's egg. GREEN PAINTS. 957 GRAY DYE. (Teinture grise, Fr.; Graufarbe, Germ.) The gray dyes, in theii numerous shades, are merely various tints of black, in a more or less diluted state, from the deepest to the lightest hue. The dyeing materials are essentially the tannic and gallic acid of galls or other astringents, along with the sulphate or acetate of iron, and occasionally wine stone. Ash gray is given for 30 pounds of woollen stuff, by one pound of gall-nuts, - lb. of wine stone (crude tartar), and 2- lbs. of sulphate of iron. The galls and the wine stone being boiled with from 70 to 80 pounds of water, the stuff is to be turned through the decoction at a boiling heat for half an hour, then taken out, when the bath being refreshed with cold water, the copperas is to be added, and, as soon as it is dissolved, the stuff is to be put in and fully dyed. Or, for 36 pounds of wool; 2 pounds of tartar, 1 pound of galls, 3 pounds of sumach, and 2 pounds of sulphate of iron are to be taken. The tartar being dissolved in 80 pounds of boiling water, the wool is to be turned through the solution for half an hour, and then taken out. The copper being filled up to its former level with fresh water, the decoction of the galls and sumach is to'se poured in, and the wool boiled for half an hour in the bath. The wool is then taken out, while the copperas is being added and dissolved; after which it is replaced in the bath, and dyed gray with a gentle heat. If the gray is to have a yellow cast, instead of the tartar, its own weight of alum is to be taken; instead of the galls, one pound of old fustic; instead of the copperas, A of a pound of Saltzburg vitriol, which consists, in 221 parts, of 17 of sulphate of iron, and 51 of sulphate of copper; then proceed as above directed. Or the stuff may be first stained in a bath of fustic, next in a weak bath of galls with a little alum; then the wool being taken out, a little vitriol (common or Saltzburg) is to be put in, previously dissolved in a decoction of logwood; and in this bath the dye is completed. Pearl gray is produced by passing the stuff first through a decoction of sumach and logwood (2 lbs. of the former to cne of the latter), afterwards through a dilute solution of sulphate or acetate of iron; and finishing it in a weak bath of weld containing a little alum. Mouse-gray is obtained, when with the same proportions as for ash-gray, a small quantity of alum is introduced. For several other shades, as tawny-gray, iron-gray, and slate-gray, the stuff must receive a previous blue ground by dipping it in the indigo vat; then it is passed first through a boiling bath of sumach with galls, and lastly through the same bath at a lower temperature after it has received the proper quantity of solution of iron. For dyeing silk gray, fustet, logwood, sumach, and elder-tree bark, are employed instead of galls. Archil and annotto are frequently used to soften and beautify the tint. The mode of producing gray dyes upon cotton has been sufficiently explained in the articles CALICO PRINTING and DYEING. GREEN DYE is produced by the mixture of a blue and yellow dye, the blue being first applied. See DYEING; as also BLUE and YELLOW DYES, and CALICO PRINTING. GREEN PAINTS. (Couleurs vertes, Fr.; Grine pigmente, Germ.) Green, which is so common a color in the vegetable kingdom, is very rare in the mineral. There is only one metal, copper, which affords in its combinations the various shades of green in general use. The other metals capable of producing this color are, chromium in its protoxyde, nickel in its hydrated oxyde, as well as its salts, the seleniate, arseniate, and sulphate; and titanium in its prussiate. Green pigments are prepared also by the mixture of yellows and blues; as, for example, the green of Rinman and of Gellert, obtained by the mixture of cobalt blue, and flowers of zinc; that of Barth, made with yellow lake, Prussian blue, and clay; but these paints seldom appear in the market, because the greens are generally extemporaneous preparations of the artists. Mountain green consists of the hydrate, oxyde, or carbonate of copper, either factitious, or as found in nature. Bremen or Brunswick green is a mixture of carbonate of copper with chalk or lime, and sometimes a little magnesia or ammonia. It is improved by an admixture of white lead. It may be prepared by adding ammonia to a mixed solution of sulphate of copper and alum. Frise green is prepared with sulphate of copper and sal ammoniac. Mittis green is an arseniate of copper; made by mixing a solution of acetate or sulphate of copper with arsenite of potash. It is in fact Scheele's green. Sap green is the inspissated juice of buckthorn berries. These are allowed to ferment for 8 days in a tub, then put in a press, adding a little alum to the juice, and con centrated by gentle evaporation. It is lastly put up in pigs' bladders, where it beeome~ dry and hard 958 GUANO Schweinfurt green; see SCHWEINFURT. Verona green is merely a variety of the mineral called green earth GREEN VITRIOL is sulphate of iron in green crystals. GROWAN. The name given by the Cornish miners to granite, and to rocks of like structure. GUAIAC, (Gaiac, Fr.; Guajaharz, Germ.) is a rerin which exudes from the trunk of the Guaiacum officinale, a tree which grows in the West India islands. It 3or.es to us in laige greenish-brown, semi-transparent lumps, having a conchoidal or splintery fracture, brittle and easy to pulverize. It has an aromatic smell, a bitterish, acrid taste, melts with heat, and has a spec. grav. of from 1'20 to 1-22. It consists of 57 88 carbon; 7'05 hydrogen; and 25'07 oxygen; and contains two different resins, the one of which is soluble in all proportions in ammonia, and the other forms, with water of ammonia, a tarry consistenced mixture. It is soluble in alkaline lyes, in alzohol, incompletely in ether, still less so in oil of turpentine, and not at all in fat oils. Its chief use is in medicine. GUANO. This extraordinary excrementitious deposite of certain sea-fowls, which occurs in immense quantities upon some parts of the coasts of Peru, Bolivia, and Africa, has lately become an object of great commercial enterprise, and of intense interest to our agricultural world. Four or five years ago it was exhibited and talked of merely as a natural curiosity. No one could then have imagined that in a short period it would be imported from the coasts of the Pacific in such abundance, and at such a moderate price, as to cheer by its fertilizing powers the languid and depressed spirits of the farmers throughout the United Kingdom. Such, however, is now the result, as attested by the concurring reports of almost all the agricultural societies of Great Britain and Ireland. No less than 28,500 tons of guano have been already imported from Peru and Bolivia, 1,500 from Chili, and 8,000 from Africa, altogether 38,000 tons, while more is on the way. The store of it, laid up from time immemorial in the above localities, seems to be quite inexhaustible; especially since it is receiving constant accessions from myriads of cormorants, cranes, &c. Having been much occupied with the chemical analyses of guano during the last two years for Messrs. Gibbs, of London, and Messrs. Myers, of Liverpool, who are the co-agents of the Peruvian and Bolivian governments, I have enjoyed favorable opportunities of examining samples of every description, and hope to show that many of the analyses of guano hitherto published have been made upon specimens not in their normal or sound state, like the best imported by the above houses from Chincha and Bolivia, but in a certain state of eremacausis and decay. Huano, in the language of Peru, signifies dung; a word spelt by the Spaniards guano. The natives have employed it as a manure from the remotest ages, and have by its means given fertility to the otherwise unproductive sandy soils along their coasts. While Peru was governed by its native incas, the birds were protected from violence by severe laws. The punishment of death was decreed to persons who dared to land on the guaniferous islands during the breeding period of the birds, and to all persons who destroyed them at any time. Overseers were appointed by the government to take care of the guano districts, and to assign to each claimant his due share of the precious dung. The celebrated Baron Von Humboldt first brought specimens to Europe in 1$04, which he sent for examination to Foureroy, Vauquelin, and Klaproth, the best analytical chemists of the day; and he spoke of it in the following terms: "The guano is deposited in layers of 50 or 60 feet thick upon the granite of many of the South sea islands off the coast of Peru. During 300 years the coast birds have deposited guano only a few lines in thickness. This shows how great must have been the number of birds, and how many centuries must have passed over in order to form the present guano-beds." The strata have undergone many changes, according to the length of time they have been deposited. Here and there they are covered with silicious sand, and have thus been protected from the influence of the weather; but in other places, they have lain open to the action of light, air, and water, which have produced important changes upon them. Fresh guano is of a whitish or very pale drab color, but it becomes progressively browner and browner by the joint influence of the above three atmospherical agents. Only one guano examined by Fourcroy and Vauquelin was found to contain a fourth of its weight of uric acid combined with ammonia, whence that appears to have been well selected by Baron Von Humboldt. They also found phosphates of ammonia, of lime, with urate and oxalate of ammonia, and some other constituents of little value in agriculture. Klaproth's analysis reported 16 per cent. of urate of ammonia, no less than 12-75 of oxalate of lime, 10 of phosphate of lime, 32 of clay and sand,.vith 28-75 of water and indeterminate organic matter. From the great proportion of flay and sand, Klaproth's sample of guano was obviously not genuine. I have met vith no specimen of Peruvian guano that contained any appreciable quantity of clay, ntd none that contained above 4 or 5 per cent. of silicious sand. GUANO. 959 To Mr. Bland, of the firm of Messrs. Myers and Co., I am indebted for the following raluable information:The Chincha islands, which afford the best Peruvian guano, are three in number, and lie in one line from north to south, about half a mile apart. Each island is from five to six miles in circumference, and consists of granite covered with guano in some places to a height of 200 feet, in successive horizontal strata, each stratum being from 3 to 10 inches thick, and varying in color from light to dark brown. No earthy matter whatever is mixed with this vast mass of excrement. At Mr. Bland's visit to these islands in 1842, he observed a perpendicular surface of upward of 100 feet of perfectly uniform aspect from top to bottom. In some parts of these islands, however, the deposite does not exceed 3 or 4 feet in thickness. In several places, where the surface of the guano is 100 feet or more above the level of the sea, it is strewed here and there with masses of granite, like those from the Alpine mountains, which are met with on the slopes of the Jura chain. These seem to indicate an ancient formation for the guano, and terraqueous convulsions since that period. No such granite masses are found imbedded within the guano, but only skeletons of birds. The good preservation of the Chincha guano is to be ascribed to the absence of rain; which rarely, if ever, falls between the latitude of 14~ south, where these islands lie, about 10 miles from the main land, and the latitude of Paquica, on the island of Bolivia, in 21~ S. L. By far the soundest cargoes of guano which I have analysed have come from Chincha and Bolivia. Beyond these limits of latitude where rain falls in greater or less abundance, the guano is of less value-and what has been imported from Chili has been found by me far advanced in decay-most of the ammonia and azotised animal substances having been decomposed by moisture, and dissipated in the air (by the eremacausis of Liebig), leaving phosphate of lime largely to predominate along with effete organic matter. The range of the American coast from which the guano is taken must therefore be well considered; and should not extend much beyond the Chincha islands as the northern limit, and Paquica, in Bolivia, as the southern. The relative estimation of guano and nitrate of soda among the Peruvians is well shown by the following fact communicated to me by Mr. Bland: "C Near the coast of Peru, about 45 miles from Iquique (the shipping port of guano) there is the chief deposite of nitrate of soda. The farmers, who collect and purify this natural product, carry it to the place of shipment, and always require to be paid in return with an equivalent quantity of guano, with which they manure their land, to the exclusion of the far cheaper nitrate of soda. We can not be surprised at this preference, when we learn that in the valley of Chancay, about 40 miles distant from Lima, the soil produces, when farmed with irrigation in the natural way, a return upon maize of only 15 for 1; whereas, with the aid of guano, it produces 500 for 1! Hence the Peruvian proverb: Huano, though no saint, works many miracles. In the pamphlet recently published by Messrs. Gibbs and Myers, intitled "Peruvian and Bolivian Guano, its nature, properties, and results," we have a very interesting view of the best established facts with regard to its operation and effects upon every variety of soil, and in every variety of circumstance, as ascertained by the most intelligent agriculturists of the United Kingdom. The general conclusion that may be fairly deduced from the whole evidence is, that good guano will, under judicious application, increase the crops of grain, turnips, potatoes, and grass, by about 33 per cent.; and with its present price of 101. per ton, at a cost considerably under the average cost of all other manures, whether farm-yard dung and composts, or artificial compounds. Guano is, moreover, peculiarly adapted to horticultural and floricultural improvement, by its relative cleanliness and facility of application. The following observations upon guano, by Dr. Von Martius, of Munich, addressed to the agricultural society of Bavaria, deserve attention. Among animal manures, says he. it clearly claims the first place. It is uncommonly rich in ammoniacal salts, which act very favorable on vegetation. The ease with which these salts are decomposed, and exhale their ammonia into the air, is by him assigned as the reason why plants manured with guano generally present early in the morning accumulations of dew on the points of their leaves. The guano absorbs the atmospheric vapor, as well as carbonic acid; whereby it becomes so valuable a manure in dry barren regions. If we compare guano with other excrementitious manures, we shall find it far preferable to those afforded by man or other mammalia, which do not generally contain morethan 20 per cent. of food that can be appropriated by plants. It is therefore five times better than night-soil, and also very superior to the French poudrette, which, being dried nightsoil, loses, through putrefaction and evaporation, the greater proportion of its ammoniacal elements. In birds, the excretions both of the kidneys and intestines are contained in the cloaca; whereby the volatile elements of the former get combined with the more fixed components of the latter. The guano is also a richer manure, on account of its being produced b: sea-fowl. which live entirely on fish, without admixture of vegetable 960 GUANO. matter. The exposure also of the guano as soon as deposited to the heat of a'tropical sun, in a rainless climate, prevents the components from fermenting, and mummifies them, so to speak, immediately into a concrete substance not susceptible of decomposition till it gets moisture; whereas the dung of our dove-cotes suffers a considerable loss by exposure to our humid atmosphere. But in their action on vegetation, and in their chemical composition, these two bird excreients are analogous. Davy found in fresh dove-cote manure 23 parts in 100 soluble in water, which yielded abundance of car bonate of ammonia by distillation, and left carbonaceous matter, saline matter, principally common salt, and carbonate of lime as a residuum. Pigeons' dung readily ferments, but after fermentation afforded only 8 per cent. of soluble matter, which gave proportipnably less carbonate of ammonia in distillation than the dung recently voided. Dr. Von Martius proceeds to compare the proportion of soluble salts in guano and pigeons' dung, and thinks that by that comparison alone he can establish the superiority of the former; but he should have considered that the insoluble urate of ammonia, which is so powerful and copious a constituent of good guano, and is present in much smaller proportion in pigeons' dung, is sufficient of itself to turn the balance greatly in favor of the Peruvian manure. His general estimate, however, that the manuring power of genuine guano is four times greater than that of pigeons' dung, is probably not wide of the truth. Besides the above-mentioned constituents, guano derives no small portion of its fertilizing virtue from the great store of phosphoric acid which it contains, in various states of saline combination, with lime, magnesia, and ammonia. Of all the principles furnished to plants by the soil, the phosphates are, according to Liebig, the most important. They afford, so to speak, the bones and sinews of vegetable bodies, while ammonia supplies them with their indispensable element, azote. Their carbon, hydrogen, and oxygen, are derived from the air and water. Those products of vegetation which are most nutritious to man and herbiverous animals, such as bread-corn, beans, peas, and lentils, contain the largest proportion of phosphates. The ashes of these vegetable substances afford no alkaline carbonates. A soil in which phosphates are not present, is totally incapable of producing the above cereals. Agreeably to these views, Liebig believes that the importation of 1 cwt. of guano is equivalent to the importation of 8 cwts. of wheat; so that 1 cwt. of that manure assumes, with due culture, the form of 8 cwts. of substantial foodifor man. Since all these testimonies concur to place this remarkable excrementitious product in such high estimation, it becomes a paramount duty of the chemist to investigate its composition, and to discover certain means of distinguishing what may be termed the sound or normal state of guano, from the decomposed, decayed, and effete condition. The analysis by Fourcroy and Vauquelin of a sample of guano presented to them by Baron Von Humboldt, gave the following composition in 100 parts:Urate of ammonia.- - - 9'0 Oxalate of ammonia - - - - - - 10*6 Oxalate of lime - -. - - 7-0 Phosphate of ammonia - - - 6'0 Phosphate of ammonia and magnesia - 296 Sulphate of potash - - - - - 5 soda - - - - - 3-3 Sal ammoniac - - 4'2 Phosphate of lime - - - - - - 14-3 Clay and sand - - - -. - 47 Water and organic matters - - - - - 32-3 How different are these constituents from those assigned by Klaproth-a no less sklnful analyst than the French chemists! and how much this difference shows not only the complexity of the substance, but its very variable nature! The general results of an analysis by Professor Johnston, published in his paper on guano, in the 3d part of the 2d vol. of the Journal of the Royal Agricultural Society of England, are as follows:Ammonia - - - - 7'0 Uric acid - - - - - - 0 8 Water and ca:bonic and oxalic acids, &c., expelled by a red heat 51'5 Common salt, with a little sulphate and phosphate of soda - 11*4 Phosphate of lime, &c. - - - - 293 00'0 The specimen of guano represented by this analysis must have been iaX advanced in decomposition, as shown by the very scanty portion of uric acid; and must have betn originally impure (spurious?) from the large proportion of common salt, of which I haA e GUANO. 961 not found above 4 or 5 per cent. in any of the genuine guanos which I have had occasion to analyze. In another sample, Professor Johnston found 44'4 of phosphate of lime, with a little phosphate of magnesia, and carbonate of lime. These results resemble, to a certain degree, those which I have obtained in analyzing several samples of Chilian and African guanos, especially in the predominance of the earthy phosphates. The proportion of ammonia which can be extracted by the action of hydrate of soda and quicklime, at an elevated temperature, is the surest criterion of the soundness of the guano; for by this process we obtain not only the ready formed ammonia, from its several saline compounds, but also the ammonia producible from its uric acid, and undefined animal matter. These two latter quantities have been hitherto too little regarded by most analysts, though they constitute the most durable fund of azote for the nutrition of plants. Uric acid, and urate of ammonia, which contains 10-1lths of uric acid, being both nearly insoluble in water, and fixed at ordinary temperatures, continue to give out progressively to plants in the soil, the azote, of which they contain fully one-third of their weight. Under the influence of oxygen and a certain temperature, uric acid passes through a very remarkable series of transformation; producing allantoin, urea, and oxalic acid, which eventually becomes carbonic acid. These changes are producible immediately by the action of boiling water and peroxide of lead. From these metamorphoses, we can readily understand how much oxalate of ammonia and of lime is reported in many analyses of guano, though none, I believe, is to be found in the normal state, as it is occasionally imported from the Chincha Islands and Bolivia; nor were any oxalates found in the dung of the gannet, as analyzed by Dr. Wollaston, or of the sea eagle, according to the following analysis of Coindet: amrmonia, 9'21 per cent.; uric acid, 84-65; phosphate of lime, 6'13=100. The Peruvian sea-fowl, by feeding exclusively on fish, would seem to swallow a large proportion of earthy phosphates; since, in the purest guano that has come in my way, I have found these salts to amount to from 10 to 15 per cent. Dr. Von Martius proposes to use the degree of solubility of the guano in water as a good criterion of its quality; but this is a most fallacious test. Sound guano contains from 15 to 25 per cent. of insoluble urate of ammonia; nearly as much undefined animal matter, along with from 15 to 20 of earthy phosphates, leaving no more than 50 or 55 per cent. of soluble matter, exclusive of moisture; whereas decayed guano yields often 60 or 70 per cent. of its weight to water, in consequence of the uric acid and animal matter being wasted away, and the large portion of moisture in it, the latter amounting very often to from 25 to 35 per cent. The good Peruvian guano does not lose more than from' 7 to 9 per cent. by drying, even at a heat of 212~ Fahr.; and this loss necessarily includes a little ammonia. Each analysis of guano executed for the information of the farmer should exhibit definitely and accurately to at least 1 per cent.:1. The proportion of actual ammonia. 2. The proportion of ammonia producible also from the uric acid and azotized animal matter present; and which may be called the potential ammonia. This is a most valuable product, which is, however, to be obtained only from well-preserved dry gl ano. 3. The proportion of uric acid, to which, if 1 10th of the weight be added, the quantity of urate of ammonia is given. 4. The proportion of the phosphates of lime and magnesia. 5. The proportion of fixed alkaline salts, distinguishing the potash from the soda salts; the former being more valuable, and less readily obtainable, than the latter can be 1-y the use of common salt. Wheat, peas, rye, and potatoes, require for their successful ealtivation, a soil containing alkaline salts, especially those of potash. 6. The proportion of sandy or other earthy matter, which, in genuine guano, carefully collected, never exceeds 2 per cent. and that is silica. 7. The proportion of water, separable by the heat of 212~ F. The farmer should never purchase guano except its composition in the preceding particulars be warranted by the analysis of a competent chemist. He should cork up in a bottle a half-pound sample of each kind of guano that he buys; and if his crop shall disappoint reasonable expectation, he should cause the samples to be analyzed; and should the result not correspond to the analysis exhibited at the sale, he is fairly entitled to damages for the loss of his labor, rent, crop, &c. The necessity of following this advice will appear on considering the delusive if not utterly false analyses, under which cargoes of guano have been too often sold. In a recent case which came under my cognizance, in consequence of having been employed professionally to analyze the identical cargo, I found the guano to be nearly rotten and effete; containing alto gether only 24 per cent. of ammonia, 2 per cent. of urate of ammonia, nearly 9 of sea salt, 24 of water, and 45. of earthy phosphates. Now, this large cargo, of many hundred tons, fetched a high price at a public sale, under the exhibition of the follow, ng analysis by a chemist of some note: 962 GUANO. Urate of ammonia, ammoniacal salts, and decayed animal matter 17.4 Phosphate of lime, phosphate of magnesia, and oxalate of lime - 48 1 Fixed alkaline salts - - 10'8 Earthy and stony matter - - 1-4 Moisture - - -- - - 22'3 100.0 The purchasers, I was told by the broker, bought it readily under a conviction that the guano contained 17'4 of ammonia, though the proportion of ammonia is not stated, but merely mystified, and adroitly confounded with the decayed animal matter. By the following hypothetical analysis, much guano has been well sold:"Bone earth, 35; lithic acid, &c., 15; carbonate of ammonia, 14; organic matter, 36 =100." I am quite certain that no sample of guano can contain 14 per cent. of carbonate of ammonia-a very volatile salt. We shall see presently the state of combination in which the ammonia exists. It may contain at the utmost 4 or 5 per cent. of the carbonate; but such guano must have been acted upon powerfully by humidity, and will therefore contain little or no uric acid. In the very elaborate examination of guano by T. Oellacher, apothecary at Innsbruck, published in a recent number of Buchner's Repertorium of Pharmacy, it is said, that if a glass rod dipped into muriatic acid be held over guano, strong fumes are developed; and the solution of guano has an alkaline reaction with litmus-paper. These phenomena evidently indicate the presence of carbonate of ammonia, and of course a partially decomposed guano; for sound Chincha and Bolivian guanos have an acid reaction, proceeding from the predominance of phosphoric acid. Farmers frequently judge of the goodness of guano by the strength of the ammoniacal odor; but in this judgment they may egregiously err, for the soundest guano has no smell of ammonia whatever; and it begins to give out that smell only when it is more or less decomposed and wasted. Oellacher could find no evidence of urea in his guano; I have obtained fully 5 per cent. of this substance from good Peruvian guano. I shall now describe my own system of analysis:1. In every case I determine, first of all, the specific gravity of the guano; which I take by means of spirits of turpentine, with a peculiar instrument contrived to render the process easy and precise. If it exceeds 1'75 in density, water being 1'0, it must contain sandy impurities, or has an excess of earthy phosphates, and a defect ofazotized animal matter. 2. I triturate and digest 200 grains of it with distilled water, filter, dry the insoluble matter, and weigh it. 3. The above solution, diffused in 2,000 gr. measures, is examined as to its specific gravity, and then with test paper, to see whether it be acid or alkaline. 4. One half of this solution is distilled along with slaked lime in a matrass connected with a small quintuple globe condenser, containing distilled water, and immersed in a basin of the same. As the condensing apparatus terminates in a water-trap, no part of the ammonia can be lost; and it is all afterward estimated by a peculiar meter, whose indications make manifest one hundredth part of a grain. 5. The other half of the solution is mixed with some nitric acid, and divided into 3 equal portions. a, the first portion, is treated with nitrate of barytes, and the resulting sulphate ot barytes is collected, ignited, and weighed. b, the second portion, is treated with nitrate of silver, and the resulting chloride of silver ignited and weighed. c, the third portion, has a certain measure of a definite solution of ferric nitrate mixed with it, and then ammonia in excess. From the weight of the precipitated subphosphate of iron after ignition, the known amount of oxide used being deducted, the quantity of phosphoric acid in the soluble portion of the guano becomes known. d, the three above portions are now mixed, freed by a few drops of dilute sulphuric and hydrochloric acids from any barytes and silver left in them, and then tested by nitrate of lime for oxalate of ammonia. The quantity of oxalate of lime obtained, determines that point. 6. The last liquor filtered, being freed from any residuary particles of lime by oxalate of ammonia, is evaporated to dryness and ignited, to obtain the fixed alkaline matter. This being weighed, is then dissolved in a little water, neutralized with acid, and treated with soda-chloride of platinum. From the quantity of potash-chloride of platinum, which precipitates, after being filtered, dried, and weighed, the amount of potash present is deducted-the rest is soda. These bases may be assigned to the sulphuric, hydro-chloric, and phosphoric acids, in proportions corresponding to their respective affinities. 7. The proportion of organic matter in the above solution of guano, is determined directly by evaporating a certain portion of it to dryness, and igniting. The loss of GUANO. 963 weight, minus the ammonia and oxalic acid, represents the amount of organic matter. 8. A second portion of a solution of the guano is evaporated to dryness by a gentle steam heat, weighed, enclosed in a stout well-closed phial along with alcohol of 0-825, and heated to 212~. After cooling, the alcoholic solution is decanted or filtered clear, evaporated to dryness by a gentle heat, and weighed. This is urea, which may be tested hy its conversion into carbonate of a amonia, when heated in a test tube or small retort. In this way, I have obtained from Bolivian guano, 5 per cent. of urea; a certain proof of its entire soundness. 9..nalysis of the insoluble matter. One third of it is digested with heat in abundance of Borax-water, containing - of the salt, filtered, and the filter dried by a steam heat. The loss of weight indicates the amount of uric acid, which is verified by supersaturating the filtrate with acetic or hydrochloric acid, thus precipitating the uric acid, throwing it upon a filter, drying, and weighing it. This weight should nearly agree with the above loss of weight, the small difference being due to soluble organic matter, sometimes called geine and ulmic acid. The uric acid is evidenced, 1, by its specific gravity, which 1 find to be only 1-25, as also that of the urate of ammonia; 2. by its affording fine purple murexide when heated in a capsule alongwith nitric acid, and then exposed to the vapor of ammonia from a feather held over it; 3, by its dissipation when heated, without emitting an empyreumatic odor. 10. Another third of the solid matter is distilled along with half its weight of slaked lime, and 10 times its weight of water, in the apparatus already described, and the ammonia obtained from it estimated. 11. The remaining third having been ignited, is digested with a gentle heat in weak hydrochloric acid, and the undissolved silica and alumina washed on a filter, dried, and weighed. To the hydrochloric solution, dilute sulphuric acid is added, and the mixture is heated till all the hydrochloric acid be expelled, with the greater part of the water. Alcohol of 0-850 is now poured upon the pasty residuum, and the whole, after being well stirred, is thrown upon a filter. The phosphoric acid passes through, as also the magnesia in union with sulphuric acid. The sulphate of lime, which is quite insoluble in spirits of wine, being washed with them, is dried, ignited, and weighed. From the weight of sulphate of lime, the quantity of phosphate of that earth, that was present, becomes known. 12. Ammonia in excess is now added to the filtrate, which throws down the granular Phosphate of ammonia and magnesia. After washing and drying this powder at a heat sf 1F0, its weight denotes the quantity of that compound in the guano. 13. To the filtered liquor (of 12), if a little ammonia be added, and then muriate of magnesia be slowly dropped in, phosphate of ammonia and magnesia will precipitate, from the amount of which the quantity of phosphoric acid may be estimated. 14. The proportion of oxalate of lime is determined by igniting the washed residuum (of 9) and placing it in an apparatus for estimating the quantity of carbonic acid given off in dissolving carbonate of lime. The apparatus, either fig. 1 or 2, described in my little Treatise on Alkalimetry, will serve that purpose well. I have rarely obtained more than 2 gr. of carbonic acid from the insoluble residuum of 100 gr. of good guano, and that corresponds to less than 1 per cent. of oxalate of lime in the guano. Sometimes no effervescence at all is to be perceived in treating the washed residuum with acid after ignition. 15. The carbonate of ammonia in guano is readily determined by filtering the solution of it in cold water, and neutralizing the ammonia with a test or alkalimetrical acid. (See the Treatise on Alkalimetry, above referred to.) 16. Besides the above series of operations, the following researches must be made to complete our knowledge of guano. The insoluble residuum (of 10) which has been deprived by two successive operations of its uric acid and ammonia, may contain azotized organic matter. It is to be therefore well dried, mixed with 5 times its weight of the usual mixture of hydrate of soda and quicklime, and subjected to gentle ignition in a glass or iron tube closed at one end, and connected at the other with an ammonia condensing apparatus. The amount of ammonia being estimated by a proper ammonia meter, represents the quantity of azote, allowing 14 of this element for 17 of ammonia, being the potential ammonia corresponding to the undefined animal matter. In a sample of Peruvian guano I obtained 5 per cent. of ammonia from this source. 17. The whole quantity of ammonia producible from guano is to be determined by gently igniting 25 gr. of it well dried, and mixed with ten times its weight of the mixture of hydrate of soda and quicklime (2 parts of the latter to I of the former'. The ammonia disengaged is condensed and measured, as described above. 18. The ready-formed ammonia is in all cases determined by distilling a mixture ot 100 gr. of it with 50 gr. of slaked lime, condensifg the disengaged ammonia, and esti mating it exactly by the meter. 19. The relation of the combustible and volatile to the incombustible and fixed convtituents of guano, is determined by igniting 100 gr. of it in a poised platinum capsule. 62 964 GUANO. The loss of weight denotes the amount of combustible and volatile matter, including the moisture, which is known from a previous experiment. 20. The insoluble matter is digested in hot water, thrown upon a filter, dried, and weighed. The loss of weight is due to the fixed alkaline salts, which, after concentrating their solutions, are investigated by appropriate tests: 1, nitrate of barytes for the sulphates; 2, nitrate of silver for the chlorides and sulphates; and 3, soda-chloride of platinum, for distinguishing the potash from the soda salts. 21. The insoluble matter (of 20) is digested with heat in dilute nitric or hydrochloric acid, and the whole thrown upon a filter. The silica which remains on the filter is washed, ignited, and weighed. The lime, magnesia, and phosphoric acid, may be determined as already pointed out. 22. I have endeavored to ascertain if muriate of ammonia be present in guano, by evaporating its watery solution to dryness, and subliming the residuum, but I have never obtained a satisfactory portion of sal ammoniac; and therefore I am inclined to think there is little of it. The quantity of chlorine to be obtained from guano is too inconsiderable to lead to a suspicion of its presence, except in combination with sodium and potassium. Phosphate of soda is also a doubtful product-but if present, it may be obtained from the saline matter (of 20), by acidulating it with nitric acid; precipitating first with nitrate of barytes, next with nitrate of silver, taking care to use no excess of these two re-agents, then supersaturating the residuum with ammonia, and adding acetate of magnesia, when the characteristic doul', phosphate of this earth should fall, in case phosphate of soda be present. By the preceding train of researches, all the constituents of this complex product may be exactly disentangled and estimated; but they manifestly require much care, patience, time, and dexterity, and also a delicate balance, particularly in using the appropriate apparatus for generating the potential ammonia, and for measuring the whole of this volatile substance separated in the several steps of the process. It may be easily i:nagined how little confidence can be reposed in many of the analyses of guano, framed, I fear, too often with the view of promoting the sale of an indifferent or even spurious article of commerce. A. I shall now give in detail my analytical results upon three different samples of a good South American guano; and next the general results upon three samples of African and Chilian guanos:I. Guano from Bolivia, imported by the Mary and Anne. This sample was taken by myself, as an average out of several bags in the lighter, before the cargo was landed. Pale yellow brown color, dry, partly pulverulent, partly concreted, in small lumps, with a few small fragments of granite interspersed, and which, being obvious, were separated prior to the analysis. Specific gravity of the pulverulent portion without the granite, 1.606; of the concretions, 1-66; mean 1-63. Water digested on the former portion is neutral to litmus, that on the latter is faintly acid. 2. 100 parts lose 6'5 by the heat of boiling water, and exhale no ammonia. When digested and triturated with cold water, 30'5 parts dissolve, and 69*5 are obtained after drying, at 212~ F. Of those 30-5 parts, 6-5 are therefore water, easily separable, and 24*5 parts are solid matter. 3. 100 parts, mixed with 9 times their weight of water, and 50 of lime, being distilled in an alembic connected with the five-globe condenser, &c., afforded exactly 4'2 of ammonia. 20 grains in fine powder, along with 200 of a mixture, consisting of 2 parts of dry lime and 1 of hydrate of soda, were gently ignited in a combustion-tube connected with the ammonia-condensing apparatus, and they produced 4*25 grains of ammoniaequivalent to 21'25 from 100 grains of the guano. Thus only 4-2 per cent. of ammonia were ready formed; while 17'05 lurked, so to speak, in their azotized elements. From its aspect, and its want of ammoniacal odor, this guano, the first cargo received from Bolivia, was imagined by the importers to be of bad quality; and, accordingly, my very favorable report of its analysis surprised them not a little, and rather unsettled the little faith they at that time (January, 1843) had in chemistry. But about a fortnight after the date of my report they received a letter from Peru, apprizmg them of the excellence of that cargo of Bolivian guano, and of its being prized by the Americans, as possessing fertilizing powers in a pre-eminent degree. I consider this guano, therefore, as a type of the substance in its best state. II. The soluble matter was analyzed, in the manner already detailed, and was found to consist of1. Urea - - 5-00 2. Sulphate of potash - - - 790 3. Chloride of sodium - - - 5'00 4. Biphosphate of ainmonia - - 550 5. Oxalate of ammonia - - - 0'60 24-0 GUANO. 965 In these ammoniacal salts there are only 1-65 parts of ammonia; but I obtained 2-55 grains in distilling the soluble matter of 100 grains of the guano. The remaining 09 parts, therefore, must have proceeded from the partial decomposition of the urea during the long ebullition necessary to extract every particle of ammonia, in distilling thp guano along with lime. Il. The insoluble matter =69'5 parts, was found to consist ofI. Silica - - - - 2'25 2. Subphosphate of lime - - - - - 900 3. Phosphate of magnesia and ammonia - - - 1'25 4. Urate of ammonia - - - - - - 15*27 5. Undefined azotized organic matter, affording, with the 14 parts of uric acid, by ignition with hydrate of soda, 17*05 parts of ammonia - - - - 4173 69*50 This result as to the large proportion of organic matter in the dried insoluble residuum was verified by igniting a given quantity of it, when it was found to lose, out of 69'5 parts, 57; corresponding to the 15'27 urate of ammonia, 41*73 of undefined organic matter, and 0'08 of ammonia, in the double magnesian phosphate. In the urate and double phosphate are 1'35 of ammonia, which, with the 2Lr*', make 3'9 parts; the other 0-3 parts may be traced to the urea. As these results differ very considerably in many respects from those of the analyses made by respectable German chemists, I was careful to verify them by manifold variations of the process, as follows:1. The soluble matter, with acid reaction, of 100 parts of the lumps of the Bolivian guano, was examined by per-acetate of iron and ammonia, for phosphoric acid, and afforded 4 parts of it, which is more than had been found in the neutral pulverulent guano. After the phosphoric acid was separated by that method, chloride of calcium gave no cloud with the filtered liquor, proving that no oxalic acid was present in these nodules. The washed insoluble matter, when gently ignited, and treated with dilute nitric acid, afforded no effervescence whatever, and therefore showed that no oxalate of lime had been present, for it would have become a carbonate. It is necessary to determine from time to time the quantity of ferric oxide in the acetate or nitrate, as it is liable to be deposited from the solution when this is kept for some time. If this point be not attended to, serious errors would be committed in the estimation of the phosphoric acid. 2. The quantity of uric acid was verified by several repetitions, and found to be 14 per cent. 3. The undefined organic matter, when deprived of the uric acid by prolonged digestion with weak borax, being subjected to ignition along with hydrate of soda, yielded the quantity of ammonia requisite to constitute the whole sum, that producible from the uric acid also being taken into account. 4. The little lumps of the guano afforded, by distillation along with quicklime, 5.27 per cent. of ready-formed ammonia, probably from the uric acid having been partially decomposed by the moisture which had caused them to concrete. It is a curious fact, that the solution of borax, from being of an alkaline, becomes of an acid reaction, after digestion with the Bolivian guano. 5. For distinguishing and separating the soda salts from those of potash, I tried the antimoniate of potash, according to Wackenroder's prescription, but I found reason to prefer very much the crystallized soda-chloride of platinum, for that purpose. From another specimen of the Bolivian guano, I extracted 3*5 per ct. of the ammoniaphosphate of magnesia. B. A sample of guano from the Chincha islands, of nearly the same light color as the preceding, and the same dryness, being an early importation of 250 tons in the present year, was subjected by me to a careful analysis. 1. The solution in water of this guano had an alkaline reaction from carbonate of ammonia, which, being neutralized by test acid, indicated 0-34 per cent. of ammonia, eluivalent to about 1 of the smelling sesqui-carbonate. 2. Of this guano, 47 per cent. were soluble in water, and 53 per cent. remained, after drying at a heat of 212~ F. Of the above 47 parts, 8*5 were moisture in the guano. 3. The solution being acidulated with nitric acid, was treated with acetate of barytes, in a quantity equivalent to the sulphuric acid present, and it afforded 12 parts of sulphate of barytes. With the filtered liquor, 700 water grain measures of ferric acetate were mixed, and then ammonia in excess; 18-5 parts of washed and ignited sub-phosphate Df iron were obtained, from which deducting 8-8 parts present in the acetate, 9'7 remain as tile quantity of phosphoric acid; but 9'7 of acid produce 13'25 of bi-phosphate of ammonia, which contain only 2-3 of ammonia, combined wi-: 0'95 of water. 966 GUANO. or its elements. From the alkaline excess in the guano, there can be no doubt, hew Ever, that it contained the sub-phosphate (found in the urine of Carnivora), and not the bi-phosphate of that base. In this case, 9-7 of acid produce 14-32 of dry saline compound, containing 4-62 of ammonia, which, with the 0-34 of ammonia in the carbonate, Constitute a sum of 4-96. To the liquor freed from the phosphate of iron, and acidulated with nitric acid, acetate of lime being added, 3-33 parts of oxalate of this base were obtained, which are equivalent to 3-23 oxalate ammonia, containing 0*89 of am[nonia. 4. Nitrate of silver now produced from the filtered residual solution 8 parts of chloride, corresponding to nearly 3 of sal ammoniac, which contain nearly 0-95 of ammonia. 5. The 53 parts insoluble in water were digested with weak solution of borax at a boiling heat, thrown on a filter, and the uric acid being precipitated from the filtrate by means of a little hydrochloric acid, washed and dried, was found to weigh 13-5 parts. There were left on the filter 36-5 parts, dried at 212~ F., so that 3 parts of soluble organic matter had passed through the filter. These 36-5 parts lost by ignition only 9-7 parts in organic matter, became white, and afforded a very faint effervescence with hydro-chloric acid, showing that a very little oxalate of lime had been present. 1-25 parts of silica were left after the action of the acid. To the solution of the 26'55 parts, sulphuric acid was added, and the mixture being heated to expel the hydro-chloric acid and the excess of the sulphuric, the residuary matter was digested and washed with dilute alcohol, and thrown on a filter; the solution of magnesia passed through, while the sulphate of lime remained. After ignition, this weighed 27'5 parts, equivalent to 22 of sub-phosphate of lime. On supersaturating the filtrate with ammonia, 4'5 parts of the magnesian ammonia phosphate were precipitated, containing 0.32 of ammonia. With the 13*5 parts of uric acid, 1-23 of ammonia had been originally combined, forming 14-73 of urate. 6. 25 grains of the dry guano afforded, by ignition in the combustion-tube along with 200 grains of the mixed lime and hydrate of soda, 4'165 of ammonia, which correspond to 16-66 in 100 parts of the dry, or to 15-244 in the natural state; leaving therefore ~ parts for the quantity of potential ammonia, or of ammonia producible from the de composition of its azotized organic matter. This guano is, therefore, well adapted tc promote permanently the fertility of a soil. It yields besides to alcohol a notable quantity of urea, which I did not think it worth while to determine quantitively, and from which undoubtedly a portion of the ammonia proceeded, in the distillation witl milk of lime. 7..100 parts afforded by distillation with milk of lime, 10-2 of ammonia. 8. The total constituents of that guano, being tabulated, areI. Matter soluble in water - - - 47-00 consisting ofAmmonia. 1. Sulphate of potash, with a little sulphate of soda - 6-00 2. Muriate of ammonia - - - - 300 0.95 3. Phosphate of ammonia - - - 14-32 4-62 4. Sesqui-carbonate of ammonia - - - 1.00 0-34 5. Sulphate of ammonia - - - - 200 0-50 6. Oxalate of ammonia - - - - 323 0-89 7. Water - - - - - - 8-50 8. Soluble organic matter and urea - - - 8-95 47-00 11. Matter insoluble in water 53-00:onsisting of1. Silica - - - 1-25 2. Undefined organic matter - - - - 952 3. Urate of ammonia - - - - - 1473 1-23 4. Oxalate of lime - - - - - 100? 5. Sub-phosphate of lime - - - - 2200 6. Phosphate of magnesia and ammonia - - 4-50 0-32 53-00 9-80 The remaining 1.25 of actual ammonia may be fairly traced to the partial decomposi tion of the urea during the distillation with lime; whereas the 5 per cent. of potential ammonia proceeded from the transforming decomposition of the uric acid. C. Foliated guano, from Peru, in caked pieces, the layers very thin, parallel, and in-.erspersed with white streaks. This guano was somewhat dense for a pure specimen, baving a specific gravity of 1-7. The insoluble matter afforded by digestion with borax GUANO. 967 water, no less than 25'2 per ct. of pale yellow uric acid; 9 of other combustible oiganic matter, and 15 of earthy matter; consisting of silica, 3'5; phosphate of magnesia and ammonia, 6-5; and only 5 of sub-phosphate of lime or bone earth. It lost 10 per cent. when dried in a heat of 212~ F. The remaining 30'8 parts soluble in water, had a strong acid reaction, and afforded, by ferric acetate and ammonia, 6 of phosphoric acid, equivalent to 9*7 of crystallized bi-phosphate of ammonia, after acetate of barytes had separated the sulphuric acid. No less than 17 parts of chloride of silver were obtained, by precipitating with nitrate of silver the liquor filtered from the phosphate of iron, and acidulated with nitric acid. As the present is an accidental sample, and not an average of any importation, I did not prosecute the research further. D. Chincha guano, of a somewhat darker color than the preceding, and alkaline reaction; specific gravity, 1'62. Digested with water and strained, 56-75 parts remained after drying it at 2120 F. The solution, evaporated and dried also at 212~, afforded 31-25 of saline matter. This saline mass being mixed with four fifths of its weight of slaked lime, nine times its weight of water, and distilled, afforded of ammonia 14'28 per cent. Some chemists have prescribed potash instead of lime, for separating the ammonia in distillation; but no person of intelligence who has made the experiment once will choose to repeat it, because the potash forms with the organic matter of the guano a viscid compound, that froths up like a mass of soap-bubbles, and coming over with the vapors, obstructs and vitiates the result. 2. When dried altogether by a steam heat, 100 parts lost 12 in moisture; whereas by evaporating and drying the soluble matter by itself, the loss amounted to 16'3, no doubt by the dissipation of some of the ammoniacal salts; for 100 parts of the entire guano afford, by distillation with quicklime, 9 parts of ammonia, and by the transforming decomposition with hydrate of soda and lime, 16-25, indicating 7-25 of potential ammonia, in addition to the 9 of ready formed. The insoluble matter of 100 parts afforded to borax-water a solution containing 16-5 of uric acid, corresponding to 18 of urate of ammonia. There remained on the filter, after drying it at 212~ F., only 33*8 parts; so that about 5 parts of soluble organic matter had passed through the filter in the borax water. These 33-8 consisted of subphosphate of lime 17, magnesian phosphate of ammonia 5-5, silica 0-7, and combustible organic matter 10-6. The ammonia in the soluble portion was in the state chiefly of phosphate; there was merely a faint trace of oxalate of ammonia. E..frican Guano.-Among the many samples of African guano which I have had occasion to analyze for the importers, none has contained any appreciable quantity of uric acid, or by consequence of potential ammonia. The best afforded me 10 per cent. of ready-formed ammonia, existing chiefly in the state of a phosphate, though they all contain carbonate of ammonia, and have of consequence an alkaline reaction. The said sample contained 21-5 of moisture, separable by a heat of 212~ F. Its specific gravity was so low as 1-57, in consequence of the large proportion of moisture in it. It contained 23 per cent. of subphosphate of lime, 3 of magnesian phosphate of ammonia, 1 of silica, and 1-5 of alkaline sulphate and muriate. The remaining 50 parts consisted of decayed organic matter, with phosphate of ammonia, and a little carbonate, equivalent to half a grain of ammonia, which is the largest quantity in such guanos. Other African guanos have afforded from 24 to 36 of moisture, no uric acid; no potential ammonia; but decayed organic matter; from 5 to 7 of ready-formed ammonia in the state of phosphate, with a little carbonate; from 25 to 35 per cent. of subphosphate of lime; 5 or 6 of the magnesian phosphate of ammonia; more or less oxalates from the decomposition of the uric acid, and 3 to 5 per cent. of fixed alkaline salts. F. The Chilian Guano gathered on the coast, already adverted to, contained a remarkable proportion of common salt, derived probably from the sea spray. The following is the general report of the chemical examination of several samples of guano, which I made for Messrs. Gibbs of London, and Messrs. Myers of Liverpool:" In these various analyses, performed with the greatest care, and with the aid of the most complete apparatus for both inorganic and organic analysis, my attention has been directed, not only to the constituents of the guano which act as an immediate manure, but to those which are admitted by practical farmers to impart durable fertility to the grounds. The admirable researches of Professor Liebig have demonstrated that AZOTE, the indispensable element of the nourishment of plants, and especially of wheat and others abounding in gluten (an azotized product), must be presented to them in the state of ammonia, yet not altogether ammonia in the pure or saline form, for, as such, it is too readily evaporated or washed away; but'n the dormant, or as one may say, in the potential condition in contradistinction from t-.e actual. Genuine Peruvian and Bolivian guanos, like those which I have minutely analyzed, surpass very far all other species of manure, whether natural or artificial, in the quantity of potential ammonia, and, therefore, in the permanency of their action upon the roots of plants, while, in conse quence of the ample store of actual ammonia which they contain ready formed, they 968 GUANO. are qualified to give immediate vigor to vegetation. Urate of ammonia constitutes a considerable portion of the azotized organic matter in well-preserved guano; it is nearly insoluble in water, net at all volatile, and is capable of yielding to the soil, by its slow decomposition, nearly one third of its weight of ammonia. No other manure can rival this animal saline compound. One of the said samples cf guano afforded me no less than 17 per cent. of potential ammonia, besides 4- per cent. of the actual or ready formed; others from 7 to 8 per cent. of ammonia in each of these states re spectively. These guanos which I have examined are the mere excrement of birds, and are quite free from the sand, earth, clay, and common salt, reported in the analyses of some guanos, and one of which (sand) to the amount of 30 per cent. I found myself n a sample of guano from Chile. " The Peruvian guano, moreover, contains from 10 to 25 per cent. of phosphate of lime, the same substance as bone-earth, but elaborated by the birds into a pulpy consistence, which, while it continues insoluble in water, has been thereby rendered more readily absorbable and digestible (so to speak) by the roots of plants. I have there fore no doubt, that by the judicious application of these genuine guanos, mixed with twice or thrice their weight of a marly or calcareous soil, to convert their phosphate of ammonia into phosphate of lime and carbonate of ammonia, as also to dilute all their am;moniacal compounds-such crops will be produced, even on sterile lands, as the farmer has never raised upon the most improved soil by the best ordir ary manure. To the West India planter, guano will prove the greatest boon, since it condenses in a portable and inoffensive shape the means of restoring fertility to his exhausted cane fields, a benefit it has long conferred on the poorest districts of Peru. "I respectfully observe, that no analysis of guano hitherto made public at all exhibits the value of the cargoes referred to above, while none gives the quantity of ammonia dormant in the azotized animal matter of the birds' dung, which, called into activity with the seeds in the soil, becomes the most valuable of its constituents, as a source of perennial fertility. In the detailed account of my analyses of this complex excretion (now preparing for publication), all the above statements will be biouglh within the scope of general comprehension. I shall also describe my' ammonia gene. rator,' based on the process invented in the laboratory of Professor Liebig, and also my'ammonia meter,' which, together, can detect and measure one hundredth part of a grain weight of absolute ammonia, whether potential or actual, in any sample of guano. "Meanwhile the following may be offered as the average result of my analyses of genuine guano in reference to its agricultural value:"1. Azotized animal matter, including urate of ammonia, together capable of affording from 8 to 16 per cent. of ammonia by slow decomposition in the soil - -50 2. Water - - - - - - 8 to 11 3. Phosphate of lime - - - - - 12 to 25 4. Phosphate of ammonia, sulphate of ammonia, ammoniaphosphate of magnesia, together containing from 5 to 9 parts of ammonia - - - - 13 5. Siliceous sand - - - - - - 1 100 "Very moist guano has in general more actual and less potential ammonia than the try guano. "ANDREW URE. "London, 13 Charlotte street, Bedford square, "February 14, 1843." Oellacher's analysis of a brownish yellow guano is as follows [see top of next page]:I am satisfied from its large proportion of oxalate of ammonia, that the sample thi:q analyzed was by no means a fair or normal specimen of guano; and it is in fact widely different from all the fresh samples which have passed through my hands. It is k:scribed as " knobby, being mixed with light laminated crystalline portions, in white grains, from the size of a pea to that of a pigeon's egg." Having some lumpy concre tions of a similar aspect in my possession, I submitted them to chemical examination. G. 1,000 grains being digested in boiling water and strained, afforded a nearly colorless solution. This was concentrated till crystals of oxalate of ammonia appeared. It was then acidulated with hydrochloric acid, to protect the phosphoric acid from precipitation, and next treated carefully with a solution of nitrate of lime equivalent to the oxalic acid present. The oxalate of lime thus obtained being converted into carbonate weighed 80-5 grains, corresponding to 100 of oxalats of ammonia, being 10 per cent. of the we'ght of the guano. GUANO. 969 Ammonia. 1. Urate of ammonia - 12-20 1-06 2. Oxalate of ammonia - 17'73 6-50 3. Oxalate of lime - - - - 30 4. Phosphate of ammonia - - - - 690 179 5. Phosphate of ammonia and magnesia - 11-63 1'68 6. Phosphate of lime - - - - -20-16 7. Muriate of ammonia - - - - 225 0'72 8. Chloride of sodium (common salt) - - - 040 9. Carbonate of ammonia - - - - 080 0'23 10. Carbonate of lime - - - - 165 11. Sulphate of potash - - - - 4-00 12. Sulphate of soda - - - 4-92 13. Humate of ammonia - - - 1-06 0'09 14. Substance resembling wax - - - - 075 15. Sand - - - - - - 168 16. Water (hygroscopic) - - - 431 17. Undefined organic matter - - - 8-26 100-00 12-07 The liquor filtered from the oxalate was precipitated by nitrate; " barytes, and afforded 112 grains of sulphate of barytes==38 sulphuric acid; and *'e last filtrate being mixed with a given measure of ferric acetate, and the mixture supersaturated with ammonia, yielded subphosphate of iron, equivalent to 5 per cent of phosphoric acid. I digested with heat other 500 grains of the same guano in a weak solution of borax, filtered, acidulated the liquid, but obtained merely a trace of uric acid. It is clear therefore that the oxalate of ammonia had been formed in this guano at the expense of the uric acid, and that its concreted state, and the crystalline nodules disseminated through it, were the result of transformation by moisture in a hot climate, which had agglomerated it to a density of 1-75; whereas clean fresh guano, friable and dry like the above, is seldom denser than 1'65. The guano contained only 3-23 of ammonia; 65 of insoluble matter, 53 of earthy phosphates, 5 silica, 3 alkaline salts (fixed), and 7 organic matter. Oxalate of ammonia, being readily washed away, it is a bad substitute for the urato of ammonia, urea, and azotized animal matter, which it has replaced. Oellacher could find no urea in the guano which he analyzed; another proof of its disintegration. Bartel's analysis of a brown-red guano is as follows:1. Muriate of ammonia - - 6'500 2. Oxalate of ammonia - - - - 13*351 3. Urate of ammonia ------ - 3244 4. Phosphate of ammonia - - - - 6'450 5. Substances resembling wax and resin - - 600 6. Sulphate of potash - - - - - - 1277 7. Sulphate of soda - - - 1 119 8. Phosphate of soda - - - 5-291 9. Phosphate of lime - - - - - - - - 9940 10. Phosphate of ammon'a and magnesia - - - 4-196 11. Common salt - - - - - 0'100 12. Oxalate of lime - - - - - - 16360 13. Alumina- -- - - 0-104 14. Sand insoluble in nitric acid, and iron - - - - 5800 15. Loss (water and volatile ammonia and undefined organic matter) - - -- 22-718 100-000 Voelckel, in his analysis of guano, states 7 per cent. of oxalate of' ime-a result quite at variance with all my experience-for I have never found so much as 2 per cent. of carbonate of lime in the washed and gently ignited insoluble matter; whereas, according to Bartels and Voelckel, from 10 to 5 per cent. of carbonate should be obtained, as the equivalents of the proportions of the oxalate assigned by them. All these analyses are defective moreover in not showing the total quantity of ammonia which the guano is capable of giving out in the soil; and since it appears that the freshest guano abounds most in what I have called potential ammonia, it must nossess of consequence, the greatest fertilizing virtue. 970 GUM REr4NS A sample of decayed dark-brovkn moist guano from Chile, being examined as above described, for oxalate of ammonia, was found to contain none whatever; and it contained less than 1 per cent. of uric acid. H. An article offered to the public, by advertisement, as Peruvian guano, was lately sent to me for analysis. I found it to be a spurious composition; it consisted of1. Common salt 2- 32-0 2. Common siliceous sand - - - 280 3. Sulphate of iron or copperas - - - 5'2 4. Phosphate of lime - - - - 4'0, with 5. Organic matter from bad guano, &c. (to give it smell) 23-3 6. Moisture - 75100'0 Genuine guano, when burned upon a red hot shovel, leaves a white ash of phosphate of lime and magnesia; whereas this factitious substance left a black fused mass of sea salt, copperas, and sand. The specific gravity of good fresh guano is seldom more than 1'66, water being 100; whereas that of the said substance was so high as 2-17 produced by the salt, sand, and copperass GUM (Gomme, Fr.; Gummi, Pflanzenschleim, Germ.):s the name of a proximate vegetable product, which forms with water a slimy solution, but is insoluble in alcohol, ether and oils; it is converted by strong sulphuric acid into oxalic and mucic acids. There are six varieties of gum: 1. gum arabic; 2. gum senegal; 3 gum of the cherry and other stone fruit trees: 4. gum tragacanth; 5. gum of Bassora; 6. the gum of seeds and roots. The first five spontaneously flow from the branches and trunks of their trees, and sometimes from the fruits, in the form of a mucilage which dries and hardens in the air. The sixth kind is extracted by boiling water. Gum arabic and gum senegal consist almost wholly of the purest gum rclled arabine by the French chemists; our native fruit trees contain some cerasine, along with arabine; the gum of Bassora and gum tragacanth consist of arabine and bassorine. Gum arabic flows from the acacia arabica, and the acacia vera, which grow upon the banks of the Nile and in Arabia. It occurs in commerce in the form of small pieces, rounded upon one side and hollow upon the other. It is transparent, without smell, brittle, easy to pulverize, sometimes colorless, sometimes with a yellcw or brownish tint. It may be bleached by exposure to the air and the sun-beams, at the temperature of boiling water. Its specific gravity is 1'355. Moistened gum arabic reddens litmus paper, owing to the presence of a little supermalate of lime, which may be removed by boiling alcohol; it shows also traces of the chlorides of potassium and calcium, and the acetate of potash. 100 parts of good gum contain 70-40 of arabine, 17-60 of water, with a few per cents. of saline and earthy matters. Gum arabic is used in medicine, as also to give lustre to crapes and other silk stuffs. Gum senegal is collected by the negroes during the month of November, from the acacia senegal, a tree 18 or 20 feet high. It comes to us in pieces about the size of a partridge egg, but sometimes larger, with a hollow centre. Its specific gravity is 1-436. It consists of 81-10 arabine; 16'10 water; and from 2 to 3 of saline matters. The chemical properties an! uses of this gum are the same as those of gum arabic. It is much employed in calico-printing. Cherry-tree gum consists of 52-10 arabine; 54-90 cerasine; 12 water; and 1 saline matter. Gum tragacanth is gathered about, te end of June, from the astragalus tragacantha of Crete and the surrounding islands. It has the appearance of twisted ribands; is white or reddish; nearly opaque, and a little ductile. It is difficult to pulverize, without heating the mortar. Its specific gravity is 1'384. When plunged in water, it dissolves in part, swells considerably, and forms a very thick mucilage. 100 parts of it consist of 53-30 arabine; 33'30 bassorine and starch; 11'0 water; and from 2 to 3 parts ofsalin: matters. It is employed in calico printing, and by shoemakers. Gum of Bassora; see BASSORINE. Gum of seeds, as linseed, consists of 52-70 arabine; 28-9 of an insoluble matter; 10-' water; and 7'11 saline matter. Neither bassorine nor cerasine seems to be present in seeds and roots. For British Gum, see STARCH. GUM RESINS. (Gomme-risines, Fr.; Schleimharze, Germ.) When incisions are made in the stems, branches, and roots of certain plants, a milky juice exudes, which gradually hardens in the air; and appears to be formed of resin and essential oil, held suspended in water charged with gum, and sometimes with other vegetable matters, such as caoutchouc, bassorine, starch, wax, and several saline matters. TLe said concrete juice is called a gum-resin; an improper name, as it gives a false idea of the nature of the substance. They are all solid; heavier than water; in general opaque and brittle; GUNPOWDER. 971 many have an acrid taste, and a strong smell; their colour is very variable. They are partially soluble in water, and also in alcohol; and the solution in the former liquid seldom becomes transparent. Almost all the gum resins are medicinal substances, and little employed in the arts and manufactures. The following is a list of them: assafcetida; gum ammoniac; bdellium: euphorbium; galbanum; gamboge; myrrh; oliba. num or frankincense; opoponax; and scammony. Some of these are described in this work under their peculiar names. GUMS. Under the generic name Gum several substances have been classed, which differ essentially, though they possess the following properties in common; viz. forming a thick mucilaginous liquid with water, and being precipitable from that solution by alcohol. Properly speaking, we should style gums only such substances as are transformed into mucic acid by nitric acid; of which bodies there are three: 1. Arabine, which constitutes almost the whole of gum arabic; 2. Bassorine, which forms the chief part of gum tragacanth; and 3. Cerasine, which occurs in cherry-tree gum, and is convertible into gum arabic by hot water. 1. Gum arabic, in its ordinary state, contains 17 per cent. of water, separable from it by a heat of 212~ Fahr. 2. Cherry-tree gum consists of 52 per cent. of arabine, and 35 of a peculiar gum, which has been called Cerasine. This latter substance is convertible into grape sugar oy boiling it with very dilute sulphuric acid. GUNPOWDER. The following memoir upon this subject was published by me in the Journal of the Royal Institution for October, 1830. It contains the results of several careful analytical experiments, as also of observations made at the Roval Gunpowder Works at Waltham Abbey, and at some similar establishments in the neighbourhood of London. GUNPOWDER is a mechanical combination of nitre, sulphur, and charcoal; deriving the intensity of its explosiveness from the purity of its constituents, the proportion in which they are mixed, and the intimacy of the admixture. 1. On the nitre.-Nitre may be readily purified, by solution in water and crystallization, from the muddy particles and foreign salts with which it is usually contaminated. In a saturated aqueous solution of nitre, boiling hot, the temperature is 240~ F.; and the relation of the salt to its solvent is in weight as three to one, by my experiments: not five to one, as MM. Bott6e and Riffault have stated. We must not, however, adopt the general language of chemists, and say that three parts of nitre are soluble in one of boiling water, since the liquid has a much higher heat and greater solvent power than this expression implies. Water at 60~ dissolves only one fourth of its weight of nitre; or, more exactly, this saturated solution contains 21 per cent. of salt. Its specific gravity is 11415; 100 parts in volume of the two constituents occupy now 97'91 parts. From these data we may perceive that little advantage could be gained in refining crude nitre, by making a boilinghot saturated solution of it; since on cooling, the whole would concrete into a moist saline mass, consisting by weight of 2] parts of salt, mixed with 1 part of water, holding X of salt in solution, and in bulk of 17 of salt, with about 1 of liquid; for the specific gravity of nitre is 2*005, or very nearly the double of water. It is better, therefore, to use equal weights of saltpetre and water in making the boiling-hot solution. When the filtered liquid is allowed to cool slowly, somewhat less than three fourths of the nitre will separate in regular crystals; while the foreign salts that were present will remain with fully one fourth of nitre in the mother liquor. On redissolving these crystals with heat, in about two thirds of their weight of water, a solution will result, from which crystalline nitre, fit for every purpose, will concrete on cooling. As the principal saline impurity of saltpetre is muriate of soda (a substance scarcely more soluble in hot than in cold water), a ready mode thence arises of separating that salt from the nitre in mother waters that contain them in nearly equal proportion. Place an iron ladle or basin, perforated with small holes, on the bottom of the boiler in which the solution is concentrating. The muriate, as it separates by the evaporation of the water, will fall down and fill the basin, and may be removed from time to time. When small needles of nitre begin to appear, the solution must be run off into the crystallizing cooler, in which moderately pure nitre will be obtained,'to be refined by another similar operation. At the Waltham Abbey gunpowder works the nitre is rendered so pure by successive solutions and crystallizations, that it causes no opalescence in a solution of nitrate of silver. Such crystals are dried, fused in an iron pot at a temperature of from 500~ to 600~ F., and cast into moulds. The cakes are preserved in casks. About the period of 1794 and 1795, under the pressure of the first wars of their revolution, the French chemists employed by the government contrived an expeditious, economical, and sufficiently effective mode of purifying their nitre. It must be observed.hat this salt, as brought to the gunpowder-works in France, is in general a much cruder 972 GUNPOWDER. article than that imported into this country from India. It is extracted from tit nitrous salts contained in the mortar-rubbish of old buildings, especially those of the lowest and filthiest descriptions. By their former methods, the French could not refine their nitre in less time than eight or ten days; and the salt was obtained in great lumps, very difficult to dry and divide; whereas the new process was so easy and so quick, that in less than twenty-four hours, at one period of pressure, the crude saltpetre was converted into a pure salt, brought to perfect dryness, and in such a state of extreme division as to supersede the operations of grinding and sifting, whence also considerable waste was avoided. The following is a brief outline of this method, with certain improvements, as now practised in the establishment of the A.dministration des poudres et saltpetres, in France. The refining boiler is charged over night with 600 kilogrammes of water, and 120C kilogrammes of saltpetre, as delivered by the salpetriers. No more fire is applied than is adequate to effect the solution of this first charge of saltpetre. It may here be observed, that such an article contains several deliquescent salts, and is much more soluble than pure nitre. On the morrow morning the fire is increased, and the boiler is charged at different intervals with fresh doses of saltpetre, till the whole amounts to 3000 kilogrammes. During these additions, care is taken to stir the liquid very diligently, and tc skim off the froth as it rises. When it has been for some time in ebullition, and when it may be presumed that the solution of the nitrous salts is effected, the muriate of soda is scooped out from the bottom of the boiler, and certain affuSions or inspersions of cold water are made into the pot, to quicken the precipitation of that portion which the boiling motion may have kept afloat. When no more is found to fall, one kilogramme of Flanders glue, dissolved in a sufficient quantity of hot water, is- poured into the boiler; the mix. ture is thoroughly worked together, the froth being skimmed off, with several successive inspersions of cold water, till 400 additional kilogrammes have been introduced, constituting altogether 1000 kilogrammes. When the refining liquor affords no more froth, and is grown perfectly clear, all manip. ulation must cease. The fire is withdrawn, with the exception of a mere kindling, so as to maintain the temperature till the next morning at about 88~ C. = 190'4 F. This liquor is now transferred by hand-basins into the crystallizing reservoirs, taking care to disturb the solution as little as possible, and to leave untouched the impure matter at the bottom. The contents of the long crystallizing cisterns are stirred backwards and forwards with wooden paddles, in order to quicken the cooling, and the consequent precipitation of the nitre in minute crystals. These are raked, as soon as they fall, to the upper end of the doubly-inclined bottom of the crystallizer, and thence removed to the washing chests or boxes. By the incessant agitation of the liquor, no large crystals of nitre can possibly form. When the temperature has fallen to within 7~ or 8~ F., of the apartment, that is, after seven or eight hours, all the saltpetre that it can yield will have been obtained. By means of the double inward slope given to the crystallizer, the supernatant liquid is collected in the middle of the breadth, and may be easily laded out. The saltpetre is shovelled out of the crystallizer into the washing chests, and heaped up in them so as to stand about six or seven inches above their upper edges, in order to allow for the subsidence which it must experience in the washing process. Each of these chests being thus filled, and their bottom holes being closed with plugs, the salt is besprinkled from the rose of a watering-can, with successive quantities of water saturated with saltpetre, and also with pure water, till the liquor, when allowed to run off, indicates by the hydrometer, a saturated solution. The water of each sprinkling ought to remain on the salt for two or three hours; and then it may be suffered to drain off through the plug-holes below, for about an hour. All the liquor of drainage from the first watering, as well as a portion of the second, is set aside, as being considerably loaded with the foreign salts of the nitre, in order to be evaporated in the sequel with the mother waters. The last portions are preserved, because they contain almost nothing but nitre, and may therefore serve to wash another lose of that salt. It has been proved by experience, that the quantity of water employed in washing need never exceed thirty-six sprinklings in the whole, composed of three waterings, of which the first two consist of fifteen, and the last of six pots = 3 gallons E.; or in other words, of fifteen sprinklings of water saturated with saltpetre, and twentyone of pure water. The saltpetre, after remaining five or six days in the washing chests, is transported into the drying reservoirs, heated by the flue of the nearest boiler; here it is stirred up from time to time with wooden shovels, to prevent its adhering to the bottom, or running into lumps, as well as to quicken the drying process. In the course of about four hours, it gets completely dry, in which state it no longer sticks to the shovel, but falls down into a soft powder by pressure in the hand, and is perfectly white and pulverulent. It is now GUNPOWDER. 973 passed through a brass sieve, to separate any small lumps or foreign particles accidentally present, and is then packed up in bags or barrels. Even in the shortest winter days, the drying basin may be twice charged, so as to dry 700 or 800 kilogrammes. By this operation, the nett produce of 3000 kilogrammes (3 tons) thus refined, amounts to from 1750 to 1800 kilogrammes of very pure nitre, quite ready for the manufacture of gunpowder. The mother waters are next concentrated; but into their management it is needless to enter in this memoir. On reviewing the above process as practised at present, it is obvious that, to meet the revolutionary crisis, its conductors must have shortened it greatly, and have been content with a brief period of drainage. 2. On the sulphur.-The sulphur now imported into this country, from the volcanic districts of Sicily and Italy, for our manufactories of sulphuric acid, is much purer than the sulphur obtained by artificial heat from any varieties of pyrites, and may, therefore, by simple processes, be rendered a fit constituent of the best gunpowder. As it is not my purpose here to repeat what may be found in common chemical compilations, I sLall say nothing of the sublimation of sulphur; a process, moreover, much too wasteful for the gunpowder-maker. Sulphur may be most easily analyzed, even by the manufacturer himself; for I find it to be soluble in one tenth of its weight of boiling oil of turpentine, at 316~ Fahrenheit, forming a solution which remains clear at 180~. As it cools to the atmospheric temperature, beautiful crystalline needles form, which may be washed sufficiently with cold alcohol, or even tepid water. The usual impurities of the sulphur, which are carbonate and sulphate of zinc, oxyde and sulphuret of iron, sulphuret of arsenic and silica, will remain unaffected by the volatile oil, and may be separately eliminated by the curious, though such separation is of little practical importance. Two modes of refining sulphur for the gunpowder works have been employed; the first is by fusion, the second by distillation. Since the combustible solid becomes as limpid as water, at the temperature of about 230~ Fahrenheit, a ready mode offers of removing at once its denser and lighter impurities, by subsidence and skimming. But I may take the liberty of observing, that the French melting pot, as described in the elaborate work of MM. Bott6e and Riffault, is singularly ill-contrived, for the fire is kindled right under it, and plays on its bottom. Now a pot for subsidence ought to be cold set; that is, should have its bottom part imbedded in clay or mortar for four or six inches up the side, and be exposed to the circulating flame of the fire only round its middle zone. This arrangement is adopted in many of our great chemical works, and is found to be very advantageous. With such a boiler, judiciously heated, I believe that crude sulphur might be made remarkably pure; whereas by directing the heat against the bottom of the vessel, the crudities are tossed up, and incorporated with the mass. See EVAPORATION. The sulphur of commerce occurs in three prevailing colors; lemon yellow verging on green, dark yellow, and brown yellow. As these different shades result from the different degrees of heat to which it has been exposed in its original extraction on the great scale, we may thereby judge to what point it may still be heated anew in the refinery melting. Whatever be the actual shade of the crude article, the art of the refiner consists in regulating the heat, so that after the operation it may possess a bri2iant yellow hue, inclining somewhat to green. In seeking to accomplish this purpose, the sulphur should first be sorted according to its shades; and if a greenish variety is to be purified, since this kind has been but little heated in its extraction, the fusion may be urged pretty smartly, or the fire may be kept up till everything is melted but the uppermost layer. Sulph:;- of a strong yellow tinge cannot bear so great a heat, and therefore the fire must be withdrawn whenever three fourths of the whole mass have been melted. Brown-colored brimstone, having been already somewhat scorched, should be heated as little as possible, and the fire may be removed as soon as one half of the mass is fused. Instead of melting, separately, sulphurs of different shades, we shall obtain a better result by first filling uy the pot to half its capacity, with the greenish-colored article, putting over this layer one quarter volume of the deep yellow, and filling it to the brim with the brown-colored. The fire must be extinguished as soon as the yellow is fused. The pot must then be closely covered for some time; after which the lighter impurities will bt found on the surface in a black froth, which is skimmed off, and the heavier ones sink to the bottom. The sulphur itself must be left in the pot for ten or twelve hours, after which it is laded out into the crystallizing boxes or casks. Distillation affords a more complete and very economical means of purifying sulphur which was first introduced into the French gunpowder establishments, when their importation of the best Italian and Sicilian sulphur was obstructed by the British navy. Here the sulphur need not come over slowly in a rare vapor, and be deposited IL 974 GUNPOWDER. n a pulverulent form called flowers; for the only object of the refiner is to bring over the whole of the pure sulphur into his condensing chamber, and to leave all its crudities:n the body of the still. Hence a strong fire is applied to elevate a denser mass of vapors, of a yellowish color, which passing over into the condenser, are deposited in a liquid state on its bottom, whilst only a few lighter particles attach themselves to the upper and lateral surfaces. The refiner must therefore give to the heat in this operation very considerable intensity; and, at some t eight above the edge of the boiler, he should provide an inclined plane, which may let the first ebullition of the sulphur overflow into a safety recipient. The condensing chamber should be hot enough to maintain the distilled sulphur in a fluid state-an object most readily procured by leading the pipes of several distilling pots into it; while the continuity of the operations is secured, by charging each of the stills alternately, or in succession. The heat of the receiver must be never so high as to bring the sulphur to a sirupy consistence, whereby its color is darkened. In the sublimation of sulphur, a pot containing about 4 cwts. can be worked off only once in twenty-four hours, from the requisite moderation of its temperature, and the precaution of an inclined plane, which restores to it the accidental ebullitions. But, by distillation, a pot containing fully ten cwts. may complete one process in nine hours at most, with a very considerable saving of fuel. In the former plan of procedure, an interval must elapse between the successive charges; but in the latter, the operation must be continuous to prevent the apparatus from getting cooled; in sublimation, moreover, where communication of atmospheric air to the condensing chamber is indispensable, explosive combustions of the sulphurous vapors frequently occur, with a copious production of sulphurous acid, and correspondent waste of the sulphur; disadvantages from which the distillatory process is in a great measure exempt. I shall here describe briefly the form and dimensions of the distilling apparatus employed at Marseilles in purifying sulphur for the national gunpowder works, whicl was found adequate to supply the wants of Napoleon's great empire. This apparatus consists of only two still-pots of cast iron, formed like the large end of an egg, each about three feet in diameter, two feet deep, and nearly half an inch thick at the bottom, but much thinner above, with a horizontal ledge four inches broad. A pot of good fast iron is capable of distilling 1000 tons of sulphur before it is rendered unserviceable, by the action of the brimstone on its substance, aided by a strong red heat. The pot is covered in with a sloping roof of masonry, the upper end of which abuts on the brickwork of the vaulted dome of condensation. A large door is formed in the masonry in front of the mouth of the pot, through which it is charged and cleared out; and between the roof-space over the pot, and the cavity of the vault, a large passage is opened. At the back of the pot a stone step is raised to prevent the sulphur boiling over into the condenser. The vault is about ten feet wide within, and fourteen feet from the bottom up to the middle of the dome, which is perforated, and carries a chimney about twelve feet high, and twelve feet diameter inside. As the dome is exposed to the expansive force of a strong heat, and to a very considerable pressure of gases and vapors, it must possess great solidity, and be therefore bound with iron straps. Between the still and the contiguous wall of the condensing chamber, a space must be left for the circulation of air; a precaution found by experience indispensable; for the contact of the furnaces would produce on the wall of the chamber such a heat as to make it crack and form crevices for the liquid sulphur to escape. The sides of the chamber are constructed of solid masonry, forty inches thick, surmounted by a brick dome, covered with a layer of stones. The floor is paved with tiles, and the walls are lined with' them up to the springing of the dome; a square hole being left in one side, furnished with a strong iron door, at which the liquid sulphur is drawn off at proper intervals. In the roof of the vault are two valve-holes covered with light plates of sheet-iron, which turn freely on hinges at one end, so as to give way readily to any sudden expansion from within, and thus prevent dangerous explosions. As the chamber of condensation is an oblong square, terminating upwards it> an oblong vault, it consists of a parallelopiped below, and semi-cylinder above, having the follcwmng dimensions:Length of the parallelopiped... 16J feet Width....... 104 Height.. 7I Radius of the cylinder 5 Height or length of semi-cylinder... 16J Whenever the workman has introduced into each pot its charge of ten o; twelve hunared weight of crude sulphur, he closes the charging doors carefully with their iron plates and cross-bars, and lutes them tight with loam. He then kindles his fire, and makes the GUNPOWDER. 975 sulphur boil. One of his first duties (and the least neglect in its discharge maj occasion serious accidents) is to inspect the roof-valves and to clean them, so that they may play freely and give way to any expulsive force from within. By means of a cord and chain, connected with a crank attached to the valves, he can, from time to time, ascertain their state, without mounting on the roof. It is found proper to work one of the pots a certain time before fire is applied to the other. The more steadily vapors of sulphur are seen to issue from the valves, the less atmospherical air can exist in the chamber, and therefore the less danger there'is of combustion. But if the air be cold, with a sharp north wind, and if no vapors be escaping, the operator should stand on his guard, for in such circumstances a serious explosion may ensue. As soon as both the boilers are in full work the air is expelled, the fumes cease, and every hazard is at an end. He should bend his whole attention to the cutting off all communication with the atmosphere, securing simply the mobility of the valves, and a steady vigor of distillation. The conclusion of the process is ascertained by introducing his sounding-rod into the pot, through a small orifice made for its passage in the wall. A new charge must then be given. By the above process, well conducted, sulphurs are brought to the most perfect state of purity that the arts can require; while not above four parts in the hundred of the sulphur itself are consumed; the crude, incombustible residuum varying from five to eight p&rts, according to the nature of the raw material. But in the sublimation of sulphur, the frequent combustions inseparable from this operation carry the loss of weight in flowers to about twenty per cent. See SULPHUR, for a figure of the subliming apparatus. The process by fusion, performed at some of the public works in this country, does not afford a return at all comparable with that of the above French process, though a much better article is operated upon in England. After two meltings of rough sulphur Q(s imported from Sicily or Italy), eighty-four per cent. is the maximum amount obtained, the average being probably under eighty; while the productis certainly inferior in quality to that by distillation. 3. On the charcoal.-Tender and light woods, capable of affording a friable and porous charcoal, which burns rapidly away, leaving the smallest residuum of ashes, and containing therefore the largest proportion of carbon, ought to be preferred for charring in gunpowder works. After many trials made long ago, black dogwood came to be preferred to every plant for this purpose; but modern experiments have proved that many other woods afford an equally suitable charcoal. The woods of black alder, poplar, lime-tree, horse-chestnut, and chestnut-tree, were carbonized in exactly similar circumstances, and a similar gunpowder was made with each, which was proved by the same proof-mortar. The following results were obtained:Toises. Feet. Poplar-mean range - - 113 2 Black alder - - - - 10 4 Lime -- 11( 3 Horse-chesthlt - - - 110 3 Chestnut-tree - - - 109 By subsequent experiments, confirmatory of the above, it has been further found that the willow presents the same advantages as the poplar, and that several shrubs, such as the hazel-nut, the spindle-treee, the dogberry, the elder-tree, the common sallow, and some others, may be as advantageously employed. But whichever wood be used, we should always cut it when full of sap, and never after it is dead; we should choose branches not more than five or six years old, and s.rip them carefully, because the old branches and the bark contain a larger proportion of earthy constituents. The branches ought not to exceed three quarters of an inch in thickness, and the larger ones should be divided lengthwise into four, so that their pith may be readily burned away. Wood is commonly carbonized in this country into gunpowder-charcoal in cast-iron cylinders, with their axes laid horizontally, and built in brick-work, so that the flame of a furnace may circulate round them. One end of the cylinder is furnished with a door, for the introduction of the wood and the removal of the charcoal; the other end terminates in a pipe, connected with a worm-tub for condensing the pyroligneous acid, and giving vent to the carbureted hydrogen gases that are disengaged. Towards the end of the operation, the connexion of the cylinder with the pyroligneous acid cistern ought to be cut off, and a very free egress opened for the volatile matter, otherwise the charcoal is apt to get coated with a fuliginous varnish, and to be even penetrated wir.h condensable matter, which materially injure its qualities. ( ~- - - 976 GUNPOWDER. In France, the wood is carbonized for the gunpowder works either in oblong vaulted ovens, or in pits, lined with brick-work or cylinders of strong sheet-iron. In either case, the heat is derived from the imperfect combustion of the wood itself to be charred. In general, the product in charcoal by the latter method is from 16 to 17 parts, by weight, from 100 of wood. The pit-process is supposed to afford a more productive return, and a better article; since the body of wood is much greater, and the fuliginous vapors are allowed a freer escape. The surface of a good charcoal should be smooth, but not glist ening. See CHARCOAL. The charcoal is considered by the scientific manufacturers to be the ingredient most influential, by its fluctuating qualities, upon the composition of gunpowder; and, therefore, it ought always to be prepared under the vigilant and skilful eye of the director of the powder establishment. If it has been kept for some time, or quenched at first with water, it is unsuitable for the present purpose. Charcoal extinguished in a close vessel by exclusion of air, and afterwards exposed to the atmosphere, absorbs only from three to four per cent. of moisture, while red-hot charcoal quenched with water may lose by drying twenty-nine per cent. When the latter sort of charcoal is used for gunpowder, a deduction of weight must be made for the water present. But charcoal which has remained long impregnated with moisture, constitutes a most detrimental ingredient of gunpowder. 4. On mixing the Constituents and forming the Powder. The three ingredients thus prepared are ready for manufacturing into gunpowder. They are, 1. Separately ground to a fine powder, which is passed through sorted silk sieves or bolting machines. 2. They are mixed together in the proper proportions, which we shall afterwards discuss. 3. The composition is then sent to the gunpowder taill, which consists of two edge-stones of a calcareous kind, turning by means of a horizontal shaft, on a bed-stone of the same nature; incapable of affording sparks by col. lision with steel, as sand-stones would do. On this bed-stone the composition is spread, and moistened with as small a quantity of water as will, in conjunction with the weight ot the revolving stones, bring it into a proper body of cake, but by no means into a pasty state. The line of contact of the rolling edge-stone is constantly preceded by a hard copper scraper, which goes round with the wheel, regularly collecting the caking mass, and bringing it into the track of the stone. From 50 to 60 pounds of cake are usually worked at one operation, under each millstone. When the mass has been thoroughly kneaded and incorporated, it is sent to the corning-house, where a separate mill is employed to form the cake into grains or corns. Here it is first pressed into a hard firm mass, then broken into small lumps; after which the corning process is performed, by placing these lumps in sieves, on each of which is laid a disc or fiat cake of lignum vite. The sieves are made of parchment skins, or of copper, perforated with a multitude of round holes. Several such sieves are fixed in a frame, which, by proper machinery, has such a motion given to it as to make the lignum vitae runner in each sieve move about with considerable velocity, so as to break down the lumps of the cake, and force its substance through the holes, in grains of certain sizes. These granular particles are afterwards separated fro.n the finer dust by proper sieves and reels. The corned powder must now be hardened, and its rougher angles removed, by causing it to revolve in a close reel or cask turning rapidly round its axis. This vessel resemg les somewhat a barrel-churn, and is frequently furnished inside with square bars parallel to its axis, to aid the polish by attrition. The gunpowder is finally dried, which is now done generally with a steam heat, or in some places by transmitting a current of air, previously heated in another chamber, over canvass shelves, covered with the damp grains. 5. On the proportion of the Constituents. A very extensive suite of experiments, to determine the proportions of the constituents'oriproducing the best gunpowder, was made at the Essonne works, by a commission of French chemists and artillerists, in 1794. Powders in the five following proportions were prepared:Nitre. Charcoal. Sulphur. 1 76 14 10 Gunpowder of Bale. 2 76 12 12 Gunpowder works of Grenelle. 3 76 15 9 M. Guyton de Morveau. I 4 77-32 13-44 9-24 Idem. 5 77.5 i 15 7.5 M. Riffault........... GUNPOWDER. 977 The lesult of more than two hundred discharges with the proof-mortar showed that the first and third gunpowders were the strongest; and the commissioners in consequence recommended the adoption of the third proportions. But a few years thereafter it was thought proper to substitute the first set of proportions, which had been found equal in force to the other, as they would have a better keeping quality, from containing a little more sulphur and less charcoal. More recently still, so strongly impressed have the French government been with the high value of durability in gunpowders, that they have returned to their ancient dosage of 75 nitre, 12- charcoal, and 12- sulphur. In this mixture, the proportion of the substance powerfully absorbent of moisture, viz., the charcoal, is still further reduced, and replaced by the sulphur, or the conservative ingredient. If we inquire how the maximum gaseous volume is to be produced from the chemical reaction of the elements of nitre on charcoal and sulphur, we shall find it to be by the generation of carbonic oxyde and sulphurous acid, with the disengagement of nitrogen. This will lead us to the following proportions of these constituents. Hydrogen = 1. Percent 1 prime equivalent of nitre - - - 102 75-00 I sulphur - - 16 11-77 3 charcoal - - 18 13-23 1 136 100-00 The nitre contains five primes of oxygen, of which three, combining with the three of charcoal, will furnish three of carbonic oxyde gas, while the remaining two will convert the one prime of sulphur into sulphurous acid gas. The single prime of nitrogen is, therefore, in this view, disengaged alone. The gaseous volume, on this supposition, evolved from 136 grains of gunpowder, equi valent in bulk to 751 grains of water, or to three tenths of a cubic inch, will be, at the atmospheric temperature, as follows:Grains. Cubic Inches. Carbonic oxyde 42 = 141-6 Sulphurous acid - 32 = 47-2 Nitrogen - - - - 14 47-4 2362 being an expansion of one volume into 787-3. But as the temperature of the gases at the instant of their combustive formation must be incandescent, this volume may be safely estimated at three times the above amount, or considerably upwards of two thou. sand times the bulk of the explosive solid. But this theoretical account of the gases developed does not well accord with Uhe experimental products usually assigned, though these are probably not altogether exact. Much carbonic acid is said to be disengaged, a large quantity of nitrogen, a little oxyde of carbon, steam of water, with carbureled and sulphureted hydrogen. From experiments to be presently detailed, I am convinced that the amount of these latter products printed in italics must be very inconsiderable indeed, and unworthy of ranking in the calculation; for, in fact, fresh gunpowder does not contain above one per cent. of water, and can therefore yield little hydrogenated matter. Nor is the hydrogen in the carbon of any consequence. It is obvious that the more sulphur is present, the more of the dense sulphurous acid will be generated, and the less forcibly explosive will be the gunpowder. This is sufficiently confirmed by the trials at Essonne, where the gunpowder that contained 12 of sulphur and 12 of charcoal in 100 parts, did not throw the proof-shell so far as that which contained only 9 of sulphur and 15 of charcoal. The conservative property is, however, so capital, especially for the supply of our remote colonies and for humid climates, that it justifies a slight sacrifice of strength, which at any rate mav be compensated by a small addition of charge. 978 GUNPOWDER. Table of Composition of different Gunpowders. Nitre. Charcoal. Sulphur. Royal Mills at Waltham Abbey - - 75 15 10 France, national establishment - - 75 12'5 12'5 French, for sportsmen - 78 12 10 French, for mining - - - 65 15 20 United States of America - - - - 75 12'5 12-5 Prussia - - 75 13*5 11'5 Russia - -.- 73-78 13-59 12-63 Austria (musquet) -. - - 72 17 16 Spain - - - - 76'47 10-78 12-75 Sweden -..... 76 15 9 Switzerland (a round powder) - 76 14 10 Chinese - -- -- 75 14-4 9'9 Theoretical proportions (as above) - - 75 13-23 11.77 6. On the Chemical Examination of Gunpowders. I nave treated five different samples: 1. The government powder made at Waltham Abbey; 2. Glass gunpowder made by John Hall, Dartford; 3. The treble strong gunpowder of Charles Lawrence and Son; 4. The Dartford gunpowder of Pigou and Wilks; 5. Superfine treble strong sporting gunpowder of Curtis and Harvey. The first is coarse-grained, the others are all of considerable fineness. The specific gravity of each was taken in oil of turnentine: that of the first and last three was exactly the same, being 1-80; that of the second was 1*793, all being reduced to water as unity. The above density for specimen first, may be calculated thus:75 parts of nitre, specific gravity = 2'000;5 parts of charcoal, specific gr. = 1-154 10 parts of sulphur, specific gr. = 2-000 The volume of these constituents is 55-5 (the volume of their weight of water being 100); by which if their weight 100 be divided, the quotient is 1-80. The specific gravity of the first and second of the above powders, including the interstices of their grains, after being well shaken down in a vial, is 1-02. This is a curious result, as the size of the grains is extremely different. That of Pigou and Wilks, similarly tried, is only 0-99; that of the Battle powder is 1-03; and that of Curtis and Harvey is nearly 1-05. Gunpowders thus appear to have nearly the same weight as water, under an equal bulk; so that an imperial gallon will hold from 10 pounds to 10 pounds and a half, as above shown. The quantities of water which 100 grains of each part with on a steam bath, and absorb when placed for 24 hours under a moistened receiver standing in water, arc as follows:100 grains of Waltham Abbey, lose 1'1 by steam heat, gain 0'8 over water. of Hall - - 05 - - - 2'2 Lawrence - - 1'0 - - - 11 Pigou and Wilks - 06 - - - 2'2 Curtis and Harvey - 0-9 - - - 17 lhus we perceive that the large grained government powder resists the hygrometric influence better than the others; among which, however, Lawrence's ranks nearly as high. These two are therefore relatively the best keeping gunpowders of the series. The process most commonly practised in the analysis of gunpowder, seems to be tolerably exact. The nitre is first separated by hot distilled water, evaporated and weighed. A minute loss of salt may be counted on, from its known volatility with boiling water. I have evaporated always on a steam bath. It is probable that a small portion of the lighter and looser constituent of gunpowder, the carbon, flies off in the operations of corning and dusting. Hence, analysis may show a small deficit of charcoal below the synthetic proportions originally mixed. The residuum of charcoal and sulphur left on the double filter-paper, being well dried by the heat of ordinary steam, was estimated, as usual, by the difference of weight of the inner and outer papers. This residuum was cleared off into a platina capsule with a tooth-brush, and digested in a dilute solution of potash at a boiling temperature. Three parts of potash are fully sufficient to dissolve out one of sulphur. When the above solution is thrown on a filter, and washed...,... GUNPOWDER. 979 first with a very dilute solution of potash boiling hot, then with boiling water, and afterwards dried, the carbon will remain; the weight of which deducted from that of the mixed powder, will show the amount of sulphur. I have tried many other modes of estimating the sulphur in gunpowder more directly, but with little satisfaction in the results. When a platina capsule, containing gunpowder spread on its bottom, is floated in oil, heated to 400~ Fahrenheit, a brisk exhalation of sulphur fumes rises, but, at the end of several hours, the loss does not amount to more than one half of the sulphur present. The mixed residuum of charcoal and sulphur digested in hot oil of turpentine gives up the sulphur readily; but to separate again the last portions of the oil from the charcoal or sulphur, requires the aid of alcohol. When gunpowder is digested with chlorate of potash and dilute muriatic acid, at a moderate heat in a retort, the sulphur is acidified; but this process is disagreeable and slow, and consumes much chlorate. The resulting sulphuric acid being tested by nitrate of baryta, indicates of course the quantity of sulphur in the gunpowder. A cur ous fact occurred to me in this experiment. After the sulphur and charcoal of the gunpowder had been quite acidified, I poured some solution of the baryta salt into the mixture, but no cloud of sulphate ensued. On evaporating to dryness, however, and redissolving, the nitrate of baryta became effective, and enabled me to estimate the sulphuric acid generated; which was of course 10 for every 4 of the sulphur. The acidification of the sulphur by nitric or nitro-muriatic acid is likewise a slow and unpleasant operation. By digesting gunpowder with potash water, so as to convert its sulphur into a sulphurct, mixing this with nitre in great excess, drying and igniting, I had hoped to convert the sulphur readily into sulphuric acid. But on treating the fused mass with dilute nitric acid, more or less sulphurous acid was exhaled. This occurred even though chlorate of potash hacd been mixed with the nitre to aid the oxygenation. The following are the results of my analyses, conducted by the first described method: 100 grains afford, of Nitre. Charcoal. Sulphur. Water. Waltham Abbey - - 745 14-4 10 0 1-1 Hall, Dartford - - - 76-2 14-0 9-0 0-5 loss 0-3 Pigou and Wilks - - 774 13-5 8-5 0-6 Curtis and Harvey - 76-7 12-5 9-0 1-1 loss 0-7 Battle gunpowder - 77-0 13-5 8-0 0-8 loss 0-7 It is probable, for reasons already assigned, that the proportions mixed by the manufacturers may differ slightly from the above. The English sporting gunpowders have long been an object of desire and emulation in France. Their great superiority for fowling pieces over the product of the French national manufactories, is indisputable. Unwilling to ascribe this superiority to any genuine cause, M. Vergnaud, captain of French artillery, in a little work on fulminating powders lately published, asserts positively, that the English manufacturers of' poudre de chasse' are guilty of the' charlatanisme' of mixing fulminating mercury with it. To determine what truth was in this allegation, with regard at least to the above five celebrated gunpowders, I made the following experiments. One grain of fulminating mercury, in crystalline particles, was mixed in water with 200 grains of the Wa.iham Abbey gunpowder, and the mixture was digested over a,amp with a very little muriatic acid. The filtered liquid gave manifest indications of the corrosive sublimate, into which fulminating mercury is instantly convertible by mu riatlc acid; for copper was quicksilvered by it; potash caused a white cloud in it that oecame yellow, and sulphareted hydrogen gas separated a dirty yellow white precipitate of bisulphuret of mercury. When the Waltham Abbey powder was treated alone with dilute muriatic acid, no effect whatever was produced upon the filtered liquid by the sulphureted hydrogen gas. 200 grains of each of the above sporting gunpowders were treated precisly in the same way, but no trace of mercury was obtained by the severest tests. Since by this process there is no doubt but one 10,000th part of fulminating mercury could be detected, we may conclude that Captain Vergnaud's charge is groundless. The superiority of our sporting gunpowders is due to the same cause as the superiority of our cotton fabrics-the care of our manufacturers in selecting the best materials, and their skill in combining them. I shall subjoin here some miscellaneous observations upon gunpowder. 63 980 GUNPOWDER. In Bengal, mixng is performed by shutting up the ingredients in barrels, which ait turned either by hand or machinery; each containing 50 lbs. weight, or more, of small brass balls. They have ledges on the inside, which occasion the balls and composition to tumble about and mingle together, so that the intermixture of the ingredients, after tne process has been gone through, cannot fail to be complete. The operation is con. tinued two or three hours; and I think it would be an improvement in Her Majesty's system of manufacture if this method of mixing were adopted. In England two or three pints of water are used for a. 42 lb. charge: but the quantity is variable; both the temperature and the humidity of the atmosphere influence it. Bramah's hydrostatic press, or a very strong wooden press working with a powerful screw, lever, and windlass, constitutes the description of mechanism by which density is imparted to gunpowder. The incorporated or mill-cake powder is laid on the bed or follower of the press, and separated, at equal distances, by sheets of copper, so that when the operation is over, it comes out in large thin solid cakes, or strata, distinguished by the term press-cake. The mill-cake powder at Waltham Abbey, is submitted to a mean theoretic pressure of 70 to 75 tons per superficial foot. Gunpowder should be thoroughly dried, but not by too high a degree of heat; that of 140~ or 150~ of Fahrenheit's thermometer is sufficient. It appears to be of no consequence whether it be dried by solar heat, by radiation from rM-hot iron, as in the gloom stove, or by a temperature raised by means of steam. Her Majesty's gunpowder is dried by the last two methods. The grain should not be suddenly exposed to the highest degree of heat, but gradually. The method of trial best adapted to show the real inherent strength and goodness of gunpowder, appears to be an eight or ten inch iron or brass mortar, with a truly spherical solid shot, having not more than one tenth of an inch windage, and fired with a low charge. The eight-inch mortar, fired with two ounces of powder, is one of the established methods of proof at Her Majesty's works. Gunpowders that range-equally in this mode of trial, may be depended on as being equally strong. Another proof is by four drachms of powderlaid in a srhall neat heap, on a clean, polished copper plato; which heap is fired at the apex, by a red hot iron. The explocion should be sharp and quick; not tardy, nor lingering; it should produce a sudden concussion in the air; and the force and power of that concussion ought to be judged of by comparison with that produced by powder of known good quality. No sparks should fly off, nor should beads, or globules of alkaline residuum, be left on the copper. If the copper be left clean, i. e. without gross foulness, and no lights, i. e. sparks, be seen, the ingredients may be considered to have been carefully prepared, and the powder to have been well manipulated, particularly if pressed and glazed; but if the contrary be the result, there has been a want of skill or of carefulness manifested in the manufacture. " Gunpowder," says Captain Bishop, " explodes exactly at the 600~ of heat by Fah renheit's thermometer; when gunpowder is exposed to 500~ it alters its nature altoge ther; not only the whole of the moisture is driven off, but the saltpetre and sulphur are actually reduced to fusion, both of which liquefy under the above degree. The powder, on cooling, is found to have changed its color from a gray to a deep black; the grain has oecome extremely indurated, and by exposure even to very moist air, it then suffers no alteration by imbibing moisture." The mill for grinding the gunpowder cake may be understood from the following I t I. t t u B r A05,'140 representation (fig. 740); p, is the water wheel, which may drive several pairs of stones; q, q, two vertical bevel wheels, fixed upon the axis of the great wheel' r, r, two GUTTA PERCHA. 981 horizontal beve,' wheels working in q, q, and turning the shafts s, s; t, t, two horizontal spur wheels fixed to the upper part of the vertical shafts, and driving the large wheels u, u. To the shafts of these latter wheels are fixed the runners v, v, which traverse upon the bed stone w, w; x, x, are the curbs surrounding the bed stone to prevent the powder fiom falling off; o is the scraper. Mill A represents a view, and mill B a section of the bed stone and curb. GUNPOWDER, Analysis of. M. Bolley dissolves out the sulphur from charcoal in gun. powder (previously freed from its nitre by water) by digesting it, at a boiling heat for 2 hours, with the solution of 20 times its weight of sulphite of soda, which is thereby converted into hyposulphite. To the mixture water must be added, as it is wasted by the boiling. If the residum be heated on platinum foil, it will exhale sulphur, if this had not been all removed by the sulphurous salt. GUTTA PERCHA (NATIVE). "Although the trees yielding this substance abound in the forests of the Indian Archipelago, the first notice taken of it appears to have been by Dr. W. Montgomerie, in a letter to the Bengal Medical Board, in the beginning of -843, wherein he recommends the substance as likely to prove useful for some surgical purposes, and supposes it to belong to the fig tribe. In April, 1843, the substance was taken to Europe by Dr. D'Almeida, who presented it to the Royal Society of Arts of London, but it did not at first attract much attention, as the Society simply acknowledged the receipt of the gift; whereas shortly after they thought proper to award a gold medal to Dr. W. Montgomerie for a similar service. Now, as the discovery of both of these gentlemen rested pretty much upon the same foundation, the accidental falling in with it in the hands of some Malays, who had found out its greatest peculiarity, and availed themselves thereof, manufactured it into whips, which were brought into town for sale, there does not appear any plausible reason for the passing over the first, and rewarding the second. Both gentlemen are highly to be commended for endeavouring to introduce to public notice a substance which has proved so useful and interesting. The gutta percha having of late attracted much attention, and as yet but little being known or published about it, I would now propose to supply, to the best of my ability, this desideratum, and give a description of the tree, its product and uses, so far as it has been made available for domestic and other purposes in the place of its origin. " The gutta percha, tree, or gutta tuban, as it ought more properly to be called, the percha producing a spurious article, belongs to the natural family Sapotece, but differs so much from all described genera, having alliance with both Achras and Bassia, but differing in some essentials from both, that I am disposed to think it is entitled to rank as a new genus. I shall, therefore, endeavour to give its general character, leaving the honour of naming it to some more competent botanist, especially as I have not quite satisfied myself regarding the stamens, from want of specimens for observations, "The tree is of a large size, from 60. to 10 feet in height, and from 2 to 3 feet in diameter. Its general appearance resembles the genus Durio, or well known Doorian, so much so as to strike the most superficial observer. The under surface of the leaf, however, is of a more reddish and decided brown than in the Durio, and the shape is somewhat different. " It is quite extraordinary how difficult it is to obtain specimens of either the flower or the fruit of this tree, and this is probably the reason of its not having been earlier recognised and described by some of the many botanists who have visited these parts. " Only a short time ago the tuban tree was tolerably abundant on the island of Singapore; but already all the large timber has been felled, and few, if any, other than small plants are now to be found. The range of its growth, however, appears to be considerable, it being found all up the Malayan Peninsula, as far as Penang, where I have ascertained it to be abundant; although, as yet, the inhabitants do not seem to be aware of the fact, several of the mercantile houses there having sent down orders to Singapore for supplies of the article, when they have the means of supply close at hand. The tree is also found in Borneo, and, I have little doubt, is to be found in most of the islands adjacent. " The localities it particularly likes are the alluvial tracts along the foot of hills, where it flourishes luxuriantly, forming, in many spots, the principal portion of the jungle. But, notwithstanding the indigenous character of the tree, its apparent abundance and widespread diffusion, the gutta will soon become a very scarce article, if some more provident means be not adopted in its collection than those at present in use by the Malays and Ci\nese. " The mode in which the natives obtain the gutta is by cutting down the trees of full growth, and ringing the bark at distances of about 12 to 18 inches apart, and placing a cocoa-nut shell, spathe of a palm or such like receptacle, under the fallen trunk, to receive the milky sap that immediately exudes upon every fresh incision. This sap is collected in bamboos, taken to their houses, and boiled, in order to drive off the watery particles and inspissate it to the consistence it finally assumes. Although 982 GUTTA PERCHA. the process of boiling appears necessary when the gutta is collected in large quantitie5 if a tree be freshly wounded, a small quantity allowed to exude, and it be collected and moulded in the hand, it will consolidate perfectly in a few minutes, and have all tile appearance of the prepared article. "When it is quite pure the colour is of a grayish white; but, as brought to market, it is more ordinarily found of a reddish hue, arising from chips of bark that fall into the sap in the act of making the incisions, and which yield their colour to it. Besides these accidental chips there is a great deal of intentional adulteration by sawdust and other materials. Some specimens I have lately seen brought to market could not have contained much less than i lb. of impurities; and even in the purest specimens I could obtain for surgical purposes, one pound of the substance yielded on being cleansed one ounce of impurities; fortunately, it is neither difficult to detect or clean the gutta of foreign matter, it being only necessary to boil it in water until well softened, roll out the substance into thin sheets, and then pick out all impurities, which is easily done as the gutta does not adhere to anything, and all foreign matter is merely entangled in its fibres, not incorporated in its substance. The quantity of gutta obtained from each tree varies from 5 to 20 catties, so that, taking the average at 10 catties, which is a tolerably liberal one, it will require the destruction of ten trees to produce one picul. Now, the quantity exported from Singapore to Great Britain and the continent, from 1st January 1845 to the present date, amounted to 6,918 piculs, to obtain which 69,180 trees must have been sacrificed. How much better would it, therefore, be to adopt the method of tapping the tree, practised by the Burmese in obtaining the caoutchouc from the Ficls elastica (viz. to make oblique incisions in the bark, placing bamboos to receive the sap which runs out freely), than to kill the goose in the manner they are at present doing! True, they would not at first get so much from a single tree, but the ultimate gain would be incalculable, particularly as the tree seems to be one of slow growth; by to means so rapid as the Eicus elastica. I should not be surprised, if the demand increases, and the present method of extermination be persisted in, to find a sudden cessation of the supply.' Properties of the G-utta.-This substance when fresh and pure is, as already mentioned, of a dirty white colour, and of a greasy feel, with a peculiar leathery smell. It is not affected by boiling alcohol, but dissolves readily in boiling spirits of turpentine, also in naphtha and coal-tar. A good cement for luting bottles and other purposes is formed by boiling together equal parts of gutta and coal-tar and resin. I am indebted for this hint to Mr. Little, surgeon, and the above were his proportions. I have, however, found it necessary to put two parts of the gutta, that is, one-half instead of one-third, to enable the cement to stand the heat of this climate. When required for use, it can always be made plastic by putting the pot containing it over the fire for a few minutes. The gutta itself is highly inflammable; a strip cut off takes light, and burns with a bright flame, emitting sparks, and dropping a black residuum in the manner of sealing wax, which in its combustion it very much resembles. But the great peculiarity of this substance, and that which makes it so eminently useful for many purposes, is the effect of boiling water upon it. When immersed for a few minutes in water above 150~ Fahr., it becomes soft and plastic, so as to be capable of being moulded to any required shape or form, which it retains upon cooling. If a strip of it be cut off and plunged into boiling water, it contracts in size both in length and breadth. This is a very anomalous and remarkable phenomenon, apparently opposed to all the laws of heat. " It is this plasticity when plunged into boiling water that has allowed of its being applied to so many useful purposes, and which first induced some Malays to fabricate it into whips, which were brought into town, and led to its further notice. The natives have subsequently extended their manufactures to buckets, basins, and jugs, shoes, traces, vessels for cooling wines, and several other domestic uses; but the number of patents lately taken out for the manufacture of the article in England, proves how much attention it has already attracted, and how extensively useful it is likely to become. Of all the purposes, however, to which it may be adapted, none is so valuable as its applicability to the practice of surgery. Here it becomes one of the most useful auxiliaries to that branch of the healing art which of all is the least conjectural. Its easy plasticity and power of retaining any shape given to it when cool, at once pointed it out as suitable for the manufacture of bougies; and accordingly my predecessor, Dr. W. Montgomerie, availed himself of this, made several of the above instruments, and recommended the use of it to the Bengal Medical Board. But, like many other good hints, for want of sufficient inquiry, I fear it was disregarded. The practice, how ever, has been continued by me, and I find many advantages in the use of this sub. stance. It also answers very well for the tubes of syringes, which are always gettino out of order in this country, when made of caoutchouc. But my late experiments have given it a much higher value, and proved it the best and easiest application ever yet GUTTA PERCHA. 983 discovered in the management of fractures, combining ease and comfort to the patient, and very much lessening the trouble of the surgeon. When I think of the farrago of bandages and splints got rid of, the lightness and simplicity of the application, the gutta would be no trifling boon to mankind, were it to be used solely for this and no other purpose. The injuries coming under my observation, wherein I have tested its utility, have, as yet, only been two compound fractures of the leg, and one of the jaw; but so admirably has it not only answered, but exceeded my expectations, that I should think myself culpable in not giving the facts early publicity. Its utility in fracture of the lower jaw must at once strike any surgeon. So well does it mould itself to every sinuosity, that it is more like giving the patient a new bone than a mere support. A man lately brought into hospital, who had his lower jaw broken by the kick of a horse, and which was so severe as to cause haemorrhage from the ears, smashing the bone into several fragments, was able to eat and speak three days after the accident, and felt so well with his gutta splint that he insisted on leaving the hospital within ten days. My mode of applying this substance to fractures of the leg is as follows:-' The gutta having been previously rolled out into sheets of convenient size, and about one-fourth of an inch in thickness, is thus kept ready for use. When required, a piece of the necessary length and breadth is plunged into a tub of boiling water. The limb of the patient is then gently raised by assistance, making extension in the usual manner. The surgeon, having ascertained that the broken bone is in its place, takes the sheet of gutta out of the hot water, and allows it to cool for a couple of minutes. It is still soft and pliable as wash leather. Place it whilst in this state under the limb, and gently lower the latter down on it. The gutta is then to be brought round and moulded carefully to the whole of the back and sides of the leg, bringing the edges close together, but not uniting them. If there be any superfluous substance, it can be cut off with scissors, leaving an open slit down the front of the leg. You have now the leg in a comfortable, soft, and smooth case, which in ten minutes will be stiff enough to retain any shape the surgeon may have given it, and which will also retain the bone in situ. Place the leg so done up on a double incline plane, and secure it thereto by passing three of the common loop bandages around the whole; that is, one at the top, one in the middle, and one at the lower end. Let the foot be supported by a foot-board, and a case of gutta put over the dorsum of the foot, to bear off the pressure of the small bands generally used to secure it to the board. Having done this, the surgeon need not cause the patient another twinge of pain until he thinks he can use the leg, or he deems the bone sufficiently united to bear the weight of his patient. If it be a compound fracture, it will be only necessary to untie the loop bandages, separate the edges of the gutta splint to the required distance, wash and cleanse the limb without shifting anything except the dressings, and, having done so, shut it up again. The most perfect cleanliness can be maintained, as the gutta is not affected by any amount of ablution; neither is it soiled or rendered offensive by any discharge, all which washes off as easily from the gutta case as from oil-cloth. I have had a patient where the tibia protruded through the integuments fully two inches, walking about in six weeks from the injury, with a leg as straight and well formed as ever it had been. It is quite obvious, therefore, that if it answers so well for compound, it will answer equally, if not better, for simple fractures; and that any broken bone capable of receiving mechanical support can be supported by the gutta better than by any other contrivance; for it combines lightness, and smoothness, and durability, and a capability of adjustment not possessed by any other known substance. All new experiments have to run the gauntlet of opposition; and I do not suppose that these recommendations will prove any exception to the rule; but all I ask of any surgeon is, to try the experiment ere he argues on its propriety, and I feel fully convinced that all other splints and bandages will be consigned to the tomb of the Capulets. There are some other uses for which I have tried this substance, viz., as capsules for transmission of the vaccine virus, which ought to keep well when thus protected, for it is most perfectly and hermetically sealed; but I have not had sufficient experience in this mode of using it to pronounce decidedly on its merits. I am at present trying the effects of it on ulcers, by enclosing the ulcerated limb in a case of gutta, so as to exclude all atmospheric air; and so far, the experiment promises success. "Since writing the foregoing observations, I have had an official intimation from Penang, of the vaccine virus transmitted in the gutta capsules having been received in good order, and of its having succeeded satisfactorily. I have also opened a capsule containing a vaccine crust that had been kept here for one month, and it also seems to have lost none of its efficacy, as the case inoculated has taken. This will appear the more striking when it is recollected that, to preserve the vaccine virus hitherto in Singapore, even for a few days, has been almost impossible; that this settlement, notwithstanding every exertion on the part of both private and public practitioners, has neen without the benefit of this important prophylactic for an interval sometimes of two 984 GUTTA PERCHA. ears; and that, at all times, the obtaining and transmitting this desirable remedy has been a cause of trouble and difficulty to all the medical officers I have ever met with in the Straits."-Mr. T. Oxley, Surqeon, Prince of Wales Island and Mlalacca. "I observed in the Mechanics' Magazine for March, 1847, a notice of several patents taken out for the working of the article by Mr. Charles Hancock, in which an elaborate process is described for cleaning the gutta, as also mention of its having a disagreeable acid smell. The gutta, when pure, is certainly slightly acid, that is, it will cause a very slight effervescence when put into a solution of soda, but is unaffected by liquor potasse. The smell, although peculiar, is neither strong nor unpleasant, so that the article experimented upon must have been exceedingly impure, and possibly derived a large portion of its acidity from the admixture and fermentation of other vegetable substances. Again; it appears to me that, if the gutta be pure, the very elaborate process described as being necessary for cleaning it, is superfluous. The gutta can be obtained here in a perfectly pure state by simply boiling it in hot water until well softened, and then rolled out into thin sheets, when, as I have before gaid, all foreign matter can be easily removed. I would recommend that the manufacturers at home should offer a higher price for the article if previously strained through cloth at the time of being collected, when they will receive the gutta in a state that will save them a vast deal more in trouble and expense than the trifling addition necessary to the original prime cost."Mr. Oxley. In February, 1847, Mr. Charles Hancock obtained a patent for improvements in the manufacture of gutta percha, consisting, in the first place, in the construction of a slicing machine, consisting of a circular iron plate, formed with three radial slots, in which knives are fixed in a similar manner to the irons of an ordinary plane or spoke shave; the shaft which carries the plate is caused to rotate by steam or other power. The lumps of gutta percha drop against the knives, a plate by which they are cut into slices, of a degree of thickness corresponding to the projection given to the knives. These slices are then soaked in a vessel of hot water till they become pliable. Instead of a circular revolving cutter, a vertical cutter or chopper may be used; curved knives may be had recourse to for refractory lumps. The softened slices are next subjected to the action of breakers or rollers with serrated blades, which are mounted transversely over the tank. In front of each breaker there is a pair of fluted feeding rollers; and the pieces of gutta percha are passed to the rollers of the first breaker. There is an inclined endless web mounted upon two rollers, the front one of which is immersed in the water, and the other is situated opposite the space between the feeding rollers of the second breaker. There is a second inclined web placed before the third breaker. There is also a mincing cylinder with radial blades working partly in the water. The feeding-rollers, and the carrying-rollers of the endless webs, are made to revolve in a forward direction, while the breakers, the mincing cylinder, and the agitator, are made to revolve in the opposite direction. The breakers and mincing cylinder should revolve at the rate of from 600 to 800 revolutions per minute, but the feeding rollers and endless webs need not move faster than about one-sixth of that rate. Thus, the substance is reduced to small fragments and washed in the water, the heavy impurities falling to the bottom of the tanks, and the lighter and purer matter floating. The water should be used cold. When the gutta percha has a fetid smell, it is treated with carbonate of soda or chloride of lime. The said apparatus may be used also for purifying caoutchouc and jintawan; Mr. Hancock now considers the use of sulphur to be altogether objectionable by itself on account of its offensive smell and efflorescing property as a means of vulcanizing caoutchouc. He has found that if a minute portion of sulphur be used along with a sulphuret the best result is obtained; the proper proportions being 6 parts of sulphuret of antimony, or hydrosulphuret of lime, and I part of sulphur to 48 parts of gutta percha or caoutchouc. When these materials have been mixed, the compound is put into a boiler and heated under pressure to a temperature of from 260~ to 300~ F. and is to be left in this state for a period varying from half an hour to two hours, according to the thickness of the materials. He prefers for effecting the union of the sulphurous constituent the following method to the masticating machine. 1st. He subjects the purified gutta percha to the conjoined action of steam and the fumes of orpiment and sulphur mixed in the proportions stated, in a metal chamber, provided with a steam-tight cover secured by screw-bolts. There is also a steam boiler connected therewith, and when the heat in it is raised to about 280~ Fahr., a fire is lighted beneath the pot containing the sulphuring materials. But the gutta percha, &c. should be heated with the steam before it is sulphured. In from half an hour to two hours the sulphuring is finished. Or, the gutta percha may be rubbed strongly over with the sulphurous mixture and then heated, either drv or with the aid of steam, or coated in the form of a paste along with gutta percha. Another of Mr. Hancock's inventions is to expose the gutta percha to the deutoxide f azote, or chloride of zinc, concentrated and boiling hot, and then washed with an GUTTA PERCHA. 985 Alkaline solution or mere water. Gutta percha thus treated by the action of nitious gas, as it is evolved from nitric acid and copper, iron, or zinc, becomes exceedingly smooth, and of a lustre aDproaching to metallic; so also does common unsulphured caoutchouc. It is thus also freed from all stickiness; while the sulphured acquires under this treatment the dDwny softness of velvet. Chloride of zinc and nitrous gas remove the smell of vulcanized caoutchouc in a great measure, especially if it be afterwards washed. Other new inventions are practised by masticating either gutta percha, caoutchouc, or jintawan, in the proportion of 6 parts with 1 of chloride of zinc; all which compounds may be afterwards sulphured. A further modification consists in producing a spongy gutta percha, caoutchouc, or jintawan, for stuffing sofas, &c. 48 parts of one of these, moistened with oil of turpentine, coal naphtha, bisulphuret of carbon, or other proper solvent, 6 parts of hydrosulphuret of lime, sulphuret of antimony, or other analogous sulphuret, 10 parts of carbonate of ammonia, carbonate of lime, ct other substance that is either volatile or capable of yielding a volatile produc, and 1 part of sulphur. He mixes these materials together in a masticator, and then subjects them to a high degree of heat, observing the same conditions which are stated in the former description, except only that the heat may be pushed with advantage several degrees higher, say from 260~ to 300~ Fahr. Articles are manufactured of ordinary gutta percha, caoutchouc, or jintawan, such as single and double texture waterproof fabrics, boots, galoshes, belts, bandages, trousers' and other straps, capes, life-preservers, tubes, knapsacks, caps, cups, and other vessels of capacity, hammer cloths, cotton spinning rollers, backs of cards for carding wool, pianoforte hammers, paper holders, springs, trusses, &c. By taking the gutta percha, caoutchouc, or jintawan, after it has been sulphured, and brushing it with a solution of resin in boiling oil (linseed?), placing it in a chamber heated to from 75~ to 100~ Fahr., and afterwards polishing it by the means usually employed by the japanners, it acquires the lustre of japanned wares. Mr. Hancock has also contrived a machine for cutting gutta percha into strips or ribands, thread, or cord of any required shape. It consists of two grooved rollers of iron or steel, mounted in a suitable framework. The grooves of each roller are semicircular, and the projecting divisions between the grooves are made with knife edges, so as to divide readily any sheet or mass of gutta percha presented to them. The under roller is flanged at both ends, and the upper roller is made to fit inside of these flanges, in order to keep the cutting edges from shifting or being damaged. To cut thin sheets of gutta percha with this machine into strips or ribands, the material is passed through it in. a cold state, and only the cutting edges are brought into operation. To make round cord or thread by means of it, either a sheet of gutta percha of a thickness equal to the diameter of the holes formed by the grooves, and at a temperature of 200~ Fahr. (produced by supplying it fiom a feeding-chamber heated to that degree) is passed through the machine, and the threads or cords are received in a tank of cold water, from which they are led away to be wound on reels or drums; or the gutta percha is employed in a plastic state, and passed under a gauge before it enters the machine. If it be desired to produce a cord of a semicircular form in the transverse section, a plane roller is substituted for the lower grooved roller; or should cord of a square, triangular, or hexangular, or any other form be required, the two rollers must be shaped tc suit.-Newton's Journal, xxxv. 96. Gutta Percha Letters. Gutta Percha has been patented for making letters for shop signs by Mr. Moore, Barrister. Gutta Percha Tubes; strength of. A series of interesting experiments have just been concluded at the Birmingham Waterworks, relative to the strength of Gutta Percha Tubing, with a view to its applicability for the conveyance of water. The experiments were made (under the direction of Henry Rofe, Esq., engineer,) upon tube - of an inch diameter, and one eighth of gutta percha. These were attached to the iron main, and subjected for two months to a pressure of 200 feet head of water, without being in the slightest degree deteriorated. In order to ascertain if possible the maximum strength of the tubes#they were connected with the Water Company's hydraulic proving pump, the regular load of which is 250 lbs. on the square inch. At this point the tubes were unaffected, and the pump was worked up to 337 lbs., but to the astonishment of every one the tubes still remained perfect. It was then proposed to work the pump up to 500 lbs., but it was found that the lever of the valve would not bear this weight. The utmost power of the hydraulic pump could not break the tubes. The gutta percha being somewhat elastic, allowed the tubes to become slightly expanded by the extraordinary pressure which was applied, but on its withdrawal they resumed their former size. Gutta Percha Tubing. This tubing is such an extraordinary conductor of sound, that its value, not only to deaf persons, but to the public generally, will speedily be appre 986 GUTTA PERCHA. ciated. It has already been fitted up in dwelling houses, in lieu of bells;-as speaking tubes for giving and receiving messages in mines, railway stations, prisons, workhouses, hotels, and all large establishments, it is invaluable. GUTTA PERCHA-its Properties, Analysis, Elementary Composition and Applications, by M. Payen. Without possessing any exact information regarding the extraction of the substance which comes to us from the Eastern Archipelago under the name of gutta percha, we know that this substance is contained in the descending sap of the Isonandra Gutta, Hooker, belonging to the natural order Sapotacece. This tree attains a great size, being sometimes as much as a yard in diameter, and 60 or 70 feet in height; its soft and fibrous wood is useless for industrial purposes; its fruit furnishes a fatty oil. It is said that a tree, when cut down, will yield 18 kilogrammes of gutta percha or solid gum. The juices, dried in thin strata laid one upon another, form irregular masses of greater or less thickness, of a reddish or grayish colour, of which a gradually increasing quantity has been annually imported into Europe and America since 1845. During many years the natives of the countries where it is produced have employed it almost solely in the formation of handles for axes, which possess when cold a certain degree of flexibility with great toughness. At present, the gutta percha is purified by rasping it in cold water, which removes the greater part of the soluble organic matter and salts, and also facilitates the separation of any portions of wood or earthy matters. The purification is completed by means of warm water in several basins; the gutta percha is afterwards dried, and formed into a pasty mass by heating it to about 230~ F. in a vessel with a steam jacket. The gutta percha thus prepared becomes sufficiently soft to be readily joined, stretched out into sheets or straps of any thickness, drawn into tubes of various diameters, and moulded into any form, whilst, on being slowly cooled, it acquires great tenacity and solidity. It is necessary, however, to remark, that the presence of a small quantity of water is sufficient to prevent the adhesion of its parts.. Properties of common Gutta Percha.-The gutta percha thus purified for manufacturing purposes, is of a reddish-brown colour; it readily becomes electrical by friction and is a bad conductor of both electricity and heat. At the ordinary temperature of our climate, say from 32~ to 17~, it possesses about as much tenacity as thick leather, with rather less flexibility; it softens and becomes sensibly doughy towards 120~, although still very tough. Its ductility is such, at a temperature of from 1100 to 241~, that it is readily extended into thin sheets, or drawn into threads or tubes; its flexibility and ductility diminish as the temperature becomes lower. It does not possess at any temperature the peculiar elastic extensibility which characterizes caoutchouc. Exposed for an hour to a temperature of 14~, its flexibility is slightly diminished. In its various forms, gutta percha possesses a peculiar porosity, as may be shown in the following manner:-A drop of its solution in sulphuret of carbon is to be placed on a glass slip; the spontaneous evaporation soon reduces this solution to a whitish plate; if it be then examined with the microscope, the numerous cavities with which it is pierced may be distinctly perceived. These cavities may be rendered still more visible by means of a drop of water; the liquid gradually insinuates itself, the mass appears more opake, and by means of the microscope the cavities are seen to be enlarged. Similar results are obtained by keeping immersed in water for a considerable time thin transparent laminae, obtained by the evaporation by heat of a solution of gutta percha. The preceding observations led me to think, that this substance retaining, in consequence of its porosity, a great many minute particles of air, owed to this circumstance its appearance of possessing a less density than that of water, namely 0'979. In fact, on stretching gutta percha under strong pressure, and immediately cutting the strips thus produced into very small pieces under water, the greater part of the fragments fell to the bottom of the vessel-some immediately, others after absorbing a certain quantity of water. The same result was also obtained by keeping very thin leaves of gutta percha, prepared by different methods, immersed for a month in water deprived of air; their pores becoming gradually filled with the liquid, they became heavier than the water, and then ceased to float. Gutta percha is also heavier in proportion to the length of time it has been exposed to the air, particularly in thin leaves. The porous structure of gutta percha becomes changed into a fibrous texture when it is drawn out so as to double its length; then retaining but little extensibility, it supports, without breaking, the action of a force equal to double that required for its elongation in the first instance. Common gutta percha resists cold water, damp, and also the various influences which excite fermentation; but it can be softened, and experience a sort of superficial doughy fusion by the action of the solar rays in summer. It is not attacked by alkaline solutions, even when caustic and concentrated; ammonia, saline solutions, water containing carbonic acid, the various vegetable and GUTTA PERCHA. 987 mineral acids, do not act upon it;.alcoholic liquors (wines, beer, &c.) do not touch it; even brandy scarcely dissolves a trace of it. Olive-oil does not appear to attack gutta percha when cold; when hot, it dissolves a small portion of it, which is again precipitated on cooling. Sulphuric acid with one equiv. of water colours it brown, and disintegrates it with a sensible evolution of sulphurous acid. Muriatic acid, in its saturated solution in water at a temperature of 68~ F., attack. gutta percha slowly, and gives it a more or less deep brown colour, at length rendering it brittle. Monohydrated nitric acid attacks it rapidly, with effervescence and an abundant evolution of fumes of hyponitrous acid; the substance is decomposed, and coloured of a brownish-orange red; it becomes doughy, and afterwards solidifies by degrees and remains friable. In the cold, and even by heat, only a part of the gutta percha (0-15 to 0-22) is dissolved by anhydrous.alcohol or ether. Benzine and spirits of turpentine dissolve it partially when cold, but nearly completely by heat. Sulphuret of carbon and chloroform dissolve gutta percha when cold; the solutions may be filtered beneath a bell-glass to prevent evaporation; the filter retains the foreign matters of a reddish-krown colour, whilst the solution passes perfectly clear and almost colourless. The filtered liquid, exposed to the air in a saucer, allows the solvent to escape, and deposits the white gutta percha in a plate of greater or less thickness, which shrinks gradually in proportion to the evaporation of the liquid. Except the colour, which has disappeared, the gutta percha offers then the characters and properties mentioned above as belonging to the commercial substance. Submitted to a gradually-raised temperature, it softens and melts, and may be made to boil without acquiring a sensible colour; the transparent fluid gives abundant vapours which are condensable into a nearly colourless oily liquid. The portions last distilled have a brownish-orange colour, and a thin layer of carbonaceous deposit remains adherent to the sides of the vessel. Analysis.-We have said above that alcohol and ether can dissolve only a portion of gutta percha; this is because that substance consists, in fact, of three proximate principles, the separation of which has required very delicate observation, although they are very clearly distinguished by several of their properties.* When gutta percha in thin leaves is brought into contact, in a close vessel, with 15 to 20 vols. of cold anhydrous alcohol, and the temperature raised slowly by means of the water-bath to the point of ebullition (172~ F.), and kept at this point during several hours, the liquid, if filtered whilst boiling and left in a closed flask, will, at the end of from 12 to 36 hours, begin to deposit on the sides of the vessel and on the surface of the solution white opaline granules, distant fiom one another, but some of them in groups; their size will gradually increase for some days. These granules, carefully examined under the microscope, will be found to have the form of spherules truncated by the sides of the vessel. Their surface is either smooth or bristling, with very small transparent, elongated, lamellar crystals. Some superficial fissures appear to indicate that these spherules are formed of a sort of transparent yellow kernel covered with a white pellicle. Such is really their singular crystalline structure, of which perhaps no other example is known. In fact, cold anhydrous alcohol dissolves the whole of the yellow, subjacent spheroidal substance, while the superficial pellicle, in the interior of which the alcohol has substituted itself for the solid globule, appear whiter and less transparent. The alcoholic solution which has been for some days depositing this complex spheroidal crystallization, can again take up by heat a portion of the two proximate principles remaining in the substance, allowing a fresh quantity to crystallize on cooling. The extraction is completed by returning the boiling alcohol several times upon the gutta percha until it no longer dissolves anything. The solid substance which has resisted the action of the solvent, possesses, with some modifications, the principal properties of crude gutta percha; we shall here call it puriutta or gutta. As to the two other organic principles, one is a yellow resin, which is much more soluble in cold alcohol than the other, the white crystalline resin. By taking advantage of these different degrees of solubility, we are enabled, with time and patience, to effect the complete purification of these three principles. The separation may also be effected by treating finely-divided gutta percha with cold ether, which dissolves the mixture of the two resins more abundantly than alcohol; they are afterwards separated from one another by the same treatment already described for alcohol The tendency of the white resin to form itself into groups of radiated lamellae is manifested in a rather remarkable circumstance, which it is easy to reproduce. Narrow * The author apt sars to be unacquainted with the researches of M. Arppe on this subject. See Chem. Gaz. vol. ix. p. 471. 988 GUTTA PERCHA ribbons cut from a thin leaf of ordinary gutta percha are to be placed in a tube,'ed immersed in anhydrous alcohol. The tube is then'closed, and left for twenty or thirty days, when a few whitish points appear here and there on the ribbons, and afterwards or the sides of the tube. These points, which become gradually larger, are formed of crys talline tufts of the white resin. Thus this proximate principle is separated directly, and in the cold, even when the atmospheric temperature is gradually rising, for instance during the spring or early summer. The crystalline white resin, when completely purified by washings with alcohol, and then redissolved in anhydrous alcohol, is deposited by slow spontaneous evaporation in the air, in radiated lamellar crystals, forming sometimes symmetrical tufts arranged in stars, and then presenting the appearance of a sort of efflorescence. Distinctive Characters and Properties of the Three Proximate Principles which constitute common Gutta Percha.-The most abundant of these three principles, forming at least from 75 to 82 per cent. of the whole mass, is the pure gutta, which presents the principal properties of the commercial substance; it is white, transparent at a temperature of 212~ F., when all its parts are melted together; opake or semi-transparent when cold, from its then acquiring a structure which causes the interposition of air, or of a liquid possessing a different refraction from its own. This structure appears still more distinct than in the natural substance containing all three principles. In thin sheets, and at a temperature of 50~ to 68~ F., it is supple, tough, extensible but not very elastic. At 112~ F., it softens and turns back upon itself, and becomes more and more adhesive and translucent in proportion to the elevation of temperature, undergoing a sort of doughy fusion, which becomes more distinct towards 212~ to 230~. Heated beyond this point, it melts, boils and distils, furnishing a pyrogenous oil and carburetted gases. 1ure gutta, like the other two proximate principles, is quickly rendered electrical by friction, and is a bad conductor of heat; it generally floats on water but sinks to the bottom as soon as its pores are filled with this liquid. It is insoluble in alcohol and ether, almost completely insoluble in benzine at 32~ F., it is soluble at 77~, and becomes more and more so in proportion as the temperature is raised. The saturated solution at 86~ forms itself into a semi-transparent mass when cooled below 32~; alcohol precipitates the gutta from its solution inbenzine. At 32~, spirits of turpentine dissolves very like gutta, whilst it disintegrates and dissolves it readily when hot. Chloroform and sulphuret of carbon dissolve the gutta in the cold. After the extraction by means of ether of the two resins interposed in the thin leaves of white gutta percha, leaving the last portion of ether with which they were impregnated to evaporate in the open air, these leaves, enclosed in a flask, experienced, after remaining there for two months at a temperature of from 68~ to 82~ F., an alteration which appeared to depend on their porosity, the action of the air, and perhaps the ether retained in their pores. However it be, these leaves had then acquired new properties; they were brittle; exhaled a very distinct sharp odour; brought into contact with an excess of anhydrous ether, they were partially dissolved; the soluble portion, obtained by the evaporation of the ether and desiccation at 194~ F., was glutinous and translucent; it became opake and hard by cooling down to 14~ F. Sulphuret of carbon, renewed three times in six days, and evaporated each time after two days' contact, left as residue a white flexible leaf. The portion not dissolved, swelled and transparent, did not appear to undergo any change when left in sulphuret of carbon for ten days. This kind of spontaneous transformation would perhaps become complete if more prolonged; its study will require much time; it will perhaps put us in the way of ascertaining the causes of certain changes observed in some small objects formed of gutta percha. I have already been able to ascertain, that thin leaves, exposed for eight consecutive days to the action of the sun in moist air, were discoloured, and that their substance had become in great part soluble in ether. Monohydrated sulphuric acid disintegrates, and communicates a brown colour to the pure gutta, with evolution of sulphurous acid; after eight days' contact, the deep brown liquid, on dilution with water, becomes turbid, and furnishes a brown flocculent precipi. tate. Nitric acid, with a single equivalent of water, attacks the pure gutta with a lively effervescence, and the evolution of orange vapours of hyponitrous acid. Muriatic acid, in its saturated solution, slowly attacks the thin leaves of gutta, giving them a deep brown colour; at tile end of eight days it becomes friable. The reaction of muriatic acid establishes an additional distinctive character between this proximate principle and the two others. Crystalline White Resin.-Obtained pure by means of the operations above described; it presents itself as a light pulveru.ent mass, apparently opake, which under the microscope exhibits the transparent lamellar crystals. From 82~ to 212~ F it does not GYPSU 1. 989 experience any sensible change; its fusion commences at 32C~; at 347~ to 356~ it acquires an oleiform fluidity and complete transparency, without any noticeable colour; it solidifies on cooling, shrinks, which causes it to split, and remains transparent and a little heavier than water. The crystallized resin is very soluble in spirits of turpentine, in benzine, sulphuret of carbon, ether and chloroform; on the spontaneous evaporation of the two last solvents, it crystallizes in long, narrow, thin, pearly laminae, forming separate groups radiating from common centres. Anhydrous alcohol dissolves it pretty readily at the temperature of 167~ F.: on cooling, groups of crystals separate, which increase during several days; the cold solution, decanted after crystallization, and left to spontaneous evaporation, yields similar crops of more voluminous lamellae. These crystals are not attacked or readily moistened by either cold or boiling water, as is also the case with hot or cold caustic alkaline solutions, ammonia, and the various dilute acids. Monohydrated sulphuric and nitric acids attack it rapidly, producing similar phenomena to those observed in their action upon pure gutta. Muriatic acid, on the contrary, does not act upon the white resin; in several of these characters it approaches to the breane extracted by M. Scribe from the resin of Icica.* It would be well to submit these two principles to a comparative study. Yellow Resin.-This amorphous transparent resin of a lemon or orange colour according to its thickness, is a little heavier than water, solid, and even hard and brittle, at 32~ F.; it gradually becomes more flexible in proportion as the temperature is raised; at 122~ F. it becomes pasty; it does not become completely fluid below 212~ to 230~. Heated beyond this point, it boils, but then gradually undergoes considerable alteration, becomes brown, and evolves acid fumes and carburets of hydrogen. This resin strongly retains the alcohol in which it has been dissolved; it is separated from it by heating in vacuo to 212~ F. until bubbling entirely ceases. It is soluble in the cold in alcohol, ether, benzine, essential oil or turpentine, sulphuret of carbon and chloroform; all these liquids, when evaporated, leave as residue the amorphous resin. Dilute acids, concentrated alkaline solutions, and ammonia do not attack the yellow resin. Monohydrated sulphuric and nitric acids act upon it rapidly, producing phenomena analogous to those exhibited with the other two principles. Muriatic acid, even in its saturated solution at 68~ F., is without action upon it. But the most remarkable character of this resin is the power of forming, under the circumstances already indicated, those globose crystals covered with a white pellicle of another resin, and offering in their complex form the appearance of opaline spherules. We see thus that the gutta percha, as it occurs in crmmerce, consists of three distinctly characterized proximate principles, besides some other matters in small quantities; the most abundant of these principles possesses the properties of the original substance; I give it the name of pure gutta or gutta; the two other principles are neutral resins. In order to recal their characteristic properties, I will give the name of crystalbane or albane to that which is obtained without difficulty in white crystals; and that of luavile to the third, which is yellow, and becomes sensibly fluid at a low temperature. The commercial varieties which I have examined have given me the following proportions:Gutta - - - 5 82 Albane - - - 16 14 Fluavile - - - 6 4 GYPSUM, Sulphate of Lime, Alabaster, or Paris Plaster. This substance is found in three geological positions in the crust of the earth; among transition rocks; in the red marl formation; and above the chalk, in the tertiary beds. 1. The alpine gypsums are ranged by M. Brochant among the transition class, and are characterized by the presence of anthracite or stone coal; some of them are white and pure, others gray or yellowish, and mixed with mica, talc, steatite, black oxide of iron, pyrites, compact carbonate of lime, sulphur, and common salt. Examples of such localities are found in the gypsum of Val-Canaria at the foot of Saint Gothard, that of Brigg in the upper Valais; of the Grilla in the valley of Chamouni, and of Saint Gervais-les-Bains, near Sallenches in Savoy. 2. The secondary gypsun, or that of the salt mine districts, belongs to the red ground, immediately beneath the lias in the order of stratification, and therefore a rock relatively ancient. Near Northwick, the red marl beds above the great deposit of rock salt, are irregularly intersected with gypsum, in numerous laminax or plates. At Newbiggin in Cumberland, the gypsum lies in red argillaceous marl, between two strata of sandstone; and a mile south of Whitehaven, the subterraneous workings for the alabaster extend * Chem. Gaz. vol. iv. p. 151. 99G GYPSUM. 80 yards in a direct line; with two or three lateral branches extending about 10 yards, at whose extremities are large spaces where the gypsum is blasted with gunpowder. It is generally compact, forming a regular and conformable bed, with crystals of selenite (crystallized gypsum) in drusy cavities. Gypsum occurs in the red marl in the isle of Axholme, and various other places in Nottinghamshire. In Derbyshire some considerable deposits have been found in the same red sandstone, several of which are mined, as at Chellaston hill, which would exhibit a naked and water-worn rock of gypsum, were it not for a covering of alluvial clay. It appears in general to present itself chiefly in particular patches, occasioning a sudden rise, or an insulated hill, by the additional thickness which it gives to the stratum of the red ground in these places. The principal demand for the pure white gypsum, or that faintly streaked with red, is by the potters in Staffordshire, who form their moulds with the calcined powder which it affords; only particularly fine blocks are selected for making alabaster ornaments on the turning lathe. In one of the salt pits near Droitwich, the strata sunk through were vegetable mould, 3 feet; red marl, 36 feet; gypsum, 40 feet; a river of brine, 22 inches; gypsum,'5 feet; a rock of salt, bored into only five, but probably extending much deeper. On the Welsh side of the Bristol Channel, gypsum occurs in the red marl cliffs of Glamorganshire, from Pennarth to Lavernock. No organic remains or metallic minerals have hitherto been found in the gypsum of this formation. 3. The most interesting gypsums in a general point of view, are certainly the tertiary, or those of the plains, or hills of comparatively modern formation. They are characterized by the presence of fossil bones of extinct animals, both mammifera and birds, by shells, and a large proportion of carbonate of lime, which gives them the property of effervescing with acids, and the title of limestone gypsums. Such are the gypsums of the environs of Paris, as at the heights of Montmartre, which contain crystallized sulphate of lime in many forms, but most commonly the lenticular and lance-shaped. Sulphate of lime occurs either as a dense compound without water, and is called anhydrite from that circumstance; or with combined water, which is its most ordinary state. Of the latter there are 6 sub-species; sparry gypsum or selenite in a variety of crystalline forms; the foliated granular; the compact; the fibrous; the scaly foliated; the earthy. The prevailing colour is white, with various shades of gray, blue, red, and yellow. More or less translucent. Soft, sectile, yielding to the nail. Specific gravity 2'2. Water dissolves about one five-hundredth part of its weight of gypsum, and acquires the quality of hardness, with the characteristic selenitic taste. When exposed on red hot coals, it decrepitates, becomes white, and splits into a great many brittle plates. At the heat of a baker's oven, or about 400~ Fahr., the combined water of gypsum escapes with a species of ebullition; at a higher temperature the particles get indurated. When rightly calcined and pulverized, gypsum is mixed with water to the consistence of cream, and poured into moulds by the manufacturers of stucco ornaments and statues. A species of rapid crystallization ensues, and the thin paste soon acquires a solid consistence, which is increased by drying the figure in proper stoves. During the consolidation of the plaster, its volume expands into the finest lines of the mould, so as to give a sharp and faithful impression. The plaster stone of the Paris basin contains about 12 per cent. of carbonate of lime. This body, ground and mixed with water, forms an adhesive mortar much used in building, as it fixes very speedily. Works executed with pure gypsum never become so hard as those made with the calcareous kind: and hence it might be proper to add a certain portion of white slaked lime to our calcined gypsum, in order to give the stucco this valuable property. Coloured stuccos of great solidity are made by adding to a clear solution of glue, any desired colouring tincture, and mixing in the proper quantity of the calcined calcareous gypsum. The compact, fine-grained gypseous alabaster is often cut into various ornamental figures, such as vases, statuary groups, &c., which take a high polish and look beautiful, but from their softness are easily injured, and require to be kept enclosed within a glass shade. In America and France, the virtues of gypsum in fertilizing land have been highly extolled, but they have not been realized in the trials made in this kingdom. Pure gypsum consists of lime 28; sulphuric acid 40; water 18; which are the respective weights of its prime equivalent parts. M. Gay Lussac, in a short notice, in the Annales de Chimis for April 1829, on the setting of gypsum, says that the purest plasters are those that harden least, and that the addition of lime is of no use towards promoting their solidity, nor can the heat proper for boiling gypsum ever expel the carbonic acid gas from the calcareous carbonate present in the gypsum of Montmartre. He conceives that a hard plaster-stono having lost its water, will resume more solidity in returning to its first state, than a plasterstone naturally tender or soft; and that it is the primitive molecular arrangement which is regenerated. See ALABASTER, and STONE ARTIFICIAL. HADE. 991 H. TIADE signifies, among English miners, the inclination, or deviation from the vertical of any mineral vein. HAIR (Cheveu, Crin, Fr.; Haar, Germ.) is of all animal products, the one, least liable to spontaneous change. It can be dissolved in water only at a temperature somewhat above 230~ F., in a Papin's digester, but it appears to be partially decomposed by this heat, since some sulphureted hydrogen is disengaged. By dry distillation, hair gives off several sulphureted gases, while the residuum contains sulphate of lime, common salt, much silica, with some oxyde of iron and manganese. It is a remarkable fact that fair hair affords magnesia, instead of these latter two oxydes. Horse-hair yields about 12 per cent. of phosphate of lime. Hairs are tubular, their cavities being filled with a fat oil, having the same color with themselves. Hair plunged in chlorine gas, is immediately decomposed and converted into A viscid mass; but when immersed in weak aqueous chlorine, it undergoes no change, except a little bleaching. The application of nitrate of mercury to hairy skins in the process of secretage, is explained under PELTRY. For the dyeing of horse-hair, see the next article. Living hairs are rendered black by applying to them, for a short time, a paste made by mixing litharge, slaked lime, and bicarbonate of potash, in various proportions, according to the shade of color desired. We have no recent analysis of hair. Vauquelin found nine different substances in black hair; in red hair, a red oil instead of a greenish-black one. The salts of mercury, lead, bismuth, as well as their oxydes, blacken hair, or make it of a dark violet, by the formation, most probably, of metallic sulphurets. Hair as an object of manufactures is of two kinds, the curly and the straight. The former, which is short, is spun into a cord, and boiled in this state, to give it the tortuous springy form. The long straight hair is woven into cloth for sieves, and also for ornamental purposes, as in the damask-hair cloth of chair bottoms. For this purpose the hair may be dyed in the following way. Forty pounds of tail hair about 26 inches long are steeped in lime water during twelve hours. Then a bath is made with a decoction of 20 pounds of logwood, kept boiling for three hours, after which time the fire is withdrawn from the boiler, and ten ounces of copperas are introduced, stirred about, and the hair is immersed, having been washed from the lime in river water. The hair should remain in this cooling bath for 24 hours, when the operation will be finished. For other colors, see the respective dyes. The looms for weaving hair differ from the common ones, only in the templet and the shuttle. Two templets of iron must be used to keep the stuff equably, but lightly stretched. These templets, of which one is represented in fig. 741, are constructed in the shape of flat pincers; the jaws c c being furnished with teeth inside. A screw D, 1741 binds the jaws together, and hinders the selvage D from going inwards. Upon the side cross beam C e r~ F of the loom, seen in section at I, a bolt is fixed'<- ~, iwhich carries a nut F at its end, into which a C~ I r - " -- t -r ~ screwed iron rod E enters, on one of whose ends L. is the handle B. The other extremity of the B screw E is adapted by a washer and pin to the back of the pincers at the point H, so that by turning the handle to the right or the left, we draw onwards or push backwards the pincers and the stuff at pleasure. The warp of the web is made of black linen yarn. The weft is of hair, and it is thrown with a long hooked shuttle; or a long rod, having a catch hook at its end. The length of this shuttle is about 3 feet; its breadth half an inch, and its thickness one sixth. It is made of box-wood. The reed is of polished steel; the thread warps are conducted through it in the usual way. The workman passes this shuttle between the hairs of the warp with one hand, when the shed or shuttle way is opened by the treddles; a child placed on one side of the loom presents a hair to the weaver near the selvage, who catches it with the hook of his shuttle, and by drawing it out passes it through the warp. The hairs are placed in a bundle on the side where the child stands, in a chest filled with water to keep them moist, for otherwise they would not have the suppleness requisite to form a web. Each time that a hair is thrown across, the batten is driven home twice. The warp is dressed with paste in the usual way. The hair cloth, after it is woven, is hot calendered to give it lustre. 992 HARDNESS. HAIR PENCILS OR BRUSHES for painting. Two sorts are made; those with coarse nair, as that of the swine, the wild boar, the dog, &c., which are attached usually to short wooden rods as handles; these are commonly called brushes; and hair pencils, properly so called, which are composed of very fine hairs, as of the minever, the marten, the badger, the polecat, &c. These are mounted in a quill when they are small or of moderate size, but when larger than a quill,.they are mounted in white-iron tubes. The most essential quality of a good pencil is to form a fine point, so that all the hairs without exception may be united when they are moistened by laying them upon the tongue, or drawing them through the lips. When hairs present the form of an elongated cone in a pencil, their point only can be used. The whole difficulty consists after the hairs are cleansed, in arranging them together so that all their points may lie in the same horizontal plane. We must wash the tails of the animals whose hairs are to be used, by. scouring them in a solution of alum till they be quite free from grease, and then steeping them for 24 hours in luke-warm water. We next squeeze out the water by pressing them strongly from the root to the tip, in order to lay the hairs as smooth as possible. They are to be dried with pressure in linen cloths, combed in the longitudinal direction, with a very fine-toothed comb, finally wrapped up in fine linen, and dried. When perfectly dry, the hairs are seized with pincers, cut across close to the skin, and arranged in separate heaps, according to their respective lengths. Each of these little heaps is placed separately, one after the other, in small tin pans with flat bottoms, with the tips of the hair upwards. On striking the bottom of the pan slightly upon a table, the hairs get arranged parallel to each other, and their delicate points rise more or less according to their lengths. The longer ones are to be picked out and made into so many separate parcels, whereby each parcel may be composed of equally long hairs. The perfection of the pencil depends upon this equality; the tapering point being produced simply by the attenuation of the tips. A pinch of one of these parcels is then taken, of a thickness corresponding to the intended size of the pencil; it is set in a little tin pan, with its tips undermost, and is shaken bv striking the pan on the table as before. The root end of the hairs being tied by the fisnerman's or seaman's knot, with a fine thread, it is taken out of the pan, and then hooped with stronger thread or twine; the knots being drawn very tight by means of two little sticks. The distance from the tips at which these ligatures are placed, is of course relative to the nature of the hair, and the desired length of the pencil. The base of the pencil must be trimmed flat with a pair of scissors. Nothing now remains to be done but to mount the pencils in quill or tin-plate tubes as above described. The quills are those of swans, geese, ducks, lapwings, pigeons, or larks, according to the size of the pencil. They are steeped during 24 hours in water, to swell and soften them, and to prevent the chance of their splitting when the hair brush is pressed into them. The brush of hair is introduced by its tips into the large end of the cut quill, having previously drawn them to a point with the lips, when it is pushed forwards with a wire of the same diameter, till it comes out at the other and narrower end of the quill. The smaller the pencils, the finer ought the hairs to be. In this respect, the manufacture requires much delicacy of tact and experience. It is said that there are only four first-rate hands among all the dexterous pencil-makers of Paris, and that these are principally women. HALOGENE is a term employed by Berzelius to designate those substances which form compounds of a saline nature, by their union with metals; such are Bromime, Chlorine, Cyanogene, Fluorine, Iodine. Haloid is his name of the salt thereby formed. HANDSPIKE is a strong wooden bar, used as a lever to move the windlass and capstan in heaving up the anchor, or raising any heavy weights on board a ship. The handle is smooth, round, and somewhat taper; the other end is squared to fit the holes in the head of the capstan or barrel of the windlass. HARDNESS (Durete, Fr.; Hdrte, Festigkeit, Germ.) is tnat modification of cohesive attraction which enables bodies to resist any effort made to abrade their surfaces. Its rel. ative intensity is measured by the power they possess of cuttng or scratching other sub. stances. The following table exhibits pretty nearly the successive hardnesses of the several bodies in the list:-.A_ _ ___ _ _ _ HARTSHORN. 993 Substances. A Hardness. Specific Gravity. Diamond from Ormus - 20 3*7 Pink diamond - - - - 19 3'4 Bluish diamond - - - - 19 3'3 Yellowish diamond - - - - 19 3-3 Cubic diamond - - - - 18 3-2 Ruby -... 17 4-2 Pale ruby from Brazil - - - 16 3'5 Deep blue sapphire- - - 16 3'8 Ditto, paler - - - - - 17 3-8 Topaz - - - - 15 4-2 Whitish topaz - - 14 3-5 Ruby spinell - 13 34 Bohemian topaz - - - - - 11 2'8 Emerald - - - 2 2-8 Garnet.- - - 12 4-4 Agate - 12 2-6 Onyx. -. 12 2-6 Sardonyx - - - 12 2-6 Occidental amethyst - - - 11 27 Crystal - - - - - 11 2-6 Cornelian - - - 11 2-7 Green jasper - - - 11 27 Reddish yellow do. - - - -9 2-6 Schoerl - - 10 3-6 Tourmaline - - - - - 10 3-0 Quartz - - o 10 2-7 Opal - - - - - 10 2-6 Chrysolite - - - 10 3-7 Zeolite - - - - - 8 2'1 Fluor - - - 7 3-5 Calcareous spar - - - 6 2-7 Gypsum - - - - - 5 2-3 Chalk - - 3 2'7 HARTSHORN, SPIRIT OF, is the old name for water of ammonia. HATCHING OF CHICKENS. See INCUBATION, ARTIFICIAL. HAT MANUFACTURE. (L'art de Chapelier, Fr.; Hutmacherkunst, Germ.) Hat is the name of a piece of dress worn upon the head by both sexes, but principally by the men, and seems to have been first introduced as a distinction among the ecclesiastics in the 12th century, though it was not till the year 1400 that it was generally adopted by respectable laymen. As the art of making common hats does not involve the description of any curious machinery, or any interesting processes, we shall not enter into very minute details upon the subject. It will be sufficient to convey to the reader a general idea of the methods employed in this manufacture. The materials used in making stuff hats are the furs of hares and rabbits freed from the long hair, together with wool and beaver. The beaver is reserved for the finer hats. The fur is first laid upon a hurdle made of wood or wire, with longitudinal openings; and the operator, by means of an instrument called the bow (which is a piece of elastic ash, six or seven feet long, with a catgut stretched between its two extremities, and made to vibrate by a bowstick), causes the vibrating string to strike and play upon the fur, so as to scatter the fibres in all directions, while the dust and filth descend through the grids of the hurdle. After the fur is thus driven by the bow from the one end of the hurdle to the other, it forms a mass called a bat, which is only half the quantity sufficient for a hat. The'at or capade thus formed is rendered compact by pressing it down with the hardening skin (a piece of half-tanned leather), and the union of the fibres is increased by covering them with a cloth, while the workman presses them together repeatedly with his hands. The cloth being taken off, a piece of paper, with its corners doubled in, so as to give it a triangular outline, is laid above the bat. The opposite edges of the bat are then folded over the paper, and being brought together and pressed again with the hands, they form a conieal cap. This cap is next laid upon another bat, ready hardened, so that the joined 994 HAT MANUFACTURE. edges of the first bat rest upon the new one. This new bat is folded over the other, and its edges joined by pressure as before; so that the joining of the first conical cap is opposite to that of the second. This compound bat is now wrought with the hands for a considerable time upon the hurdle between folds of linen cloth, being occasionally sprinkled with clear water, till the hat is basined or rendered tolerably firm. The cap is now taken to a wooden receiver, like a very flat mill-hopper, consisting of eight wooden planes, sloping gently to the centre, which contains a kettle filled with 742 fl --- A- S water acidulated with sulphuric acid. The technical name of this vessel is the battery. It consists of a kettle A; and of the planks, B c, c/ ------ B which are sloping planes, usually eight in num. ber, one being allotted to each workman. The half of each plank next the kettle is made of lead, the upper half of mahogany. In this liquor the hat is occasionally dipped, and wrought by the hands, or sometimes with a roller, upon the sloping planks. It is thus fulled or thickened during four or five hours; the knots or hard substances are picked out by the workman, and fresh flllljij h\ felt is added by means of a wet brush to those parts that require it. The beaver is applied at the end of this operation. In the manufacture of beaver hats, the grounds of beer are added to the liquor in the kettle. Stopping, or thickening the thin spots, seen by looking through the body, is performed by daubing on additional stuff with successive applications of the hot acidulous liquor from a brush dipped into the kettle, until the body be sufficiently shrunk and made uniform. After drying, it is stiffened with varnish composition rubbed in with a brush; the inside surface being more copiously imbued with it than the outer; while the brim is peculiarly charged with the stiffening. When once more dried, the body is ready to be covered, which is done at the battery. The first cover of beaver or napping, which has been previously bowed, is strewed equably over the body, and patted on with a brush moistened with the hot liquor, until it gets incorporated; the cut ends towards the root, being the points which spontaneously intrude. The body is now put into a coarse hair cloth, then dipped and rolled in the hot liquor, until the root ends of the beaver are thoroughly worked in. This is technically called rolling off, or roughing. A strip for the brim, round the edge of the inside, is treated in the same way; whereby every thing is ready for the second cover (of beaver), which is incorporated in like manner; the rolling, &c. being continued, till a uniform, close, and well-felted hood is formed. The hat is now ready to receive its proper shape. For this purpose the workman turns up the edge or brim to the depth of about 11 inch, and then returns the point of the cone back again through the axis of the cap, so as to produce another inner fold of the same depth. A third fold is produced by returning the point of the cone, and so on till the point resembles a flat circular piece having a number of concentric folds. In this state it is laid upon the plank, and wetted with the liquor. The workman pulls out the point with his fingers, and presses it down with his hand, turning it at the same time round on its centre upon the plank, till a flat portion, equal to the crown of the hat, is rubbed out. This flat crown is now placed upon a block, and, by pressing a string called a commander, down the sides of the block, he forces the parts adjacent to the crown, to assume a cylindrical figure. The brim now appears like a puckered appendage round the cylindrical cone; but the proper figure is next given to it, by working and rubbing it. The body is rendered waterproof and stiff by being imbued with a varnish composed of shellac, sandarach, mastic, and other resins dissolved in alcohol or naptha. The hat being dried, its nap is raised or loosened with a wire brush or card, and sometimes it is previously pounced or rubbed with pumice, to take off the coarser parts, and afterwards rubbed over with seal-skin. The hat is now tied with pack-thread upon its block, and is afterwards dyed. See HAT-DYEING, infra. The dyed hats are now removed to the stiffening shop. Beer grounds are next applied on the inside of the crown, for the purpose of preventing the glue from coming through; and when the beer grounds are dried, glue (gum Senegal is sometimes used) a little thinner than that used by carpenters, is laid with a brush on the inside of the crown, and the lower surface of the brim. The hat is then softened by exposure to steam, on the steaming basin, and is brushed and ironed t:l it receives the proper gloss. It is lastly cut round at the brim by a knife fixed at the end of a gauge, which rests against the crown. The brim, however, is not L —------------------ ---------- HAT MANUFACTURE. 995 cut entirely through, but is torn off so as to leave an edging of beaver round the external rim of the hat. The crown being tied up in a gauze paper, which is neatly ironed down, is then ready for the last operations of lining and binding. The furs and wools of which hats are manufactured contain, in their early stage of preparation, hemps and hairs, which must be removed in order to produce a material for the better description of hats. This separation is effected by a sort of winnowing machine, which wafts away the finer and lighter parts of the furs and wools from the coarser. Messrs. Parker and Harris obtained a patent in 1822 for the invention and use of such an apparatus, whose structure and functions may be perfectly understood, from its analogy to the blowing and scutching machine of the cotton manufacture; to which I therefore refer my readers. I shall now proceed to describe some of the recent improvements proposed in the manufacture of hats, but their introduction is scarcely possible, on account of the perfectly organized combination which exists among journeyman hatters throughout the kingdom, by which the masters are held in a state of complete servitude, having no power to take a single apprentice into their works beyond the number specified by the Union, nor any sort of machine which is likely to supersede hand labor in any remarkable degree. Hence the hat trade is, generally speaking, unproductive to tbe capitalist, and incapable of receiving any considerable development. The public of a free country like this, ought to counteract this disgracefll state of things, by renouncing the wear of stuff hats, a branch of the business entirely under the control of this despotic Union, and betake themselves to the use of silk hats, which, from recent improvements in their fabric and.dyeing, are not a whit inferior to the beaver hats, in comfort, appearance, or durability, while they may be had of the best quality for one fourth part of their price. The annexed figures represent Mr. Ollerenshaw's machine, now generally employed or ironing hats. Fig. 743 is the frame-work or standard upon which three of these 744'745 74 C 743 _ - I -1111 lathes are mounted, as A, B, c. The lathe A is intended to be employed when the crown of the hat is to be ironed. The lathe B, when the flat top, and the upper side of the brim is ironed, and lathe c, when its under side is ironed; motion being given to the whole by means of a band passing from any first mover (as a steam-engine, water-wheel, &c.) to the drum on the main shaft a a. From this drum a strap passes over the rigger b,which actuates the axle of the lathe A. On to this lathe a sort of chuck is screwed, and to the chuck the block c is made fast by screws, bolts, or pins. This block is represented in section, in order to show the manner in which it is made, of several pieces held fast by the centre wedge-piece, as seen at fig. 144. The hat-block being made to turn round with the chuck, at the rate of about twenty turns per minute, but in the opposite direction to the revolution of an ordinary turning lathe, the workman applies his hot iron to the surface of the hat, and thereby smooths it, giving a beautiful glossy appearance to the beaver; he then applies a plush cushion, and rubs round the surface of the hat while it is still revolving. The hat, with its block, is now removed to the lathe B, where it is placed upon the chuck d, and made to turn in a horizontal direction, at the rate of about twenty revolutions per minute, for the purpose of ironing the flat-top of the crown. This lathe B moves upon an upright shaft e, and is actuated by a twisted band passing from the main shaft, round the 64 996 HAT MANUFACTURE. riggerf. In order to iron the upper surface of the brim, the block c is removed from the lathe, and taken out of the hat, when the block fig. 745, is mounted upon the chuck d, and made to turn under the hand of the workman, as before. The hat is now to be removed to the lathe c, where it is introduced in an inverted position, between the arms g g supporting the rim h h, the top surface of which is shown at fig. 746. The spindle i of the lathe turns by similar means to the last, but slower; only ten turns per minute will be sufficient. The workman now smooths the under side of the brim, by drawing the iron across it, that is, from the centre outwards. The hat is then carefully examined, and all the burs and coarse hairs picked out, after which the smoothing process is performed as before, and the dressing of the hat is complete. Messrs. Gillman and Wilson, of Manchester, obtained a patent in 1823, for a peculiar kind of fabric to be made of cotton, or a mixture of cotton and silk, for the covering of hats and bonnets, in imitation of beaver. The foundation of the hat may be of felt, hemp, wool, which is to be covered by the patent fabric. This debased article does not seem to have got into use; cotton, from its want of the felting property and inelasticity, being very ill-adapted for making hat-stuff. A more ingenious invention of John Gibson, hatter, in Glasgow, consistirog of an elastic fabric of whalebone, was made the subject of a patent, in June, 1824. The whalebone, being separated into threads no larger than hay stalks, is to be boiled in some alkaline liquid for removing the oil from it, and rendering it more elastic. The longest threads are to be employed for warp, the shorter for weft; and are to be woven in a hair-cloth loom. This fabric is to be passed between rollers, after which it is fit to be cut out into forms for making hats and bonnets, to be sewed together at the joints, and stiffened with a preparation of resinous varnishes, to prevent its being acted upon by perspiration or rain. A very considerable improvement in the lightness and elasticity cf silk hats has been the result of this invention. The foundation of men's hats, upon whose outside the beaver, down, or other fine fur is laid to produce a nap, is, as I have described, usually made of wool felted together by hand, and formed first into conical caps, which are afterwards stretched and moulded upon blocks to the desired shape. Mr. Borradaile, of Bucklersbury, obtained a patent in November, 1825, for a machine, invented by a foreigner, for setting up hat bodies, which seems to be ingeniously contrived; but I shall decline describing it, as it has probably not been suffered by the Union to come into practical operation, and as I shall presently give the details of another later invention for the same purpose. Silk hats, for several years after they were manufactured, were liable to two objec. tions; first, the body or shell over which the silk covering is laid, was, from its hardness, apt to hurt the head; second, the edge of the crown being much exposed to blows, the silk nap soon got abraded, so as to lay bare the cotton foundation, which is not capable of taking so fine a black dye as the silk; whence the hat assumed a shabby appearance. Messrs. Mayhew and White of London, hat-manufacturers, proposed in their patent of February, 1826, to remedy these defects, by making the hat body of stuff or wool, and relieving the stiffness of the inner part round the brim, by attaching a coating of beavel upon the under side of the brim, so as to render the hat pliable. Round the edge of the tip or crown, a quantity of what is called stop wool is to be attached by the ordinary operation of bowing, which will render the edge soft and elastic. The hat is to be afterwards dyed of a good black color, both outside and inside; and being then properly stiffened and blocked, is ready for the covering of silk. The plush employed for covering silk hats, is a raised nap or pile woven usually upon a cotton foundation; and the cotton, being incapable of receiving the same brilliant black dye as the silk, renders the hat apt to turn brown whenever the silk nap is partially worn off. The patentees proposed to counteract this evil, by making the foundation of the plush entirely of silk. To these two improvements, now pretty generally introduced, the present excellence of the silk hats may be, in a good measure, ascribed. The apparatus above alluded to, for making the foundations of hats by the aid of mevhanism, was rendered the subject of a patent, by Mr. Williams, in September, 1826; but I fear it has never obtained a footing, nor even a fair trial in our manufactures, on ac count of the hostility of the operatives to all labor-saving machines. Fig, 747 is a side view of the carding engine, with a horizontal or plan view of the lower part of the carding machine, showing the operative parts of the winding apparatus, as connected to the carding engine. The doffer cylinder is covered with fillets of wire cards, such as are usually employed in carding engines, and these fillets are divided into two, three, or more spaces extending round the periphery of the cylinder, the object of which division is to separate the sliver into two, three, or more breadths, which are to be conducted to, and wound upon distinct blocks, for making so many separate hats or caps. BAT MANUFACTURE. 997 The principal cylinder of the carding engine is made to revolve by a rigger upon its axle, actuated by a band frai any first mover as usual, and the Subordinate rollers of 748:yliaders belonging to the carding engine, are all turned by pulleys, and bands, and gear, as in the ordinary construction. The wool or other material is supplied to the feeding cloth, and carried through the engine to the doffer cylinder, as in other carding engines; the doffer comb is actuated by a revolving crank in the common way, and by means of it the slivers are taken from the doffer cylinder, and thence received on to the surfaces of the blocks e e. These blocks, of which two only are shown to prevent confusion, are mounted upon axles, supported by suitable bearings in a carriage ff, and are made to revolve by means of a band g g, leading from a pulley on the axle of a conical drum beneath. The band g passes over a pulley h, affixed to the axle of one of the blocks, while another pulley i, upon the same axle, gives motion, by means df a band, to as many other blocks as are V I adaptedt to the machine. As it is necessary, in winding the slivers on to the blocks, to cross them in different 748 diretions, and alsonging to pass the arding engine, are all the hemispherical eulleys, an dsof the blocks, in as in the ordinary construction. order that the wool or other material is supplied to the feeding cloth, d carried through forming the inecap or hood for the doshell or cyfounder, as in ofther carding ended hat, the doffer carriage f, with the blocks, is made to traverse to and fro in lateral directions upon rollers at each end. actuated by alternatevolving motion of the commonarriage is caused by means of it the sliversen in taken from the doffer cylinderg. 7), moving upon a fulcrum n at w, which lever ics attache e. to the carriageks of which two only are, and at the otherend has a weighte od upowhich axles, suppothe side of this tablever agaings in a carriagm wheel o. This cam is made to revolve by means means of a band g g, leading from a pulley on the axle of a conical drum beneathss screw q, and this endless screw taking inpulley h, affixed tothed wheel r, on e aof the blocks, whilcauses the cam to revolve, the same axle, gives motion, by means a band, to a friction rollmany other on the side of adapthe lever, causes the lever to vibrate, and the carriage attached to it, to traverse to As it is necessary, in winding the slivers describon to the blocks, tse meancross them in differs are laid in oblique directions a also to pass the caliver over the hemispherical ends of the blocs, blocks. order that the wool or other formed, or of other irregular figuread over the surfacessary, in orin the cap oslivers wiood for the shell uniform tension, to vary their speed accordit, the carriage with the blocks, is made to traverse to and fro in lateral directions upon rollers at each end. This alternating motion of the carriage is caused by a horizontal lever I1 (seen in the horizontal view fig. 147), moving upon a fulcrum pin at m, which lever is attached to the carriage at one extremity n, and at the other end has a weighted cord which diameter ofraws that partside of this lever areceiving the sliverel o. This cam is made to revolve by means of a band and pulley, which turns the shaft and endless screw q, and this giving diffess scrent velocities taking into a toothe pulley on the axle of the conical drm s, corres the ponding to revolve, there is a similary o which cam running against a friction roller on the side of the lever I, causes the lever to vibrate, and the carriage f f attached to it, to traverse to and fro upon the supporting rollers, as described. By these means the slivers are laid in oblique directions (varying as the carriage traverses), over the surface of the blocks. The blocks being conically formed, or of other irregular figures, it is necessary, ih order to wind the slivers with uniform tension, to vary their speed according to the diameter of that part of the block which is receiving the sliver. This is effected by giving different velocities to the pulley on the axle of the conical drlum s, corresponding with e. There is a similar conical drum t, placed in a reverse position in the lowe 998 HAT MANUFACTURE. part of the frame, which is actuated by a band from any convenien part of the machine passing over a pulley u, upon the axle of t. From the drum t, to the drum s, there is a band v, which is made to slide along the drums by the guidance of two rollers at the end of the lever 1. It will now be seen that when the larger diameter of the cam wheel o forces the lever outwards, the band v will be guided on to the smaller part of the conical drum t and tile larger part of s, consequently the drum s will at this time receive its slowest motion, and the band g will turn the blocks slower also; the reverse end of the lever I having, by the same movement, slidden the carriage into that position which causes the slivers to wind upon the larger diameter of the blocks. When the smaller diameter of the cam is acting against the side of the lever, the weighted cord draws the end of the lever to the opposite side, and the band v will be guided on to the larger part of the cord t, and the smaller part of the cone s; consequently, the quicker movement of the band g will now cause the blocks e e to revolve with a corresponding speed. The carriagef will also be moved upon its rollers, to the reverse side, and the sliver of wool or other material be now wound upon the smaller parts and ends of the blocks, at which time the quicker rotation of the blocks is required. It may be here observed, that the cam wheel o should be differently formed according to the different shaped blocks employed, so as to produce the requisite movements of the lever and carriage suited thereto. It only remains to state, that there are two heavy conical rollers w w, bearing upon the peripheries of the blocks e e, which turn loosely upon their axles by the friction of contact, for the purpose of pressing the slivers of wool or other material on the blocks as it comes from the doffer cylinder of the carding engine, and when the blocks have been coated with a sufficient quantity of the sliver, the smaller end of the pressing rollers is to be raised, while the cap is withdrawn from the block. The process being continued as before, the formation of other bodies or caps is effected in the manner above described. After the caps or bodies of hats, &c. are formed in the above described machine, they are folded in wet cloths, and placed upon heated plates, where they are rolled under pressure, for the purpose of being hardened. Fig. 748 represents the front of three furnaces a a a, the tops of which are covered with iron plates b b b. Upon these plates, which are heated by the furnace below, or by steam, the bodies wrapped in the wet cloths c c c, are placed, and pressed upon by the flaps or covers d d d, sliding upon guide rods, to which flaps a traversing motion is given, by means of chains attached to an alternating bar e e. This bar is moved by'a rotatory crank f, which has its motion by pulleys from any actuating power. When any one of the flaps is turned up to remove the bodies from beneath, the chains hang loosely, and the flap remains stationary. These caps or hat bodies, after having been hardened in the manner above described, may be felted in the usual way by hand, or they are felted in a fulling mill, by the usual process employed for milling cloths, except that the hat bodies are occasionally taken out of the fulling mill, and passed between rollers, for the purpose of rendering the felt more perfect. 749 152 Mr. Carey, of Basford, ob.. ----- -. —] tained a patent in October, 1834, for an invention of certain machinery to be employed in the,- manufacture of hats, which is d i _c""T d d ingenious, and seems to be worthy B av A~ r~of notice in this place. It con. _ fi ='= * i39P A~i _ = ^p-S sists in the adaptation of a sys. E__ $ I a _ _ v tem of rollers, forming a machine) X c i- --- 3 _ c by means of which the operation:p _ _ = _^_r ~ of roughing or plaiting of hats' Ad Sfc~' ~^l j 4'~ ~may be performed; that is, the:,ll^ 7 I |beaver or other fur may be made to attach itself, and work into the felt or hat body, without the necessity of the ordinary manual operations. The accompanying drawings represent the machine in several views, for the purpose of showing the construction of all its parts. Fig. 749 is a front elevation of the machine; fig. 750 is a side elevation of the same; fig. 751 is a longitudinal section of the ma. chine; and fig. 752 is a transverse section; the similar letters indicating the same parts in all the figures. HAT MANUFACTURE. 999 Upon a brick or other suitable base a furnace or fire-place a, is made, having a descendi50 ing flue b, for the purpose of carry ing away the smoke. A pan or shallow vessel c c, formed of lead, _J^ h J|^~l ls.is placed over the furnace; which vessel is intended to contain a sour. i =f a t d liquor, as a solution of vitriolic acid crs=!~~l. ^s /^, } /~ Band water. On the edge of this |- - jc' Tpan is erected a wooden casing d d d, which encloses three sides, I I t I I I > I A leaving the fourth open for the I, I I' I purpose of obtaining access to the'I_|~~ I I' ^ -I-,-! —! ~ working apparatus within. A series of what may be termed lantern rollers, e e e, is mounted on axles turning in the.side casings; and'751 another series of similar lantern rollers, ff f, is in like manner mounted above. These lantern JYV~f fJ l) 3 e,\Tirollers are made tc revolve by means of bevel pinions, fixed on the ends k of their axles, which are turned F^^lR^ ^/k ^J7/ /by similar bevel wheels on the lateeQb^,) /^^I^^ eral shafts g and h, driven by a winch i, and gear, as shown in figs. 749 and 750. d =g _ _-Having prepared the bodies of the hats, and laid upon their sur. J E- _ 6b H faces the usual coatings of beaver,./ I/t / or other fur, when so prepared they are to be placed between hair cloths, and these hair cloths folded within a canvass or other suitable wrapper. Three or more hats being thus enclosed in each wrapper, the packages are severally put into bags or pockets in an endless band of sackzloth, or other suitable material; which endless band is extended over the lantern rollers in the machine. In the first instance, for the purpose of merely attaching the furs to the felts (which is called slicking, when performed by hand), Mr. Carey prefers to pass the endless band k k k, with the covered hat bodies, over the upper series f f f, of the lantern rollers, in ordet to avoid the inconvenience of disturbing the fur, which might occur from subjecting them to immersion in the solution contained in the pan, before the fur had become attached to the bodies. After this operation of slicking has been effected, he distends the endless band k k k, over the lower series of lantern rollers.e e e, and round a carrier roller I, as shown illfig. 151; and having withdrawn the hat bodies for the purpose of examining them, and changing their folds, he packs them again in a similar way in flannel, or other suitable cloths, and introduces them into the pockets or bags of the endless bands, as before. On putting the machinery in rotatory motion in the way described, the hats will be carried along through the apparatus, and subjected to the scalding solution in the pan, as also to the pressure, and to a tortuous action between the ribs of the lantern rollers, as they revolve, which will cause the ends of the fur to work into the felted bodies of the hats, and by that means permanently to attach the nap to the body; an operation which, whela performed by hand, is called rolling off. The improved stiffening for hat bodies proposed by Mr. Blades, under his patent of January, 1828, consists in making his solution of shellac in an alkaline ley, instead of spirits of wine, or pyroxylic spirit, vulgarly called naptha. He -prepares his water-proof stiffening by mixing 18 pounds of shellac with i pounds of salt of tartar (carbonate of potash), and 51 gallons of water. These materials are to be put into a kettle, and made to boil gradually until the lac is dissolved; when the liquor will become as clear as water, without any scum upon the top, and if left to 2ool, will have a thin crust upon its surface of a whitish cast, mixed with the light im-,urities of the gum. When this skin is taken off,the hat body is to be dipped into the mixture in a cold state, so as to absorb as much as possible of it; or it may be applied with a brush or sponge. The hat body, being thus stiffened, may stand till it become dry, or nearly so; and after it has been brushed, it must be immersed in very dilute sulphuric or acetic acid, in ord(- to neutralize the potash, and cause the shellac t9 ____________________________________________________________ 1000 HAT MANUFACTURE. set. If the hats are not to be napped immediately, they may be thrown into a cistern cA pure water, and taken out as wanted. Should the hat bodies have been worked at first with sulphuric acid (as usual), the3 must be soaked in hot water to extract the acid, and dried before the stiffening is applied mare being taken that no water falls upon the stiffened body, before it has been immersed in the acid. This ingenious chemical process has not been, to the best of my knowledge, intro duced into the hat manufacture. A varnish made by dissolving shellac, mastic, sand arach, and other resins in alcohol, or the naptha of wood vinegar, is generally employee as the stiffening and water-proof ingredient of hat bodies. A solution of caoutchouc is often applied to whalebone and horse-hair hat bodies. The following recipe has been prescribed as a good composition for stiffening hats; four parts of shellac, one part of mastic, one half of a part of turpentine, dissolved in five parts of alcohol, by agitation and subsequent repose, without the aid of heat. This stiffening varnish should be applied quickly to the body or foundation with a soft oblong brush, in a dry and rather warm workshop; the hat being previously fitted with its inside turned outwards upon a block. The body must be immediately afterwards taken off, to prevent adhesion. Hat-Dyeing.-The ordinary bath for dyeing hats, employed by the London manufacturers, consists, for 12 dozen, of144 pounds of logwood; 12 pounds of green sulphate of iron, or copixras; 7- pounds of verdigris. The copper is usually made of a semi-cylindrical shape, and should be surrounded with an iron jacket or case, into which steam may be admitted, so as to raise the temperature of the interior bath to 190~ F., but no higher, otherwise the heat is apt to affect tht stiffening varnish, called the gum, with which the body of the hat has been imbued. The logwood having been introduced and digested for some time, the copperas and verdigris are added in successive quantities, and in the above proportions, along with every successive two or three dozens of hats, suspended upon the dipping machine. Each set of hats, after being exposed to the bath wth h occasional airings during 40 minutes, is taken off the pegs, and laid out upon the ground to be more completely blackened by the peroxydizement of the iron with the atmospheric oxygen. In 3 or 4 hours the dyeing is completed. When fully dyed, the hats are well washed in running water. Mr. Buffum states that there are four principal objects accomplished by his patent invention for dyeing hats. 1. in the operation; 2. the production of a better color; 3. the prevention of any of the damages to which hats are liable in the dyeing; 4. the accomplishment of the dyeing process in a much shorter time than by the usual methods, and consequently lessening the injurious effects of the dye-bath upon the texture of the hat. Fig 753 shows one method of constructing the apparatus. a a is a semi-cylindrical 753 754 shaped copper vessel, with flat ends, in which the dyeing process is carried on. b b b is a wheel with several circular rims mounted upon arms, which revolve upon an axle c. [n the face of these rims a number of pegs or blocks are set at nearly equal distances apart, upon each of which pegs or blocks it is intended to place a hat, and as the wheel HAT MANUFACTURE. 1001'evolves, to pass it into and out of the dyeing liquor in the vat or copper. This wheel nay be kept revolving with a very slow motion, either by gear connecting its axle, c. with any moving power, or it may be turned round by hand, at intervals of ten minutes: whereby the hats hung upon the pegs, will be alternately immersed for the space of ten minutes in the dyeing liquor, and then for the same space exposed to the atmospheric air. In this way, the process of dyeing, it is supposed, may be greatly facilitated and improved, as the occasional transition from the dye vat into the air, and from the air again into the bath, will enable the oxygen of the atmosphere to strike the dye more per fectly and expeditiously into the materials of which the hat is composed, than by a continued immersion in the bath for a much longer time. A variation in the mode of performing this process is suggested, and the apparatus fig. 754 is proposed to be employed. a a is a square vat or vessel containing the dyeing liquor; b b is a frame or rack having a number of pegs placed in it for hanging the hats upon, which are about to be dyed, in a manner similar to the wheel above described. This frame or rack is suspended by cords from a crane, and may in that way be lowered down with the hats into the vat, or drawn up and exposed in the air; changes which may be made every 10 or 20 minutes. I have seen apparatus of this kind doing good work in the hat-cq^ing manufactories of London, that being a department of the business with which the Union has not thought it worth their while to interfere. Mr. William Hodge's patent improvements in hat dyeing, partly founded upon an invention of Mr. Bowler, consist, first in causing every alternate frame to which the suspenders or blocks'are to be attached, to slide in and out of grooves, for the purpose 757 755 756 of more easily removing the said suspenders when required. Fig. 755 represents the improved dye0!M i. s ing frame, consisting of two circular rims, a a, which are connected together at top and bottom, by three fixed perpendicular bars or the frame-work b b b. Two other perpendicular frames c c, similar to the former, slide in grooves, d d d d, fixed to the upper and lower rims. These grooves Jll r ---- ~ ----- have anti-friction rollers in them, for the purpose of making the pI 1[ P II Il d!frames c c, to slide in and out more freely. The suspenders or 1 L[ I i [ substitutes for blocks, by these e c!.! - means, may be more easily got at /'e 11 II 1. by drawing out the frames c c, about half way, when the suspend1p I [~! [ ~ 1ers, which are attached to the frames with the hats upon them, 1..r _[ o 1__ I!, a * [ may be easily reached, and either ____ _ a-__________ I removed or altered in position; and. when it is done on one side, the sliding frame may be brought out on the other, and the remaining quantity of "suspenders" undergo the same operation. The patentee remarks, that it is well known to all hat dyers, that after the hats have been in the dyeing liquor some time, they ought to be taken out and exposed to the action of the atmospheric air, when they are again immersed in the copper, that part of the hat which was uppermost in the first immersion, being placed downwards in the second. This is done for the purpose of obtaining a uniform and regular dye. The patentee's mode of carrying this operation into effect, is shown in the figure: e e are pivots for the dyeing-frame to turn upon, which is supported by the arms f, from a crane above. The whole apparatus may be raised up or lowered into the copper by means of the crane or other mechanism. When the dyeing-frame is raised out of the copper, the whole of the suspenders or blocks are reversed, by turning the apparatus over upon the pivots e e, and thus the whole surfaces of the hats are equally acted upon by the dyeing material. It should be observed, that when the dyeing-frame is raised up out of the copper, it should be tilted on one side, so as to make all the liquor run out of the hats, as also tc cause the rims of the hats to hang down, and not stick to the body of the hat, or leave a bad place or uneven dye upon it. The second improvement described by the patentee. is the construction of " suspenders," to be substituted instead of the ordinary blocks. 10C2 HATS. These " suspenders" are composed ot thin plates of copper, bent into the reqairef lbrm, that is, nearly resembling that of a hat block, and made in such a manner as to be capable of contraction and expansion to suit different sized hats, and keep them distended, which may be altered by the workmen at pleasure, when it is required to place the hats upon them, or remove them therefrom. The dyeing-frame at fig. 755 is shown with only two of these " suspenders," in order to prevent confusion. One of these suspenders is represented detached at fig. 756, which exhibits a side view; and fig. 757 a front view of the same. It will be seen by reference to the figure, that the suspenders consist of two distinct parts, which may be enlarged or collapsed by a variety of means, and which means may be suggested by any competent mechanic. The two parts of the suspenders are proposed to be connected together by arms g g, and at the junction of these arms a key is connected for turning them round when required. It will be seen on reference to the front view, fig. 757, that the " suspenders" or substitutes for blocks, are open at the top or crown part of the hat; this is for the purpose of allowing the dyeing liquor to penetrate. From the mixture of copperas and verdigris employed in the hat-dye, a vast quantity of an ochreous muddy precipitate results, amounting to no less than 25 per cent. of the weight of the copperas. This iron mud forms a deposite upon the hats, which not only corrodes the fine filaments of the beaver, but causes both them and the felt stuff to turn speedily of a rusty brown. There is no process in the whole circle of our manufactures so barbarous as that of dyeing stuff hats. No ray of chemical science seems hitherto to have penetrated the dark recesses of their dye shops. Some hatters have tried to remove this corrosive brown ochre by a bath of dilute sulphuric acid, and then counteract the evil effect of the acid upon the black dye by an alkaline bath; but with a most unhappy effect. Hats so treated are most deceptious and unprofitable; as they turn of a dirty brown hue, when exposed for a few weeks to sunshine and air HATs. The body of a beaver hat is made of fine wool and coarse fur mixed and felted together, then stiffened and shaped; the covering consists of a coat of beaver fui felted upon the body. Cheap hats have their bodies made of coarse wool, and their coverings of coarse fur or fine wool. The body or foundation of a good beaver hat, is at present made of 8 parts of rabbit's fur, 3 parts of Saxony wool, and 1 part of lama, ~vicunia, or red wool. About two ounces and a half of the above mixture are sufficient for one hat, and these are placed in the hands of the bower; his tool is a bow or bent ashen staff, from 5 to 7 feet long, having a strong catgut string stretched over a bridge at each end, and suspended at its middle by a cord to the ceiling, so as to hang nearly level with the work-bench, and a small space above it. The wool and coarser fur are laid in their somewhat matted state upon this bench, when the bower, grasping the bent rod with his left hand, and by means of a small wooden catch plucking the string with his right, makes it vibrate smartly against the fibrous substances, so as to disentangle them, toss them up in the air, and curiously arrange themselves in a pretty uniform layer or fleece. A skilful bower is a valuable workman. The bowed materials of one hat are spread out and divided into two portions, each of which is compressed, first with a light wicker frame, and next under a piece of oil cloth or leather, called a hardening skin, till by pressing the hands backward and forward all over the skin, the filaments are linked together by their serrations into a somewhat coherent fleece of a triangular shape. The two halves or " bats" are then formed into a cap; one of them is covered in its middle with a 3-cornered piece of paper, smaller than itself, so that its edges may be folded over the paper, and by overlapping each other a little, form a complete envelope to the paper; the junctions are then partially felted together by rubbing them hard, care being taken to keep the base of the triangle open by means of the paper; the second bat being made to enclose the first by a similar process of folding and friction This double cap, with its enclosed sheet of paper, is next rolled up in a damp cloth and kneaded with the hands in every direction, during which it is unfolded and creased up again in different forms, whereby the two layers get thoroughly incorporated into one body; thus, on withdrawing the paper, a hollow cone is obtained. The above operations have been partially described in the body of the Dictionary, and the remaining steps in making a hat are there sufficiently detailed. In a great hat factory women are employed, at respectable wages, in plucking the beaver skins, cropping off the fur, sorting various qualities of wool, plucking and cutting rabbit's fur, shearing the nap of the blocked hat, picking out unseemly filaments of fur, and in trimming the hats; that is, lining and binding them. The annual value of the hats manufactured at present in the United Kingdom is estimated at 3,000,0001. sterling. The quantity exported in 1840, was 22,522 dozens, valued at 81,5831. With regard to the stiffening of hats, I have been furnished oy a skilful operator with the following valuable information: "All the solutions of gums which I have hitherto acen prepared by hatters, have not been perfect, but, in a certain degree, a mixture, more or less, of the gums, which are merely suspended, owing to the consistency of the corm position, When this is thinned by the addition of spirit, and allowed to stand, it lets HEAT-REGULATOR. 1003 fall a curdy-looking sediment, and to this circumstance may be ascribed the frequent breaking of hats. My method of proceeding is, first to dissolve the gums by agitation in twice the due quantity of spirits, whether of wood or wine, and then, after complete solution, draw off one-half the spirit in a still, so as to bring the stiffening to a propel consistency. No sediment subsequently appears on diluting this solution, however much it may be done. "Both the spirit and alkali stiffenings for hats made by the following two recipes, have been tried by some of the first houses in the trade, and have been much approved of:Spirit Stiffening. 7 pounds of orange shellac. 2 pounds of gum sandarac. 4 ounces of gum mastic. Half a pound of amber rosin. 1 pint of solution of copal. 1 gallon of spirit of wine or wood naphtha. "The shellac, sandarac, mastic, rosin, are dissolved in the spirit, and the solution of copal is added last. Alkali Stiffening. 7 pounds of common block shellac. 1 pound of amber rosin. 4 ounces of gum thus. 4 ounces of gum mastic. 6 ounces of borax. Half a pint of solution of copal. "The borax is first dissolved in a little warm water (say 1 gallon); this alkaline liquor is now put into a copper pan (heated by steam), together with the shellac, rosin, thus, and mastic, and allowed to boil for some time, more warm water being added occasionally until it is of a proper consistence; this may be known by pouring a little on a cold slab somewhat inclined, and if the liquor runs off at the lower end, it is sufficiently fluid; if, on the contrary, it set before it reaches the bottom, it requires more water. When the whole of the gums seem dissolved, half a pint of wood naphtha must be introduced, and the solution of copal; then the liquor must be passed through a fine sieve, and it will be perfectly clear and ready for use. This stiffening is used hot. The hat bodies, before they are stiffened, should be steeped in a weak solution of soda in water, to destroy any acid that may have been left in them (as sulphuric acid is used in the making of the bodies). If this is not attended to, should the hat body contain any acid when it is dipped into the stiffening, the alkali is neutralized, and the gums consequently precipitated. After the body has been steeped in the alkaline solution, it must be perfectly dried in the stove before the stiffening is applied; when stiffened and stoved it must be steeped all night in water, to which a small quantity of sulphuric acid has been added; this sets the stiffening in the hat body, and finishes the process. A good workman will stiffen 15 or 16 dozen hats a day. If the proof is required cheaper, more shellac and rosin must be introduced." HEALDS, is the harness for guiding the warp threads in a loom; that is, for lifting a certain number of them alternately to open the shed, and afford passage to the decussating weft threads of the shuttle. See WEAVING. HEARTH; (Foyer, Fr.; Heerde, Germ.) is the flat or hollow space in a smelting fur. nace upon which the ore and fluxes are subjected to the influence of flame. See COPPER, IRON, METALLURGY, &C. HEAT, is that power or essence called caloric, the discussion of whose habitudes with the different kinds of matter belongs to the science of chemistry. HEAT-REGULATOR. The name given by M. Bonnemain to an ingenious apparatus for regulating the temperature of his incubating stove rooms. See INCUBATION, ARTIFICIAL, for the manner of applying the Heat-Regulator. The construction of the regulator is founded upon the unequal dilatations of different metals by the same degree of heat. A rod of iron x, fig. 758., is tapped at its lower end into a brass nut y, enclosed in a leaded box or tube, terminated above by a brass collet z. This tube is plunged into the water of the boiler, alongside of the smoke-pipe. (Fig. 759. is a bird's-eye view of the dial, &c.) The expansion of the lead being more than the iron for a like degree of temperature, and the rod enclosed within the tube being less easily warmed, whenever the heat rises to the desired pitch, the elongation of the tube puts the collet z in contact with the heel a. of the bent level 1004 HEAVY-SPAR. 758, a, b, d; thence the slightest increase of heat lengthens the tube anew -or5 ae A=^ ^ J Wand the collet lifting the heel of * idE7 the lever, depresses the other end?'I~~::a:59 d through a much greater space, I.q~,~ 1 ~ ~on account of the relative lengths of its legs. This movement operates near the axis of a balance-bar e, sinks one end of this, and there-r by increases the extent of the move-,~J ~ i ~~ment which is transmitted directly iv to the iron skewer v. This pushing down a swing register diminishes or cuts off the access of air to the fire-place. The combustion is thereby obstructed, and the temperature falling by degrees, the tube shrinks and disengages the heel of the lever. The counterpoise g, fixed at the balance-beam e, raises the other extremity of this beam by raising the end d of the lever as much as is necessary to make the heel bear upon the collet of the tube. The swing register acted upon by this means, presents a greater section to the passage of the air; whence the combustion is increased. To counternalance the effect of atmospheric changes, the iron stem which supports the regulator is terminated by a dial disc, round the shaft of the needle above h,fig. 759.; on turning this needle, the stem below it turns, as well as a screw at its under end, which raises or lowers the leaden tube. In the first case, the heel falls, and opens the swing register, whence a higher temperature is required to shut it, by the expansion of the tube. We may thus obtain a regularly higher temperature. If, on the contrary, we raise the tube by turning the needle in the other direction, the register presents a smaller opening, and shuts at a lower temperature; in this case, we obtain a regularly lower temperature. It is therefore easy, says M. Bonnemain, to determine d priori the degree of temperatur'e to be given to the water circulating in the stove pipes. In order to facilitate the regulation of the apparatus, he graduated the disc dial, and inscribed upon its top and bottom, the words, Strong and Weak heat. See THERMOSTAT, for another HEAT-REGULATOR. HEAVY-SPAR, sulphate of Baryta, or Cawk; (Spath pesant, Fr.; Schwerspath, Germ.) is an abundant mineral, which accompanies veins of lead, silver, mercury, &c., but is often found, also, in large masses. Its colour is usually white, or flesh coloured. It occurs in many crystalline forms, of which the cleavage is a right rhomboidal prism. It is met with also of a fibrous, radiated, and granular structure. Its spec. grav. varies from 4-1 to 4-6. It has a strong lustre, between the fatty and the vitreous. It melts at 35~ Wedgw. into a white opaque enamel. Its constituents are 65-63 baryta, and 34'37 sulphuric acid. It is decomposed by calcination in contact with charcoal at a white heat, into a sulphuret of baryta; from which all the baryta salts may be readily formed. Its chief employment in commerce is for adulterating white lead; a purpose which it readily serves on account of its density. Its presence here is easily detected by dilute nitric acid, which dissolves the carbonate of lead, and leaves the heavy spar. It is also a useful ingredient in some kinds of pottery, and glass. HECKLE; (Seran, Fr.; Rechel, Germ.) is an implement for dissevering the filaments of flax, and laying them in parallel stricks or tresses. See FLAX. HELIOGRAPHY may be regarded as the appropriate title of the new and elegant art of making sun pictures; an art which originated with Niepce and Daguerre, and which has been much improved by Mr. Fox Talbot. See the articles CALOTYrE and DAGUERREOTYPE. It has been called photography, being a picture produced by the action of light; but as the sunbeams are essential to a good result, I have called it Heliography. Iodide of silver is the principal agent applied to paper, to make it very sensible to the impressions of the sunbeam. The bromide has also been used, and preferably in mixture. Le Gray in his new treatise of photography, lately published, recommends a mixture of the Iodide, cyanide and fluoride, as the excitable fluid; this compound being used in union with potassium. The paper thus impregnated, is laid on the aceto-nitrate of silver, and then exposed to the light. A picture may thus be obtained in the focus of the camera obscura in 30 seconds in fine weather; a circumstance of great consequence in taking living portraits, on account of the mobility of the human countenance. Waxed paper applied dry possesses a like sensibility. One of the main difficulties in heliography lies in the choice of the paper. The post paper of Whatman of London, is preferred for the preliminary trials, when it is slightly glazed. Thin paper is better for portraiture, and thick for landscapes. Well sized paper.s to be preferred, and of equal texture. The first step in preparing the paper, is to fill up all its pores with fine white-wax HELIOGRAPHY. 1006 and thui give it the aspect of parchment. Provide a large plate of silver-plated, as for the daguerreotype process, place it on a tripod horizontally, heat it by passing the flame of a spirit of wine lamp to and fro under it, or rather set it over a water bath, while with the other hand a piece of white wax is rubbed over it. The coat of wax being equally fused, lay the paper upon it, and cause it to apply evenly by putting a card on it. It is then to be removed, and laid between two or three folds of blotting paper, and gently pressed over with a hot smoothing iron, to remove the excess of wax. It is indispensable that no wax remain on the surface, but only in the texture of the paper; which should have no glistening spot, and be perfectly transparent. Thin paper should be preferred for waxing. Well prepared paper should allow the proof of the picture to develop itself in the gallic acid for a considerable time, without spotting either the proof or the acid. Its principal quality is, to permit the aceto-nitrate of silver to be prepared beforeLand, and thus have a store of ready waxed paper. This preparation affords very intense blacks upon thin papers. The bath of iodide of potassium completely penetrates the wax, and deprives it of its greasy aspect, by a sort of decomposition, which causes the subsequent preparations to apply uniformly. This paper should be left from half an hour to an hour, in the solution of th6 iodide, according to the thickness of the paper; to ensure the decomposition of the wax, care must be taken to keep the waxed paper cool. The iodized paper assumes a violet tint when completely dry. This hue, resulting from the union of the wax with the iodine, is beneficial, because it affords sufficient time to leave the paper on the acetonitrate of silver, till the violet tint disappears. The preparations that follow may be applied to either the waxed or plain paper; but in the latter case, the paper should be somewhat thick. First Preparation.-Negative Paper.-Boil in a porcelain or earthen pan, 3 litres of distilled water, with 250 grammes of rice, till this merely bursts, lest the water becomes too glutinous. Strain through calico. This forms an excellent size, and affords a good body and fine blacks. In a litre of the above rice water, dissolve 40 grammes of sugar of milk; 15 of iodide of potassium; 80 centigrammes of cyanide of potassium, and 50 centigrammes of fluoride of potassium. Filter the solution, and set aside for use in a bottle. To prepare the paper, pour this solution into a large plate, and plunge the waxed paper into it, leaf by leaf over each other, taking care to expel the air bubbles. Take them.out, return them for about half an hour; then hang them up to dry, by means of a bent pin hooked to the corner; and favour their drainage by placing a bit of blotting paper on their lower point. This' process is to be repeated. French and English papers should not be mixed in the same cistern. The English paper is said to contain a free acid, which precipitates iodide of starch in the French paper, and gives it a deep violet tint. The paper is to be cut down to the size of the camera obscura, and put up for use in a portefeuille. The liquid which has been used will serve again. The paper thus prepared, is called iodized. Paper spceiallyfor Portraiture-is prepared as follows. Take 400 grammes of distilled water, 20 of iodide of potassium, 2 of cyanide of potassium, 0-50 centigrammes of fluoride of potassium;-dissolve. Pour 2 or 3 millimetres of this solution into a flat plate of porcelain, or on a flat glass, quite horizontal. Take a piece of glazed paper by the two corners, the rough side uppermost, and apply the smooth face upon the liquid in the plate; beginning the immersion with the side next your body, and pushing the leaf before you, so that it may always fall at right angles upon the liquid. This movement is to be repeated two or three times, so as to press out any air bubbles. Take care that the liquid does not pass to the other side of the paper. It is to remain on the bath not more than two minutes at most. It is then to be lifted and perfectly dried between folds of blotting paper, of a fine tissue, rubbing it in all directions with the hands, and changing Ets place, that it may be perfectly dry. Remove the paper and smooth it with a soft brush. Lay the same side upon the bath of aceto-nitrate of silver (about to be indicated); leaving it there not more than 8 or 10 seconds at most, and then place it upon the slate in the camera, (which has been previously furnished with a leaf of blotting paper well soaked in water, as will be described further on. It is requisite to make immediate use oi this paper, because its great sensibility depends chiefly on the nascent state of the iodide of silver that it operates upon. In summer, from 4 to 10 seconds are required for an impression; in winter, from 18 to 40. The second operation is to give sensibility to the iodized papers, either in the dry or humid way. Take of Distilled water - - - - 150 grammes Crystallized nitrate of silver - - 5 When this is dissolved, add of crystallizable acetic acid 12 grammes. Care must be taken to prepare this solution by the light of a feeble taper, and to surround the phial with a case of blackened paper. No more of this mixture should be put into the caplii. 1006 HELIOGRAPHY. eule than is sufficient for once. If not to be kept more than 4 days upon the paper, the following mixture may be used: Distilled water - - - 150 grammes Acetate of silver - - - 10 " Crystallizable acetic acid - - - 2 " For the humid operation the paper may preferably be employed moist. At the moment of commencing, pour one of those mixtures of aceto-nitrate of silver upon a plate of porcelain or glass, quite horizontal, to about one millimetre in depth. A pipette or small sucking glass tube is convenient for this purpose, as its fine point prevents any drops from being spilled irregularly. And the surface of the liquid may be skimmed if necessary with a piece of white paper. The leaf of iodized paper is now to be seized by the two corners on the side only which was iodized, and to be laid down and raised several times so as to expel the air. This may be done with the thumb by the help of a pallet ivory knife to save staining the fingers. Take care that none of the nitro-acetate of silver goes on the other side of the paper. Allow the paper to receive the chemical action till the formation of a very sensible layer of cyano-iodo-fluoride of silver. Five minutes may suffice for the French paper, and a little longer for the English; both being imbued with the sugar of milk preparations. Time should be given for the violet hue to disappear,4 or 5 minutes; but with the portrait paper, 9 or 10 seconds should be sufficient. The longer this interval the less is the sensibility. Apply the paper quite moist upon a slate, on which there has been previously spread to receive it, a well soaked leaf of unsized paper. The sole of the camera may also be made use of, if it has been well covered with a coat of white wax. But the slate is preferable; care being had to lay the surface with the aceto-nitrate uppermost to receive the radiations of light. The undermost piece of paper should be free from iron stains. The slate should be marked so as to be preserved always in one posture, both when they are applied and when put up in the frame. If these precautions be neglected, the liquid collects below and falls upon the prepared paper, and may cause spots. The paper, when thus put on the slate, may be left there for three or four hours without being removed, and may be placed during this interval in the camera. On going a little way off to take a proof, the fold of the leaf may be dipped in thick mucilage of gum-arabic, which serves to preserve the moisture and the adhesion. Two panes of glass may also be used for laying the papers between; not sparing blotting paper in cleaning them. In the dry way, waxed paper is to be used. It will require more time to develop the image with the gallic acid; but this comes out equally well, only there will be a pretty strong contrast between the whites and the blacks. The aceto-gallic acid, and the acetonitric, which are added should be fresh, extremely pure, and well filtered. Two porcelain basins of some depth are to be taken; into the first put from 5 to 6 millimetres of acetonitric acid (noted above) and into the second put distilled water. Plunge completely on the two sides the waxed and iodized paper, into the bath of the aceto-nitrate of silver of the first cistern, and leave it there 4 or 5 minutes, then transfer it immediately into the bath of distilled water in the second cistern, and leave it at least 4 minutes or more if you wish to keep the paper some time before using it. You may prepare next in the same baths, ten leaves one after the other. Lastly, the paper is to be taken from the water to be dried between folds of blotting paper, and laid by in a blotting-book equally dry. The paper is not to be dried by suspension in the air. Kept in the dark the paper will thus keep its qualities fully 5 days, before going into the camera. The aceto-nitrate of silver deteriorates after 8 days. It is good not to put at once more than one or two proofs into the same bath of gallic acid. The period of exposure in the camera is not longer in the dry than in the humid way, but the proof must stand a little longer in the gallic acid, which may have 15 or 20 drops added to it of the nitro-acetate of silver filtered, and fresh made, or not previously used. The granular and soiled look of the paper under the gallic acid when it becomes dry, should give no concern, as it disappears completely on re-melting the wax, of the proof on the exposure of its negative to a suitable heat. This precaution should never be neglected, for it is superior to any varnish. These operations being finished, invert the aceto-nitrate of silver into a phial, but don't reserve any for fresh proofs, which would prove a constant cause of failures. It may be thrown down by common salt, in the state of chloride of silver, which serves to give to hyposulphite of soda, the quality necessary for producing fine tones. The aceto-nitrate may be decoloured and revived by means of bone black, with which it is to be boiled a short time and then filtered. Third Operation: Exposure in the Camera.-Place the point of the image in the depolished glass most scrupulously in the middle of the lens. After the exposure to the luminous rays the image in the camera has little appearance, being developed only by HELIOGRAPHY. 1001 the subsequent operation, which may be performed some hours afterwards, on the moist paper, or even some days with the waxed paper in the dry state. Development of the Image.-This is effected by the gallic acid diluted with pure water, in the proportion of 1 litre of the latter and 4 grammes of the former. Pour out of this solution into a horizontal flat shallow plate, to the thickness of 3 or 4 millimetres. Plunge the proof completely into it, so that jt may be covered all round. Watch its development, which is readily perceived across the thickness of the paper. It may be left here from 10 minutes for an hour or two, till it be arrived at perfection. The development is much quickened by adding 20 or 21 drops of aceto-nitrate of silver, when the image begins to appear. Very intense blacks are thus obtained, but the action must then be followed up, because it is rapid, and it gives such intense blacks, as to be disagreeable if the time be prolonged. When it is sufficiently deep, withdraw it smartly, and pour several streams of water over it, upon a plate or dish, rubbing the back of the paper at the same time with a finger to remove any crystalline grains which might spoil it. The gray hue of the waxed paper need cause no alarm as it disappears, and leaves beautiful whites and blacks. The tone which the image takes from the gallic acid will enable you to judge whether the exposure to the light has been adequate. If it becomes immediately of a gray black everywhere (looked well through), it shows it to have been too long under the light. If the greatest lights, which should be the greatest blacks of the negative, do not become deeper than the semi-tints, the exposure has also been too long. A first proof serves to regulate the time of exposure in the camera for the rest. Its period may be shortened by warming the gallic acid, for which a little appa ratus has been used, consisting of a little square copper basin filled with water, supported over a small spirit lamp, which communicates heat to the shallow dish containing the gallic acid, &c. The picture taken as above described will not be permanent. It must be fixed by the Fifth Operation, or that of the Negative Proof.-Dissolve in a bottle 100 grammes of hyposulphite of soda in 800 grammes of filtered water. Put the solution into a basin to the depth of half a centimetre, and plunge the negative proof completely in it, taking care to free it from air bubbles. The hyposulphite takes possession of the cyano-iodofluoride of silver, and the proof remains clear; but it does not affect the gallate of silver, which on the contrary continues black. Never put more than one proof at a time in this bath; but you may put several proofs in it one after the other. The hyposulphite of soda which has been already used is to be collected, and when kept, lets fall flocks of gallate of iron and sulphuret of silver. When filtered it serves well for fixing weak proofs. On examining the proof after it has remained some time in the bath, we might be tempted to believe that it has lost its strength from its transparency, because the iodide of silver, which has a straw yellow tint, being completely removed from its place and resting at other spots, annihilates the image in appearance. But if we consider that the whole iodide of silver is removed, as is recognized when the yellow tint of the proof is also gone-one becomes astonished at the whiteness and the transparency of the paper; as well as the beauty of the blacks of the image. For these effects it requires from half an hour to three quarters of an hour with the ordinary papers. An abode of too much length in the bath weakens the blocks of the proof; and, therefore, this process should be looked after. With waxed papers, from 10 to 15 minutes are sufficient for fixing. The proof is to be next washed with several waters, and left to drain off its hyposulphite into a basin for the space of half an hour. It is then dried by hanging it up by a corner; and is now inalterable at the light, since there does not remain any more in the paper than the black gallate of iron. Sixth Operation: Waxing of the Negative Proof.-When the negative proof is weak and the paper very transparent, counterproofs should be made with it without waxing. The proofs obtained from paper previously waxed should not be waxed anew, but only approached near the fire to restore their transparency, which they had lost by their successive baths. Before this operation they have a granular aspect. The negative proof should be waxed, which counteracts the ill effect of any of the nitrate of silver remaining on the surface of the positive paper. The waxing of the negative proof is done by melting with a spirit lamp a layer of white wax on a piece of plated copper like that of a daguerreotype, laying the negative upon it, and promoting its adhesion by the weight of a card. When it is equally soaked, place it between folds of smooth writing paper, and glide a hot smoothing iron over all to remove the excess of wax. The iron should not be too hot. Seventh Preparation; that of Positive Paper.-Saturate a bottle of water with sea salt. Dilute 1 part of this solution with 3 parts of water. Put into a plate this brine to the depth of 4 or 5 millimetres. Into another bottle put of distilled water 100 grammes; crystallized nitrate of silver 20 grammes. Dissolve. Of which pour out into a plate to the above thickness. 1008 HELIOGRAPHY. Take stout paper weighing about 15 kilogrammes the ream, previously cut of a suita ble size, and free from iron stains or any impurities. Mark a cross on the side of the paper which bears the metallic mark of the manufacturer. Le Gray says the Englisb paper should not be used unless a red tone be wanted in the pictures. Place the papel upon a plate of porcelain or glass moistened (as formerly directed) with the dilute brine, and leave it there from 2 to 4 minutes; dry it between folds of pink blotting paper rubbing it at the same time with the hand. Prepare thus 3 leaves before beginning, to put them in the bath of nitrate of silver, in order that all traces of humidity may be removed. Take the dried leaves and clear them by a somewhat hard flat brush from all particles of salt or other impurities. Put a leaf of the pink blotting paper upon the nitrate of silver of the salted side only, and leave it there the time requisite to prepare another leaf upon the salt. By leaving it for a little on the nitrate of silver, red tones are obtained; but, by leaving it longer, blacker tones. The paper is then to be dried, hanging it up by a corner; but all must be done by candlelight. The positive paper should be very dry before laying a negative upon it, for fear of staining t with nitrate of silver. On this account it is good to dry it well tie previous night, but not too many days beforehand, lest the silver should darken. Eighth Operation: Taking the Positive Proof.-Put the negative upon one of the glasses of the frame of reproduction, lay above it a leaf of glazed paper, then one of positive paper prepared by the preceding operation, the side of the preparation upon the place of the negative, then lay above it a leaf of black paper, and the second glass of the frame. Shut the cover of the frame, which will exert a slight pressure upon the glasses, and secure their contact. A sheet of transparent and waxed paper, or a piece of papier glace in gelatine, should be placed between the negative proof and the leaf of the positive paper. This does not hurt the nicety of the proof, and preserves the negative from contact with the nitrate of silver,,which would spoil it. It is proper to allow one of the sides of the positive paper to overlap on the side of the negative, in order to judge of the action of the light. Expose the frame to the solar or diffuse light, so that the rays fall vertically upon the surface of the proof. Trace the progress of the proof by the tone of the folded over-part of the paper, as per the following gradations of tint: Gray blue, neutral tint, violet blue, black blue, black, bistre, coloured sepia, yellowish sepia, dead leaf colour, greenish-gray; always wearing away, till the oxide of silver be at last reduced to the state of a metallic oxide. It is proper to stop at some one of these tones, accordto the greater or less vigour of the negative, and the depth of the proof that is desired. Once we have obtained a proof with a negative, we may be sure when we stop at the same tint of the overlapping edge, we shall have the same result. To have a proof of a black tint, for example, after the fixing of the hyposulphite, the deep parts should have the tone of sepia, and the parts which should form the whites, have a blue-gray, on withdrawing it from beneath the frame, in order to repair the loss of tone given by the hyposulphite. The precise time of the exposure to the light cannot, therefore, be fixed, and is subordinate to the intensity both of the negative, and also of the proof which is desired. Ninth and last Operation: Fixing of the Positive Proof.-This proof would not be permanent without being immediately fixed by the following process: Dissolve in a bottle 100 grammes of hyposulphite of soda, with 600 of filtered water; and in another bottle dissolve 5 grammes of nitrate of silver in a couple of glasses of water, and add a solution of common salt, till no more white precipitate falls. After letting it settle to the bottom of the vessel, collect the chloride of silver in a piece of calico, and put it into the preceding solution of the hyposulphite. Thus, black tones may be obtained with this new hyposulphite. The older this hyposulphite is the better. When it becomes turbid, a little more fresh solution need only be added to it. We must also beware of filtering it to remove the black deposit which is formed; we have only to let it remain at rest in a large bottle, and decant the clear liquor for use, so as not to lose the black deposit, and to redissolve it by means of fresh hyposulphite. By means of a stay shorter or longer in this bath, almost all the tones ma, be obtained from the red to the black, and the pale yellow; so that, with a little practice, any desired tint may be secured. The proof should be left in the bath at least an hour to be sufficiently fixed; and it may remain in it from 3 to 4 hours to bring out the sepia anc the yellow tones. By heating the hyposulphite, we may quicken the operation, but we must not leave the proof an instant to itself, because the action is rapid, and the picture might become effaced. In this case it is good to add a little acetic acid to the hyposulphite, in order to preserve the whites. On adding to the preceding solution of the hyposulphite 25 grammes of ammonia. very pretty bistre tones are obtained along with very pure whites. English paper suits these effects very well. Very fine velvety tones are obta ined by putting the proof (on taking out of the hyposulphite) upon a bath of salt of gold (1 gramme of the salt into a litre ol water), sharpened with 5 grammes of nitro-muriatic acid. *~~~~~~ ~ -: -', ___I —---- HEPAR. 1009 Very fine yellow tones have been obtained by putting a proof pretty strong at first into the hyposulphite, then into a bath composed of a litre of water, and 50 grammes of hydrochloric acid; finally rinsing it with water. Water of ammonia used in the same dose, without putting the proof previously in the hyposulphite of soda, gives also remarkable tones. When the proof is of the desired tone, wash it with several waters, and leave it two or three hours in a basin, taking it out only when the proof has no longer a sweet taste on the tongue, characteristic of the hyposulphite of silver. It is to be then dried by hanging by a corner; when it is finished. The hyposulphite bath may contain as many proofs as we please at a time. But great care must be taken to entangle no air bubbles among the leaves, which would produce indelible black spots. A longhaired pencil is useful for clearing away these bubbles. The taking of the positive proofs requires all the attention of a skilful operator, and it must not be disregarded. It is necessary to calculate rightly the shade of a proof with the subject, and the effect wished to be produced.. A superior fine proof should be put by itself in the hyposulphite of soda. Heliographs or Photographs have been recently taken of extreme accuracy and fineness of delineation, upon glass coated with albumen, by the following recipe:-Put the whites of ten eggs into a large basin; dissolve in them, by beating them with a box-wood fork, 4 grammes of iodide of potassium; - gramme of bromide of ammonia, and as much chloride of sodium. Reduce it to a white thick froth, leave it to settle for a night, and next morning decant the viscid liquor which has fallen, and keep it for use. This glairy compound is best when applied to depolished glass. A film of collodium on glass is now preferred. For the remaining minute precautions and directions, I refer to the publication of M. Le Grey, entitled Nouveau Traite Theorique et Pratique de Photographie. HELIOTROPE; is a variety of jasper, mixed with chlorite, green earth, and diallage; occasionally marked with blood-red points; whence its vulgar name of blood-stone. HEMATINE; is the name given by its discoverer Chevreul to a crystalline substance, of a pale pink colour, and brilliant lustre when viewed in a lens, which he extracted from logwood, the hcematoxylon Campechianum of botanists. It is, in fact, the characteristic principle of this dye-wood. To procure hematine, digest during a few hours ground logwood in water heated to a temperature of about 130~ Fahr.; filter the liquor, evaporate it to dryness by a steam bath, and put the extract in alcohol of 0-835 for a day. Then filter anew, and after having inspissated the alcoholic solution by evaporation, pour into it a little water, evaporate gently again, and then leave it to itself in a cool place: In this way a considerable quantity of crystals of hematine will be obtained, which may be readily purified by washing with alcohol and drying. When subjected to dry distillation in a retort, hematine affords all the usual products of vegetable bodies, along with a little ammonia; which proves the presence of azote. Boiling water dissolves it abundantly, and assumes an orange-red colour, which passes into yellow by cooling, but becomes red again with heat. Sulphurous acid destroys the colour of solution of hematine. Potash and ammonia convert into a dark purple-red tint, the pale solution of hematine; when these alkalis are added in large quantity, they make the colour, violet blue, then brown-red, and lastly brown-yellow. By this time the hematine has become decomposed, and cannot be restored to its pristine state by neutralizing the alkalis with acids. The waters of baryta, strontia, and lime exercise an analogous power of decomposition; but they eventually precipitate the changed colouring matter. A red solution of hematine subjected to a current of sulphuretted hydrogen becomes yellow; but it resumes its original hue when the sulphuretted hydrogen is removed by a little potash. The protoxide of lead, the protoxide of tin, the hydrate of peroxide of iron, the hydrate of oxides of copper and nickel, oxide of bismuth, combine with hematine, and colour it blue with more or less of a violet cast. Hematine precipitates glue from its solution in reddish flocks. This substance has not hitherto been employed in its pure state; but as it constitutes the active principle of logwood, it enters as an ingredient into all the colours made with that dye stuff. These colours are principally violet and black. Chevreul has proposed hematine as an excellent test of acidity. IHMATITE; (Fer Oligiste, Fr.; Rotheisenstein, Germ.) is a native reddish-brown peroxide of iron, consisting of oxygen 30-66; iron 60-34. It is the kidney ore of Cumberland which is smelted at Ulverstone with charcoal, into excellent steel iron. HEMP; (Chanvre, Fr.; Hanf, Germ.) is the fibrous rind of the bark of the cannabis sativa, which is spun into strands or yarn for making rope, sail-cloth, &c. It is prepared for spinning in the same way as flax, which see. Hemp-seed contains an oil which is employed for making soft soap, for painting, and for burning in lamps. See OILS. The importation of undressed hemp for tome consumption in 1851 and 1852, was respectively 1,048,635 cwts. and 1,293,412 cwts. HEPAR; which signifies liver in Latin, was a name given by the older chemists to 11 = = == == = ^ 1010 HOMBOURG MINERAL WATERS. some of those compounds of sulphur with the metals which had a liver-brown colour Thus the sulphuret of potassium was called liver of sulphur. HEPATIC AIR; sulphuretted hydrogen gas. HERMETICAL SEAL, is an expression derived from Hermes, the fabulous parent of Egyptian chemistry, to designate the perfect closure of a hollow vessel, by the cementing or melting of the lips of its orifice; as in the case of a glass thermometer, or matrass. HIDE; (Peau, Fr.; Haut, Germ.) the strong skin of an ox, horse, or other large animal. See LEATHER. Imports. Exports. 1851. 1852. 1851. 1852. Untanned, dry - - cwts. 150,575 187,091 83,799 113,727 wet - cwts. 441,346 485,076 29,779 43,200 Tanned, tawed, curried or dressed (except Russia hides) - - lbs. 1,876,557 2,275,107 105,924 79,817 HIRCINE; from hircus, a ram; is the name given by Chevreul to a liquid fatty substance, which is mixed with the oleine of mutton suet, and gives it its peculiar rank smell. Hircine is much more soluble in alcohol than oleine. It produces hircic acid by saponification. HOG'S LARD; see FATS. HOLLOW FOUNDING. Candlesticks are cast in sand and made hollow, by the introduction into the mould of what is called a "core," viz., a piece of sand corresponding in size to the hollow of the pillar. Upon his skill in making this in such a manner as to produce uniform thickness of metal throughout, depends the success of the workman; the metal must also be of a proper temperature, or the casting is rendered useless by the presence of flaws. Candlesticks are finished by being turned and polished by friction, when in a state of motion in the lathe; the bottoms, when round, are also turned; when square, they are filed and polished. The composition of metal in this case is copper and zinc, in the proportion of 10 ounces of the former to 8 ounces of the latter. HOMBOUR(G; MINERAL WATERS OF. The city of Hombourg near Frankfort, is situated at the bottom and to the east of the mountains of Taunus, 600 ft. above the level of the sea, in a picturesque position. The Elizabeth spring consists by Liebig's analysis in 16 ozs. ofGrains. Chlor. sodium. - - 79'1547 Sulphate of soda - 0-3809 Chlor. calcium - - - 7-7568 Chlor. magnesium - - - -'7670 Silica -..... 0-3157 Carbonate of lime - - - 10-9824 Do. of magnesia... 2-0111 Proto-carbonate of iron - - 0-4608 Free carbonic acid. - -. 21-4808 130-3102 THE BATH SPRING. Contains for 16 oz. of water, 22-728 cubic in. of carbonic acid combined withGrains. Sulphate of lime - - - - - 0-212 Chlor. calcium - -. 15-285 Brom. magnesium - - - 0-002 Chlor. do. -. 5-904 Chlor. potassium - - - - 0-384 Do. sodium..... 108-392 Silica -. - 0-164 Proto-carbonate of iron - -. 0-480 Alumina - - -. - - 0-054 Carbonate of lime - - - 9-698 Do. magnesia - - 2-485 143.060 HOP. 1011 To this water are added occasionally some of the salt springs of Bingen, which contain considerable quantities of the compounds of bromine and iodine. Mother Water, is the name given to the clear liquor which remains in the boiler, when, after evaporating the water, the common salt has been crystallized and separated. This residuum is greasy to the touch, but a little thinner than oil, and when applied to the skin covers it with small scales, as if it had been washed with chlor-calcium. Iodine and bromine exist in it, and are supposed to give it efficacy against scrofulous and chronic diseases. HONEY; (Mel, Fr.; Honig, Germ.) is a sweet viscid liquor, elaborated by bees from.he sweet juices of the nectaries of flowers, and deposited by them in the waxen cells of their combs. Virgin honey is that which spontaneously flows with a very gentle heat from the comb, and common honey is that which is procured by the joint agency of pressure and heat. The former is whitish or pale yellow, of a granular texture, a fragrant smell, and a sweet slightly pungent taste; the latter is darker coloured, thicker, and not so agreeable either in taste or smell. Honey would seem to be simply collected by the bees, for it consists of merely the vegetable products; Such as the sugars of grape, gum, and manna; along with mucilage, extractive matter, a little wax and acid. HONEY-STONE; (Mellite, Fr.; Honigstein, Germ.) is a mineral of a yellowish or reddish colour, and a resinous aspect, crystallizing in octahedrons with a square base; specific gravity 1-58. It is harder than gypsum, but not so hard as calc-spar; it is deeply scratched by a steel point; very brittle; affords water by calcination; blackens, then burns at the flame of the blowpipe, and leaves a white residuum which becomes blue, when it is calcined after having been moistened with a drop of nitrate of cobalt. It is a mellate of alumina, and consists of: Klaproth. Wohler. Mellitic acid - - 46 44-4 Alumina.- 16 14-5 Water -. -- 81 41-1 100' 100-0 The honey-stone, like amber, belongs to the geological formation of lignite. It has been hitherto found clearly in only one locality, at Artern in Thuringia. HOP; (Houblon, Fr.; Hopfen, Germ.) is the name of a well-known plant of the natural family of Urticete, and of the dicecia pentandria of Linnaeus. The female flowers, placed upon different plants from the male, grow in ovoid cones formed of oval leafy scales, concave, imbricated, containing eaclh at the base an ovary furnished with two tubular open styles, and sharp pointed stigmata. The fruit of the hop is a small rounded seed, slightly compressed, brownish coloured, enveloped in a scaly calyx, thin but solid, which contains, spread at its base, a granular yellow substance, appearing to the eve like a fine dust, but In the microscope they seem to be round, yellow, transparent, grains; deeper coloured, the older the fruit. This secretion, which constitutes the useful portion of the hop, has been examined in succession by Ives, Planche, Payen, and Chevallier. I have given a pretty full account of the results of their researches in treating of the hop under the article BEER. Annual Amount of Hop Duty, Average Price per Cwt., and Number of Acres. Year. Duty. Average Price. No. of Acres. ~ ~ s. d. 1838 171,556 5 17 0 55,045 1839 205,537 4 10 0 52,305 1840 34,091 13 11 0 44,805 1841 146,159 6 6 0 45,769 1842 169,773 4 18 0 43,720 1843 133,508 8 0 0 43,1f6 1844 140,322 7 15 0 44,485 1845 158,003 7 10 0 48,058 65 1012 HORN. Pounds Weight of Hops which paid Duty from 1840 to 1846 Lbs. 184:0... 7,114,917 1841 -. - - 30,504,106 1842 -.. - 35,432,142 1843 - -. - - 27,862,725 1844 - - - - 29,285,092 1845 - - - - - - 32,974,749 Number cf Acres under the Cultivation of Hops in England. f 1807 ~38,218 1813 39,521 1819 51,014 1825 46,718 1831 47,129 1837 56T323 1808 38,436 1814 40,571 1820 50,148 1826 50,471 1832 47,101 1838 55,045. 1809 38,357 1815 42,150 1821 45,662 1827 49,485 1833 t1,187 1839 52,305 1810 38,265 1816 44,219 1822 43,766 1828 48,365 1834 51,273 1840 44,805 1811 38,401 1817 46,493 1823 41,458 1829 46,135 1835 53,816 1841 45,769 L 1812 38,700 1818 48,593 1824 43,449 1830 46,726 1836 55,422 1842 Annual amount of hop duty. Yrs. Amount. Yrs. Amount. Yrs. Amount. Yrs. Amount. Yrs. Amount. Yrs. Amount. 1711 ~43,437 1733 ~70,215 1755 ~82,157 1777 ~43,581 1799 ~73,279 1821 ~154,609 1712 30,278 1734 37,716 1756 48,106 1778 159,891 1800 72,928 1822 203,724 1713 23,018 1735 42,745 1757 69,713 1779 55,800 1801 241,227 1823 26,058 1714 14,457 1736 46,482 1758 72,896 1780 122,724 1802 15,463 1824 148,832 1715 44,975 1737 56,492 1759 42,115 1781 120,218 1803 199,305 1825 24,317 1716 20,354 1738 86,575 1760 117,992 1782 14,895 1804 177,617 1826 269,331 1717 54,669 1739 70,742 1761 79,776 1783 75,716 1805 32,904 1827 140.848 1718 15,005 1740 37,875 1762 79,295 1784 94,359 1806 153,102 1828 172,027 1719 90,317 1741 65,222 1763 88,315 1785 112,684.307 100,071 1829 38,398 1720 38,169 1742 45,550 1764 17,178 1786 95,973 1808 251,089 1830 88,047 1721 61,362 1743 61,072 1765 73,778 1787 42,227 1809 63,452 1831 174,864 1722 49,443 1744 46,708 1766 116,445 1788 143,168 1810 73,514 1832 139,018 1723 30,279 1745 34,635 1767 25,997 1789 104,063 1811 157,025 1833 156,905 1724 61,271 1746 91,879 1768 114,002 1790 106,841 1812 30,633 1834 189,713 1725 6,526 1747 62,993 1769 16,201 1791 90,059 1813 131,482 1835 235,207 1726 80,031 1748 87,155 1770 101,131 1792 162,112 1814 140,202 1836 200,332 1727 69,409 1749 36,805 1771 33,143 1793 22,619 1815 123,878 1837 178,578 1728 41,494 1750 72,138 1772 102,650 1794 203,063 1816 46,302 1838 171,556 1729 48,441 1751 73,954 1773 45,847 1795 82,342 1817 66,522 1839 205,537 1730 44,419 1752 82,163 1774 138,887 1796 75,223 1818 199,465 1840 34,091 1731 22,600 1753 91,214 1775 41,597 1797 157,458 1819 242,476 1841 146,159 1732 35,135 1754 102,012 1776 125,691 1798 56,032 1820 138,330 1842 169,776 Hop duties of particular districts. 1839. 1840. 1841. 1842. Rochester - - ~60,802 16 6 ~23,256 19 8 ~51,490 3 8 ~58,812 4 7 Canterbury - - 50,649 3 0 5,757 0 4 33,960 14 10 31,019 13 5! Kent - - 111,451 19 6 29,014 0 0 85,450 18 6 90,731 18 0 Sussex - 65,026 19 7 3,080 12 9 38,086 13 10 43,561 10 0 Worcester - 16,639 16 4 239 19 0 12,076 19 8 19,815 2 11 Farnham - 7,730 7 2 1,643 18 7 7,702 10 2 11,678 18 4 North Clays - 2,005 13 10 57 4 1 1,159 7 10 1,724 2 7 Essex - - - 1,624 5 9 35 17 1 977 3 0 2,050 19 11 Sundries - - 1,058 11 5 20 4 8 705 8 7 203 14 3 205,538 12 7 34,091 17 2 146,159 1 7 169,776 6 0 HORDEINE is the name given b) Proust to the peculiar starchy matter of barley. Ik seems to be a mixture of the starch, lignine, and husks, which constitutes barley meal. See BEER. HORN (Eng. and Germ.; Corne, Fr.), particularly of oxen, cows, goats, and sheep, is a substance soft, tough, semi-transparent, and susceptible of being cut and pressed into a variety of f.'rms; it is this property that distinguishes it from bone. Turtle or tortoise HORN. 1013 shell seems to be of a nature similar to horn, but instead of being of a uniform color, it is variegated with spots. These valuable properties render horn susceptible bf being employed in a variety of works fit for the turner, snuff-box, and comb maker. The means of softening the horn need not be described, as it is well known to be by heat; but those of cutting, polishing, and soldering it, so as to make the plates of large dimensions, suitable to form a variety of articles, may be detailed. The kind of horn to be preferred is that of goats and sheep, from its being whiter and more transparent than the horn of any other animals. When horn is wanted in sheets or plates, it must be steeped in water, in order to separate the pith from the kernel, for about fifteen days in sum mer, and a month in winter; and after it is soaked, it must be taken out by one end, well shaken and rubbed, in order to get off the pith; after which it must be put for half an hour into boiling water, then taken out, and the surface sawed even, lengthways; it must again be put into the boiling water to soften it, so as to render it caqable of separating; then, with the help of a small iron chisel, it can be divided into sheets or leaves. The thick pieces will form three leaves, those which are thin will form only two, whilst young horn, which is only one quarter of an inch thick, will form only one. These plates or leaves must again be put into boiling water, and when they are sufficiently soft, they must be scraped with a sharp cutting instrument, to render those parts that are thick even and uniform; they must be put once more into the boiling water, and finally carried to the press. At the bottom of the press employed, there mus; be a strong blcck, in which is formed a cavity, of nine inches square and of a proportionate depth; the sheets of horn are to be laid within this cavity, in the following manner at the bottom: first a sheet of hot iron, upon this a sheet of horn, next again a sheet of hot iron, and so on, taking care to place at the top a plate of iron even with the last. The press must then be screwed down tight. There is a more expeditious process, at least in part, for reducing the horn into sheets, when it is wanted very even. After having sawed it with a very fine and sharp saw, the pieces must be put into a copper made on purpose, and there boiled, until sufficiently soft, so as to be able to split with pincers; the sheets of horn must then be put in the press, where they are to be placed in a strong vice, the chaps of which are of iron and larger than the sheets of horn, and the vice must be screwed as quick and tight as possible; let them cool in the press or vice, or it is as well to plunge the whole into cold water. The last mode is preferable, because the horn does not shrink in cooling. Now draw out the leaves of horn, and introduce other horn to undergo the same process. The horn so enlarged in pressing, is to be submitted to the action of the saw, which ought to be set in an iron frame, if the horn is wanted to be cut with advantage, in sheets of any desired thickness, which cannot be done without adopting this mode. The thin sheets thus produced must be kept constantly very warm between plates of hot iron to preserve their softness; every leaf being loaded with a weight heavy enough to prevent its warping. To join the edges of these pieces of horn together, it is necessary to provide strong iron moulds suited to the shape of the article wanted, and to place the pieces in contact with copper-plates or with polished metal surfaces against them; when this is done, the whole is to be pnt into a vice and screwed up tight, then plunged into boiling water, aid after some time it is to be removed from thence and immersed in cold water. The edges of the horn will be thus made to cement together and become perfectly united. To complete the polish of the horn, the surface must be rubbed with the subnitrate 6f bismuth by the palm of the hand. The process is short, and has this advantage, that it makes the horn dry promptly. When it is wished to spot the horn in imitation of tortoise-shell, metallic solutions must be employed as follows:-To spot it red, a solution of gold, in aqua regia, must be employed; to spot it black, a solution of silver in nitric acid must be used; and for brown, a hot solution of mercury in nitric acid. The right side of the horn must be impregnated with these solutions, and they will assume the colors intended. The brown'spots can be produced on the horn by means of a paste made of red lead, with a solution of potash, which must be put in patches on the horn, and subjected some time'to the action of heat. The deepness of the brown shades depends upon the quantity of potash used in the paste, and the length of time the mixture lies on the horn. A decoction of Brazil wood, or a solution of indigo, in sulphuric acid, or a deoction of saffron. and Barbary wood may also be used. After having employed these materials, the horn may be left for half a day in a strong solution of vinegar and alum. In France, Holland, and Austria, the comb-maker and horn-turners use the clippings of horn, which are of a whitish yellow, and tortoise-shell skins, out of which they make snuff-boxes, powder-hsrns, and many curious and handsome things. They first soften the horn and shell in boiling water, so as to be able to submit them to the press in iron 1014 HORNSTONE. inoulds, and by means of heat form them into one mass. The degree of oeat necessary to join the horn clippings must be stronger than that for shell skins, and it can only be found out by experience. The heat must not however be too great, for fear of scorching the horn or shell. Considerable care is required in these operations, not to touch the horn with the fingers, or with any greasy body, because the grease will prevent the perfect joining. Wooden instruments should be used to move them, while they are at the fire, and for carrying them to the moulds. In making a ring of horn for bell-pulls, &c., the required piece is to be first cut out in the flat of its proper dimensions, and nearly in the shape of a horse-shoe; it is then pressed in a pair of dies to give its surface the desired pattern; but previous to the pressure, both the piece of horn and the dies are to be heated: the piece of horn is to be introduced between the dies, squeezed in a vice, and when cold, the impression or pattern will be fixed upon the horn. One particular condition, however, is to be observed in the construction of the dies, for forming a ring. They are to be so made, that the open ends of the horse-shoe piece of horn, after being pressed, shall have at one end a nib, and at the other a recess of a dovetailed form, corresponding to each other; and the second operation in forming this ring of horn is to heat it, and place it in another pair of dies, which shall bring its open ends together, and cause the dovetailed joints to be locked fast into each other, which completes the ring, and leaves no appearance of the junction. In forming the handles of table knives and forks, or other things which require to be made of two pieces, each of the two pieces or sides of the handle is formed in a separate pair of dies; the one piece is made with a counter-sunk groove along each side, and the other piece with corresponding leaves or projecting edges. When these two pieces are formed, by the first being cut out of the flat horn, then pressed in the dies in a heated state, for the purpose of giving the pattern, the two pieces are again heated and put together, the leaves or edges of the one piece dropping into the counter-sunk grooves of the other piece, and being introduced between another pair of heated dies, the joints are pressed together and the two pieces formed into one handle. In making the knobs for drawers which have metal stems or pins to fasten them. ilto the furniture, the face of the knob is to be first made in a die, as above described, and then the back part of the knob with a hole in it; a metal disc of plate-iron is next provided in which the metal stem or screw pin is fixed, and the stem being passed through the aperture in the back piece, and the two, that is, the back and the front pl.ces v7 horn put together, they are then heated and pressed in dies as.,bove described; the edge of the back piece falling into the counter-sunk groove of the front piece, wiile by the hea'. they are perfectly cemented together. Mr. J. James has contrived a method of opening un the h-;ms of cattle, by which he avoids the risk of scorching or frizzling. -'which is ap. to happen in heating them over ar open fire. He takes a solid block of iron picrced lwith a conical hole, which is fitted with a conical iron plug, heats themr in a stove to the temperature of melting lead, anl having previously cut up the horn lengthwise on one side with a saw, he inserts it: narrow end into the bole, and drives the plug into it with a mallet. By the heat of the irons, the horn ge-p so softenei in hIe course of about a minute, as to bear flatting out it the usual way. HORNSILVER; (Argent Corne, or Kerargyre, Fr.; Hornsilber, Germ.) is a whit(, or brownish mineral, sectile like wax or horn; and crystallizing in the cubic system. its specific gravity varies from 4-75 to 5-55. Insoluble in water; not volatile; fusibl at the blowpipe, but difficult of reduction by it. It deposits metallic silver when rubbed with water upon a piece of clean copper or iron. It consists of 24'67 chlorine, and 75-32 silver. Hornsilver is rare in the European mines, but it occurs in great quantity in the districts of Zacatecas, Fresnillo, and Catarce, in Mexico: and in Huantajaya, Yauricocha, &c., in Peru; where it is abundantly mixed with the ores of hydrate of iron, called Pacos and Colorados, interspersed with veins of metallic silver, which form considerable deposits in the pencean limestones. There it is profitably mined as an ore of silver. HORNSTONE; is a variety of rhomboidal quartz. Being both hard and tough, it is' well adapted to form the stones of pottery mills for grinding flints; it is called chert in Derbyshire, where it abounds. Hornstone occurs under three modifications: splintery hornstone, conchoidal hornstone, and woodstone. The colours of the first two are gray, white and red; they are all massive; dull, or of a glimmering lustre. Translucent only on the thin edges. Difficult to break. Hornstone is less brittle than flint; and by its infusibility before the blowpipe it may be distinguished from petrosilex, which it resembles in external appearance. The geological locality of hornstone is remarkable; for it occurs in both ancient and modern form. ations. It is found frequently in the veins that traverse primitive crystalline rocks filling up the interstices, and enveloping their metallic ores. In the lead mine of Huel HORSE POWER. 1015 go.; in Brittany it is whitish; but its prevailing colour is gray. It occurs likewise in the middle beds of the coarse limestone (calcaire grossier) in the Paris basin, which is a comparatively modern formation, as well as in the sand beds of the upper parts of this district, near Saint Cloud, Neuilly &c. The hornstone which occurs in secondary limestone is called chert by the English miners. It is valuable for forming the grinding blocks of lint mills in the pottery manufacture. HORSE POWER, in steam engines, is estimated by Mr. Watt at 32,000 pounds avoirdupois lifted one foot high per minute, for one horse. Mr. D'Aubuisson, from an examination of the work done by horses in the whims, or gigs (machines d molottes) for raising ore from the mines at Freyberg, the horses being of average size and strength, nas concluded that the useful effect of a horse yoked during eight hours, by two relays of four hours each, in a manege or mill course, may be estimated at 40 kilogrammes raised 1 metre per second; which is nearly 16,440 pounds raised one foot per minute: being very nearly one-half of Mr. Watt's liberal estimates for the work of his steam engines. -Results of the Application of Horse Power to raising Water from the working Shafts at Stattwood Tunnel, on the South Eastern Railway, in 1842. By Frederick William Sinms, M. Inst. C. E.-This tunnel is driven in the middle bed of the lower green sand, between which and the surface of the ground is interposed only the upper bed of the same stratum; but in sinking the eleven shafts for the work, it was found that the level of the top of the tunnel, the ground assumed the character of a quicksand, saturated with water, in such quantity that it could not be reduced by manual labour. Under these circumstances horse gins were erected for drawing the water by barrels, containing one hundred gallons each, weighing when full about 1310 lbs. The engineer's intention was, to dive simultaneously from these shafts, in the direction of the tunnel, an adit or heading to carry off the water; but the earth, which was sand mixed with fine particles of blue clay, was so filled with water as to become a mass of semifluid mud, great exertions were therefore necessary to overcome the water, without erecting pumps. At first this was accomplished by making each horse work for 12 hours and then for 8 hours per day, allowing one hour for food and rest: as the water increased it became necessary to work night and day, and the time of each horse's working was reduced generally to 6 hours, and sometimes to 3 hours. As all the horses were hired at the rate of seven shillings per day, the author, who had the direction of the works, ordered a daily register to be kept of the actual work done by each horse, for the double purpose of ascertaining whether they all performed their duty, and also hoping to collect a body of facts relative to horse power, which might be useful hereafter. This detailed register, which was kept by Mr. P. N. Brockedon, is appended to the communication. The author gives as a proposition, "that the proper estimate of horse power would be that which measures the weight that a horse would draw up out of a well; the animal acting by a horizontal line of traction turned into the vertical direction by a simple pulley, whose friction should be reduced as much as possible." He states that the manner in which the work was performed, necessarily approached very nearly to these conditions; and after giving the principal dimensions of the horse gins, he analyzes each set of experiments, and by taking the mean of those, against which no objections could be urged, he arrives at the following results:The power of a horse for 8 hours = 23,412 lbs. raised 1 foot high in one minute. do. do. 6 = 24,360 do. do. do. 4~ = 27,056 do. do. do. 3 32,943 do. Of these results, he thinks the experiments for 6 hours and for 3 hours alone should be adopted as practical guides, all the others being in some degree objectionable. As a means of comparison, the following table of estimates of horse power is given: Pounds raised Name. 1 Foot high Woro. Authority. in a Minute. Boulton and Watt - - - 33,000 8 Robinson's Mech. Phil., ii. 145. Tredgold - - - 27,500 8 Tredgold on Railroads, p. 69. Desaguliers -- - 44,000 8 Ditto - - - 27,500 Not stated. Gregory's Mathematics Dr. Gregory's Mathematics More, for Society of Arts 21,120 Not stated or PracticalMen, p. 188. Smeaton -- - 22,000 Not stated..... _ J~~~~~~~~~~~~~~~~~~~~~~. 1016 HORSE POWER. These are much higher results than the average of his experiments, and would more nearly accord with the extremes obtained by him; but under such excessive fatigue, the horses were speedily exhausted, and died rapidly. Nearly one hundred horses were employed; they were of good quality; their average height was 15 hands i inch, ar.d their weight about 10~ cwts., and they cost from 201. to 401. each. They had as murlcorn as they could eat, and were well attended to. The total quantity of work done by the horses, and its cost, was as under:tons. Registered quantity of water drawn 104 feet, the average height, t 128,535 28,220,800 gallons - - - - s do. earth, 3,500 yds. 1 ton 6 cwt. per yard - - 4,550 Total weight drawn to the surface - - 133,955 ~ s. d. Total cost of horse labour, including a boy to drive each horse - 1,585 15 3 Or 2-86d. per ton the average height of 104 ft. As soon as the adit was driven, all the water was carried off by it, and the works are stated to be perfectly dry. Mr. Palmer said, it should be understood, that in stating 32,000 lbs. raised one foot high in a minute, as the measure of the power of a horse, Boulton and Watt had not intended to fix that as the average work which horses were capable of performing: they had taken the highest results of duty performed by powerful horses, in order to convince the purchasers of their steam-engines that they received all that had been contracted for. He had made some experiments on the amount of work performed by horses tracking boats on canals; orn the upper end of the mast of the boat a pulley was hung; over this the towing rope was passed, with the means of suspending to its extremity given weights, so as exactly to balance the power exerted by the horse. The results arrived at by these means were so various, that he could not deduce any average conclusions; as the power exerted varied between 30 lbs. and 120 lbs., the power diminishing as the speed was increased; he thought that 2t miles was too high an average estimate, and that it should not exceed 2 miles per hour. Mr. Field remarked that in all estimates of horse power, the speed was considered to be at an average of 2~ miles per hour, and all experiments were reduced to that standard. Mr. Hawkins said, that some years since, he had made numerous inquiries respecting the work done by horses in drawing upon common turnpike roads, and found that four good horses could draw an ordinary stage-coach, with its complement of passengers, 8 miles a day, at the rate of 10 miles an hour; that if they ran stages 10 miles in the hour, the horses must rest one day in each week; that good horses, so worked, would last only five years, each horse drawing about half a ton: he had been informed by waggoners, that good horses would walk at the rate of 21 miles per hour, for twelve hours out of twenty-four, making 30 miles a day; and that they would continue to do such work day by day, each horse drawing one ton, for many years, provided they had not been worked hard when young. Mr. Gravatt observed, that although there might exist some hesitation in receiving these results of work actually performed, as a general measure of a horse's power, yet as engineers frequently required to know what could be performed by horses, when employed for short periods, in works of haste or difficulty, he thought that the experiments were useful, and would form good data for reference: he was sorry to observe that in too many cases, an idea was prevalent, that it was cheaper to work a small number of horses to death, than to keep a large number, and to work them fairly; the results which he had been enabled to arrive at, were perhaps not a fair value of a horse's work, continued fox any length of time, at the best rate of economy, for both the contractor and the employer. The President believed that however, in cases of emergency, which he allowed did occur in engineering works, the forced system of labour mentioned by Mr. Gravatt might be tolerated, he was convinced that it was not the most economical, but, on the contrary humanity and economy would be found to go hand in hand. It would be desirable to know the average speed at which the different rates of work had been performed; this was essential in order to found any calculation upon the results given. Coach proprietors calculated that at a speed of 10 miles per hour, a horse was required for every mile going and returning, so that one horse was kept for every mile'f road. Now supposing a four-horse coach, with an average load to weigh 2 tons HORSE POWER. 1017 the load for each horse was 10 cwts.; whereas in the case of a horse drawing a cart, the gross load frequently amounted to 2 tons, but the speed was reduced to 2j miles per hour, at which pace he conceived that 16 miles per day might be considered a fair day's work; this therefore was double the distance with four times the load, or eight times the coach work, but with a heavier horse. The law that the quantity of work done was as the square root of the velocity, or as the cube root of the velocity, in equal times, was confined to work upon canals, or bodies moving through the water. Mr. Rennie had tried some experiments on the force of traction of the boats on the Grand Junction Canal. The towing rope was attached to adynamometer, which had previously been tested by weights. The horse, although urged at first starting, was afterwards allowed to fall into his natural speed, which was 2j miles per hour on the average of 20 miles. The maximum speed was 4 miles, and the minimum 2 miles, per hour. The dynamometer indicated an average of 108 lbs., which was capable of overcoming the resistance of the loaded barge of 25 tons, being in the ratio of 15-00. The weight of the horse was about 11 cwts. He also tried many experiments upon a fast boat, lent to him in 1833 by the late Colonel Page. These experiments were principally made in order to ascertain the comparative resistance of vessels moving through water at different velocities, and the Grand Junction Canal afforded a convenient opportunity of undertaking them. The boat was 10 feet in length, 4 feet in breadth, and drew 9 inches of water The traction indicated by the dynamometer the following resistance:Miles per hour. lbs. At 2~ the resistance was 20 83 " 27 3 " 830 4 " 50 4~ " 60 5 " 0 to 75 One horse was employed in these experiments. Miles per hour. lbs. At 6 the resistance was 97 to 214 7 " 250 8 336 9.69 " 411 10 375 11 " 392 Average 336 Tw) horses were employed in these experiments. Stakes were fixed near the margin of the canal, so as to ascertain the rise and fall of the wave caused by the boat in passing; and it was observed that when a boat passed with a velocity of from 4 to 6 miles per hour, the rise of the wave was 5 inches, and the fall 5 inches, making a wave of 10 inches in depth; and when the velocity was 11~ miles, the rise was reduced to 2A inches, and the fall to 2j inches. Great difference existed in the power of horses, their weights and structure; and the large dray horses used by Messrs. Barclay, Perkins, & Co. did a full average duty as assumed by Boulton and Watt; but considering the average power of strong and weak animals, he had adopted 22,000 Ibs. raised 1 foot high as the standard; much, however, depended on the nature of the work performed. Mr. Charles Wood remarked, that although on an emergency it might be necessary to work horses to the extent which had been mentioned, it had always been found more economical to feed them well, and not unduly to force the speed; the weight drawn, or the hours of labour. By the recorded experiments on ploughing, which were tried at Lord Ducie's and by Mr. Pusey, it was shown that any increase of speed diminished the amount of work done, in a greater ratio than it was affected by an increase of the load. In drawing loads the weight of the animal was a point of consideration and importance, and when extra exertions and muscular action were required, the nearer horses approached to " thorough bred," the greater was the result. Mr. Davidson gave the following statement of the work performed by a London brewer's horse per day; the cost of feed and of wear and tear per horse per annum being derived from actual experience among a large number of horses at Messrs. Truman, Hanbury, & Co.'s brewery. The feed, &c. is supposed to have cost the same per quarter per truss, &c. each year. 1018 HORSE POWER. Ponds Weight Pounds Weight Average Pounds Cost of Feed Difference per Years. drawn 6Q Miles drawn 61 Miles Weight drawn and Straw per Horse of Horses per Horse per per Horse return- 13 Miles per Horse per bought and sold Day. ing per Day. Horse per Day. Annum. per Annum. Lbs. Lbs. Lbs. ~ s. d. ~ s. d. 1835 5,148 1,716 3,342 43 2 7 10 0 3 1836 5,072 1,767 3,389 43 16 6 9 18 0 1837 1838 5,057 1,698 3,377 41 18 0 9 15 9 18.39 5,287 1,740 3,518 42 9 11 9 7 1 1840 5,786 1,820 3,803 46 11 7 717 11 1841 5,311 1,750 3,530 45 0 1 10 16 11 1842 5,263 1,740 3,501 47 0 9 10 8 0 Total 36,924 12,171 24,455 309 19 5 68 3 11 Average 7 years nearly - 5,275 1,738 3,506 44 5 7 9 14 10 Mr. Home stated that Messrs. Tredwell had a contract on the South Eastern Railway, near where Mr. Simms' experiments were made; they had upwards of 100 horses, whose average cost was about 301.; they were worked 10 hours per day, and were well fed, so that their value was but little reduced, and they were eventually sold for nearly the same prices as they originally cost. These contractors had about 400 horses on the Southampton Railway, which cost them about 251. each. The same course of not over-working, and of feeding them well, was pursued from motives of economy, and they found it answer. It was Mr. Jackson's practice to keep so many horses for his work as not to be under the necessity of working them more than 10 hours per day; he gave to each a peck of corn a-day; by this means he had been able to keep up their value. On the Chester and Crewe Railway he had about 300 horses at work, and towards the end of the contract, owing to circumstances over which he had no control, he was obliged to work them 14 or 15 hours per day; and in the course of four months horses that had been worth 251. were so reduced as not to be valued at above 71. He is a great advocate for steady work and good keep. On the Tame Valley Canal there had been sometimes between 300 and 400 horses, but as the work was nearly finished, many had been sold. Those sub-contractors who had kept a sufficient number of horses for the work, so as not to have them in harness Aore than i hours per day, had realized nearly the same prices they had given for them in the first instance. The horses belonging to Mr. Edwards, the sub-contractor for the excavation of Newton Hill, and those of Mr. W. Tredwell, sub-contractor for the Friar Park Farm cuttings, were purchased from the same parties at prices varying from 201. to 351. The former had been acting on the principle of getting out of the horses all he could, working them frequently 15 and 16 hours at a time; and the consequences were, that all his stock was in bad condition, and he would be glad to get 61. or 71. a-piece for them. On the other hand, Mr. W. Tredwell, who was an excellent horse master, and who did not work his horses beyond their strength, would be able to sell them for about as much as he gave for them,-indeed he had done so already for those that he had parted with. Having been a good many years in the service of the late Mr. McIntosh, Mr. Horne could state that it never was his system to over-work his horses. It did sometimes happen that there was no alternative, but the deviation from the regular rule in every instance showed that his system was founded on right principles. The over-worked horses were most liable to disease, and the time lost by illness formed an important item; whereas there were plenty of instances in which horses that had worked their regular 10'hours per day, and had been properly fed, had worked for five or six years without losing a single day by illness. On the whole he felt convinced, that both on the score of humanity and economy, the horse was the more valuable servant when treated with kindness. Mr. Beardmore said that a case had occurred in a work near Plymouth, which he believed would give the fair value of the work actually performed daily by a horse for a considerable period. A quarry-wagon, weighing 24 tons, carrying an average load of stone of 5H tons, was drawn by one horse along a railway 960 feet in length, 260 of it being level, and the remaining 700 feet having an inclination of 1 in 138. During 48 working days the numbel HOSIERY 1019 of trips was 1,302, or an average of 27-1 trips each day; the time of performing each trip was 4 minutes, or at a speed of 2-72 miles per hour; and the total weight drawn including that of the waggons, was 23,959,600 lbs. Repeated experiments proved, that upon the incline of 1 in 138 the waggons in their ordinary working state would just remain stationary; the friction was therefore assumed to be 16-2 lbs. per ton; by calculation it was found that the horse raised 39,320 lbs. 1 foot high per minute during the 8 working hours each day: the useful effect, or net amount of stone carried, being 21,738 Ibs. raised 1 foot high per minute. This difference between the work done and the useful effect arose from the necessary strength and weight of the waggons. The animal employed was a common Devonshirs cart-horse, 8 years old, 15 hands high, and weighed 10$ cwts.; he continued doing the same work throughout a whole summer, remaining in good condition; but a lighter horse was found unequal to it. HOSIERY (Bonneterie, Fr.; Strumpfweberei, Germ.). The stocking frame, which is the great implement of this business, though it appears at first sight to be a complicated machine, consists merely of a repetition of parts easily understood, with a moderate degree of attention, provided an accurate conception is first fzrmed of the nature of the hosiery fabric. This texture is totally different from the rectangular decussation which constitutes cloth, as the slightest inspection of a stocking will show;'r this, instead of having two distinct systems of thread, like the warp and the weft, which are woven together, by crossing each other at right angles, the whole piece is composed of a single thread united or looped together in a peculiar manner, which is called stocking-stitch, and sometimes chain-work. This is best explained by the view in fig. 760. A single thread is formed into a number of loops or waves; by arranging it'60 1 S R over a number of parallel needles, as shown at R: these are retained or kept in the form of cI^^ L- ^_ j loops or waves, by being drawn or looped through similar loops or waves formed by the thread of the preceding course of the work, s. The fabric thus formed by the union of a num her of loops is easily unravelled, because the stability of the whole piece depends upon the BRig ultimate fastening of the first end of the thread; Adp\ r' and if this is undone, the loops formed by that 761 Wt~ I "end will open, and release the subsequent loops, one at a time, until the whole is unravelled, and drawn out into the single thread from which it was made. In the same manner, if a thread in a stocking-piece fails, or breaks at any part, or drops a stitch, as it is called, it immediately produces a hole, and the extension of the rest can only be prevented by fastening the end. It should be observed that there are many different fabrics of stocking-stitch for various kinds of ornamental hosiery, and as each requires a different kind of frame or machine to produce it, we should greatly exceed our limits to enter into a detailed description of them all. That species whichwe have represented in fig. 760 is the common stocking-stitch used for plain hosiery, and is formed by the machine called the common stocking-frame, which is the groundwork of all the others. The operation, as we see, consists in drawing the loop of a thread successively through a series of other loops, so long as the work is continued, as is very plainly shown for one stitch in fig. 761. There is a grat variety of different frames in use for producing various ornamental kinds of hosiery. The first, which forms the foundation of the whole, is that for knitting plain hosiery, or the common stocking-frame. Of this valuable machine, the invention of Mr. Lee, of Cambridge, a side elevation is given in fig. 762, with the essential parts. The framing is supported by four upright posts, generally of oak, ash, or other hard wood. Two of these posts appear at A A, and the connecting cross rails are at c c. At B is a small additional piece of framing, which supports the hosier's seat. The iron-work of the machine is bolted or screwed to the upper rails of the frame-work, and consists of two parts. The first rests upon a sole of polished iron, which appears at D, and to which a great part of the machinery is attached. The other part, which is generally called the carriage, runs upon the iron sole at D, and is supported by four small wheels, or trucks, as they are called by the workmen. At the upper part of the back standard of iron are joints, one of which appears at Q; and to these is fitted a frame, one side of which is seen extending to H. By means of these joints, the end at H may be depressed by the hosier's hand, and it returns, when relieved, by the operation of a strong spring of tempered steel, acting between a cross bar in the frame and another below. The action of this spring is trery apparent in fig. 763. In the front of the frame, immediately opposite to where the hosier sits, are placed the needles which form the'cops. These needles, or rathei 1020 HOSIERX. hooks, are more or less numerous, according to the coarseness or fineness of tht stocking; and this, although unavoidable, proves a very considerable abatement of 762 162o the value of a stocking-frame. Ix D o,^===^a~ /^^ IS~ ~ almost every other machine (foi / \ example, those employed in spin..o |; J _ r g — _ Add\f ning or weaving), it is easy tc If IA-. 1-1" -^ K ~ radapt any one either to work I lo coarser or finer work, as it may I T |I \N be wanted. But in the mann \ l ID; |(^S,%? facture of hosiery, a frame once. __ _.__ _ A__ _ finished, is limited for ever in its C! operation to the same quality of _ —-- ^ ________~ ~work, with this exception, that by changing the stuff, the work may be made a little more dense A X | L or flimsy; but no alteration in A the size or quantity of loops can take place. Hence where the lJUHE)4~~ Smanufacture is extensively prosecuted, many frames may be 3-^ ~ B thrown idle by every vicissitude 3,, gE5~ [ Eof demand; and where a poor.'M U|~~ ~mechanic does purchase his own frame, he is for ever limited to N__ I 3 1 I the same kind of work. The gauge, as it is called, of a stocking-frame is regulated by the number of loops contained in three inches of breadth, and varies very much; the coarsest frames in common use being about what are termed Fourteens, and the finest employed in great extent about Forties. The needles are of iron wire, the manufacture of which is very simple; but long practice in the art is found necessary before a needle-maker acquires the dexterity which will enable him both to execute his work well, and in sufficient quantity to render his labor productive. The process of making the needles is as follows:-Good sound iron wire, of a proper fineness, is to be selected; that which is liable to split or splinter, either in filing, punching, or bending, being totally unfit for the purpose. The wire is first to be cut into proper lengths, according to the fineness of the frame for which the needles are designed, coarse needles being considerably longer than fine ones. When a sufficient number (generally some thousands) have been cut, the wire must be softened as much as possible. This is done by laying them in rows in a flat iron box, about an inch deep, with a close cover; the box being filled with charcoal between the strata of wires. his box, being placed upon a moderate fire, is gradually heated until both the wires and charcoal have received a moderate red heat, because, were the heat increased to what smiths term the white heat, the wire would be rendered totally unfit for the subsequent processes which it has to undergo, both in finishing and working. When the box has been sufficiently heated, it may be taken from the fire, and placed among hot ashes, until both ashes and box have gradually cooled; for the slower the wires cool, the softer and easier wrought they will be. When perfectly cool, the next process is to punch a longitudinal groove in the stem of every needle, which receives the point or barb, when depressed. This is done by means of a small engine worked by the power of a screw and lever. The construction of these engines is various; but a profile mj i'-|~ — D -elevation of one of the most simple and com783 the needle appears at G, and the X8_K _^^^ — - - Ksocket or level at K. At H, is a ~~~~~H ~ section of the needle-bar, on the fore part of which is a small plate of iron called a verge, to regulate the position of the needles. When placed upon the bar resting against the verge, another plate of iron, generally lined with soft leather, is screwed down upon the sockets or leads, in order to keep them all fast. This plate and the screw appear at I. When the presser at F is forced down upon the barb, this sinks into the groove of the stem, and the needle is shut; when the presser rises, the barb opens again by its own elasticity. The needles or hooks being all properly fitted, the next part of the stocking-frame to which attention ought to be paid, is the machinery for forming the loops; and this consists of two parts. The first of these, which sinks between every second or alternate needle, is represented at o, fig. 762, and is one of the most important parts of the whole machine. It consists of two moving parts; the first being a succession of horizontal levers moving upon a common centre, and called jacks, a term applied to vibrating levers in various kinds of machinery as well as the stocking-frame. One only of these jacks can be represented in the profile fig. 762; but the whole are distinctly shown in a horizontal position in fig. 766; and a profile upon a very enlarged scale is given in fig. 767. z 7 ^ 66 R [A.-i-. -.-': _ I, z 2 rr-7 IV': ~1 O' 1022 HOSIERY. The jack shown in fig. 762, extends horizontally from o to r, and the centre of motion is at R. On the front, or right hand part of the jack at o, is a joint suspending a very thin plate of polished iron, which is termed a sinker. One of these jacks and sinkers is allotted for every second or alternate needle. The form of the sinker will appear at s, fig. 767; and in order that all may be exactly uniform in shape, they are cut out and finished between two stout pieces of iron, which serve as moulds or gauges to direct the' frame-smith. The other end of the jack at., is tapered to a point; and when the jacks are in their horizontal position, they are secured by small iron springs, one of which is represented at I, fig. 762, each spring having a small obtuse angled notch to receive the point of the jack, against which it presses by its own elasticity. Infig. 767 the centre is at R; the pointed tail is omn.tted for want of room, the joint is at o, and the throat of the sinker, which forms the loois is at s. The standards at a, upon which the jack moves, ire called combs, and consist of pieces of flat smooth brass, parallel to, and equidistant from each other. The cross-bar a, which contains the whole, is of iron, with a perpenlicular edge or rim on each side, leaving a vacancy between them, or a space to receive'he bottom part or tails of the combs. The combs are then placed in the bar, with a flat piece of brass called a countercomb, between each, to ascertain and preserve their distances from each other. These countercombs are exactly of the same shape as the combs, but have no tails. When both combs and countercombs are placed in the bar, it is luted with clay so as to form a mould, into which is poured a sufficient quantity of melted tin. When the tin has had time to cool, the countercombs having no tails are easily taken out, and the combs remain well fastened and secured by the tin, which has been fused entirely ~ound them. Thus they form a succession of standards for the jacks; and a hole being Irilled through each jack and each comb, one polished wire put through, serves as a cor non centre for the whole. The jack sinkers being only used for every alternate or second needle, in order to;omplete this part of the apparatus, a second set of sinkers is employed. These are, in form and shape, every way the same as the jack sinkers, but they are jointed at the top into pieces of tin, all of which are screwed to the sinker bar H, fig. 762; and thus a sinker of each kind descends between the needles alternately. By these sinkers the loops are formed upon all the needles, and the reason of two sets different in operation being employed, will be assigned in describing the mode of working the frame. The presser of the operation, of which something has already been said, appears at r; and of the two arms which support and give motion to it, one appears very plainly at E, its centre of motion being at c. The circular bend given to these arms, besides having an 768 ornamental effect, is very useful, in order to prevent any part from ________ A interfering with the other parts c 11! 11 ii -z which are behind, by elevating 1 3ff i them entirely above them. The X = w 11" ~ irll0 ie I xtremities of these arms at the v2' _V__~, _ l \_~ ~termination of the bends behind, < > III~-~-l~ll'llH l'- CE J' > are connected by a cross bar, U1' I -A _II~ "~ 1~ which has also a circular bend in the middle, projecting down. wards, for a reason similar to that cZa' \ b cff already assigned. This bend is L\ x,^^ / concealed in fig. 762, but visible in the front elevation, fig. 768, B[}[) ^_^~ -0~p~~ ~From the middle of the bend, the presser is connected with the __________________~ ~ middle treadle by a depending wire appearing at M, fig. 762, and thus, by the pressure of that treadle, the presser is forced down to close the barbs of the needle. ~.~ jiThe re-ascent of the presser is?! j|J t 3 [sometimes effected by means of 2 _! 3 _ a counterpoising weight passing'~ —--------- — over a pulley behind; and someLr J-o B ~ times by the reaction of a wooden. —_- Ls=^=r- j _ B ~ spring, formed of a strong hoop A like that represented at K. The latter of these is preferred, espe7'"/-.~64 ~ cially by the Nottingham hosiers, ___* _764 because, as they assert, it makes L-..... - _ 5 _..... --' -the presser spring up with greater HOSIERY. 1023 rapidity, and coasequently saves time in working. How far this may be practically the case, it would be superfluous here to investigate; but it is obvious that the wooden spring, if very stiff, must add much to the hosier's exertion of his foot, already exercised against the united spring of all his barbs; and this inconvenience is much complained of by those who have been accustomed to work with the counterpoise. At L are twovpulleys or wheels, of different diameters, moving upon a common centre, by which the jack sinkers are relieved from the back springs, and thrown downwards to form the loops upon the needles. About the larger wheel is a band of whipcord, passing twice round, the extremities of which are attached to what is called the slur, which disengages the jacks from the back springs. The smaller pulley, by another band, communicates with the right and left treadle; so that these treadles, when pressed alternately, turn the pulleys about in an inverted order. The directions of these bands also appear more plainly in the front elevation, fig. 768. The construction of the slur, and its effect upon the jacks, will also be rendered apparentl by fig.'769. In this figure, eight jacks are represented in section, the tail part of three of which, 1, 2, 3, are thrown up by the slur in its progress from left to right; the fourth is in the act of rising, and the remaining four, 5, 6, 7, and 8, are still unacted upon, the slur not yet having reached them. As the slur acts in the direction of the dotted line x, x, fig.'766, behind the centres of the jacks, it is hardly necessary to remark, that this forcing up of the tails must of course depress the joints by which the sinkers in front are suspended. The jack sinkers falling successively from the loops on every alternate needle, in the way A =3.46 BD represented at fig. 770, where bcLh' 2 3 4 (r 6 f II Ikinds of sinkers appear in section, the 7T"~n~70.U~ H] Hlight part expressing what is above 770f"~~~~~~~ J the point at which the throat of the ~ 4 6 6 V y U /^^ ~ sinker operates upon the thread, and the dark part what is below. The CT I TI T I! Ql_ I _I _ T I_ _;D second set, or, as they are called, the lead sinkers, from the manner of jointing them, and suspending them from the bar above, appear still elevated; the position of the bar being represented by the line A, B. But when these are pulled down to the level of the former by the operator's hands, the whole looping will be completed, and the thread c, D, which is still slack, will be brought to its full and proper degree of tension, which is regulated by stop screws, so as to be tempered or altered at pleasure. The sinking of this second set of 0771 1 A HU/1G D sinkers, may be easily explained by'77 / =1= | fig. 771. The direction of the sinkers is expressed by the line E; the TE(C {bar from which they are suspended will be at A; the top frame is in the ~E ~\\^ ^it ~F I direction from A to B; the back standards at D, and the joint at B, is -//-/ I- ~the centre of motion. If E is pulled perpendicularly downwards, the spring c will be contracted, and its upper extreme point G, will be brought nearer to its lower extreme point F, which is fixed. Again, when the force which has depressed E is removed, the spring c will revert to its former state, and the sinkers will rise. The raising of the jack sinkers and jacks takes place at the same time, by the hosier raising his hands; and for the cause of this we must revert to fig. 766. The lead sinkers in rising lay hold of notches, which raise the extreme parts of the set of jacks z, z, which are called half-jacks. Between the extremities of these at z, z, is a cross bar, which, in descending, presses all the intermediate jacks behind the common centre, and restores them to their original posture, where they are secured by the back springs, until they are again relieved by the operation of the slur recrossing at the next course. Working of the frame.-In order to work a frame, the whole apparatus being previously put into complete order, the hosier places himself on the seat B in front, and pro. vides himself with a bobbin of yarn or stuff. This bobbin he places loosely on a vertical pin of wire, driven into one side of the frame contiguous to the needles, so that it may turn freely as the stuff is unwound from it. Taking the thread in his hand, he draws it loosely along the needles, behind the barbs, and under the throats of the sinkers. He then presses down one of the treadles to pass the slur along, and unlock the jacks from the back springs, that they may fall in succession. When this is done, the number of loops thus formed is doubled by bringing down the lead sinkers, and the new formed loops are lodged under the barbs of the needles by bringing forward the sinkers. The preceding course, and former fabric, being then again pushed back, the barbs are shut by depressing the middle treadle, and forcing down the presser upon the needles. The?ormer work is now easily brought over the shut needles, after which by raising the 1024 HOSIERY. hands, both sets of sinkers are raised; the jacks are locked by the back springs, and the hosier goes on to another course. From this it will be apparent, that the remark made in the outset is well founded, that there are, in reality, no complicated or difficult movements in the stocking-frame. Almost the whole are merely those of levers moving upon their respective fulcra, excepting that of the carriage which gives the horizontal motion to the sinkers, add that is merely an alternate motion on four wheels. Yet the frame is a machine which requires considerable experience and care, both to work it to advantage, and also to keep it in good order. This circumstance arises greatly from the small compass in which a number of moving parts must be included. Owing to this, the needles, unless cautiously and delicately handled, are easily bent or injured. The same circumstance applies with equal or greater force to the sinkers, which must be so very thin as to be easily injured. But as these must work freely, both in a perpendicular and horizontal direction between the needles, in a very confined and limited space, the slightest variation in either, from being truly and squarely placed, unavoidably injures the others. When a hosier, either ignorant of the mechanical laws, of their relation to each other, or too impatient to wait for the assistance of another, attempts to rectify defects, he in most cases increases them tenfold, and renders the machine incapable of working at all, until repaired by some more experienced person. This circumstance has given rise to a set of men employed in this trade, and distinguished by the name of upsetters; and these people, besides setting new frames to work, have frequently more employment in repairing old ones injured by want of care or skill, than many country apothecaries, who live in unhealthy parishes, find in tampering with the disorders of mankind. It seems unnecessary to go further into detail respecting a machine so well known, and which requires practical attention even more than most others. It may, therefore, be sufficient to describe shortly some of its varieties, the most simple and common of which is the rib stocking-frame. Rib stocking-frame. -This frame, which, next to the common frame, is most extensively in use, is employed for working those striped or ribbed stockings, which are very common in all the different materials of which hosiery is formed. In principle it does not differ from the common frame, and not greatly in construction. The preceding general description will nearly apply to this machine with equal propriety as to the former; that part, however, by which the ribs or stripes are formed, is entirely an addition, and to the application of this additional machinery it may be proper to pay the chief attention, referring chiefly to fig. 768, which is a front elevation. This figure has been already referred to for the illustration of those parts of the machinery which are common to both, and those parts therefore require no recapitulation. The principle of weaving ribbed hosiery possesses considerable affinity to that which subsists in the weaving of that kind of cloth which is distinguished by the name of tweeling, for the formation of stripes, with some variation arising merely from the different nature of the fabric. In cloth weaving, two different kinds of yarn inter secting each other at right angles, are employed; in hosiery only one is used. In the tweeling of cloth, striped as dimity, in the cotton or kerseymere, and in the woollen manufacture, the stripes are produced by reversing these yarns. In hosiery, where only one kind of yarn is used, a similar effect is produced by reversing the loops. To effect this reversing of the loops, a second set of needles is placed upon a vertical frame, so that the bends of the hooks may be nearly under those of the common needles. These needles are cast into tin moulds, pretty similar to the former, but more h72 \' j oblique or bevelled towards the point, so as to prevent obstructions in 9 working them. They are also screwed to a bar of iron, generally lighter than the other, and secured by means of plates: this bar is not fixed, but has a pivot in each end, by means of which the bar may have a kind of oscillatory motion on these pivots. The two frames of iron support this a bar; that in which it oscillates being nearly vertical, but inclined a little towards the other needles. Fig.'72, which is a profile elevation, will serve to illustrate the relative position of each bar to the other. The lower or horizontal frame, the ends only of which can be seen in fig. 7 68 under a a, appears in profile in fig. 172, where it is distinguished by d. The vertical frame at a is attached to this by two centre screws, which serve as joints for it to move in. On the top of this frame is the rib-needle bar at f, in figs.'62 and 772, and one needle is represented in fig. 772 at f. At g is a small presser, to shut the barbs of the ribneedles, in the same manner as the large one does those of the frame. At h is one of the frame needles, to show the relative position of the one set to the other. The whole of the rib-bar is not fitted with needles like the other; for here needles are only placed where ribs or stripe are to be formed, the intervals being fillet up with blank leads, that is HOT-FLUE. 1025 to say, with sockets of the same shape as the others, but without needles; being merely designed to fill the bar and preserve the intervals. Two small handles depend from the needle bar, by which the oscillatory motion upon the upper centres is given. The rising and sinking motion is communicated to this machine by chains which are attached tc iron sliders below, and which are wrought by the hosier's heel when necessary. The pressure takes place partly by the action of the small presser, and partly by the motion of the needles in descending. A small iron slider is placed behind the rib-needles, which rises as they descend, and serves to free the loops perfectly from each other. In the weaving of ribbed hosiery, the plain and rib courses are wrought alternately. When the plain are finished, the rib-needles are raised between the others, but no additional stuff is supplied. The rib-needles, intersecting the plain ones, merely lay hold of the last thread, and, by again bringing it through that which was on the rib-needle before, give it an additional looping, which reverses the line of chaining, and raises the rib above the plain intervals, which have only received a single knitting. HOT-FLUE is the name given in England to an apartment heated by stoves or steam pipes, in which padded and printed calicoes are dried hard. Fig. 773 represents 773 the simplest form of such a flue, heated Ly the vertical round iron stove c, from whose top a wide square pipe proceeds upwards in a slightly inclined direction, which receives the current of air heated by the body and capital of the stove. In this wide channe. there are pulleys, with cords or bands which suspend by hooks, and conduct the web of 1026 HOT-FLUE. calico, from the entrance at B, where the operative sits, to near the point A, and back again. This circuit may be repeated once or oftener till the goods are perfectly dried. At D the driving pulley connected with the main shaft is shown. Near the feet of the operative is the candroy or reel upon which the moist goods are rolled in an endless web; so that their circulation in the hot-air channel can be continued without interruption, as long as may be necessary. Fig. 774 is a cross section of the apparatus of the regular hot-flue, as it is mounted 774 in the most scientific calico works of England, those of James Thomson, Esq., ~J"^~~~~~ \vsx~v ^ of Primrose, near Clitheroe, Lancashire. a a a a a, is an arched apartment, nearly 30 yards long, by 13 feet high, and 10 feet wide. Through about one half of this gallery there is a horizontal floor supported on arches, above which is the driest fl r_ ^ space, through which the goods are finally passed before they escape from the hot-flue, A,1k. sik after they have been previously exposed to I.1 -j L the hot but somewhat moist air of the A e. II: I. ~ lower compartment. A large square flue X 1|t ^ ^l..,'t.' t S covered with cast-iron plates runs along m-In.:the whole bottom of the gallery. It is m. @^ 2t i~ $~ divided into two lotl, parallel vaults,, * sc U Uz a u W whose sections are seen at u, u, fig. 774, az W. ^ j^ J^ mIH~ covered with the cast-iron plates v v, grooved at their ends into one another. The thickness of these plates is increased progressively as they come nearer to the fireplace or furnace. There are dampers which regulate the draught, and of course the heat of the stove. h h are the air-passages or vent-holes, left in the side walls, and which by means of a long iron rod, mounted with iron plates, may be opened or closed together to any degree. k k are the cast-iron supports of the tinned brass rollers which guide the goods along, and which are fixed to the cross pieces represented by r r, fig.'74. 1 1 are iron bars for supporting the ventilators or fans (see the fan under FOUNDRY). These fans are here enclosed within a wire grating. They make about 300 turns per minute, and expel the moist air with perfect effect. s indicates the position of the windows, which extend throughout the length of the building. t is a gas-light jet, placed at the side of each window to supply illumination for night work. The piece is stretched along the whole extent of the gallery, and runs through it in the course of one minute and a half; being exposed during its passage to the heat of 212~ Fahr. In fig. 775, A is the iron door of entrance to the hot-flue gallery; at b is the pad ding machine, where the goods are imbued with the general mordant. The speed of 775 this machine may be varied by means of the two conical drums c c, which drive it; sinec when the band c c is brought, by its forks and adjusting screws, nearer to the narrow end of the lower drum, the cylinder upon the same. shaft with the latter is driven quicker; and vice versa. Over D D the cords are shown for drawing the drum mechanism into gear with the main shaft band, r r E; or for throwing it out of gear. The pulleys F F carry the bands which transmit the motion to the padding machine. A cylindrical drum exterior to the hot-flue, covered with flannel, serves to receive the end of the series of pieces. and to draw them through the apartment. This mode of drying JACQUARD. 1027 the padded calicoes requires for each piece of 28 yards, 3 pounds of coals for the furnace when a fan is employed, and four pounds without it. HYDRATES; are compounds of the oxides, salts, &c. with water in definite or equivalent proportions. Thus slaked lime consists of one atom of quick-lime = 28, - one atom of water = 9, of which the sum is 37 on the hydrogen scale. HYDRAULIC PRESS. See OIL, PRESS, and STEARINE. HYDRYODIC ACID; (Acide Hydriodique, Fr.; Hydriodsdure, Germ.) is an acid formed by the combination of 99'21 parts of iodine, and 0'79 hydrogen. When pure, it occurs in the gaseous state, but it combines with water, like the hydrochloric or muriatic acid gas, into a liquid acid. HYDROCHLORIC ACID; the new chemical name of muriatic acid, which see. HYDROGEN; (Eng. and Fr.; Wasserstoff, Germ.) an undecomp< unded gaseous body; the lightest of all ponderable matter, whose examination belongs to chemistry. HYDROMETER; an instrument for ascertaining the specific gravities of liquids. Baume's hydrometer, which is much used in France, and other countries of the continent of Europe, when plunged in pure water, at the temperature of 58~ Fahr., marks 0 upon its scale; in a solution containing 15 per cent. of common salt (chloride of sodium), and 85 of water by weight, it marks 15~; so that each degree is meant to indicate a density corresponding to one per cent. of that salt. See AREOMETER, for comparative tables of hydrometers. HYDROSULPHURETS; chemical compounds of bases with sulphuretted hydrogen. HYMENCEA COURBARIL; a tree growing in South America, from which the resin anime exudes. HYOSCIAMUS NIGER. Henbane is a plant used in medicine, fiom which modern chemistry has extracted a new crystalline vegetable principle called hyosciamine, which is very poisonous, and when applied in solution to the eye, determines a remarkable dilatation of the pupil; as belladonna also does. HYPOSULPHATES; HYPOSULPHITES; saline compounds of the hyposulphuric or hyposulphurous acid with bases. HYPEROXYMURIATES; the old and incorrect name for CHLORATES. HYPOSULPHATE OF SODA. Pure crystallized carbonate of soda is dried as much as possible, and reduced to a fine powder; 1 lb. of it is then mixed with 10 ozs. of flowers of sulphur, and the mixture is heated in a glass or porcelain dish, gradually, until the sulphur melts. The mass which cakes together is kept at this temperature and is divided, stirred and mixed, in order that each part may be brought into contact with the atmosphere. The sulphuret of sodium formed passes, under these circumstances, by the absorption of oxygen from the atmosphere, with a slight incandescence, gradually into sulphite of soda. It is dissolved in water; filtered, the liquid immediately boiled with flowers of sulphur; the filtered, nearly colourless, strongly concentrated liquid affords hyposulphate of soda in very pure and beautiful crystals, and in large quantity. When the mixture is heated too quickly, some sulphur is easily burnt; there then remains a portion of undecomposed carbonate of soda, which contaminates the hyposulphite in the first crystallization, but which may very readily be separated from it. HYPOSULPHITE OF SODA. This salt, so extensively used in the practice of Daguerreotyping, may be easily prepared in quantities by the following process:-Mix one pound of finely pulverised ignited carbonate of soda with ten ounces of flowers of sulphur, and heat the mixture slowly in a porcelain dish till the sulphur melts. Stir the fused mass so as to expose all its parts freely to the atmosphere, whereby it passes from the state of a sulphuret, by the absorption of atmospherical oxygen, into that of a sulphite, with the phenomenon of very slight incandescence. Dissolve in water, filter the solution, and boil it immediately along with flowers of sulphur. The filtered concentrated saline liquid will afford, on cooling, a large quantity of pure and beautiful crystals of hyposulphite of soda.. & J. JACK, called also jack in a box, and hand-jack, is a portable, mechanical instrument, consisting of a rack and pinion, or a pair of claws and ratchet bar, moved by a winch handle for raising heavy weights a little way off the ground. JACK and JACK-SINKERS, are parts of a stocking frame. See HOSIERY. JACK-BACK, is the largest jack of the brewer. JACQUARD. A peculiar and most ingenious mechanism, invented by M. Jacquart of Lyons, to be adapted to a silk or muslin loom for superseding the employment 66 1028 JACQUARD LOOM. of draw-boys, in weaving figured goods. Independently of the ordinary play of the warp threads for the formation of the ground of such a web, all those threads which should rise simultaneously to produce the figure, have their appropriate healds, which a child formerly raised by means of cords, that grouped them together into a system, in the order, and at the time desired by the weaver. This plan evidently occasioned no little complication in the machine, when the design was richly figured; but the apparatus of Jacquart, which subjects this manceuvre to a regular mechanical operation, and derives its motion from a simple pedal put in action by the weaver's feet, was generally adopted soon after its invention in 1800. Every common loom is susceptible of receiving this beautiful appendage. It costs in France 200 francs, or 81. sterling, and a little more in this country. Fig. 776. is a front elevation of this mechanism, supposed to be let down. Fig. 777. Is a cross section, shown in its highest position. Fig. 778. the same section as the preceding, but seen in its lower position. A, is the fixed part of the frame, supposed to form a part of the ordinary loom; there are two uprights of wood, with two cross-bars uniting them at their upper ends, and leaving an interval x y between them, to place and work the movable frame B, vibrating round two fixed points a a, placed laterally opposite each other, in the middle of the space x y, fig. 776. c, is a piece of iron with a peculiar curvature, seen in front, fig. 776., and in profile, Jigs. 777. and 778. It is fixed on one side upon the upper cross-bar of the frame B, and on the other, to the intermediate cross-bar b of the same frame, where it shows an inclined curvilinear space c, terminated below by a semicircle. D, is a square wooden axis, movable upon itself round two iron pivots, fixed into its two ends; which axis occupies the bottom of the movable frame B. The four faces of this square axis are pierced with three round, equal, truly-bored holes, arranged in a quincunx. The teeth a, fig. 780., are stuck into each face, and correspond to holes a, fig. 783., made in the cards which constitute the endless chain for the healds; so that in the successive application of the cards to each face of the square axis, the holes pierced in one card may always fall opposite to those pierced in the other. The right-hand end of the square axis, of which a section is shown in double size, fig. 779., carries two square plates of sheet iron d, kept parallel to each other and a little apart, by four spindles e, passed opposite to the corners. This is a kind of lantern, in whose spindles, the hooks of the levers ff', turning round fixed points g q' beyond the right hand upright A, catch hold, either above or below at the pleasure of the weaver, according as he merely pulls or lets go the cord z, during the vibratory movement of the frame B. E is a piece of wood shaped like a T, the stem of which prolonged upwards, passes freely through the cross-bar b, and through the upper cross-bar of the frame B, which serves as guides to it. The head of the T piece being applied successively against the two spindles e, placed above in a horizontal position, first by its weight, and then by the spiral spring h, acting from above downwards, keeps the square axis in its position, while it permits it to turn upon itself in the two directions. The name press is given to the assemblage of all the pieces which compose the movable frame B B. F is a cross-bar made to move in a vertical direction by means of the lever G, in the notches or grooves i, formed within the fixed uprights A. H, is a piece of bent iron, fixed by one of its ends with a nut and screw, upon the crossbar F, out of the vertical plane of the piece c. Its other end carries a friction roller J, which working in the curvilinear space c of the piece c, forces this, and consequently the frame B, to recede from the perpendicular, or to return to it, according as the cross-bar F is in the top or bottom of its course, as shown in figs. 777. and 778. i, cheeks of sheet iron attached on either side to the cross-bar F, which serves as a safe to a kind of claw K, composed here of eight small metallic bars, seen in section fig. "77. and 778., and on a greater scale in fig. 780. J, upright skewers of iron wire, whose tops bent down hook-wise naturally place themselves over the little bars K. The bottom of these spindles likewise hooked in the eame direction as the upper ones, embraces small wooden bars 1, whose office is to keep them in their respective places, and to prevent them from twirling round, so that the uppermost hooks may be always directed towards the small metallic bars upon which they impend. To these hooks from below are attached strings, which after having crossed a fixed board m n, pierced with corresponding holes for this purpose, proceed next to be attached to the threads of the loops destined to lift the warp threads. c K, horizontal spindles or needles, arranged here in eight several rows, so that each spindle corresponds both horizontally and vertically to each of the holes pierced in the four faces of the square axis D. There are therefore as many of these spindles as there are holes in one of the faces of the square. Fig. 781. represents one of these horizontal spindles. n is an eyelet through which JACQUARD LOOM. 1029 eg,......,.,::,........ lengthwise, ithin the l imits of the length of the eyelet. p, small spiral springs placed primi tiv e position every corresponding needle, a s soon ais it c eases t o press upon it. 776 MM I3 - I primi tive position every corresponding needle, as soon as it ceases to press upon it. 1030 JACQUARD LOOM. 8 7 65 4 8 21 80,779 _'' ll lr I: a D " a 81 o 1 Fig. 782. represents the plan of the upper row of horizontal needles. Fig. 783. is n fragment of the endless chain, formed with perforated cards, which are made to circulate or travel by the rotation of the shaft D. In this movement, each of the perforated cards, whose position, form, and number, are determined by the operation of tying-up of the warp, comes to be applied in succession against the four faces of the square axis or drum,'782'83,e [[ u...,,o_ vo 0011 I ____________ *,o o 0 o".ov0, o"',,o, v.00'oU. 0oor 0"0' a O C 0*"Bs** d 0 C a 80C( *I o o o _OOO % ~ o00 o..' o oa c' oEo — * 1~ *,3os. o o o:.. o~.~:,, 9i 0 00~ 701cs1 I o X o CWo o 0o o oogO oo-g' ll' O 00 OO 0Ougo 0 o O a. o, OQ00oI *00 00 so 0 0o 0 0 leaving open the corresponding holes, and covering those upon the face of the axis, which have no corresponding holes upon the card. Now let us suppose tnat tne press B is let down into the vertical position shown is fig. 178; then the card applied against the left face of the axis, leaves at rest or un. touched the whole of the horizontal spindles (skewers), whose ends correspond to these holes, but pushes back those which are opposite to the unpierced part of the card; thereby the corresponding upright skewers, 3, 5, 6, and 8, for example, pushed out of the perpendicular, unhook themselves from above the bars of the claw, and remain in their place, when this claw comes to be raised by means of the lever G; and the skewers 1, 2, 4, and 7, which have remained hooked on, are raised along with the warp threads attached to them. Then by the passage across of a shot of the color, as well as a shot of the common weft, and a stroke of the lay after shedding the warp and lowering the press B, an element or point in the pattern is completed. The following card, brought round by a quarter revolution of the axis, finds all the needles in their first position, and as it is necessarily perforated differently from the preeding card, it will lift another series of warp threads; and thus in succession for all the other cards, which compose a complete system of a figured Pattern. This machine, complicated in appearance, and which requires some pains to be understood, acts however in a very simple manner. Its whole play is dependant upon the movement of the lever G, which the weaver himself causes to rise and fall, by means of a peculiar pedal; so that without the aid of any person, after the piece is properly read in and mounted, he can execute the most complex patterns, as easily as he coutid weave plain goods; only attending to the order of his weft yarns, when these happen to be of different colors. If some warp yarns should happen to break without the weaver observing them, or should he mistake his colored shuttle yarns, which would so far disfigure the pattern, he must undo his work. For this purpose, he males use of the lower hooked lever f, whose purpose is to make the chain of the card go backwards, while working the loom as usual, withdrawing at each stroke the shot both of the ground and of the figure. The weaver is the more subject to make mistakes, as the figured side of the web is downwards, and it is only with the aid of a bit of looking-glass that he takes a peep of his work from time to time. The upper surface exhibits merely loose threads in different points, according as the pattern requires them to lie upon the one side or the other. Thus it must be evident, that such a number of paste-boards are to be provided and mounted as equal the number of throws of the shuttle between the beginning and end of any figure or design which is to be woven; the piercing of each paste-board individually, will depend upon the arrangement of the lifting rods, and their connexion with the warp, JACQUARD LOOM. 1031 which -s according to the design and option of the workman; great care must be taken that the holes come exactly opposite to the ends of the needles; for this purpose two large holes are made at the ends of the paste-boards, which fall upon conical points, by which means they are made to register correctly. It will be hence seen, that, according to the length of the figure, so must be the number of paste-boards, which may be readily displaced so as to remount and produce the figure in a few minutes, or remove it, or replace it, or preserve the figure for future use. The machine, of course, will be understood to consist of many sets of the lifting rods and needles, shown in the diagram, as will be perceived by observing the disposition of the holes in the paste-board; those holes, in order that they may be accurately distributed, are to be pierced from a gauge, so that not the slightest variation shall take place. To form these card-slips, an ingenious apparatus is employed, by which the proper steel punches required for the piercing of each distinct card, are placed in their relative situations preparatory to the operation of piercing, and also by its means a card may be punched with any number of holes at one operation. This disposition of the punches is effected by means of rods connected to cords disposed in a frame, in the nature of a false simple, on which the pattern of the work to be performed is first read in. These improved pierced cards, slips, or paste-boards, apply to a weaving apparatus, which is so arranged that a figure to be wrought can be extended to any distance along the loom, and by that means the loom is rendered capable of producing broad figured works; having the long lever G placed in such a situation that it affords power to the foot of the weaver, and by this means enables him to draw the heaviest morintures and figured works, without the assistance of a draw-boy. The machinery for arranging the punches, consists of a frame with four upright standards and cross-pieces, which contains a series of endless cords passing under a wooden roller at bottom, and over pulleys at the top. These pulleys are mounted on axles in two frames, placed obliquely over the top of the standard frame, which pulley frames constitute the table commonly used by weavers. In order better to explain these endless cords, fig. 784 represents a single endless cord 1, 1, which is here shown in operation, and part of another endless cord 2, 2, shown stationary. There must be as many endless cords 7 84 ^ I in this frame as needles in the weaving-loom. a is \ 784 D z l the wooden cylinder, revolving upon its axis at the lower part of the standards; b b, the two pulleys of the pulley-frames above, over which the individual end1 \ less cord passes; c is a small traverse ring. To each of these rings a weight is suspended by a single thread, for the purpose of giving tension to the endless cord. 2 \2 j C (d is a board resembling a common comber-bar, which is supported by the cross-bars of the standard frame, _ p 1 (ym 1and is pierced with holes, in situation and number, _! =a? i corresponding with the perpendicular threads that 9 - \\ 112 pass through them; which board keeps the threads distinct fiom each other. At e, the endless cord passes through the eyes of wires resembling needles, which are contained in a wooden box placed in front of the machine, and shown in this figure in section only. These wires are called the punch-projectors; they are guided and supported'aV\&^ ~ by horizontal rods and vertical pins, the latter of which pass through loops formed at the hinder part of the respective wires. At f are two horizontal rods extending the whole width of the machine, for the purpose of producing the cross in the cords; g is a thick brass plate, extending along in front of the machine, and lying close to the box which holds the punch-projectors; this plate g, shown also in section, is called the punch-holder; it contains the same number of apertures as there are punch-projectors, and disposed so as to correspond with each other. In each of these apertures, there is a punch for the purpose of piercing the cards, slips, or pasteboards with holes; h is a thick steel plate of the same size as g, and shown likewise in section, corresponding also in its number of apertures, and their disposition, with the punch-projectors and the punch-holder. This plate h, is called the punch-receiver. The object of this machine is to transfer such of the punches as may be required foi piercing any individual card from the punch-holder g, into the punch-receiver h; when they will be properly situated, and ready for piercing the individual card or slip, with 1032 ICE-HOUSE. such holes as have been read in upon the machine, and are required for permitting tht warp threads to be withdrawn in the loom, when this card is b'rought against the ends of the needles. The process of transferring the patterns to the punches will be effected in the following manner. The pattern is to be read in, according to the ordinary mode, as in a false simple, upon the endless cords below the rodsf, and passed under the revolving wooden cylinder a, to a sufficient height for a person in front of the machine to reach conveniently. He there takes the upper threads of the pattern, called the beard, and draws them forward so as to introduce a stick behind the cords thus advanced, as shown by dots, for the purpose of keeping them separate from the cords which are not intended to be operated upon. All the punch-projectors which are connected with the cords brought forward, will be thus made to pass through the corresponding apertures of the punch-holder g, and by this means will project the punches out of these apertures, into corresponding apertures of the punch-receiver h. The punches will now be properly arranged for piercing the required holes on a card or slip, which is to be effected in the following manner. Remove the punch-receivers from the front of the machine; and having placed one of the slips of card or pasteboard between the two folding plates of metal, completely pierced with holes corresponding to the needles of the loom, lay the punch-receiver upon those perforated plates; to which it must be made to fit by mortises and blocks, the cutting parts of the punches being downwards. Upon the back of the punch-receiver is then to be placed a plate or block, studded with perpendicular pins corresponding to the above described holes, into which the pins will fall. The plates and the blocks thus laid together, are to be placed under a press, by which means the pins of the block will be made to pass through the apertures of the punch-receiver; and wherever the punch has been deposited in the receiver by the above process, the said punches will be forced through the slip of pasteboard, and pierced with such holes as are required for producing the figured design in the loom. Each card being thus pierced, the punch receiver is returned to its place in front of the machine, and all the punches forced back again into the apertures of t.e punch holder as at first. The next set of cords is now drawn forward by the next beard, a= above described, which sends out the punch-projectors as before, and disposes the punches in the punch-receiver, ready for the operation of piercing the next card. The process being thus repeated, the whole pattern is, by a number of operations, transferred to the punches, and afterwards to the cards or slips, as above described. JADE, axe-stone (Nephrite, Ceraunile, Fr.), is a mineral commonly of a greenish color, compact, and of a fatty lustre. Spec. Grav. 2-95; scratches glass, is very tough; fuses into a white enamel. Its constituents are, silica, 50-5; alumina, 10; magnesia, 31; oxyde of iron, 5-50; oxyde of chrome, 0-05; water, 2'75. It comes from China, is used among rude nations for making hatchets; and is susceptible of being cut into any form. JAPANNING, is a kind of varnishing or lackering, practised with excellence by the Japanese, whence the name. See VARNISH. JASPER (Jaspe calcedoine, Fr.; Jaspis, Germ.) is a sub species of calcedony quartz, of which there are five varieties. 1. The Egyptian red and brown, with ring or tendrilshaped delineations. 2. Striped jasper. 3. Porcelain jasper. 4. Common jasper. 5. Agate jasper. The prettiest specimens are cut for seals, and for the inietoor kinds of jewellery ornaments. See LAPIDARY. ICE-HOUSE; (Glaciere, Fr.; Eishaus, Germ.) Under the article FREEZING I have enumerated the different artificial methods of producing cold.* But for the uses of common life, in these climates, the most economical and convenient means of refrigeration in hot weather may be procured by laying up a store of ice in winter, in such circumstances as will preserve it solid during summer. An ice-house should not be regarded as an object of mere luxury, for pleasing the palates of gourmands with iced creams and orgeats. In the southern countries of Europe it is considered among people in easy circumstances as an indispensable appendage to a country mansion. During the Dog-days, especially at those periods and in those districts where the sirocco blows, a lassitude and torpor of mind and body supervene, with indigestion or total loss of appetite, and sometimes dysenteries, c;ach are obviously occasioned by the excessive heat, and are to be prevented or counteracted chiefly by the use of cold beverages. By giving tone to the stomach, iced drinks immediately restore the functions of the nervous and muscular systems when they are languid; while they enable persons in health to endure without much inconvenience an atmosphere so close and sultry as would be intolerable without this remedy. Ice-houses, moreover, afford to country gentlemen a great advantage in enabling them to preserve their fish, butcher meat, dead poultry, and game, which would otherwise, in particular states of the weather, immediately spoil. Considering at how little expense and:'-buble an ice-house can be ICE PRODUCING MACHINE. 1033 constructed, it is surprising that any respectable hanitation in the country should not have one attached to it. The simplest and most scientific form is a double cone, that is, twc cones joined base to base; the one being of stones or brickwork, sunk under ground with its apex at the bottom, into which the ice is rammed; the other being a conical roof of carpentry covered with thatch, and pointed at top. The entrance should be placed always on the north side; it should consist of a corridor or porch with double doors, and be screened from the sunbeams by a small shrubbery. Such are, in general, the principles upon which an ice-house should be formed; but they will be better understood by the following explanation and figure. A dry sandy soil should be selected, and, if possible, a spot sheltered by a cliff or other natural barrier from the direct rays of the sun. Here a cavity is to be dug about 16 feet in diameter, terminating below like the point of a sugar loaf. Its ordinary depth, for a moderate family, may be about 24 feet; but the larger its dimensions are, the longer will it preserve the ice, provided it be filled. In digging, the workman should slope the ground progressively towards the axis of the cone, to prevent the earth falling in. This conical slope should be faced with brick or stone work about one foot thick, and jointed with Roman cement so as to be air and water tight. A well is to be excavated at the bottom two feet wide and four deep, covered at top with an iron grating for supporting the ice, and letting the water drain away. The upper cone may likewise be built of brickwork, and covered with thatch; such a roof would prove the most durable. This is the construction shown in ft,. 785. What ever kind of roof be preferred, there must be left in it an oblong passage into the interior. This porch should face the north, and be at least 8 feet long by 2- feet wide; and perfectly closed by a well-fitted door at each end. All round the bottom of this conical cover, a gutter should be placed to carry off the rain to a distance from the ice-house, and prevent the circumjacent ground from getting soaked with moisture. Fig. 185 shows the section of a well-constructed ice-house. Under the ice —hamber A the ice is rammed into the space B. c is the grate of ths drain-sink D. The portion E E is built in brick or stone; the base L of the ice-chamber slopes inwards to wards the centre at c. The upper part of the brickwork E E is a little way below the 785 F level of the ground. The wooden frame work F F F forms the roof, and is covered with thick thatch. G H is the wooden work of the door i. At K the bucket is seen for lifting up a charge of ice, by means of the cord J passing over the pulley m, FV Fs jF JA which enables the servant to raise it easily. The icehouse should have no window to admit -AG' light; but be, so to speak, hermetically sealed in every point, except at its cess-pool, which may terminate in a water trap to prevent circulation of air. A clear day should be selected for charging the icehouse; but before beginning to fill, a quantity of long dry straw should be laid on the bottom crosswise; and as the ice is progressively introduced, straw is to be spread against the conical sides, to pre. vent the ice from coming into contact with the brick or stone work. The more firmly compacted the iet is, the better does it keep; with which view it should be broken into pieces with mallets before being thrown in. No layers of straw should be stratified among the ice, for they would make its body porous. Some persons recommend to pour in a little water with the successive layers of ice, in order to fill up its small crevices, and convert the whole into one mass. Over the top layer a thick bed of straw should be spread, which is to be covered with boards surmounted with heavy stones, to close up the interstices in the straw.'The inner and outer doors should never be opened at once; but the one should always be shut before the other is opened. Dry snow well rammed keeps equally well with hard ice, if care be taken to leave no cavities in the mass, and to secure its compactness by sprinkling a little water upon the successive charges. To facilitate the extraction of the ice, a ladder is set up against its sloping wall at one side of the door, and left there during the season. ICE PRODUCING MACHINE. It is well known that by the rapid condensation At air or other elastic fluid, so much heat may be evolved as to ignite tinder, &c. It appears from a communication in the Mechanics' Magazine of February, 1851; that Dr. Gorrie 1034 ILLUMINATION, COST OF. a physician in New Orleans, has on this principle constructed an apparatus for producing so much cold as to freeze water, by exposure to the condensed air in the act of its subsequent expansion. Gay Lussac, many years ago, made use of a jet of condensed air to refrigerate any body such as a glass globe filled with water, upon which the expanding air was allowed to play, and he even caused water contained in the globe to freeze. Now the American process is quite identical with that of the French chemist, but on a vastly enlarged scale, for he employs the power of a steam engine acting on a pump 8 inches in diameter, with a 16 inches stroke, to condense the air into one third its volume, into a vessel, where it is cooled by water. A pump is made to throw in a jet of cold water at the same time to quicken the refrigeration. It is said that in this way a block of ice of 60 lbs. was formed; a circumstance which appears to me quite incredible. In fact, the whole statement has a most apocryphal air, and I do not believe that any such result could have been produced, as the reporter says, by the labour of two men at a couple of pumps in alternate action. The inventor's object at first was to ventilate and cool the atmosphere of sick rooms, where febrile patients lay. " This case is one among the many examples of a useful scientific invention remaining long dormant or sterile." The hydrostatic paradox of Archimedes is a parallel instance, in reference to Bramah's press. ICE BY THE RED-HOT PROCESS. One of the most singularly beautiful experiments perhaps ever devised, has been recently published by M. Prevostaire, illustrative of the repellent power of heat radiating from bodies at a high temperature, and of the rapid abstraction of heat, produced by evaporation, or generally by such a change of condition as largely increases the volume of any body. The experiment is simply this:-A platina crucible is made and maintained red-hot over a large spirit lamp. Some sulphurous acid is poured into it from a pipette. This acid, though at common temperatures one of the most volatile of known bodies, possesses the singular property of remaining fixed in the red-hot crucible and not a drop of it evaporates: in fact, it is not in contact with the crucible, but has an atmosphere of its own interposed. A few drops of common water are now added to the sulphurous acid in the red-hot crucible. The diluted acid gets into immediate contact with the heated metal, instantly flashes off into sulphurous acid vapour, and such is the rapidity and energy of the evaporation that the water remains behind, and is found frozen into a lump of ice in the red-hot crucible, from which, seizing the moment before it again melts, it may be thrown out before the eyes of the astonished observer. JELLY, VEGETABLE, of ripe currants and other berries, is a compound of mucilage and acid, which loses its power of gelatinizing by prolonged ebullition. JELLY, ANIMAL; see GELATINE, GLUE and ISINGLASS. JET; (Jaiet or jais, Fr.) a species of pitch coal, or glance-coal, which, being found abundantly in a beautiful compact form, in the valley of Hers, arrondissement of Pamiers, department of the Arriege, has been worked up extensively there, from time immemorial, into a multitude of ornamental articles. With this black lignate, buttons, crosses, rosaries, necklaces, ear-drops, bracelets, waist-buckels, &c., are made, which were at one time much worn by ladies for mourning dresses. The greater number of these ornaments are fashioned upon grindstones which turn in a horizontal direction, and are kept continually wet; others are turned at the lathe, or shaped by files. About 40 years ago this manufacture employed from 1000 to 1200 operatives; at present it gives bread to only 60. This falling off may be ascribed to the successful imitation of the jet articles by those of black glass, which are equally beautiful, and not nearly so apt to lose their polish by use. JET PUMP. The purpose for which this instrument is designed, is to clear the water out of the pits of submerged water-wheels, when access to them is required for inspection or repairs. For this special purpose it is likely to prove very useful; though at the same time, there are very few other cases in which it could not be employed with advantage. The action of the jet pump depends on two principles. One of these is the same as that of steam blast used in locomotive engines, and in the ventilation of mines. The other is one which was known to the ancient Romans, and was used sometimes by them for drawing off more water from the public pipes than they paid for. The jet pump was first tried at the mill of Messrs. Herdman & Co., Belfast, when it was found most successful. ILLUMINATION, COST OF. The production, diffusion, and economy of light, are subjects of the highest interest both to men of science and men of the world; leading the former to contemplate many of the most beautiful phenomena of Physics and Chemistry, while they provide the latter with the artificial illumination so indispensable to the business and pleasures of modern society. The great cost of light from wax, spermaceti, and even stearic candles, as also the nuisance of the light from tallow ones, have led to the invention of an endless variety of lamps, of which the best hithertn known is undoubtedly the mechanical or Carcel lamp, so generally used by the opulent ILLUMINATION, COST OF. 103& families in Paris. In this lamp the oil is raised through tubes by clock-work, so as continually to overflow at the bottom of the burning wick; thus keeping it thoroughly soaked, while the excess of the oil drops back into the cistern below. I have possessed for several years an excellent lamp of this description, which performs most satisfactorily; but it can hardly be trusted in the hands of a servant; and when it gets at all deranged, it must be sent to its constructor in Paris to be repaired. The light of this lamp, when furnished with an appropiiate tall glass chimney, is very brilliant, though not perfectly uniform; since it fluctuates a little, but always perceptibly to a nice observer, with the alternating action of the pump-work; becoming dimmer after every successive jet of oil, and brighter just before its return. The flame, moreover, always flickers more or less, owing to the powerful draught, and rectangular reverberatory shoulder of the chimney. The mechanical lamp is, however, remarkable for continuing to burn, not only with unabated but with increasing splendour for seven or eight hours; the vivacity of the combustion increasing evidently with the increased temperature and fluency of the oil, which, by its ceaseless circulation through the ignited wick, gets eventually pretty warm. In the comparative experiments made upon different lights by the Parisian philosophers, the mechanical lamp is commonly taken as the standard. I lc not think it entitled to this pre-eminence: for it may be made to emit very different quantities of light, according to differences in the nature and supply of the oil, as well as variations in the form and position of the chimney. Besides, such lamps are too rare in this country to be selected as standards of illumination. After comparing lights of many kinds, I find every reason to conclude that a large wax candle of.three to the pound, either long or short, that is, either 12 or 15 inches in length, as manufactured by one of the great wax-chandlers of London, and furnished with a wick containing 27 or 28 threads of the best Turkey cotton, is capable of furnishing a most uniform, or nearly invariable standard of illumination. Its affords one tenth of the light emitted by one of the Argand lamps of the Trinity house, and one eleventh of the light of my mechanical lamp, when each lamp is made to burn with its maximum flame, short of smoking. The great obstacle to the combustion of lamps, lies in the viscidity, and consequent sluggish supply of oil, to the wicks; an obstacle nearly insuperable with lamps of the common construction during the winter months. The relative viscidity, or relative fluency of different liquids at the same temperature, and of the same liquid at different temperatures, has not, I believe, been hitherto made the subject of accurate researches. I was, therefore, induced to make the following experiments with this view. Into a hemispherical cup of platinum, resting on the ring of a chemical stand, I introduced 2,000 water-grain measures of the liquid whose viscidity was to be measured, and ran it off through a glass syphon, s of an inch in the bore, having the outer leg 3^ inches, and the inner leg 3 inches long. The time of efflux became the measure of the viscidity; and of two liquids, if the specific gravity, and consequent pressure upon the syphon, were the same, that time would indicate exactly the relative viscidity of the two liquids. Thus, oil of turpentine and sperm oil have each very nearly the same density; the former being, as sold in the shops, =0'876, and the latter from 0'876 to 08S0, when pure and genuine. Now I found that 2,000 grain-measures of oil of turpentine ran off through the small syphon in 95 seconds, while that quantity of sperm oil took 2,700 seconds, being in the ratio of 1 to 282; so that the fluency of oil of turpentine is 28- times greater than that of sperm oil. Pyroxilic spirit, commonly called naphtha, and alcohol, each of specific gravity 0'825, were found to run off respectively in 80 and 120 seconds; showing that the former was 50 per cent. more fluent than the latter. Sperm oil, when heated to 265 Fahr., runs off in 300 seconds, or one ninth of the time it took when at the temperature of 64~. Southern whale oil, having a greater density than the sperm oil, would flow off faster were it not more viscid. 2,000 grain-measures of water at 60~ run off through the said syphon in 75 seconds, but when heated'to 180~, they run off in 61 Concentrated sulphuric acid, though possessing the great density of 1-840, yet flows off very slowly at 64~, on account of its viscidity; whence its name of oil of vitriol. 2,000 grain-measures of it took 660 seconds to discharge. Mr. Samuel Parker, long advantageously known to the public for his sinumbral and pneumatic fountain lamps, as well as other inventions subservient to domestic comfort, having obtained a patent for a new lamp, in which the oil is heated by a very simple contrivance, in the cistern, to any desired degree, before arriving at the wick, I instituted an extensive series of experiments to determine its value in the production of light, and consumption of oil, compared to the value of other lamps, as well as candles, in these respects. In fig. /86, A, A, B, B, is a section of the cylinder which constitutes the cistern; the oil bein contained between the inne r and outer cylinders, and receiving heat from the flame of the lamp which passes up through the inner cylinder, and is rever. 1036 ILLUMINATION, COST OF. berated more or less against its sides by the top of the metal chimney, being notched and bent back. D is a slide-valve which is opened to allow the oil to descend to the wick, and is shut when the cistern is to be separated from the pipe of supply, at E, for the purpose of recharging it with oil. The flame is modified, not by raising or lowering the wick, as in common lamps, but by raising or lowering the bell-mouthed glass chimney which rests at its bottom on three points, and is moved by means of the rack-work mechanism F. The concentric cylindric space A,'A, and B, B, contains a pint imperial, and should be made entirely full before lighting the lamp; so as to leave no air in the cistern, which, by its expansion with the heat, would inevitably cause an overflow of the oil. The following arrangement was adopted in these experiments for determining the relative illumination of the different lights. Having trimmed, with every precaution, my French mechanical lamp, and charged it with pure sperm oil, I placed it upon an oblong table, at a distance of 10 feet from a wall, on which a white sheet of paper was stuck. One of Mr. Parker's hot-oil lamps, charged with a quantity of the same oilj was placed upon the same table; and each being made to burn with its maximum 786 w a...\... Sade. /. /, | \.' t //;,, /~~~I 5 ~~/' /, L:::.^ w;.... 5":.,,. brilliancy, short of smoking, the relative illumination of the two lamps was determined by the well-known method of the comparison of shadows; a wire a few inches long, and of the thickness of a crow-quill, being found suitable for enabling the eye to estimate very nicely the shade of the intercepted light. It was observed in numerous trials, both by my own eyes and those of others, that when one of the lamps was shifted half an inch nearer to or further from the paper screen, it caused a perceptible difference in the tint of the shadow. Professor Wheatstone kindly enabled me to verify the precision of the above method of shadows, by employing, in some of the experiments, a photometer of his own invention, in which the relative brightness of the two lights was determined by the relative brightness of the opposite sides of a revolving silvered ball, illuminated by them. ]. The mechanical lamp was furnished with a glass chimney 1-5 inches in diameter at the base, and 1-2 at top; the wide bottom part was 1l8 inches long, and the narrow upper part 8 inches. When placed at a distance of 10 feet from tte wall its light there may be estimated as the square of this number, or 100. In the first series of experiments, when burning with its maximum flame, with occasioned flickerins of smoke, t emitted a light equal to that of 11 wax candles, and consumed 912 grains of oil per nour. The sperm oil was quite pure, having a specific gravity of 0-874 compared tc ie ILLUMlhNA rION, COST OF. 1037 water at 1,000. In a E ibsequent series of experiments, when its light was less flickering, and equal only to that of 10 wax candles, it consumed only 815 grains, or 0-1164 of a lb. per hour. If we multiply this number into the price of the oil (8s. per gallon) pel lb. 11d., the product 1'2804d. will represent the relative cost of this illumination, estimated at 100. 2. The hot-oil lamp burns with a much steadier flame than the mechanical, which must be ascribed in no small degree to the rounded slope of the bell-mouthed glass chimney, whereby the air is brought progressively closer and closer into contact with the outer surface of the flame, without being furiously dashed against it, as it is by the rectangular shoulder of the common contracted chimney. When charged with sperm oil, and made to:arn with its maximum flame, this lamp required to be placed one foot further from the screen than the mechanical lamp, in order that its shadow should have the same depth of tint. Hence, its relative illumination was, in that case, as the square of 11 to the square of 10'; or as 121 to 100. Yet its consumption of oil was only 696 grains, or somewhat less than 0-1 of a pound per hour. Had its light been reduced to 100, it would have consumed only 576 grains per hour, or 0-82 of a pound. If we multiply this number by lld., the product 0-902d. will represent the relative cost of 100 of this illumination. 3. The hot-oil lamp being charged with the southern whale oil, of specific gravity 9'926, at 2s. 6d. per gallon, or 3*d. per lb., when burning with its maximum flame, required to be placed 9 feet and 1 inch from the screen to drop the same tint of shadow upon it as the flames of the other two lamps did at 10 and 11 feet with the sperm oil. The square of 9 feet and 1 inch = 82 is the relative illumination of the hot-oil lamp with the southern whale oil. It consumed 780 grains, or 0-111 of a pound per hour; but had it given 100 of light it would have consumed 911 grains, or 0-130 of a pound, which number being multiplied by its price 3-d., the product 0-4875d. will represent the relative cost of 100 of this light. 4. A hot-oil lamp charged with olive oil of specific gravity 0-914, at 5s. 6d. per gallon, or 7-d. per lb. when burning with its maximum flame, required to be placed at 9 feet 6 inches, to obtain the standard tint of shadow upon the screen. It consumed 760 grains per hour. The square of 9- feet is 90^, which is the relative intensity of the light of this lamp. Had it emitted a light = 100, it would have consumed 840 grains, or 0-12 of a pound per hour-which number multiplied by the price per pound, gives the product 0'9d. as the relative cost of 100 of this light. 5. A hot-oil lamp charged with Price and Co.'s cocoa-nut oil (oleine), of specific gravity 0-925, at 4s. 6d. per gallon, or 5-d. per lb., had to be placed 9 feet from the screen, and consumed 1,035 grains per hour. Had its light been 100 instead of 81 (92), the consumption would have been 1,277 grains, or 0-182 of a pound per hour! which number multiplied by its price per pound, the product 1-03 ld. will represent the cost of 100 of this illumination. 6. In comparing the common French annular lamp in general use with the mechanical lamp, it was found to give about one half the light, and to consume two thirds of the oil of the mechanical lamp. 7. Wax candles from some of the most eminent wax-chandlers of the metropolis were next subjected to experiment; and it is very remarkable that, whether they were threes, fours, or sixes in the pound, each afforded very nearly the same quantity of light, for each required to be placed at a distance of three feet from the screen to afford a shadow of the same tint as that dropped from the mechanical lamp, estimated at 100. The consumption of a genuine wax candle, in still air, is upon an average of many experiments, 125 grains per hour, but as it affords only 1 11th of the light ef the mechanical lamp, 11 times 125== 1,375 grains, or 0-1064 of a pound is the quantity that would need to be consumed to produce a light equal to that of the said lamp. If we multiply that number by the price of the candles per lb. = 30d. the product = 5-892d. is the cost of 100 of illumination by wax. A wax candle, three in the pound (short), is one inch in diameter, 12 inches in length, and contains 27 or 28 threads, each about 1 10th of an inch in diameter. But the quality of the wick depends upon the capillarity of the cotton fibrils, which is said to be greatest in the Turkey cotton, and hence the wicks for the best wax candles are always made with cotton yarn imported from the Levant. A wax candle, three in the pound (long), is of an inch in diameter, 15 inches long, and has 26 threads in its wick. A wax candle, six to the pound, is 9 inches long, 4 5ths of an inch in diameter, and has 22 threads in its wick. The light of this candle may be reckoned to be, at most, about 1 11th less than that of the threes in the pound. A well-made short three burns with surprising regularity in still air, being at the rate of an inch in an hour and a half, so that the whole candle will last 18 hours. A long three will last as long, and a six about 91 hours. Specific gravity of wax 0-960. 8. A spermaceti candle, three in the pound, is 9 lOths of an inch in diameter, 15 inches long, and has a plaited wick, instead of the parallel threads of a wax candle. ThE 1 _____ _ ________________________________________ 1038 ILLUMINATION, COST OF. same candles four in the pound, are 8 lOths of an inch in diameter, and 134 inches long Each gives very nearly the same quantity of light as the corresponding wax candles: viz., 1 11th of the light of the above mechanical lamp, and consumes 142 grains pet hour. Multiplying the last number by 11, the product, 1,562 grains = 0'223 of a poune would be the consumption of spermaceti requisite to give 100 of illumination. Multi plying the last number by 24d., the price of the candles per pound, the product 5-352d. is the relative cost of 100 of this illumination. 9. Stearic'acid candles, commonly called German wax, consume 168*5 grains, or &024 of a pound per hour, when emitting the same light as the standard wax candle. Multiplying the latter number by 11, and by 16d. (the price of the candles per pound), the product 4'224d. will represent the relative cost of 100 of this illumination. 10. Tallow candles: moulds, short threes, 1 inch in diameter, and 121 in length; do, long threes, 9 lOths of an inch in diameter, and 15 in length; do., long fours, 8 lOths oi an inch in diameter, and 13 in length. Each of these candles burns with a most un certain light, which varies from 1 12th to 1 16th of the light of the mechanical lampthe average may be taken at 1 14th. The threes consume each 144 grains, or 0-2 of a pound, per hour; which number, multiplied by 14, and by 9d. (the price per pound), gives the product 2-52d. for the relative cost of 100 of this illumination. 11. Palmer's spreading wick candles. Distance from the screen 3 feet 4 inches, with a shadow equal to the standard. Consumption of tallow per hour 232'5 grains, or 0'0332 of a pound. The square of 3 feet 4 inches = 11'9 is the relative illumination of this candle = 11-9: 0-3332:: 100: 0-28 X 10d. = 11-9 is the relative cost of this illumination. 12. Cocoa-nut stearine candles consumed each 168 grains per hour, and emitted a light equal to 1 16th of the standard flame. Multiplying 168 by 16, the product 30-88 grains, or 0-441 of a pound, is the quantity which would be consumed per hour to afford a light equal to 100. And 0-441 multiplied by 10d., the price per pound, gives the product 4-441d. as the cost of 100 of this illumination per hour. A gas argand London lamp, of 12 holes in a circle of ] of an inch in diameter, with a flame 3 inches long, afforded a light = 78 compared to t he mechanical lamp: and estimating the light of the said mechanical lamp as before, at 100, that of the hot-oil lamp is 121, and that of the above gas flame of 78-57, or in round numbers 80, and the common French lamp in general use 50. Collecting the preceding results, we shall have the following tabular view of the cost per hour of an illumination equal to that of the mechanical lamp, reckoned 100, or that of eleven wax candles, three to the pound. TABLE of COST per HOUR of ONE HUNDRED of ILLUMINATION. Pence. Pence 1. Parker's hot-oil lamp, with southern whale oil - 0-4875 or about -d. 2. Mechanical or Carcel lamp, with sperm oil - - 1-2804 - - 14 3. Parker's hot-oil lamp, with sperm oil - - - 0-902 - - 1 4. Ditto ditto common olive oil - - 0900 - - 1 5. Ditto ditto cocoa-nut oleine or oil - 1031 - - 1 6. French lamp in general use, with sperm oil - - 1-7072 - - 14 7. Wax candles - - - -- 5-892 - - 6 8. Spermaceti candles - - - - - 5352 - - 59. German wax (Stearic acid) ditto - - 4-224 - -410. Palmer's spreading wick candles - - - 2800 - - 2~ 11. Tallow (mould) candles - - - 2-520 - - 22 12. Cocoa-nut stearine of Price and Co. - - - 4-41 - - 44 Since the hot-oil lamp affords sufficient light for reading, writing, sewing, &c., with one fifth of its maximum flame, it will burn at that rate for 10 hours at the cost of about ONE PENNY, and it is hence well entitled to the inventor's designation, "The Economic." Sir D. Brewster, in his examination lately before the committee of the house of commons on lighting the house, stated, that the French light-house lamp of Fresnel emitted a light equal to that of forty argand flames; whereas, according to other accounts, it gave much less light. With the view of settling this point, before being examined by the said committee, I repaired to the Trinity house, and tried one of the two original Fresnel lamps, which had been deposited there by that eminent French engineer himself. This lamp consists of four concentric circular wicks, placed in one horizontal plane; the innermost wick being 7 of an inch in diameter, and the outermost 34 inches. Being carefully trimmed, supplied with the best sperm oil, surmounted with its great glass chimney, burning with its iraximum flame, and placed at a distance of 13 feet 3 inches from the screen, it let fall a shadow of the same tint as that let fal ILLUMINATION, COST OF. 1039 by the flame of my mechanical lamp, placed at a distance of 4 feet 6 inches from the screen. The squares of these two numbers are very nearly as 8I to 1 (175-5625 tc 20-25); showing that the Fresnel lamp gives less than 9 times the light of my me. chanical lamp, and about 9-6 times the light of one of the Trinity house argand lamps. The Fresnel lamp is exceedingly troublesome to manage, from the great intensity of its heat, and the frequent fractures of its chimneys-two having been broken in the course of my experiments at the Trinity house. Mr. Goldsworthy Gurnay, the ingenious inventor of the new light-house lamp, in which a stream of oxygen gas is sent up through a small tube within the burning cir. tular wick of a small argand lamp, having politely sent two of his lamps to my house, -long with a bag of oxygen gas, I made the following experiments, to ascertain their illuminating powers compared to those of the mechanical lamp and wax candles. His larger lamp has a wick | of an inch in diameter, but emits an oxygen flame of only t of an inch. The flame is so much whiter than that of the best lamp or candle that it becomes difficult to determine, with ultimate precision, the comparative depths of the shadows let fall by them. The mean of several trials showed that the above Bude-light (as Mr. Gurney calls it, from the name of his residence in Cornwall), has an illuminating power of from 28 to 30 wax candles. His smaller lamp has a flame 4 of an inch in diameter, and a wick 2 of an inch. Its light is equal to that of from 18 to 20 wax candles. The committee of the house of commons on lighting it, having asked me what was the relative vitiation of air by the breathing of men and the burning of candles, I gave the following answer:Wax contains 81*75 parts of carbon in 100, which generate by combustion 300 parts of carbonic acid gas. Now, since 125 grains of wax constitute the average consumption of a candle per hour, these will generate 375 grains of carbonic acid; equivalent in volume to 800 cubic inches of gas. According to the most exact experiments on respiration, a man of ordinary size discharges from his lungs 1,632 cubic inches of carbonic acid gas per hour, which is very nearly the double of the quantity produced from the wax candle. Hence the combustion of two such candles vitiates the air much the same as the breathing of one man. A tallow candle, three or four in the pound, generates nearly the same quantity of carbonic acid as the wax candle; for though tallow contains only 79 per cent. of carbon, instead of 81.75, yet it consumes so much faster, as thereby to compensate fully for this difference. When a tallow candle of 6 to the lb. is not snuffed, it loses in intensity, in 30 minutes, 80 hundredths; and in 39 minutes 86 hundredths, in which dim state it remains stationary, yet still consuming nearly the same proportion of tallow. A wax candle attains to its greatest intensity of light when its wick has reached the greatest length, and begins to bend out of the flame. The reason of this difference is, that only the lower part of the wick in the tallow candle is charged with the fat, so as to emit luminiferous vapor, while the upper part remains dry; whereas, in the wax candle, the combustible substance being less fusible and volatile, allows a greater length of the wick to be charged by capillary attraction, and of course to emit a longer train of light. The following table contains, according to Peclet, the illuminating powers of different candles, and their consumption of material in an hour; the light emitted by a Car. eel argand lamp, consuming 42 grammes (= 42 X 15- grains) in an hour, being called 100:Intensity of Light. Consumption per Hour Tallow Candles 6 in lb. - - 10-66 8'51 Stearine, or Pressed Tallow, 8 in lIb. - 874 7-51 5 in 11. - 7.50 7-42 Wax Candles, 5 in lb. - - - 1361 8'71 Spermaceti ditto, 5 in lb. - - 1440 8*92 Stearic Acid, commonly called Stea- rine, 5 in lb. - - - - 1440 9-33 The subjoined table shows the economical ratios of the candles, where the second column gives the quantity of material in grammes which is requisite to produce as much ight as the Carcel lamp: 040 JINTA-WAN. Quality of Price per Kilo- Cost of Light per Material. gramme. Hour. Tallow candle, 6 per lb. - 7035 1 f. 40 c. 9-8 c. -- -, 8 per lb. - - - 592 1 f. 40 c. 12-0 c. Pressed tallow, 5 pea lb. - - 9893 2 f. 40 c. 23'7 c Wax candle, 5 per lb. - - - 6404 7 f. 60 c. 48-6 c. Spermaceti ditto, 5 per b. - 6194 7 f. 60 c. 47-8 c. Stearine, 5 per lb. - - - 65-24 6 f. 371 c. These results may be compared with mine given above. A kilogramme, or 100C grammes = 15,440 grains - 21 lbs. avoirdupois. JINTA-WAN. A compound, elastic, water-repellent substance for manufacturing purposes is made by combining gutta percha with an elastic and water-repellent substance called "jinta-wan," recently imported for the first time from the East Indies, and which has never heretofore, to the best of my knowledge and belief, been used in the arts and manufactures of this country; or by combining gutta percha with "jinta-wan" and caoutchouc. The gutta percha which is intended to be combined in this way should, if necessary, be cleansed from impurities, and may if desired be previously prepared as heretofore described. The jinta-wan, or caoutchouc, should also be cleansed from its impurities, if any. Gutta percha and jinta-wan are combined by placing these two substances in the intended proportions (cut into pieces) in a masticator, such as is used for masticating caoutchouc, and then operate upon the two materials by that machine until they are intimately blended together. And the triple combination of gutta percha, jinta-wan, and caoutchouc are combined by means of a masticator, in the same manner. For the purpose of making these combinations, the proportions of the two, or of the three substances may be combined according to the quality which it is desired that the combined substance shall possess, employing a larger proportion of any one of the substances to be combined, when it is desired that the peculiar qualities of that substance shall predominate in the combined article. See GUTTA PERCHA. IMPERMEABLE, is the epithet given to any kind of textile fabric, rendered waterproof by one or other of the following substances:1. Linseed oil to which a drying quality has been communicated by boiling with litharge or sugar of lead, &c. 2. The same oil holding in solution a little caoutchouc. 3. A varnish made by dissolving caoutchouc in rectified petroleum or naphtha, applied between two surfaces of cloth, as described under Macintosh's patent. See CAOUTCHOUC. 4. Vegetable or mineral pitch, applied hot with a brush, as in making tarpauling for covering goods in ships. 5. A solution of soap worked into cloth, and decomposed in it by the action of a solution of alum; whence results a mixture of acid fats and alumina, which insinuates itself among all the woolly filaments, fills their interstices, and prevents the passage of water. 6. A solution of glue or isinglass, introduced into a stuff, and then acted upon by a clear infusion of galls, whereby the fibres get impregnated with an insoluble, impermeable, pulverulent leather. 7. Plaster work is rendered impermeable by mixing artificial or natural asphaltum with it. JEWELLERY, Art of. See GEM and LAPIDARY. iNCOMBUSTIBLE CLOTH; is a tissue of the fibrous mineral called amianthus or asbestos: This is too rare to form the object of any considerable manufacture. Cotton and linen cloth may be best rendered incapable of taking fire, or burning with flame, by being imbued with a solution of sal ammoniac.'INCUBATION, ARTIFICIAL. The Egyptians have from time immemorial been accustomed to hatch eggs by artificial warmth, without the aid of hens, in peculiar stoves, called Mammals. The inhabitants of the village Berm6 still travel through the most distant provinces of Egypt at certain seasons of the year, with a portable furnace, heated by a lamp, and either hatch chickens for sale, or undertake to hatch the eggs belonging to the natives at a certain rate per dozen. M. de Reaumur published in France about a century ago, some ingenious observations upon this subject; but M. Bonnemain was the first person who studied with due attention all the circumstances of artificial incubation, and mounted the process successfully upon the commercial scale. So far back as 1'77 he communicated to the Academy of Sciences an interesting fact, which he had -~~~~ """" ~~~ ""'____J" ""' """""" INCUBATION, ARTIFICIAL. 1041 noticed, upon the mechanism employed by chicks to break their shells; and for some time prior to the French revolution he furnished the Parisian market with excellent poultry at a period of the year when the farmers had ceased to supply it. His establishment was ruined at that disastrous era, and no other has ever since been constructed or conducted with similar care. As there can be no doubt however of the practicability and profitableness of the scheme, when judiciously managed, I shall insert a brief account of his ingenious arrangements. I had the pleasure of making the acquaintance of this amiable oldman at my first visit to Paris, many years ago, and believe all his statements to be worthy of credit. Some imitations of his plans have been made in this country, but how far they have succeeded in an economical point of view, it is difficult to determine. His apparatus derives peculiar interest from the fact, that it was founded upon the principle of the circulation of hot water, by the intestine motion of its particles, in a returning series of connected pipes; a subject afterwards illustrated in the experimental researches of Count Rumford. It has of late years been introduced as a novelty into this country, and applied to warm the apartments of many public and private buildings. The following details will prove that the theory and practice of hot-water circulation were as perfectly understood by M. Bonnemain fifty years ago, as they are by any of our stove doctors at the present day. They were then publicly exhibited at his residence in Paris, and were afterwards communicated to the world at large in the interesting article of the Dictionnaire Technologique, entitled Incubation Artificielle. The apparatus of M. Bonnemain consisted; 1. of a boiler, and pipes for the circulation of water; 2. of a regulator calculated to maintain an equable temperature; 3. of a stove-apartment, heated constantly to the degree best fitted for incubation, which he called the hatching pitch. He attached to one side a poussiniere or chick-room, for cherishing the chickens during a few days after incubation. The boiler is represented in vertical section and ground plan, in Jigs. 787 and 788. It is composed of a double cylinder of copper or cast iron 1, I, having a grate b (see 787 plan), an ash-pit at d (section). The water occupies the shaded space c, c. h,g, g, e, e, are five vertical flues, for conducting 1 d the burnt air and smoke, which first rise in the two exterior.o L. t _ F flues e, e, then descend in the two adjoining flues g, g, and _ finally re-mount through the passages i, i, in the central flue yzl E I \ h. During this upwards and downwards circulation, as shown I | | by the arrows in the section, the products of combustion are! A |g, I made to impart nearly the whole of their heat to the water by which they are surrounded. At the commencement some! e S9 } I e'-\ burning paper or wood shavings are inserted at the orifice m, to establish a draught in this circuitous chimney. The air is Al / - admitted into the ash-pit at the side, in regulated quantities, m, V' (7 I through a small, square door, moveable round a rod which runs horizontally along its middle line. This swing valve is acted c I d upon by an expanding har (see HEAT-REGULATOR), which opens it more or less according to the temperature of the stove apartment in which the eggs are placed. D is the upper orifice of the boiler, by which the hotter and consequently lighter particles of the water continually ascend, and are replaced by the cooled particles, which enter the boiler near its bottom, as shown infig. 789. at R. Into further details relative to the boiler it is needless to enter; for though its form, as designed by M. Bonnemain, is excellent and most economical of heat for a charcoal fire, it would not suit one of pit-coal, on account of the obstruction to the pipes which would soon be occasioned' by its soot. In fig. 789. the boiler is shown at R, with the rod which regulates the air door of the ash-pit. D is a stopcock for modifying the opening by which the hotter particles of water ascend; G is the water-pipe of communication, having the heating pipe of distribution attached between E F, which thence passes backwards and forwards with a very slight slope from the horizontal direction, till it reaches the poussiniere o P Q. It traverses this, apartment, and returns by N N to the orifice of the boiler, H, where it turns vertically downwards, and descends to nearly the bottom of the boiler, discharging at that point the cooled and therefore denser particles of water to replace those which continually issue upwards at D. L R is a tube surmounted with a funnel for keeping the range of pipes always full of water; and K is a syphon orifice for permitting the escape of the disengaged air, which would otherwise be apt to occupy partially the pipes and obstruct the aqueous circulation. The faster the water gets cooled in the serpentine tubes, the quicker its circulation will be, because the difference of density between the water at the top and bottom of the boiler, which is the sole cause of its movement, will be greater. N represents small saucers filled with water, to supply the requisite moisture to the heated air, and to place 1042 INCUBATION, ARTIFICIAL. 8 788 s8 9CI ~ ~ ~ ~ ~ ~ F Q eggs, arranged along the trays M M, in an atmosphere analogous to that under the body of the hen. When we wish to hatch eggs with this apparatus, the fire is to be kindled in the boiler, and as soon as the temperature has risen to about 1000 F., the eggs are introduced; but only one twentieth of the whole number intended, upon the first day; next day, a like number is laid upon the trays, and thus in succession for twenty days, so that upon the twenty-first day the eggs first placed may be hatched, for the most part, and we may obtain daily afterwards an equal number of chicks. In this way, regularity of care is established in the rearing of them. During the first days of incubation, natural as well as artificial, a small portion of the water contained in the egg evaporates by the heat, through the shell, and is replaced by a like quantity of air, which is afterwards useful for the respiration of the animal. If the warm atmosphere surrounding the eggs were very dry, such a portion of the aqueous part of the eggs would evaporate through the pores of the shells as would -endanger the future life of the chick in ovo. The transpiration from the body of the hen, as she sits upon her eggs, counteracts this desiccation in general; yet, in very dry weather, many hatching eggs fail from that cause, unless they be placed in moist decomposing straw. The water saucers N N are therefore essential to success in artificial incubation. After the chickens are hatched they are transferred into the nursery, o Q, on the front side of which there is a small grated trough filled with millet seed. Small divisions are made between the broods of successive days, to enable the superintendent to vary their feeding to their age. In order to supply an establishment of the common kind, where 100 eggs are to be hatched daily, a dozen of hens would be needed, and 150 eggs must be placed under them, as only two thirds in general succeed. At this rate, 4300 mothers would be required to sit. Now supposing we should collect ten times as many hens, or 43,000, we should not be able to command the above number of chickens, as there is seldom a tenth part of hens in a brooding state. Besides, there would be in this case no fewer than 720 hens every day coming out with a fresh brood of chickens, which would require a regiment of superintendents..drtificial Incubation by means of Hot Mineral Waters. —This curious process is uescribed very briefly in a letter by M. D'Arcet. The following are extracts from this letter:" In June, 1825, I obtained chickens and pigeons at Vichy, by artificial incubation, effected through the means of the thermal waters of that place. In 1827 I went to the baths of Chaudes-Aigues, principally for the purpose of doing the same thing there. Finding the proprietor a zealous man, I succeeded in making a useful application of this source of heat to the production of poultry. " The advantage of this process may be comprehended, when it is known that the invalids who arrive at Vichy, for instance in the month of May, find chickens only the size of quails; whereas, by this means, they may be readily supplied six months old. "The good which may be done by establishing artificial incubation in places where not springs exist is incalculable; it may be introduced into these establishments without at all interfering with the medical treatment of patients, since the hatching would go on in winter, at a time when the baths for other purposes are out of use. " There is no other trouble required in breeding chickens, by means of hot baths, than to break the eggs at the proper time; for, when the apartments are closed, the whole of the interior will readily acquire a sufficiently elevated and very constant temperature." In addition to these details by M. D'Arcet, a letter was received from M. Felgeris, the INDIGO. 1043 proprietor of the baths at Chaudes-Aigues (Cantal), in which he describes the success he had in following M. D'Arcet's process. This consists in putting the eggs into a small basket, suspending it in one of the stove-rooms heated by the hot mineral water, and turning round the eggs every day. The very first trial was attended with success, and no failure was experienced in four repetitions of it. INDIGO. This invaluable blue dye-stuff, for which no tolerable substitute has been found, was known to the ancients as a pigment under the name of indicum, whence its present denomination. In modern Europe, it first came into extensive use in Italy, but, about the middle of the 16th century, the Dutch began to import and employ it in considerable quantities. Its general introduction into the dye-houses of both England and France was kept back by absurd laws. founded upon an opinion that it was a fugitive substance, and even prejudicial to the fibie of wool. See DYEING, p. 419. The plants which afford this dye-drug grow in the East and West Indies, in the middle regions of America, in Africa, and Europe. They are all species of the genera Indigofera, Isatis, and Nerium. The following are cultivated:-Indigofera tinctoria affords n Bengal, Malabar, Madagascar, the Isle of France, and St. Domingo, an article c middling quality, but in large quantity. The indigofera disperma, a plant cultivated in the East Indies and America, grows higher than the preceding, is woody, and furnishes a superior dye stuff. The Guatimala indigo comes from this species. Indigofera.lnil grows in the same countries, and also in the West Indies. The Indigofera drgentea, which grows also in Africa; it yields little indigo, but of an excellent quality. Indigofera Pseudotinctoria, which is cultivated in the East Indies, firnishes the best of all: the Indigofera Glauca is the Egyptian and Arabian species. There are also the corulea, cinerea erecta, hirsuta, glabra, and several others. The Nerium tinctorium of the East Indies affords some indigo; as does the Isalis tinctoria, or Woad, in Europe; and the Polygonur tinctorium. The districts of Kishenagar, Jessore, and Moorshedabad, in Bengal, ranging from 88~ to 90~ E. L. and 22-0 to 24~ N. L., produce the finest indigo. That fiom the districts about Burdwan and Benares is of a coarser or harsher grain. Tyroot, in lat. 26~, yields a tolerably good article. The portion of Bengal most propitious to the cultivation of indigo lies between the river Hoogly and the main stream of the Ganges. In the East Indies, after having ploughed the ground in October, November, and the beginning of December, they sow the seed of the indigo plant in the last half of March and the beginning of April, while the soil, being neither too hot nor too dry, is most propitious to its germination. A light mould answers best; and sunshine, with occasional light showers, are most favorable to its growth. Twelve pounds of seeds are sufficient for sowing an acre of land. The plants grow rapidly, and will bear to be cut for the first time at the beginning of July, nay, in some districts, so early as the middle of June. The indications of maturity are the bursting forth of the flower buds, and the expansion of the blossoms; at which period the plant abounds most in the dyeing principle. Another indication is taken from the leaves; which, if they break across, when doubled flat, denote a state of maturity. But this character is somewhat fallacious, and depends upon the poverty or richness of the soil. When much rain falls, the plants grow too rapidly, and do not sufficiently elaborate the blue pigment. Bright sunshine is most advantageous to its production. The first cropping of the plants is the best; after two months a second is made; after another interval, a third, and even a fourth; but each of these is of diminished value. There are only two croppings in America. Two methods are pursued to extract the indigo from the plant; the first effects it by fermentation of the fresh leaves and stems; the second, by maceration of the dried'eaves; the latter process being most advantageous. 1. From the recent leaves.-In the indigo factories of Bengal there are two large stone-built cisterns, the bottom of the first being nearly upon a level with the top of the second, in order to allow the liquid contents to be run out of the one into the other. The uppermost is called the fermenting vat, or the steeper; its area is 20 feet square, and its depth 3 feet; the lowermost, called the beater or beating vat, is as broad as the other, but one third longer. The cuttings of the plant, as they come from the field, are stratified in the steeper, till this be filled within 5 or 6 inches of its brim. In order that the plant, during its fermentation, may not swell and rise out of the vat, beams of wood and twigs of bamboo are braced tight over the surface of the plants, after which water is pumped upon them till it stands within three or four inches of the edge of the vessel. An active fermentation speedily commences, which is completed within 14 or 15 hours; a little longer or shorter, according to the temperature of the air, the prevailing winds, the quality of the water, and the ripeness of the plants. Nine or ten hours after the immersion of the plant, the condition of the vat must be examined; frothy bubbles appear, which rise like little pyramids, are at first of a white color, but soon 67 1044 INDIGO. become gray-blue, and then oeep purple-red. The fermentation is at this time violent, the fluid is in constant commotion, apparently boiling, innumerable bubbles mount to the surface, and a copper-colored dense scum covers the whole. As long as the liquor is agitated, the fermentation must not be disturbed; but when it becomes more tranquil, the liquor is to be drawn off into the lower cistern. It is of the utmost consequence not to push the fermentation too far, because the quality of the whole indigo is deteriorated; but rather to cut it short, in which case there is, indeed, a loss of weight, but the article is better. The liquor possesses now a glistening yellow color, which, when the indigo precipitates, changes to green. The average temperature of the liquor is commonly 85~ Fahr.; its specific gravity at the surface is 1-0015; and at the bottom, 1-003. As soon as the liquor has been run into the lower cistern, ten men are set to work to beat it with oars, or shovels 4 feet long, called busquets. Paddle wheels have also been employed for the same purpose. Meanwhile two other laborers clear away the compressing beams and bamboos from the surface of the upper vat, remove the exhausted plant, set it to dry for fuel, clean out the vessel, and stratify fresh plants in it. The fermented plant appears still green, but it has lost three fourths of its bulk in the process, or from 12 to 14 per cent. of its weight, chiefly water and extractive matter. The liquor in the lower vat must be strongly beaten for an hour and a half, when the indigo begins to agglomerate in flocks, and to precipitate. This is the moment for judging whether there has been any error cgmmitted in the fermentation; which must be corrected by the operation of beating. If the fermentation has been defective, much froth rises in the beating, which must be allayed with a little oil, and then a reddish tinge appears. If large round granulations are formed, the beating is continued, in order to see if they will grow smaller. If they become as small as fine sand, and if the water clears up, the indigo is allowed quietly to subside. Should the vat have been over fermented, a thick fat-looking crust covers the liquor, which does not disappear by the introduction of a flask of oil. In such a case the beating must be moderated. Whenever the granulations become round, and begin to subside, and the liquor clears up, the beating must be discontinued. The froth or scum diffuses itself spontaneously into separate minute particles, that move about the surface of the liquor; which are marks of an excessive fermentation. On the other hand, a rightly fermented vat is easy to work; the froth, though abundant, vanishes whenever the granulations make their appearance. The color of the liquor, when drawn out of the steeper into the beater, is bright green; but as soon as the agglomerations of the indigo commence, it assumes the color of Madeira wine; and speedily afterwards, in the course of beating, a small round grain is formed, which, on separating, makes the water transparent, and falls down, when all the turbidity and froth vanish. The object of the beating is three-fold: first, it tends to disengage a great quantity of carbonic acid present in the fermented liquor; secondly, to give the newly developed indigo its requisite dose of oxygen by the most extensive exposure of its particles to the atmosphere;, thirdly, to agglomerate the indigo in distinct flocks or granulations. In order to hasten the precipitation, lime-water is occasionally added to the fermented liquor in the progress of beating, but it is not indispensable, and has been supposed capable of deteriorating the indigo. In the front of the beater a beam is fixed upright, in which three or more holes are pierced a few inches in diameter. These are closed with plugs during the beating, but, two or three hours after it, as the indigo subsides, the upper plug is withdrawn to run off the supernatant liquor, and then the lower -lugs in succession. The state of this liquor being examined, affords an indication of the success of both the processes. When the whole liquor is run off, a laborer enters the vat, sweeps all the precipitate into one corner, and empties the thinner part into a spout which leads into a cistern, alongside of a boiler, 20 feet long, 3 feet wide, and 3 deep. When all this liquor is once collected, it is pumped through a bag for retaining the impurities, into the boiler, and heated to ebullition. The froth soon subsides, and shows an oily looking film upon the liquor. The indigo is by this process not only freed from the yellow extractive matter, but is enriched in the intensity of its color, and increased in xteight. From the boiler the mixture is run, after two or three hours, into a general receiver called the dripping vat, or table, which, for a factory of twelve pairs of preparation vats, is 20 feet long, 10 feet wide, and 3 feet deep; having a false bottom, 2 feet under the top edge. This cistern stands in a basin of masonry (made water tight with Chunam hydraulic cement), the bottom of which slopes to one end, in order to facilitate the drainage. A thick woollen web is stretched along the bottom of the inner vessel, to act as a filter. As long as the liquor passes through turbid, it is pumped back into the receiver. Whenever it runs clear, the receiver is covered with another piece of cloth to exclude the dust, and allowed to drain at its leisure. Next morning the drained magma is put into a strong bag, and squeezed in a press. The indigo is then Carefully taken out of the bag, and cut with a brass wire into bits, about 3 inches cube. INDIGO. 1045 which are dried, in an airy house, upon shelves of wicker work. During the drying, a whitish efflorescence comes upon the pieces, which must be carefully removed with a brush. In some places, particularly on the coast of Coromandel, the dried indigo lumps are allowed to effloresce in a cask for some time, and when they become hard they are wiped and packed for exportation. From some experiments it would appear that the gas disengaged during the middle period of the fermentation is composed in 100 parts of 27'5 carbonic acid, 5-8 oxygen, and 66-7 azote; and towards its end, of 40'5 carbonic acid, 4-5 oxygen, and 55-0 azote. The fermenting leaves apparently convert the oxygen of the atmosphere into carbonic acid gas, and leave its azote; besides the quantity of carbonic acid which they spontaneously evolve. Carbureted hydrogen does not seem to be disengaged. That the liquor in the beating vat absorbs oxygen from the air in proportion as the indigo becomes flocculent and granular, has been ascertained by experiment, as well as that sunshine accelerates the separation of the indigo blue. Out of 1000 parts of the fermented liquor of specific gravity 1'003, the blue precipitate may constitute 0'75 of a part. Such a proportion upon the great scale is however above the average, which is not more than 0-5. When lime water is added, an extractive matter is thrown down, which amounts to from 20 to 47 parts in 1000 of the liquor. It has a dark brown tint, a viscid appearance, an unpleasant smell, and a bitter taste. It becomes moist in damp air, and dissolves in water without decomposition. It is precipitated by )me, alkalis, infusion of galls, and acetate of lead. All indigo contains a little lime derived from the plant, even though none has been used in its preparation. 2. Indigo from dried leaves.-The ripe plant being cropped, is to be dried in sunshine from 9 o'clock in the morning till 4 in the afternoon, during two days, and thrashed to separate the stems from the leaves, which are then stored up in magazines till a sufficient quantity be collected for manufacturing operations. The newly dried leaves must be free from spots, and friable between the fingers. When kept dry, the leaves undergo, in the course of 4 weeks, a material change, their beautiful green tint turning into a pale bluegray, previous to which the leaves afford no indigo by maceration in water, but subsequently a large quantity. Afterwards the product becomes less considerable. The following process is pursued to extract indigo from the dried leaves. They are infused in the s:eeping vat with six times their bulk of water, and allowed to macerate for two hours with Continual stirring till all the floating leaves sink. The fine green liquor is then drawn lff into the beater vat, for if it stood longer in the steeper, some of the indigo would settle among the leaves and be lost. Hot water, as employed by some manufacturers, is not necessary. The process with dry leaves possesses this advantage, that a provision of the plant may be made at the most suitable times, independently of the iicissitudes of the weather, and'the indigo may be uniformly made; and moreover, that the fermentation of the fresh leaves, often capricious in its course, is superseded by a much shorter period of simple maceration. The process for obtaining indigo from the Nerium is altogether the same, but hot water has been generally applied to the dried leaves. For woad, hot water must be employed, and also lime water as a precipitant, on account of the small proportion of indigo in the plant. Dilute muriatic acid is digested upon the woad indigo to remove the lime, without which no dye could be precipitated. According to the warmth of the summer and the ripeness of the plant, from 2 to 5 ounces of indigo may be obtained from 100 pounds of the dried woad, or upon an average 4 ounces to the hundred weight. The indigo found in European commerce is imported from Bengal, Coromandel, Madras, the Mauritius, Manilla, and Java in the Eastern hemisphere; from Senegal, Caraccas, Guatimala, Brazil (South Carolina and Louisiana in small quantity), and fot merly from the West India islands, especially St. Domingo. Its quality depends upon the species of the plant, its ripeness, the soil and climate of its growth, and mode of manu facture. The East Indian and Brazilian indigo comes packed in chests, the Guatimala in ox-hides, called surons. The organ which affords the indigo is confined entirely to the pellicle of the leaves, ann exists in largest quantity at the commencement of maturation while the plant is in flower. The indigofera is remarkable for giving a blue tinge to the urine of cows that feed upon its leaves. According to some manufacturers, the plants should be cut down in dry weather, an hour or two before sunset, carried off the field in bundles, and immediately spread upon a dry floor. Next morning the reaping is resumed for an hour and a half, before the sun acts too powerfully upon vegetation; and the plants are treated in the same way. Both cuttings become sufficiently dry by 3 o'clock in the afternoon, so as to permit the leaves to be separated from the stems by thrashing. They are now thoroughly dried in the sunshine, then coarsely bruised, or sometimes ground to powder in a mill, and packed up ur the operations of manufacture. In the spring of 1830 I subjected a variety of specimens of indigo to comparative 1046 INDIGO. analyses, by dissolving a few grains of each in strong sulphuric acid, diluting the solu tions with an equal volume of water, and determining the resulting shade of color in a hollow prism of plate glass, furnished with a graduated scale. The following are the results, compared to the shade produced by a like weight of absolute indigo. I. East India Indigos; prices as at the last October sales. No. Price Rea Indigoar Characters by the Brokers. No, Price. in 100 parts. s. d. 1 3 9 42 Broken, middling violet, and coppery violet spotted. 2 3 6 56-5 Ditto, a litt., being coppery violet and copper. 3 3 3 46'0 Ditto, middling red violet, dull violet and lean. 4 4 3 54'5 Large broken, and square, even middling red violet. 5 4 2 75-0 Much broken and very small, very crumbly and limy, soft, good violet. 6 4 9 60'0 Square and large broken, 1 middling violet, and 1 good coppery violet. 7 5 3 70'0 Large broken, very good; paste a little limy, good violet. 8 6 6 60'0 Square and large broken, soft, fine paste, fine violet. 9 6 0 66~ Square, ditto, good red violet. 10 7 0 75 Square, ditto, fine purple and blue. 11 2 3 37'5 Middling ordinary Madras. 12 3 6 60-0 Good Madras. 13 4 3 58-0 Very fine ditto. 14 2 0 Low, pale Oude.!5 2 4 273 Middling, ordinary Oude. 16 3 3 54 Good Oude. 17 1 9 29 Lundy, very low quality. II. American Indigos; wholesale prices at present. (March, 1830.) Indigo. Parts Indigo. No. Prce. Indigo. No. Price. in100. s. d. s. d. Caraccas flor. - - 1 6 0 541 Guatimala - - - 6 5 0 50 Guatimala - - - 2 5 0 33 _ 7 5 3 35 3 3 2 19 - 8 4 8 46 - 4 4 6 32 -- 9 4 8 33i _.- 55 5 4 50 10 5 4 50 Properties of Indigo.-It possesses a dark blue color, passing into violet-purple, is void of taste and smell, dull, but by rubbing with a smooth hard body, it assumes the lustre and hue of copper. It occurs sometimes less and sometimes more dense apparently than water, which circumstance depends upon its freedom from foreign impurities, as well as upon the treatment of its paste in the boiling, pressing, and drying operations. It is insoluble in water, cold alcohol, ether, muriatic acid, dilute sulphuric acid, cold ethereous and fat oils; but boiling alcohol and oils dissolve a little of it, which they deposite on cooling. Creosote has the property of dissolving indigo. Indigo is a mixture of several dye-stuffs, and other substances. Berzelius found in it a matter resembling vegetable gluten or. gliadine, a brown, red, and blue pigment, besides oxyde of iron, clay, lime, magnesia, and silica. 1. Indigo gluten or gliadine is dissolved along with the calcareous and magnesian salts by acids. If the powder be treated with dilute sulphuric acid, if the solution be saturated xwih carbonate of lime, evaporated to dryness, and its residuum treated with alcohol; the solution thus formed leaves, after being evaporated, a yellow transparent extract, easily soluble in water, more difficultly in acid liquids; showing that acids extract only a portion of the gliadine from the indigo. It yields, by dry distillation, much ammonia, a fetid oil, and comports itself in other respects like vegetable gluten. 2. Indigo-brown occurs in combination with lime, as also with vegetable acid in con siderable quantity, and more abundantly in the coarser sorts of indigo than in the finer. Indigo purified by acids is to be treated with hot strong caustic ley, which dissolves the indigo-brown; the liquid part of the mixture passes with difficulty through the filter is black-brown, opaque, and holds some indigo-blue in solution, or diffused in fine powder iNDIGO. 1047 The alhali being neutralized with acetic acid, the liquor is to be evaporated, and alcohol poured on the residuum, whereby the alkaline acetate is dissolved out from the brown. This pigment is a dark brown, almost black, but is not yet entirely deprived of the other constituents of indigo. It is nearly tasteless, is combustible, affords, by dry distillation, ammonia and fetid oil, forms with acids combinations hardly soluble in water, with alkalis soluble ones, but with earths hardly soluble. Lime possesses the property of precipitating the indigo-brown completely from its alkaline solution. Chlorine occasions a pale yellow brownish precipitate, wi'ch consists of indigo brown and muriatic acid, but causes no further change. By drying, it becomes again dark colored. Indigo-brown seems to exist also in woad. 3. Indigo-red, or more properly red resin of indigo. This may be obtained by boiling alcohol of sp. grav. 0-830 upon some indigo which has been previously treated with acids and alkalis; for the red substance is hardly soluble in cold alcohol. The solution is dark red, opaque, and leaves, by distillation, the indigo-red in the form of a black-brown powder, or a glistening varnish, slightly soluble in alcohol and ether. Alkalis do not dissolve it, but coneontrated sulphuric acid forms with it a dark yellow dye, from which water causes no precipitation; wool extracts the color from the acid solution, and becomes of a dirty brown hue. Chlorine does not seem capable of destroying the color, for though it makes it yellow, it becomes as dark as ever on being dried. Indigo-red melts with heat, burns with a bright flame, affords, when heated in vacuo, first a white crystalline sublimate, and then unchanged indigo-red. That white matter is changed by nitric acid into indigo-red. 4. Indigo-blue, or pure indigo, remains, after treating the indigo of commerce with lilute acid, alkalis, and alcohol; it retains, however, still traces of the matters thereby extracted, along with some earthy substances. In order to procure indigo-blue in its utmost purity, we must deoxydize the above blue residuum, thus form colorless indigo, which again acquires a blue color from the air, and constitutes the pure pigment. For this purpose the above moist indigo is to be mixed with slaked lime, green sulphate of iron, and hot water in an air-tight matrass. The indigo when deoxydized by protoxyde of iron being soluble in lime-water, the clear yellow solution is to be,poured off, and exposed to the air. The indigo absorbs oxygen, and becomes again blue. By digestion with dilute muriatic acid the foreign matters are dissolved, and may then be washed away with distilled water, from the absolute indigo. The indigo-blue obtained in this manner has a cast of purple red, displaying the characteristic copper lustre in a high degree, but in powder, it is blue. It is void of taste and smell, is by my experiments of specific gravity 1'50, affords at 554~ Fahr. a purple vapor, and sublimes in shining purple scales, or slender needles in an apparatus open to the air, whereby, however, much of it is destroyed. Some carbon remains after the sublimation. A quick heat produces most sublimate. These needles contain a brown oily matter, which may be dissolved out by means of hot alcohol. Their specific gravity is 1-35, according to Mr. Crum. The sublimate from common indigo does not contain any oil, but some indigo-red and the above white crystalline matter. According to Mr. Crum, indigo-blue consists of carbon, 73-22; oxygen, 12-60 azote, 11-26; hydrogen, 2-92; while according to Dumas, crystallized indigo consists of carbon, 73-26; oxygen, 10-43; azote, 13-81; and hydrogen, 2'50; precipitated indigo consists of carbon, 74-81; oxygen, 7-88; azote, 13-98; and hydrogen, 3-33; sublimed indigo, of carbon, 71-71; oxygen, 12-18; azote, 13-45; hydrogen, 2-66. My own analysis afforded-carbon, 71-37; oxygen, 14-25; azote, 10-00; hydrogen, 4-38. In another analysis of Dumas, 3-93 parts of hydrogen were obtained. Hence we must infer that considerable differences exist in the composition of indigo in its purest state. Reagents act upon it much as upon common indigo. Chlorine, iodine, and bromine convert it into a reddish brown soluble substance. Concentrated sulphuric acid, especially the smoking or anhydrous of Nordhausen, dissolves indigo-blue with the disengagement of heat, but it makes it suffer some modification; for though it retains an intense dark blue color, it has become soluble in water, and may be blanched by light, which does not happen with indigo itself. Nitric acid destroys indigo-blue, forms indigotic (carbazotic) acid, carbonic acid, artificial resin, and bitter principle. Indigo-blue may be reduced by substances oxydized, with the co-operation of alkalis or alkaline earths; for example, by such substances as have a strong affinity for oxygen, and are imperfectly saturated with this principle, as the sulphurous and phosphorous acids and their salts, the protoxydes of iron and manganese, the protoxyde salts of tin, and the corresponding compounds of chlorine, as the proto-chlorides of tin and iron; and the solution of the former in potash. When in these circumstances, in the presence of alkali, a deoxydation or reduction of the indigo-blue takes place, the other bodies get oxydized by absorption of the oxygen of the indigo-blue; the protoxydes become peroxydes, and the acids in ous become acids in ic, &c. Several metallic sulphurets alsc reduce the indigo-blue in the same predicament, as the sulphurets of potassium, of cal 1048 INDIGO. cium, of antimony, and of arsenic (orpiment.) A similar influence is exercised by fer. menting vegetable substances, su:h as woad, madder, bran, raw sugar (molasses), starch, sirup, in consequence of the formation of carbonic and acetic acids, by absorption of the oxygen of the indigo-blue, for acetic acid and acetic salts are found in the liquor of the warm blue vat, in which indigo has been reduced by means of woad, madder, and bran. Formation of colorless reduced indigo-blue, or indigoliie.-Purified indigo-blue is to be treated with copperas and slaked lime, as above described; or the clear wine-yellow supernatant liquor of the cold blue-vat mixture is to be taken, run by a syphon into a matrass, a few drops of concentrated acetic or sulphuric acid, deprived of air, are to be poured into it, and the vessel, being made quite full, is'to be well corked. The reduced indigo soon falls in white flocks, or crystalline scales. They must be edulcorated upon a filter with water deprived of its air by boiling, then pressed between folds of blottingpaper, and dried under the receiver in vacuo. Indigo-blue may likewise be reduced and dissolved by solution of hydro-sulphuret of ammonia; and the colorless indigotine may be precipitated by muriatic acid. The reduced indigo is sometimes white at the instant of its elimination, sometimes grayish, of a silky lustre, but becomes very readily greenish, blue green, and blue, in the air; in which case it absorbs, according to Berzelius, 4'2 per cent. of oxygen; but according to Liebeg, 11*5 per cent. It is void of taste and smell, is insoluble in water; well boiled water free from air is not affected by it, but is turned blue by common water. It dissolves in alcohol and ether into a yellow dye; not in dilute acids, but in concentrated sulphuric acid, whereby probably a portion of this is decomposed, and some hyposulphurous acid formed; the color of this solution is blue. Solutions of the caustic and carbonated alkalis, even the alkaline earths, readily dissolve reduced indigo into a wineyellow liquid; but in contact with air, oxygen is absorbed, and indigo-blue falls, while a purple-colored froth, passing into copper-red, appears lopon the surface, just as in the indigo vats of the dyer. The reduced indigo may be combined, by means of complex affinity, with other bases, with the exception of the oxydes of copper, zinc, and mercury, which oxydize it. These combinations are white, in part crystallizable, become speedily blue in the air, and afford by sublimation indigo-blue. Berzelius formed with lime a two-fold combination; one easily soluble in water, and another difficultly soluble, of a lemon color, which contained an excess of lime; this is formed both in the hot and the cold blue vat; in the latter it is occasioned by an overdose of lime. When pure indigo-blue is treated with concentrated sulphuric acid, and particularly with six times its weight of the smoking dry acid, it dissolves completely, and several different compounds are produced in the solution. There is first a blue sulphate of indigo; secondly, a similar compound with the resulting hyposulphurous acid; thirdly, a combination of sulphuric acid with the purple of indigo (called Phoenicin by Crum), a peculiar substance, generated from indigo-blue. These three compounds are here dissolved in an excess of sulphuric acid. The more concentrated the sulphuric acid is, the more blue hyposulphite is formed. The solution in smoking acid, when diluted with water and filtered, affords a considerable precipitate of indigo purple, which that in oil of vitriol does not. The vapor of anhydrous sulphuric acid combines with indigo-blue into a purple fluid. In order to obtain from the dark blue solution each of these blue acids in a pure state, we must dilute it with forty times its weight of water, and immerse in the filtered liquor, well washed woo- or flannel, with which the blue acids combine, while most of the sulphuric acid and some other foreign substances remain free in the liquor. The wool must be then scoured with water containing about a half per cent. of carbonate of ammonia, or potash, which neutralizes both of the blue acids, and produces a blue compound, rhis being evaporated to dryness at the temperature of 140~ F., alcohol of 0-833 is to be poured upon the residuum, which dissolves the blue hyposulphite, but leaves the blue sulphate undissolved. From either salt, by precipitating with acetate of lead, by acting upon the precipitate with sulphureted hydrogen water, and evaporation, either of the two blue acids may be obtained. They may be both evaporated to dryness, especially the blue sulphate of indigo; they both become somewhat moist in the air, they are very soluble in water, and the blue sulphate also in alcohol; they have a not unpleasant smell, and an acid astringent taste. From these habitudes, particularly in reference to the bases, it appears that indigo-blue does not comport itself like a saline base towards the acids, but rather like an acid, since it enters into the salts, just as the empyreumatic oil of vinegar and oil of turpentine do into resin soaps. The blue pigment of both acids is reduced by zinc or iron without the disengagement of hydrogen gas; as also by sulphureted hydrogen, tepid protochloride ol tin, while the liquor becomes yellow. Indigo-blue sulphate of potash, or ceruleo-sulphate of potash, may be obtained by rxtracting the blue color from the wool by water containing 1 per cent. of car donate of potash, evaporating nearly to dryness, treating the extract with alcohoc INDIGO. 1049 to remove the indigo-blue hyposulphite, then with acetic acid and alcohol to remove any excess of carbonate of potash. It is found in commerce under the name of precipitated indigo, indigo paste, blue carmine, and soluble indigo. To prepare it economically, indigo is to be dissolved in ten times its weight of concentrated sulphuric acid; the solution after twenty-four hours is to be diluted with ten times its weight of water, filtered, and imperfectly saturated with carbonate of potash; whereby a blue pow. der falls down; for the resulting sulphate of potash throws down the ceruleo-sulphate. while the hyposulphite of potash remains dissolved. It is a dark blue copper shining powder, soluble in 140 parts of cold water, and in much less of boiling water. It is made use of as a dye, and to give starch a blue tint. When mixed with starch in t cakes, it is sold under the lame of blue for washerwomen. Ceruleo-sulphate of ammonia may be formed in the same way. It is much more soluble in water. Ceruleo-sulphate of lime is obtained by Saturating the above -dilute acid with chalk, filtering to separate the andyed gypsum, and washing with water till the purple color be extracted. This liquor, evaporated and decomposed by alcohol, affords a bluish flocky precipitate, which is more soluble in water than common gypsum, and dries up in a purple-blue film. Ceruleo-sullhate of alumina may be obtained by double affinity; it is dark blue while moist, but becomes black-blue by drying, and is soluble in water. The blue present in all these salts of ceruline is destroyed by sunshine, becomes greenishgray by caustic alkalis; and turns immediately yellow-brown by alkai ne earths. But when the solution is very dilute, the color becomes first green, then yellow. The carbonates of alkalis do not produce these changes. Nitric acid decomposes the color quickly. Mr. Crum considers ceruline to be a combination of indigo-blue with water. Phenicine, or indigo-purple combined with sulphuric acid, is obtained when the solution of indigo-blue in concentrated sulphuric acid has been diluted for a few hours with water, and then filtered. It seems to be an intermediate body into which the indigo-blue passes, before it becomes soluble ceruline. Hence it occurs in greater quantity soon after digesting the indigo with the acid, than afterwards. It is dark blue, dissolves gradually in water, affords after evaporation a blue residuum, of the same appearance as the above blue acids. When a salt is added to it a purple precipitate ensues, which is a compound of indigo-purple, sulphuric acid, and the base of the salt. Indigo-purple is reduced by bodies having a strong attraction for oxygen, if a free alkali or alkaline earth be present, and its solution is yellow, but it becomes blue in the atmosphere. According to Mr. Crum, Phenicine contains half as much combined water as ceruline. The table which I published in 1830 (as given above) shows very clearly how much the real quality and value of indigo differ from its reputed value and price, as estimated from external characters by the brokers. Various test or proof processes of this drug have been proposed. That with chlorine water is performed as follows. It is known that chlorine destroys the blue of indigo, but not the indigo-red or indigo-brown, which by the resulting muriatic acid is thrown down from the sulphuric solution in flocks, and the chlorine acts in the same way on the gliadine or gluten of the indigo. Pure indigo-blue is to be dissolved in 10 or 12 parts of concentrated sulphuric acid, and the solution is to be diluted with a given weight of water, as, for example, 1000 parts for 1 of indigo-blue. If we then put that volume of liquor into a graduated glass tube, and add to it chlorine water of a certain strength till its blue color be destroyed by becoming first green and then red-brown, we can infer the quantity of color from the quantity of chlorine water expended to produce the effect. The quantity of real indigo-blue cannot, however, be estimated with any accuracy in this way, because the other coloring matters in the drug act also upon the chlorine; and, indeed, the indigo itself soon changes when dissolved in sulphuric acid even out of access of light, while the chlorine water itself is very susceptible of alteration. Perhaps a better appreciation might be made by avoiding the sulphuric acid altogether, and adding the finely powdered indigo to a definite volume of the chlorine water till its color ceased to be destroyed, just as Prussian-blue is decolored by solution of potash in making the ferro-cyanide. Another mode, and one susceptible of great precision, is to convert 10 or 100 grains of indigo finely powdered into its deoxydized state, as in the blue vat by the proper qua'ntity of slaked lime and solution of green sulphate; then to precipitate the indigo collect and weigh it. The indigo should be ground upon a muller along with the quicklime, the levigated mixture should be diluted with water, and added to the solution of the copperae. This exact analytical process requires much nicety in the operator, and can hardly be practised by the broker, merchant, or manufacturer. Employment of indigo in dyeing.-As indigo is insoluble in water, and as it can penetrate the fibres of wool, cotton, silk, and flax, only when in a state of solution, the dyer must study to bring it into this condition in the most complete and economical manner This is effected either by exposing it to the action of bodies which have an affinity fot oxygen superior to its own, such as certain metals and metallic oxydes, or by mixing i! 1050 INDIGO. with fermenting matters, or, finally, by dissolving it in a strong acid, such as the sulphuric. The second of the above methods is called the warm blue, or pastel vat; and being the most intricate, we shall begin with it. Before the substance indigo was known in Europe, woad having been used for dyeini blue, gave the name of woad vats to the apparatus. The vats are sometimes made of copper, at other times of iron or wood, the last alone being well adapted for the employ ment of steam. The dimensions are very variable; but the following may be considered as the average size: depth, 71 feet; width below, 4 feet, above, 5 feet. The vats are built in such a way that the fire does not affect their bottom, but merely their sides half way up; and they are sunk so much under the floor of the dyehouse, that their upper half only is above it, and is surrounded with a mass of masonry to prevent the dissipatior of the heat. About 3 or 3 feet under the top edge an: -n ring is fixed, called the champagne by the French, Jo which a net is attached in order to suspend the stuffs out of contact of the sediment near the bottom. In mounting the vat the following articles are required: 1. woad prepared by fermen tation, or woad merely dried, which is better, because it may be made to ferment in the vat, without the risk of becoming putrid, as the former is apt to do; 2. indigo, previously ground in a proper mill; 3. madder; 4. potash; 5. slaked quicklime; 6. bran. Ir France, weld is commonly used instead of potash. The indigo mill is represented in figs. 790 and 791. a is a four-sided iron cistern 190 791:~~~~~~ A cylindrical or rounded in the bottom, which rests upon gudgeons in a wooden frame; it has an iron lid b, consisting of two leaves, between which the rod c moves to and frQ, receiving a vibratory motion from the crank d. By this construction, a frame e, which is made fast in the cistern by two points e e, is caused to vibrate, and to impart its swing movement to six iron rollersff f, three being on each side of the frame, which triturate'he indigo mixed with water into a fine paste. Whenever the paste is uniformly ground, it is drawn off by the stopcock g, which had been previously filled up by a screwed plug, to prevent any of the indigo from lodging in the orifice of the cock, and thereby escaping the action of the rollers. The cistern is nearly three "eet long. The vat being filled with clear river water, the fire is to be kindled, the ingredients introduced, and if fermented woad be employed, less lime is needed than with the merely dried plant. Meanwhile the water is to be heated to the temperature of 160~ Fahr., and maintained at this pitch till the deoxydizement and solution of the indigo begin to show themselves, which, according to the state of the constituents, may happen in 12 hours, or not till after several days. The first characters of incipient solution are blue bubbles, called the flowers, which rise upon the surface, and remain like a head of soapsuds for a considerable time before they fall; then blue coppery shining veins appear with a like colored froth. The hue of the liquor now passes from blue to green, and an ammoniacal odor begins to be exhaled. Whenever the indigo is completely dissolved, an acetic smelling acid may be recognised in the vat, which neutralizes all the alkali, and may occasion even an acid excess, which should be saturated with quicklime. The time for doing this cannot be in general very exactly defined. When quicklime has been added at the beginning in sufficient quantity, the liquor appears of a pale wine-yellow color, but if not, it acquires this tint on the subsequent introduction of the lime. Experience has not hitherto decided in favor of the one practice or the other. As soon as this yellow color is formed in the liquor, and its surface becomes blue, the vat is ready for the dyer, and the more lime it takes up without being alkaline, the better is its condition. The dyeing power of the vat may be kept up during six months, or more, according to the fermentable property of the woad. From time to time, madder and bran must be added to it, to revive the fermentation of the sediment, along with some indigo and potash, to replace what may have been abstracted in the progress of dyeing. The quantity of indigo must be proportional, of course, to the depth or lightness of the tints required. INDIGO. 1051 During the operation of this blue vat two accidents are apt to occur; the first, which is the more common one, is called the throwing back, in French, the cure rebutS, and in Perman, the Scharf or Schwartzwerden (the becoming sharp or black); the second is aQe putrefaction of the ingredients. Each is discoverable by its peculiar smell, which it.s impossible to describe. The first is occasioned by the employment of too much quicklime, whereby the liquor becomes neutral or even alkaline. This fault may be recognised by the fading of the green, or by the dark green, or nearly black appearance of the liquor; and by a dull blue froth, owing to a film of lime. The remedy for a slight degree of this vicious condition, is to suspend in the liquor a quantity of bran tied up in a bag, and to leave it there till the healthy state be restored. Should the evil be more inveterate, a decoction of woad, madder, and bran must be introduced. Strong acids are rather detrimental. Sulphate of iron has been recommended, because its acid precipitates the lime, while its oxyde red ices the indigo to the soluble state. The decomposition or putrefaction of the blue vat is an accident the reverse of the preceding, arising from'he transition of the acetous into trh putrid fermentation, whereby the dyeing faculty is destroyed. Such a misfortune can happen only towards the commencement of working the vat, whilst the woad is still powerfil, and very little indigo has been dissolved. Whenever the vat is well charged with indigo, that accident cannot easily supervene. In both of these distemperatures the elevation of the temperature of the vat aggravates the evil. Dyeing in {he blue vat is performed as follows:Wool Is put into a net, and pressed down into the liquor with rods; but cloth is smoothly stretched and suspended by hooks upon frames, which are steadily dipped into the vat, with slight motions through the liquor; yarn-hanks must be dipped and turned about by hand. All unnecessary stirring of the liquor must however be avoided, lest the oxygen of the atmosphere be brought too extensively into contact with the reduced indigo, for which reason mechanical agitation with rollers in the vat is inadmissible. The stuffs to be dyed take at the first dip only a feeble color, though the vat be strong, but they must be deepened to the desired shade by successive immersions of fifteen minutes or more each time, with intervals of exposure to the air, for absorption of its oxygen. After the lapse of a certain time, if the fermentative power be impaired, which is recognised by the dye stuffs losing more color in a weak alkaline test ley than they ought, the vat should be used up as far as it will go, and then the liquor should be poured away, for the indigo present is not in a reduced state, but merely mixed mechanically, and therefore incapable of forming a chemical combination with textile fibres. If cotton goods previously treated with an alkaline ley are to be dyed blue, the vat should contain very little lime. Theory of the Indigo vat.-The large quantity of extractive matter in woad and madder, as also the sugar, starch, and gluten, in the bran and woad, when dissolved in warm water, soon occasion a fermentation, with an absorption of oxygen from the air, but especially from the indigo of the woad, and from. that introduced in a finely ground state. When thus disoxygenated, it becomes soluble in alkaline menstrua; the red-brown of the indigo being dissolved at the same time. When lime is added, the indigo-blue dissolves, and still more readily if a little potash is conjoined with it; but whatever indigo-brown may have been dissolved by the potash, is thrown down by the lime. Lime in too large a quantity, however, forms an insoluble combination with the reduced indigo, and thus makes a portion of the dye ineffective; at the same time it combines with the extractive. In consequence of the fermentative action, carbonic;acid, acetic acid, and ammonia are disengaged; the first two of which neutralize a portion of the lime, and require small quantities of this earth to be added in succession; hence also a con siderable quantity of the carbonate of lime is found as a deposite on the sides and bottom of the vat. In the sound condition of the indigo vat, no free lime should be perceived, but on the contrary a free acid. Yet when the disengaged carbonic and acetic acids saturate the lime completely, no indigo can remain at solution; therefore a sufficient supply of lime must always be left to dissolve the dye, otherwise the indigo would fall down and mix with the extractive matter at the bottom. Goods dyed in the blue vat are occasionatly brightened by a boil in a logwood bath, with a mordant of sulpho-muriate of tin, or in a bath of cudbear. Another mode of mounting the indigo vat without woad and lime, is by means of madder, bran, and potash. The water of the vat is to be heated to the temperature of 122C F.; and for 120 cubic feet of it, 12 pounds of indigo, 8 pounds of madder, and as much bran, are to be added, with 24 pounds of good potashes; at the end of 36 hours, 12 pounds more of potash are introduced, and a third 12 pounds in other 12 hours. In the course of 72 hours, all the characters of the reduction and solution of the indigo become apparent; at which time the fermentation must be checked by the addition of quicklime. The liquor has a bright full color, with a beautiful rich froth. In feeding the vat with indigo, an equal weight of madder and a double weight of potash, should 1052 INDIGO. be added. The odor of this vat, in its mild but active state, is necessarily different from that of the woad vat, as no ammonia is exhaled in the present case, and the sediment is much smaller. The reduced indigo is held in solution by the carbonated potash, while the small addition of quicklime merely serves to precipitate the indigo-brown. A potash vat dyes in about half the time of the ordinary warm vat, and penetrates fine cloth much better; while the goods thus dyed lose less color in alkaline and soap solutions. This vat may moreover be kept with ease in good condition for several months; is more readily mounted; and from the minute proportion of lime present, it cannot impair the softness of the woollen fibres. ft is merely a little more expensive. It is said that cloth dyed in the potash indigo vat, requires one third less soap in the washing at the fulling mill, and does not soil the hands after being dressed. At Elbeuf and Louviers, in France, such vats are much employed. Wool, silk, cotton, and linen, may all be dyed in them. Cold vats.-The copperas or common blue vat of this country is so named because the indigo is reduced by means of the protoxyde of iron. This salt should therefore be as free as possible from the red oxyde, and especially from any sulphate of copper, which would re-oxydize the indigo. The necessary ingredients are: copperas (green sulphate of iron), newly slaked quicklime, finely ground indigo, and water; to which sometimes a little potash or soda is added, with a proportional diminution of the lime. The operation is conducted in the following way: the indigo, well triturated with water or an alkaline ley, must be mixed with hot water in the preparation vat, then the requisite quantity of lime is added, after which the solution of copperas must be poured in with stirring. Of this preparation vat, such a portion as may be wanted is laded into the dyeing vat. For one pound of indigo three pounds of copperas are taken, and four pounds of lime (or 1 of indigo, 2- of copperas, and 3 of lime). If the copperas be partially peroxydized, somewhat more of it must be used. A vat containing a considerable excess of lime is called a sharp vat, and is not well adapted for dyeing. A soft vat, on the contrary, is that which contains too much cop. peras. In this case the precipitate is apt to rise, and to prevent uniformity of tint in the dyed goods. The sediment of the copperas vat consists of sulphate of lime, oxyde of iron, lime with indigo brown, and lime with indigo blue, when too much quicklime has been employed. The clear, dark wine yellow fluid contains indigo blue in a reduced state, and indigo red, both combined with lime and with the gluten of indigo dissolved. After using it for some time the vat should be refreshed or fed with copperas and lime, upon which occasion the sediment must first be stirred up, and then allowed time to settle again and become clear. For obtaining a series of blue tints, ti series of vats of different strengths is required. Linen ard cotton yarn, before being dyed, should be boiled with a weak alkaline ley, then put upon frames or tied up in hanks, and after removing the froth from the vat, plunged into and moved gently through it, For pale blues, an old, nearly exhausted vat is used; but for deep ones, a fresh, nearly saturated vat. Cloth is stretched upon a proper square dipping frame'made of wood, or preferably of iron, furnished with sharp hooks or points of attachment. These frames are suspended by cords over a pulley, and thus immersed and lifted out alternately at proper intervals. In the course of 8 or 10 minutes, the cloth is sufficiently saturated with the solution of indigo, after which it is raised and suspended so as to drain into the vat. The number of dippings determines the depth of the shade; after the last, the goods are allowed to dry, taken off the frame, plunged into a sour bath of very dilute sulphuric or muriatic acid, to remove the adhering lime, and then well rinsed in running water. Instead of the dipping frames, some lyers u e a peculiar roller apparatus, called gallopers, similar to what has been described under CALICO PRINTING; particularly for pale blues. This cold vat is applicable to cotton, linen, and silk goods. When white spots are to appear upon a blue ground, resist pastes are to be used, as described under CALICO PRINTING. The urine vat is prepared by digestion of the ground indigo in warmed stale urine, which first disoxygenates the indigo, and then dissolves it by means of'its ammonia. Madder and alum are likewise added, the latter being of use to moderate the fermentatibn. This vat was employed more commonly of old than at present, for the purpose of dyeing woollen and linen goods. The mode of making the China blue dye has been described under CALICO PRINTING; as well as the pencil blue, or blue of application. A blue dye may likewise be given by a solution of indigo in sulphuric acid. This prozess was discovered by Barth, at Grossenhayn, in Saxony, about the year 1740, and is hence called the Saxon blue dye. The chemical nature of this process has been already ully explained. If the smoking sulphuric acid be employed, from 4 to 5 parts are suffirient for 1 of indigo; but if oil of vitriol, from 7 to 8 parts. The acid is to be poured into an earthenware pan, which in summer must be placed in a tub of cold water, to pre INDIGO. 1053 vent it getting hot, and the indigo, in fine powder, is to be added, with careful stirring, in small successive portions. If it becomes heated, a part of the indigo is decom posed, with the disengagement of sulphurous acid gas, and indigo green is produced. Whenever all the indigo has been dissolved, the vessel must be covered up, allowed to stand for 48 hours, and then diluted with twice its weight of clear river water. The undiluted mass has a black blue color, is opaque, thick, attracts water from the air, and is called indigo composition, or chemic blue. It must be prepared beforehand and kept in store. In this solution, besides the cerulin, there are also indigo-red, indigobrown, and gluten, by which admixture the pure blue of the dye is rendered foul, assuming a brown or a green cast. To remove these contaminations, wool is had recourse to. This is plunged into the indigo previously diffused through a considerable body of water, brought to a boiling heat in a copper kettle, and then allowed to macerate as it cools for 24 hours. The wool takes a dark blue dye by absorbing the indigo-blue sulphate and hyposulphite, while at the same time the liquor becomes greenish blue; and if the wool be left longer immersed, it becomes of a dirty yellow. It must therefore be taken out, drained, washed in running water till this runs off colorless, and without an acid taste. It must next be put into a copper full of water, containing one or two per cent. of carbonate of potash, soda, or ammonia (to about one third the weight of the indigo), and subjected to a boiling heat for a quarter of an hour. The blue salts forsake the wool, leaving it of a dirty red-brown, and dye the water blue. The wool is in fact dyed with the indigo-red, which is hardly soluble in alkali. The blue liquor may now be employed as a fine dye, possessed of superior tone and lustre. It is called distilled blue and soluble blue. Sulphuric acid throws down from it the small quantity of indigo-red which had been held in solution by the alkali. When wool is to be dyed with this sulphate of indigo-blue, it must be first boiled in alum, then treated with the blue liquor, and thus several times alternately, in order to produce a uniform blue color. Too long continuance of boiling is injurious to the beauty of the dye. In this operation the woollen fibres get impregnated with the indigoblue sulphate of alumina. With sulphate of indigo, not only blues of every shade are dyed, but also green, olive, gray, as also a fast ground to logwood blues; for the latter purpose the preparatory boil is given with altn, tartar, sulphates of copper and iron, and the blue solution; after which the goods are dyed up with a logwood bath containing a little potash. Table of STOCKS, DELIVERIES, IMPORTS, &c., through the course of 16 Years. Arin ents. Crop of Prices 31st December. Stock 31st Delivered.___________ Bengal in December. 12 Months. course of Middlirg and Brnal* Madras, Total. Shipment. Good nnd Fine Goo and Ordinary Manilla, &c. P. V. Consuming. Consuming. 3 ~i 22,378 t 1,672 23,501 maunds. er lb. per lb. per b. 1836 22,342 22,378 21,829 1.672 23,501 115,500 7 0 8 0 6 0@6 6 5 4 5 10 1837 25,969 18,544 19,409 2,762 22,171 113,600 7 4 8 2 6 3 *6 9 5 6 6 6 1838 21,160 28,488 21,670 2,812 23,688 89,00 6 9 0 6 9 7 3 5 10 " 6 1839 15,250 23,271 13,882 3,470 11,352 123,000 8 3 9 0 6 0 7 0 50 "5 9 1840 16,344 25,811 22,823 4,082 26,905 123,00 7 6 "8 3 5 3 6 3 4 6 5 0 1841 16,478 26,599 2-2,687 4,046 26,133 16-2,000 6 0 "6 10 3 44 4 0 2 9 3 3 1842 21,927 27,820 26,594 6,675 33,269 78,900 7 9 "8 3 5 0 4 3 "4 9 1843 21,781 22,954 16,920 5,888 22,808 172,000 5 0 5 8 3 6 3 10 2 " 3 4 1844 25,975 32,253 28,228 8,219 36,447 143,500 4 10 " 5 6 3 8 3 10 3 2" 3 6 1845 33,51-2 29,968 25,458 12,047 37,505 127,800 4 10 " 5 8 3 3 3 6 2 10 "3 3 1846 33,178 28,431 19,438 8,659 28,097 101,300 5 0"6 0 38 40 32" 3 6 1847 31,902 302,428 19,576 9,576 29,152 107,200 4 6 " 5 3 2 10 " 3 3 2 4 " 8 1848 28,962 27,563 21,119 3,504 24,623 126,700 4 3 5 3 210 3 3 2 6 (2 9 1849 29,036 32,773 27,464 5.383 312,847 122,800 4 6 5 4 3 6 3 9 3 3 "3 1850 27,205 28,690 20,057 6,802 26,859 112,00 6 0 "7 0 5 2 5 6 4 7 "5 0 1851 30,332 29,241 2.2,572 9,796 32,368 122,000 4 8 "5 9 3 " 3 11 3 1 " 3 6 Yers enle-St. Stuck Stock of E. I. NDIGO, in the chief EUROPEAN PORTS, at the end of the following Years. Rott nsteAmster- ne. Ham- St. London Stock...Years. dm. ds. Antwer burgh. Peters- Trieste. Genoa. Bremen. France. and i burgh. Liverpool. jurope. chests. chests. chests. chests, c hests. shests. chests. chests. chests. chests. 1343 1,500 1,600 1 25 1,700 150 150 15 0 6,466 22,30 34,328 1844 664 1,342 170 85C 1,600 249 225 10 7,772 26,915 39,367 1 45 550 650 100 o 32 2,011 280 2.5 60 10,485 34,512 49,193 1&46 337 492 100 21 1,389 400 165 50 10,615 33.978 47,741 1847 938 560 60 150 1,918 230 13) 2) 11,1'27 32,802 47,935 1848 1042. 531;0 460 2,000 200 120 48 7,462 29,4.12 41,315 1849 595 828 100 550 1,655 150 107 20 4,501 29,240 37,745 189 395 851 150 340 1,460 150 4 0 5,311 27,215 35,962 1851 80 320 1 100 260 1,681 50 53 20 5,953 30,452 38,969 Imported for'home consumption, in 1850, 7,893,984 pounds; in 1851, 10,073,728 pounds. 10b4 INDIGO. LANDINGS, DELIVERIES, AND STOCKS OF E. I. INDIGO. Landed. Delivered. Stock 1st Janaary, 1356. Bengal. Madras, Total. Conaump- Export. Total. Bengal. &DC.S, Total In Dec. 1851 171 273 450 679 1,134 1,813 c-h - - chest. 1850 673 131 1,404 399 418 811 - - _ - " 1849 - - 473 433 1,261 1,694 - - - " In 12 months 1851 22,572 9,796 32,368 8,341 2(I,897 29,241 6,028 4,304 30,332 " 1850 20,057 6,s02 26,859 8,551 20,139 28,690 23,089 4,116 27,20 " 1849 - - 32,799 9,209 23,564 33,773 24,989 4,047 29,036 I 184.- - 24,623 10,468 17,095 27,563 23,132 5,230 28,962 " 1847 - - 29,252 9,010 21,418 30,428 24,395 7,507 31,902 " 1846 - - 28,102 10,546 17,885 28,431 25,333 7,845 33,178' 1845 - - 37,461 10,666 19,302 29,968 26,335,1771 33,512 " 1844 - - 36,808 11,664 20,589 32,253 22,823 3,152 25,975 1843 - - 22,8'8 8,253 14,701 22,954 - - 21,781 " Indigo from Spanish South America has formed a large feature in our importations of 1851. The landings amount to 7,291 serons, being 4,111 morethan the greatest quantity ever before received in one year, and 5,428 more than the average importations of the last ten years. The deliveries have been still greater; 7,887 serons-equivalent to about 3,900 chests of East Indian production. The parcels, uniformly brought to auction upon arrival, have met with very general attention. The value may be considered relatively as high as Bengal. That such quantities of this indigo were directed to this country is not the result of increased cultivation, but of the high prices current in 1850, offering a better market than those of the United States or the Mediterranean, the usual destination direct from the producing countries. LANDINGS, DELIVERIEs, AND STOCKS OF SPANISH INDIGO. Landed. Delivered. Stock 1st January. In December 1851 13 serons 207 serons - serons 1850 316 " 127 " In 12 months 1851 7,291 " 7,887 ( 403 " 1850 3,080 " 2,478 " 999 " 1849 2,352 " 3,027 " 397 " 1848 1,153 " 1,967 " 965 " 1847 2,045 1,273 " 1,779 1846 1,265 " 1,414 " 948 " 1845 1,083 " 1,047 " 1,097 " 1844 1,132 " 1,095 889 1843 2,480 " 2,641 891 " 1842 1,968 " 1,850 " 1,052'" Prices.-Bengal, fine blue, 5s. 10d. to 6s. per lb.; fine purple and violet, 5s. 2d. to 5s. 9d.; fine red violet, 5s. ld. to 5s. 7d.; good purple and violet, 4s. 8d. to 5s.; middling violet, 4s. 6d. to 4s. 8d.; middling defective, 4s. to 4s. 5d. Consuming, fine, 4s. to 4s. 6d.; middling and good, 3s. 7d. to 3s. lid.; ordinary, 3s. Id. to 3s. 6d.; ordinary and trash, 2s. 3d. to 2s. lOd. Oude, middling and good, 2s. 6d. to 3s.; ordinary, 2s. 2d. to 2s. 5d. Madras, good and fine, 4s. to 4s. 6d.; middling, 3s. to 3s. 9d.; ordinary, Is. 4d. to 2s. 9d. Kurpah, fine, 5s. to 5s. 8d.; good, 4s. to 4s. 9d.; middling, 3s. 3d. to 3s. lid.; ordinary. 2s. 3d. to 2s. 10d.; sweepings, Is. 3d. to Is. 6d. Spanish: Guatemala, good and fine, 4s. 4d. to 5s.; middling, 3s. 6d. to 4s. 2d.; ordinary, 2e. 6d. to 3s. 3d. Caracca, good, 3s. 8d. to 4s. 6d.; ordinary, 2s. 6d. to 3s. 6d. Layton, Hulbert & Co.'s Circular, 7th Jan. 1852. * Including Coastwise from Liverpool. INK. 1055 IND1GO, tested and valued. Rub one gramme of indigo to a fine powder in a porce lain mortar, pour over it 10 grammes of fuming sulphuric acid, cover it and stir occasion. ally from 6 to 8 hours. Pour the mixture into an evaporating dish, containing 2 lbs of water, and add 50 grammes of muriatic acid, and heat the whole to boiling, replacing the water lost in vapour. Dissolve one-fourth of a gramme of chlorate of potash in 100 grammes of water, in a graduated glass tube capable of holding 100 cubic centimetres of water. This quantity of salt suffices even for the very best indigo. This test liquid is to be added to the boiling hot indigo colution in question by degrees, and the quantity of it is noted, which is required to make the colour pass from blue into green, and finally to brownish red. By comparative rtsults with other indigos, and the same test, their relative value is given. INDIAN RUBBER, is the vulgar name of caoutchouc in this country. INDUSTRY. See M]ANrDACTURING INDUSTRY. INK (Encre, Fr.; Tinte, Germ.) is a colored liquid fc writing on paper, parchment, line. &c. with a pen. i,'ck ink.-Nutgalls, sulphate of iron, and gum, arc the only substances truly useful in the preparation of ordinary iak; the other things often added merely modify the shade, and considerably diminish the cost to the manufacturer upon the great scale. Many of these inks contain little gallic acid, or tannin, and are therefore of inferior quality. To make 12 gallons of ink, we may take12 pounds of nutgalls, 5 pounds of green sulphate of iron, 5 pounds of gum senegal, 12 gallons of water. The bruised nutgalls are to be put into a cylindrical copper, of a depth equal to its diameter, and boiled, during three hours, with three fourths of the above quantity of water, taking care to add fresh water to replace what is lost by evaporation. The decoction is to be emptied into a tub, allowed to settle, and the clear liquor being drawn off, the lees are to be drained. Some recommend the addition of a little bullock's blood or white of egg, to remove a part of the tannin. But this abstraction tends to lessen the product, an! will seldom be practised by the manufacturer intent upon a large return for his capital. The gum is to be dissolved in a small quantity of hot water, and the mucilage thus formed, being filtered, is added to the clear decoction. The sulphate of iron must likewise be separately dissolved, and well mixed with the above. The color darkens by degrees, in consequence of the peroxydizement of the iron, on exposing the ink to the action of the air. But ink affords a more durable writing when used in the pale state, because its particles are then finer, and penetrate the paper more intimately. When ink consists chiefly of tannate of peroxyde of iron, however black, it is merely superficial, and is easily erased or effaced. Therefore, whenever the liquid made by the above prescription has acquired a moderately deep tint, it should be drawn off clear into bottles, and well corked up. Some ink-makers allow it to mould a little in the casks before bottling, and suppose that it will thereby be not so liable to become mouldy in the bottles. A few bruised cloves, or other aromatic perfume, added to ink, is said to prevent the formation of mouldiness, which is produced by the ova of infusoria animalcules. I prefer digesting the galls to boiling them. The operation may be abridged, by peroxydizing the copperas beforehand, by moderate calcination in an open vessel; but, for the reasons above assigned, ink made with such a sulphate of iron, however agreeable to the ignorant, when made to shine with gum and sugar, under the name of japan ink, is neither the most durable nor the most pleasant to write with. From the comparatively high price of gall-nuts, sumach, logwood, and even oak bark, are too frequently substituted, to a considerable degree, in the manufacture of ink. The ink made by the prescription given above, is much more rich and powerful than many of the inks commonly sold. To bring it to their standard, a half more water may eafely be added, or even 20 gallons of tolerable ink may be made from that weight of materials, as I have ascertained. Sumach and logwood admit of only about one half of the copperas that galls will take to bring out the maximum amount of black dye. Chaptal gives a prescription in his Chimie appliquee aux arts, which, like many other things in that book, are published with very little knowledge and discrimination. He uses logwood and sulphate of copper, in addition to the galls and sulphate of iron; a per nicious combination, productive of a spurious fugitive black, and a liquor corrosive of pens. It is, in fact, a modification of the vile dye of the hatters. Lewis, who made exact experiments on inks, assigned the proportion of 3 parts of galls (______________. ____ ~ ^- -_______________ — ----- 1056 INK. to 1 of sulphate of iron, which, with average galls, will answer ve-y well; but gooa galls will admit of more copperas. Gold ink is made by grinding upon a porphyry slab, with a mrlieer, gold leaves along with white honey, till they be reduced to the finest possible division. The paste is'hen Collected upon the edge of a knife or spatula, put into a.arge glass, and diffused thre agh water. The gold by gravity soon falls to the bottom, while the honey dissolves in the water, which must be decanted off. The sediment is to be repeatedly washed till entirely freed from the honey. The powder, when dried, is very brilliant, and when to be used as an ink, may be mixed up with a little gum water. After the writing becomes dry, it should be burnished with a wolf's tooth. Silver ink is prepared in the same manner. Indelible ink.-A very good ink, capable of resisting chlorine, oxalic acid, and ablution with a hair pencil or sponge, may be made by mixing some of the ink made by the preceding prescription, with a little genuine China ink. It writes well. Many other form. ulae have been given for indelible inks, but they are all inferior in simplicity and useful. ness to the one now prescribed. Solution of nitrate of silver thickened with gum, and written with upon linen or cotton cloth, previously imbued with a solution of soda, and dried, is the ordinary permanent ink of the shops. Before the cloths are washed, the writing should be exposed to the sun-beam, or to bright daylight, which blackens and fixes the oxyde of silver. It is easily discharged by chlorine and ammonia. A good permanent ink may be made by mixing a strong solution of chloride of platinum with a little potash sugar, and gum to thicken. The writing made therewith should be passed over with a hot smoothing iron, to fix it. Red ink.-This ink may be made by infusing, for 3 or 4 days in weak vinegar, Brazil wood chipped into small pieces; the infusion may be then boiled upon the wood for an hour, strained, and thickened slightly with gum arabic and sugar. A little alum improves the color. A decoction of cochineal with a little water of ammonia, forms a more beautiful red ink, but it is fugitive. An extenporaneous red ink of the same kind may be made by dissolving carmine in weak water of ammonia, and adding a little mucilage. Green ink.-According to Klaproth, a fine ink of this color may?e prepared by boiling a mixture of two parts of verdigris in eight parts of water, with one of cream of tartai till the total bulk be reduced one half. The solution must be then passed through, cloth, cooled, and bottled for use. Yellow ink is made by dissolving 3 parts of alum in 100 of water, adding 25 parts of Persian or Avignon berries bruised, boiling the mixture for an hour, straining the liquor, and dissolving in it 4 parts of gum arabic. A solution of gamboge in water forms a conv. venient yellow ink. By examining the different dye-stuffs, and considering the processes used in dyeing with them, a variety of colored inks may be made. China ink.-Proust says, that lamp-black purified by potash ley, when mixed with a solution of glue, and dried, formed an ink which was preferred by artists to that of China. M. Merimee, in his interesting treatise, entitled, De la peinture a l'huile, says, that the Chinese dp not use glue in the fabrication of their ink, but that they add vegetable juices, which render it more brilliant and more indelible upon paper. When the best lamp-black is levigated with the purest gelatine or solution of glue, it forms, no doubt, an ink of a good color, but wants the shining fracture, and is not so permanent on paper as good China ink; and it stiffens in cold weather into a tremulous jelly. Glue may be deprived of the gelatinizing property by boiling it for a long time, or subjecting it to a high heat in a Papin's digester; but as ammonia is apt to be generated in this way, M. Merimee recommends starch gum made by sulphuric acid (British gum) to be used in preference to glue. He gives, however, the following directions foi preparing this ink with glue. Into a solution of glue he pours a concentrated solution of gall-nuts, which occasions an elastic resinous-looking precipitate. He washes this matter with hot water, and dissolves it in a spare s. ution of clarified glue. He filters anew, and concentrates it to the proper degree for being incorporated with the purified -arp-black. The astringent principle in vegetables does not precipitate gelatine when its acid is saturated, as is done by boiling the nutgalls with limewater or magnesia. The first mode of making the ink is to be preferred. The lamp-black is said to be made in China, by collecting the smoke of the oil of sesame. A little camphor (about 2 per cent.) has been detected in the ink of China, and is supposed to improve it. Infusion of galls renders the ink permanent on paper. Sympathetic ink. The best is a solution of muriate of cobalt. Printer's ink. See this article. By decomposing vanadate of ammonia with infusion of galls, a liquid is obtained of a perfectly black hue, which flows freely from the pen, is rendered blue by acids, is insoluble in dilute alkalis, and resists the action of chlorine. Whenever the metal vana INK. 1057 Mium shall become more abundant, as it probably may ere long, we shall possess the means of making an ink, at a moderate price, much superior to the tannate and gallate of iron. To prepare the above vanadic salt cheaply, the cinder or hammerschlag obtained from the iron made at Ekersholm, in Sweden, or other iron which contains vanadium, being reduced to a fine powder, is to be mixed with two thirds of its weight of nitre, and one third of effloresced soda. The mixture is to be ignited in a crucible; cooled and lixiviated, whereby solutions of the vanadates of potash and soda are obtained not pure, indeed, but sufficiently so for being decomposed, by means of sal ammoniac into a vanadate of ammonia. This being rendered nearly neutral with any acid, constitutes an excellent indelible ink. Ink, indelible, may be prepared by adding lamp-black and Indigo to a solution of the gluten of wheat in acetic acid. This ink is of a beautiful black colour, at the same time cheap, and cannot be removed by water, chlorine, or dilute acids. M. Herberger gives the following directions for its preparation: - Wheat-gluten is carefully freed from the starch, and then dissolved in a. little weak acetic acid; the liquid is now mixed with so much rain water that the solution has about the strength of wine vinegar, i. e. neutralizes % of its weight of carbonate of soda; 10 grs. of the best lamp-black and 2 grs. of indigo are mixed with 4 ozs. of the solution of gluten and a little oil of cloves added. This ink may be employed for marking linen, as it does not resist mechanical force. Ink, indelible, of Dr. Traill, is essentially the same as the above. French indelible -ink consists of Indian ink diffused through dilute muriatic acid, for writing with quills, and through weak potash lye for writing with steel pens. Ink, blue. Mr. Stephen's patent blue ink is made by dissolving Prussian blue in a solution of oxalic acid. The blue should be washed in dilute muriatic acid. M. Hornung has given the following, as the best formula for blue ink: - Mix 4 parts'of perchloride of iron, in solution, with 7'50 parts of water, then add 4 parts of cyanide of potassium dissolved in a little water; collect the precipitate formed, wash itowvith several additions of water, allow it to drain until it weighs about, 200 parts; add to this one part of oxalic acid, and promote the solution of the cyanide by shaking the bottle containing the mixture. The addition of gum and sugar is useless, and even appears to exercise a prejudicial effect on the beauty of the ink. It may be kept without any addition for a long time. Rev. -Mr. Reade's inks.-A series of writing inks of a new composition have been made the subject of a patent by the Rev. J. B. Reade, F. R. S., and they seem to deserve public patronage. They resist equally acids and alkalis, and are well adapted to metallic pens. His inks for marking linen are not acted upon by cyanide of potassium or chloride of lime. His process for obtaining a soluble Prussian blue is new to the chemical world, and inclines to raise a doubt as to the elementary nature of iodine. In the course of his researches, he has discovered two new salts of gold, which he has named ammonia-iodide, and ammonia-periodide, of gold. His specification runs thus: - Istly. I manufacture in manner following, a blue writing ink, which is wholly free from acid, and therefore well adapted for use with steel pens. I first obtain a solution of iodide of iron by the process ordinarily followed for that purpose, and then dissolve therein half the weight of iodine already employed. I next pour this mixture into a semi-saturated solution of yellow prussiate of potash, employing a weight of this salt nearly equal to the whole weight of iodine used in the above iodine solution. A decomposition of the materials, thus brought together, immediately takes place, when the cyanogen (of the prussiate of potash) and iron combine, and are precipitated in a solid form, and the potassium (of the prussiate) and iodine combine to form a neutral iodide of potassium, which remains in solution with a little excess of iodide of iron. I next filter and wash the solid precipitate of cyanogen and iron (which is soluble Prussian blue), and finally dissolve it in water, which forms the blue ink required. In this process, it will be observed that neither any acid nor persalt of iron is employed, as is usual in the formation of Prussian blue. I was led to these results by a microscopical examination of the metallic colours in salts of the ashes of plants. I employed iron and iodine to produce the same effects in pure salts; and in the course of my experiments, I ascertained that these two substances (iron and iodine) have so great an affinity for each other, that when placed together without any water, or when rubbed together, they very speedily form a liquid containing an excess of iodine in solution, which, being added to a solution of prussiate of potash, gives the compound of cyanogen and iron, or soluble Prussian blue, which has been just described. The addition of water alters the character of this iodine solution; without water, it turns litmus paper green, and with water it has the usual acid reaction, thus apparently confirming Davy's original doubt as to the elementary character of iodine. 1058 INK. 2ndly. I form a neutral iodide of potassium, of great purity, and wholly free from alkaline reaction, in manner following: I take the solution which remained over from the process first described, after the Prussian blue had been precipitated, which solution consisted, as before stated, of a neutral iodide of potassium, with iodide of iron in excess; and I get rid of that excess by the well known processes of fusion and crystallization. The result is an iodide of potassium, which is as pure as when iodine and potassium are made to act directly on one another, and is perfectly free from the alkaline reaction on turmeric paper, which invariably characterizes the most careful preparations of this salt when carbonate of potassa is employed (as usual) in its manufacture. It is also much less deliquescent than the ordinary iodide of potassium of commerce, and. bn account of its great purity, much to be preferred in medicinal preparations. 3rdly. I manufacture a blue ink of peculiar intensity, and, therefore, particularly suitable for printing purposes, by using the same materials, and manipulating them in the same way as first described, with the exception that for the iodine wherever it is used, I substitute bromine, and rub up the precipitate in oil. 4thly. I form a bromide of potassium of great purity, and wholly free from alkaline reaction, by treating the bromide of potassium, which remains over in a state of solution from the process last before described, in the same way as the iodide of potassium solution is directed to be used under the second head of this specification. 5thly. I manufacture a very superior black writing ink, by adding to gall ink of a good quality soluble Prussian blue, described under the first head of this specification. The addition of this Prussian blue makes the ink, which was already proof against alkalines, equally proof against acids, and forms a writing fluid, which cannot be erased from paper by any common method of fraudulent obliteration, without the destruction of the paper. 6thly. I manufacture in manner following a red writing ink which is generally superior to the common solutions from peach wood and Brazil wood, not only in permanent brilliancy of colour, but also in its freedom from acid, and consequent fitness ror use with steel pens. I first boil cochineal repeatedly in successive quantities of pure water, till it ceases, or nearly so, to give out any colouring matter. I then boil it in water containing liquor ammonice, which combines after the manner of an alkali with an acid, with the residue of colouring matter, and leaves the insect matter nearly white. The liquid products of these successive boilings are then thrown together into an earthenware vessel, and, in order to get rid of a peculiar element or principle, still combined with the colouring matter, and which has a great affinity for iron, I precipitate the colouring matter with ammonia-bichloride of tin. The precipitate is afterwards dissolved in ammonia, and protiodide of tin added, till a sufficient degree of brilliancy of colour is obtained, which completes the process, water being added ad libitum, according to the degree of body required to be given to the ink. Wthly. I manufacture by the improved process following a marking ink which may be used with steel pens, and is not only of great intensity of colour, but comes out most readily on the application of heat. I rub together in a mortar nitrate of silver and the proper equivalent of tartaric acid in a dry state. I then add water, on which crystals of tartrate of silver are formed and the nitric acid set free. I next neutralize this acid by adding liquor ammonike, which also dissolves the tartrate of silver. I finally add gum, colouring matter, and water, in the usual way, and in quantities which may be varied at pleasure. By this process the nitric acid, which is essential to a good marking ink, is retained and the tartrate of silver formed is soluble in less than half the quantity of liquor ammoniae ordinarily required when tartrate of silver is the basis of the ink. The tedious operation of filtering and washing the carbonate of silver in order to form the tattrate is also thereby entirely dispensed with. 8thly. I manufacture in manner following a marking ink, differing fiom the preceding and all other marking inks containing salts of silver only, in this respect, that, it cannot be acted upon by the common solvents of salts of silver, as cyanide of potassium, or chloride of lime, and is so far, therefore, more indelible. I take the ink, as it has been formed by the process last described, and add to it an ammoniacal solution of an oxide or salt of gold. I have used for this purpose the purple of Cassius, the hyiposulphite of gold, the ammonia-iodide of gold, and ammonia-periodide of gold. The two last salts, which I believe to be new salts, I obtain by dissolving iodine in liquor ammonie, under the application of heat; an operation, however, which requires to be conducted with great caution in order to prevent the formation of the explosive compound, the teriodide of nitrogen. This iodine solution is a very speedy solvent of gold. If gold leaf be placed upon it without the addition of water, a black oxide of gold is formed, which immediately dissolves, but if it be diluted with water, the process of.oxidation is less rapid, and the gold leaf assumes a fine purple colour (not black), before solution. This salt of gold crystallizes in four-sided prisms, which are soluble in water. A few drops of this solution placed on a slip of glass generally form 1* IODINE. 1059 microsocpic arborescent crystals, from which, under the application of heat, both the iodine and ammonia may be volatilized, and arborescent metallic gold alone remains. If a moderate heat only is employed, one equivalent only of iodine is expelled, and white crystals of ammonia-iodide of gold remain. 9thly. I manufacture a blue printing ink by taking the soluble precipitate of cyanogen and iron, obtained by the process described under the first head of this specification, and rubbing up the same in oil, after the manner ordinarily followed in the manufacture of printing inks; or by boiling down the blue writing ink, produced by the said process to a sufficient consistence, and then rubbing up the same in oil. 10thly. I manufacture a black printing ink by boiling down the black writing ink, produced from the materials, and by the process described under the fifth head of this specification, and rubbing it up in oil as aforesaid. 11th. I manufacture a red printing ink by taking the ammoniacal solution of cochineal, obtained by the process described under the sixth head of this specification, and rubbing it up in oil, adding protiodide of tin according to the degree of lustre required; or by boiling down the red writing ink, produced by the said process, to a sufficient consistence, and then rubbing up the same in oil as aforesaid. And 12th, I manufacture a black printing ink by boiling chips of logwood (for which an extract of logwood may be substituted), or other dye woods, containing colouring matter and tannin, along with as much of proto-salt or persalt of iron or copper, or other precipitate of tannin, as will be equal to about twice the weight of the tannin contained in the wood or extract employed; whereby I obtain a black or blueish black precipitate; the blueness of which I diminish, as may be required, by the addition of bichromate of potash, more or less. I finally rub up the whole in oil as aforesaid, adding a small quantity of the lamp-black, or other black colouring matter, ordinarily employed in the manufacture of black printing inks. INULINE (Eng. and Fr.) is a substance first extracted from the root of the Inula-Hellenium, or Elecampane. It is white and pulverulent like starch; and differs from this substance chiefly because its solution, when it cools, lets fall the inuline unchanged in powder, whereas starch remains dissolved in the cold, as a jelly or paste. Inuline is obtained by boiling the root sliced in 3 or 4 times its weight of water, and setting the strained decoction aside till it cools, when the pulverulent inuline precipitates. It exists also in the roots of colchicum, and pellitory. IODINE (lode, Fr.; Iod, Germ.) is one of the archreal undecompounded chemical bodies, which was discovered accidentally in 1812 by M. Courtois, a manufacturer of saltpetre, in the mother-waters of that salt. Its affinities for other substances are so powerful as to prevent it from existing in an insulated state. It occurs combined with potassium and sodium in many mineral waters, such as the brine spring of Ashby-de-laZouche, and other strongly saline springs. This combination exists.paringly in seawater, abundantly in many species of fucus or sea-weed, and in the kelp made from them; in sponges; in several marine mollusce, such as the doris, the venus, oysters, &c.; in several polyparies and sea plants, as the gorgonia, the zostera marina, &c.; particularly in the mother-waters of the salt-works upon the Mediterranean sea; and it has been found in combination with silver, in some ores brought from the neighborhood of Mexico. Iodine is most economically procured from the mother-water of kelp, as furnished by those manufacturers of soap in Scotland and elsewhere who employ this crude alkaline matter. By pouring an excess of sulphuric acid upon that liquid, and exposing the mixture to heat in a retort, iodine rises in violet vapors (whence its name), and condenses in the receiver into black, brilliant, soft, scaly crystals, resembling graphite or plumbago. An addition of the peroxyde of manganese to the above mixture, favors the production of iodine. Souberain has proposed as a means of extracting it in greater abundance from a given quantity of the said mother-Waters, to transform the iodide of potash or soda, present, into an insoluble iodide of copper, by pouring into them solution of sulphate of copper, which precipitates first of all one half of the iodine. He then decants the supernatant liquor, and adds to it a fresh quantity of the sulphate along with, some iron filings. The latter metal seizes the oxygen and sulphuric acid of the cupreous salt, sets the copper free, which then seizes the other half of the iodine. To separate this iodide from the remaining iron filings, he agitates the whole with water, and decants the liquor. The filings immediately subside, but the iodide of copper remains for some time in a state of suspension. This compound, separated by a filter cloth, is to be mixed with twice its weight of the black peroxyde of manganese, and as much sulphuric acid as will make the mixture into a paste; which mixture being introduced into a retort, and distilled, the iodine comes over in its characteristic violet vapors, which are condensed into the glistening black substance in the receiver. Iodine is always solid at atmospheric temperatures, though it slowly flies off with a 68 1060 IRON. peculiar offensive penetrating odor somewhat like chlorine. Its specific gravity is 4-946 at the temperature of 58~ Fahr. Its prime equivalent, according to Berzelius. is 63-283, one volume of hydrogen being 1-000; but 126-566, if two volumes of hydrogen be reckoned unity, as most British chemists estimate it, from the composition of water. It possesses in a high degree electro-negative properties, like oxygen and chlorine; and therefore makes its appearance at the positive pole, when its compounds are placed in the voltaic circuit. It stains the skin yellow; and if applied for some time to it, is apt tc produce painful ulcerations. Iodine melts only at about 390~ Fahr.; but with the vapor of water it volatilizes at 212~ It has a great affinity for hydrogen, and constitutes by that union hydriodic acid; a compound resembling in some respects muriatic or hydrochloric acid. It also can be combined with oxygen, and forms thereby iodic acid. Its compounds with carbon, phosphorus, sulphur, chlorine, azote, and many metals, have not been applied to any manufacturing purpose, and therefore need not be described here. The chief application of iodine in the arts, is for the detection of starch, which its watery solution, though containing only one part in 5000, does readily, by the production of a deep purple color; this vanishes by exposing the starch to the air for some time, or more quickly by heating it. As a medicine, iodine and its compounds, such as the iodides of potassium and iron, are supposed to possess great powers in resolving glandular swellings. The periodide of mercury is a brilliant red pigment, but somewhat evanescent. Chlorine, bromine, and iodine, are frequently associated; and it has hitherto been reckoned a difficult problem to separate them from one another. The following lan is proposed by Mr. Lovig. Heat the mixture of the dried chloride and bromide (or chloride and iodide) while a current of chlorine is made to pass over it, till no more bromine is carried off by the chlorine. Receive the gases in a solution of potash; saturate this fluid mixture of the chloride of potassium, and the chlorate and bromate of potash with nitric acid, adding afterwards nitrate of silver. A mixture of bromate and chloride of silver will precipitate. Dry the precipitate, calcine it, and calculate the proportion of bromine from the volume of oxygen gas now disengaged. It would be preferable to digest in a vial, the precipitate while moist, along with water of baryta, which decomposes the bromate of silver without acting upon the chloride. The excess of baryta being thrown down by carbonic acid, and the liquid being evaporated, a bromate of baryta is obtained, which may be \vashed with alcohol of 0-840. The solution of bromate of baryta may also be neutralized by nitric acid, and the bromic acid may be precipitated by nitrate of silver. The same method is applicable to the separation of iodine from chlorine. After throwing down the solution of the mixed salts by nitrate of silver, Berzelius digests the washed precipitate in a closed bottle of water of baryta; whence results bromate of baryta without any chloride of barium. On evaporating the liquor we ob-:ain crystallized bromate of baryta, which may be freed from a small accidental quantity of chloride, by washing with alcohol at 0-840. By calcination we then obtain bromide of barium, which, being distilled with sulphuric acid and peroxyde of manganese, affords bromine. IRIDIUM is a metal discovered by Descotils in 1803, as also by Tenant in 1804; and is so called because its different solutions exhibit all the colors of the rainbow. It occurs only in the ore of platinum, being found there in two states; 1. united to that metal, and 2. as alloy of osmium and iridium, in the form of small, insulated, hard grains. Iridium is the most refractory of all the metals; and appears as a gray metallic powder. It is not fused by the flame of the hydroxygen lamp. IRON (Fer, Fr.; Eisen, Germ.) is a metal of a bluish-gray color, and a dull fibrous fracture, but it is capable of acquiring a brilliant surface by polishing. Its specific gravity is 7-78. It is the most tenacious of metals, and the hardest of all those which are malleable and ductile. It is singularly suscelible of the magnetic virtue, but in its pure state soon loses it. When rubbed it has a slight smell, and it imparts to the tongue a peculiar astringent taste, called chalybeate. In a moist atmosphere, iron speedily oxydizes, and becomes covered with a brown coating, called rust. Every person knows the manifold uses of this truly precious metal; it is capable of being cast in moulds of any form; of being drawn out into wires of any desired strength or fineness; of being extended into plates or sheets; of being bent in every direction; of being sharpened, hardened, and softened at pleasure. Iron accommodates itself to all our wants, our desires, and even our caprices; it is equally serviceable to the arts, the sciences, to agriculture, and war; the same ore furnishes the sword, the ploughshare, the scythe, the pruning hook, the needle, the graver, the spring of a watch or of a carriage, the chisel, the chain, the anchor, the compass, the cannon, and the bomb. It is a medicine of much virtue, and the only metal friendly to the human frame. The ores of iron are scattered over the crust of the globe with a beneficent profusion, Proportioned to the utility of the metal; they are found under every latitude, and every IRON. 1061 zone; in every mineral formation, and are disseminated in every soil. Considered in a purely mineralogical point of view, without reference to their importance for reduction, they may be reckoned to be 19 in number; namely, 1. native iron of three kinds: pure, nickeliferous, and steely; 2. arsenical iron; 3. yellow sulphuret of iron; 4. white sulphuret of iron; 5. magnetic sulphuret of iron; 6. black oxyde of iron, either the loadstone, or susceptible of magnetism, and titaniferous; 7. compactfer oligiste, specular iron ore, as of Elba, and scaly fer oligiste; 8. hematite, affording a red powder; 9. hematite or hydrate of iron, affording a yellow powder, of which there are several varieties; 10. pitchy iron ore; 11. siliceo-calcareous iron, or yenite; 12. sparry carbonate of iron, and the compact clay iron-stone of the coal formation; 13. phosphate of iron; 14. sulphate of iron, native copperas; 15. chromate of iron; 16. arseniate of iron; 17. muriate of iron; 18. oxalate of iron; 19. titanate of iron. Among all these different species, ten are worked by the miner, either for the sake of the iron which they contain; for use in their native state; or for extracting some principles from them advantageous to the arts and manufactures; such are arsenical iron, sulphate of iron, sulphuret of iron, and chromate of iron. 1. Native iron A. Pure.-This species is very rare, and its existence was long matter )f dispute; though it has been undoubtedly found not only in volcanic formations, but in veins properly so called. It is not entirely like our malleable iron; but is whiter, more ductile, more permanent or less oxydizable in the air, and somewhat less dense. Among the best attested examples of pure native iron is that observed by M. Schreber, in the mountain of Oulle near Grenoble. The metal was entangled in a vein running through gneiss, and appeared in ramifying stalactites, enveloped in fibrous brown-oxyde of iron mixed with quartz and clay. B. The native nickeliferous or meteoric iron is very malleable, often cellular, but sometimes compact, and in parallel plates, which pass into rhomboids or octahedrons. It is naturally magnetic, and by its nickel is distinguishable from terrestrial native iron. Macquart, in describing the famous mass found at mount Kemir in Siberia, says that the iron is perfectly flexible, and fit for making small instruments at a moderate heat; but in too strong a fire, the metal becomes short, brittle, and falls into grains under the hammer. Meteoric iron is covered with a sort of varnish which preserves its surface from the rusting action of the air; but this preservative property does not extend to the interior. Chladni has given a list of masses of meteoric iron, which have been known to fall at different times from the atmosphere, and of many specimens which indicate their atmospheric origin, by their aspect and composition. A portion of the mass of meteoric iron found at Santa-Rosa near Santa-Fe-de-Bogota, was made into a sword and presented to Bolivar. c. Native steel-iron.-Tlis substance has all the characters of cast-steel; it occurs in a kind of small button ingots, with a finely striated surface, and a fracture exceedingly fine grained. It is hardly to be touched by the file, and will scarcely flatten under the hammer. M. Mossier found this native steel at the village of Bouiche, near Nery, department of the Allier, in a spot where there had existed a seam of burning coal. A mass of 16 pounds and 6 ounces of native steel was discovered in that place, besides a great many small globules. 2..rsenical iron, rsenikkies, or Mispickel, is a tin-white mineral, which emits a garlic smell at the blowpipe, or even when sparks are struck from it by steel, accompanied with a small train of white smoke. It contains generally more or less sulphur, and sometimes a little silver, associated with metallic arsenic and iron. 3. Yellow sulphuret of iron, commonly called Marcasite, or Martial pyrites. The bronze or brass yellow color enables us to recognise this mineral. At the blowpipe it gives off its sulphur, and is converted into a gLobule attractable by the blowpipe. It is a bisulphuret of iron onntaining 32 of sulphur and 28 of metal. Copper pyrites may be distinguished from it by its golden yellow color, which is frequently iridescent, and by its inferior hardness; for it does not strike fire with steel, like the preceding persulphuret. There is no vein, stratum, or mass of metallic ore which does not contain some iron pyrites; and it is often the sole mineral that fills the veins in quartz. It sometimes contains gold, and at other times silver. 4 White sulphuret of iron.-This is distinguishable from the preceding species only by:; color and form of crystallization, and was hence till lately confounded with it by mineralogists. Its surface is often radiated. 5. Magnetic sulphuret of iron, the Magnetkies of the Germans.-This ore is attractable by the magnet like common iron. Its color is reddish-yellow, passing into brown: its fracture is rough. It consists of 16 of sulphur and 28 of iron. 6. Black oxyde of iron, magnet ore, or native loadstone.-One variety of this species has two poles in each specimen, which manifest a repulsive action against the corresponding poles of a magnetic needle. All the varieties furnish a black powder. Its oxternal color is a gray approaching to that of metallic iron, but somewhat duller; 1062 IRON. with occasional iridescence of surface. Neither nitric acid nor the blowpipe has an] action upon it. Its specific gravity varies fiom 4'24 to 5'4; and its constituents are 71'86 peroxyde, and 28'14 protoxyde, according to Berzelius; or in 100 parts, 71'74 ot metallic iron, and 28-26 of oxygen. Assuming the prime equivalent of iron to be 28 with the British chemists, then an ore consisting, like the above, of two prime propor tions of peroxyde, and one of protoxyde, would be represented by the number 116 = 8C +- 36; and would consist in 100 parts, of iron 72'4, oxygen 27'6. Magnetic iron-ore belongs to primitive reck formations, and occurs abundantly in Sweden, Dalecarlia, Norway, Siberia, China, Siam, and the Philippine isles; but it is rare in England and France. It is worked extensively in Sweden, and furnishes an excellent iron. The titaniferous oxyde of iron, or iron sand, is also attractable by the magnet. Its color is a deep black, with some metallic lustre; it is perfectly opaque; its fracture is conchoidal; it is hard and difficult to grind under the pestle into a dull black powder, which stains the fingers when it is very fine; it melts at a high heat into a black enamel without lustre. All volcanic rocks contain a greater or less quantity of titanic iron-ore, disseminated through them, which may be recognised by its brilliant metallic lustre, anti its perfect conchoidal fracture. 7. Fer oligiste, iron-glance, specular iron, and red iron ore.-This ore has the color of polished steel; and the light transmitted through the thin edges of its crystals appears of a beautifil red. Its powder is always of a well marked brown-red hue, passing into cherry-red, which distinguishes it from the black-oxyde ore. Its fracture is rough, or vitreous in certain varieties; it breaks easily; but it is hard enough to scratch glass. It usually contains from 60 to 70 of metallic iron in 100 parts; the equivalent proportion of oxygen in the pure red oxyde of iron being 30 parts combined with 70 of metal. It is a mistake to suppose any specular iron ore capable of yielding 85 per cent. of iron, for 100 parts of even protoxyde of iron contain only 77'77 parts of metal. The compact variety comprises the crystals of the island of Elba, and of Framont in the Vosges, which have a rough-grained fracture. It exists in very great masses, constituting even entire mountains; in the cavities and fissures of these masses, the beautiful crystals so much prized by collectors of minerals, occur. The island of Elba is equally celebrated for its inexhaustible abundance of rich specular iron ore, and for the immemorial antiquity of its mining operations. Fig. 792 is a vertical 79:2...... section passing through the three workings, called Pietamonte (D), Sanguinaccio (E), Antenna'(F), through an ancient excavation a, through the coast o, and the mole p, ending at the canal of Piombino. The total height of the metalliferous mountain above the level of the sea, is no more than 180 metres, or 600 feet. The rock which constitutes the body of this little mountain d I, is called bianchetta by the workmen. It is a white slaty talc, slightly ochreous, or yellowish, consisting chiefly of silica and alumina, with some magnesia. The ore of Antenna (F) is a very hard compact fer oligiste, of a brilliant metallic aspect. The workable bed has a height of 66 feet, and consists of metalliferous blocks mixed confusedly with sterile masses of the rock; the whole covered with a rocky detritus, under a brownish mould. From its metallic appearance and toughness, this bed is called venaferrata, the iron vein. In Pietamonte the workable bed is composed entirely of micaceous specular iron ore (fer oligiste), with its fissures filled with yellow ochre. This bed rests upon the rock called bianchetta; the brilliant aspect of ore in this place has gained for it the name of vena lucciola. The metalliferous hill d 1, extends to the north-east. about a mile beyond the work. ings D E F. The ore contains about 65 per cent. of iron, and is smelted in Catalan forges. The following description of the figure will make the structure of this extraordinary mine well understood. a, is a great excavation, the result of ancient workings. 1, 1; 2, 2; 3, 3, 4, 4, 5, 6. and 7, are roads for carrying off the rubbish, in correspond ence with the several working levels. IRON. 1063 b, b, b, masses of old rubbish (deblais). c, c, ditto, from the present workings D, E, F. d, the rocky mass called bianchetta, against which the ore extracted from a abuts. e, the surface of a bed of ore, near the streamlet g. f, f, indication of beds of iron pyrites and fer oligtste. g, a small rivulet proceeding from the infiltration of rains, and which is impregnated with acidulous sulphate of iron. h, h, ravine which separates the metalliferous hill d 1 from the barren hill z. k, masses of slags from ancient smelting operations; such are very common in this island. None of any consequence now exist; nearly the whole of the ore being exported to Tuscany, the Romagna, the Genoese territories, Piedmont, Naples, and Corsica. 1, a considerable body of rubbish from ancient workings, towards the summit of the metalliferous hill d, 1. m, m, part of this hill covered with rubbish, the result of old workings. a, the site called Vigneria. o, houses upon the shore called Maril.. de Rio, where the workpeople live, and the mineral is kept in store. p, wooden pier (mole) whence the ore is shipped; terminated by a small tower, q. Compact fer oligiste occurs also in the Vosges, in Corsica, at Altenberg and Freyburg, in Saxony, Presnitz, in Bohemia, Norberg and Bisberg, in Sweden, &c. The varieties called specular fer oligiste, and scaly fer oligiste, or iron-glance, do not differ essentially from the compact. None of them affects the magnetic needle, and their powder is a red of greater or less vivacity. 8. Red oxyde of iron.-The varieties included under this species afford a red powder, do not affect the magnetic needle, and are destitute of metallic lustre. At the blowpipe *hey all become black, or deep brown; and then they act on the needle. The crystalized variety consists of 70 iron and 30 oxygen in 100 parts. The concretionary kind, or hematite, has a brown-red color; is solid, compact, and sometimes very hard; its surface may be filed and polished so as to acquire a lustre almost metallic; its internal structure is fibrous, and it exhibits sometimes a resemblance to splinters of wood. Its outer surface is constantly concretionary, mammelated, and presents occasionally sections of a sphere, or cylinders attached to each other. This is the blood-stone of the burnisher of metals. It is a very common mineral. The ochry variety or red-iron-ochre is distinguished from the solid hematite by the brightness of its color. It is used as a pigment. 9. Brown oxyde of iron, brown iron-stone.-This affords always a yellow powder, without any shade of red, which passes sometimes into the bistre brown, or velvet black. At the blowpipe this oxyde becomes brown, and very attractable by the magnet; but after calcination and cooling, the ore yields a red powder, which stains paper nearly as red as hematite does, and which is much employed in polishing metals. All the yellow or brown oxydes contain a large proportion of water, in chemical combination; and hence this species has been calle& hydrate of iron. There are several varieties which assume globular, reniform, stalactitic, and fruticose shapes. As impure varieties of the species we must consider some of the clay-iron ores, such as the granular, the common, the pisi. form, and the reniform clay-iron ore. According to D'Aubuisson, the present species consists of peroxyde of iron, from 82 to 84 per cent.; water, 14 to 11; oxyde of manganese, 2; silica, 1 to 2. It is therefore a hydrated peroxyde of iron; and ought by theory to consist, in its absolute state, of 81-63 peroxyde, and 18-37 water. It occurs both in beds and veins. The cetiles or eagle-stones form a particular variety of this ore. On breaking the balls, so named, they are observed to be composed of concentric coats, the outside ones being very hard, but the interior becoming progressively softer towards the centre, which is usually earthy and of a bright yellow color; sometimes, however, the centre is quite empty, or contains only a few drops of water. (Etites occur in abundance, often even in continuous beds in secondary mountains, and in certain argillaceous strata. These stones are still considered by the French shepherds as amulets or talismans, and may. be found in the small bags which they suspend to the necks of their favorite rams; and they are in such general use, that a large quantity is annually imported into France from the frontiers of Germany, for this superstitious purpose. When smelted, they yield a good iron. The variety called gralnular brown oxyde, or bone ore, is merely a modification of the preceding. It occurs in grains nearly round, varying in-size from a millet seed to a pea, each being composed of concentric coats, hard outside and soft within. They are generally agglutinated by a calcareous or argillaceous paste; but are occasionally quite loose. This ore occurs in calcareous formations, and is sometimes accompanied with shells, such as terebratulce. The brittle quality of the iron afforded by it has been ascribed to the phosphorus derived from the large quantity of organic bodies, with, ____ _-_-. —------------------- --------- ------------------- -------- "~~~~~~~~~~~~~~~~~~~~~~~~~ 1064 IRON. which the ore is frequently mixed. The bog-iron ore and swamp-iron ore belong to this species. 10. Pitchy hydrate of iron.-This is a rare mineral of a resinous aspect, found in a vein in the mine of Braunsdorf, two leagues from Freyberg, and seems to consist of red oxyde of iron and water. 11. Yenite is a mineral species, rather rare, composed of red oxyde of iron, silica, and lime. 12. Carbonate of iron, sparry iron, or brown-spar.-This important species has been divided into two varieties; spathose iron and the compact carbonate. The first has a sparry and lamellar fracture; with a color varying from yellowish-gray to isabella yellow, or even to brownish-red. It turns brown without melting at the blowpipe, and becomes attractable by the magnet after being slightly roasted in the flame of a candle. Even by a short exposure to the air, after its extraction from the mine, it also assumes the same brown tint, but without acquiring the magnetic quality. It affords but a slight effervescence with nitric acid, changing merely to a red-brown color. Its specific gravity varies from 3-00 to 3'67. Its primitive form is like that of carbonate of lime, an obtuse rhomboid. Without changing this form, its crystals are susceptible cf containing variable quantities of carbonate of lime, till it passes wholly into this minaal. Manganese and magnesia enter also occasionally into its composition. Sparry carbonate of iron belongs to primitive formations; forming powerful veins in mountains of gneiss, and is associated in these veins with quartz, copper pyrites, gray copper, fibrous brown oxyde of iron, and a variety of ramose carbonate of lime, vulgarly called flos ferri. Thus it is found at Allevard and Vizille, near Grenoble, at SaintGeorge d'Huretiere, in the Alps of Savoy; at Baigorry, in the Lower Pyrenees; at Eisenerz, in Styria; at Huttenberg, in Carinthia; at Schwartz, in the Tyrol; in Saxony, Hungary, other places in Germany, as also in Spain, Sweden, Norway, and Siberia. It also occurs, along with galena and other ores of lead, in the mines of Lead-Hills and Wanlockhead, in Scotland; and in the mines of Cumberland, Northumberland, and Derbyshire; likewise with tin-ore, at Wheal Maudlin, Saint-Just, and other places in Cornwall. This ore, viewed as a metallurgic object, is one of the most interesting and valuable that'is known; it affords natural steel with the greatest facility, and accommodates itself best to the Catalan smelting forge. It was owing in a great measure to the peculiar quality of the iron which it produces, that the excellence long remarked in the cutlery of the Tyrol, Styria, and Carinthia, was due. It was called by the older mineralogists steel ore. The carbonate of iron of the coal formation, is the principal ore from which iron is smelted in England and Scotland, and it yields usually from 30 to 33 per cent. of cast metal. We are indebted to Dr. Colquhoun for several elaborate analyses of the sparryirons of the Glasgow coal field; ores which afford the best qualities of iron made in that district. The richest specimen, out of the nine which he tried, came from the neighborhood of Airdrie; it had a specific gravity of 3-0533, and afforded in 100 parts, carbonic acid, 35-17; protoxyde of iron, 53'03; lime, 3*33; magnesia, 1-77; silica, 1'4; alumina, 0'63; peroxyde of iron, 0'23; carbonaceous or bituminous matter, 3-03; moisture and loss, 1'41. Its contents in metallic iron are 41'25. The compact carbonate of iron has no relation externally with the sparry variety. It comprehends most of the clay-iron stones, and particularly that which occurs in flattened spheroidal masses of various size, among the coal measures. The color of this ore is often a yellowish-brown, reddish-gray, or a dirty brick-red. Its fracture is close grained; it is easily scratched, and gives a yellowish-brown powder. It adheres to the tongue. has an odor slightly argillaceous when breathed upon, makes no effervescence with any acid, blackens at the blow-pipe without melting, and becomes attractable by the magnet with the slightest calcination. This ore affords from 30 to 40 per cent. of iron of excellent quality; and it is the object of most extensive workings in Great Britain. It occurs in the slaty clay which serves as a roof or floor to the strata of coal; and also in continuous beds, fiom 2 to 18 inches thick, among the coal measures, as in Staffordshire, Shropshire, and Wales. It is remarkable, that the coal-basin of Newcastle contains little clay iron-stone, while thei coal-basin of Dudley is replete with it. 13. Phosphate of iron.-A dull blue color is the most remarkable externai character of this species, which occurs in small masses composed of aggregated plates, sometimes in an excessively fine powder, or giving other bodies a blue tinge. It assumes at the blowpipe a rusty hue, and is then reduced to a button of a metallic aspect. It dissolves completely in dilute nitric acid, as well as in ammonia, but it doee not communicate its color to them, and oil turns it black; characters which distinguish it readily from blue carbonate of copper, whose color is net altered by ammonia. It is of no use as a smelting ore. IRON. 1065 14. Sulphate of iron, native green vitriol.-This is formed by the oxygenation of sul phuret of iron, and is unimportant in a metallurgic point of view. 15. Chromate of iron.-For the treatment and use of this ore, see CHROME. 16..Arseniate of iron, Wurfelerz. 17. Muriate of iron. 18. Oxalate of iron; Humboldtite, found by M. Breithaupt in the lignite of Kolaw. It consists of protoxyde of iron, 53-86; oxalic acid, 46*14; in 100. 19. Titanate of iron consists of protoxyde and peroxyde of iron, 86; titanic acid, 8; oxyde of manganese, 2; gangue, 1 = 97. See Black Oxyde of iron. Of the assay of iron-ores byfusion.-In the assays by the dry way, the object is to separate exactly all the iron which the ore may contain, with the view of comparing the result with the product of smelting on the great scale. In order to succeed in this operation, we must deoxydize the iron, and produce at the same time such a temperature as will melt the metal and the earths associated with it in the ore, and obtain the former in a dense button at the bottom of a crucible, and the latter in a lighter glass or slag, above it. Sometimes the gangue of the ores, consisting mostly of a single earth, as quartz, alumina, or lime, is of itself very refractory, and hence some flux must be added to bring about the fusion. The substance most commonly employed for this purpose is borax; but ordinary flint glass may be substituted for it. Sometimes, also, instead of adding borax, which always succeeds, lime or clay may be added to the ore, according to the nature of its mineralizer; that is, lime for a clay iron-stone, and clay for a calcareous carbonate of iron; and both, when the gangue is silicious, as occurs with the black oxyde. The ore, pulverized and passed through a silk sieve, is to be well mixed with the flux, and the mixture introduced into the smooth concavity made in the centre of a crucible lined with hard-rammed damp charcoal dust. Were the mixture diffused through the charcoal, the reduced iron wofild be apt to remain scattered in little globules through the crucible, and no metallic button would be formed at its bottom. The mingled ore and flux must be covered with charcoal. The crucible thus filled must be shut with an earthen lid luted on with fire-clay; and it is then set on its base, either in an air furnace, or on the hearth of a forge urged with a smith's bellows. The heat should be very slowly raised, not employing the bellows till three quarters of an hour have expired. In this way, the water of the damp charcoal (brasque) is allowed to exhale sldwly, and the deoxydation is completed before the fusion begins; for by acting otherwise, the slags formed would dissolve some oxyde of iron, and the assay would not indicate the whole of the iron to be obtained from the ore. At the end of the above period, the fire must be raised progressively to a white heat, at which pitch it must be maintained for a quarter of an hour, after which the crucible should be withdrawn. Whenever it has cooled, it is to be opened, the brasque must be carefully removed or put aside, and the button of cast-iron taken out and weighed. The brasque may sometimes contain a few globules, which must be collected by washing in water, or the application of a magnetic bar. The quantit3 of iron denotes, of course, the richness of the ore. These assays furnish always a gray cast-iron; and, therefore, the quality of the products can hardly be judged of, except by an experiment on the large scale. The temperature necessary for the success of an assay is about 150~ of Wedgewood. In the assays by the humid way, we may expect to find manganese, silica, alumina, lime, magnesia, and sometimes carbonic acid, associated with the iron. 100 grains of the ore in fine powder are to be digested with nitro-muriatic-acid; which will leave only the silica with perhaps a very little alumina. If an effervescence takes place in the cold with a dilute acid, the loss of weight will indicate the amount of carbonic acid gas expelled. The muriatic solution contains the iron, the manganese, the lime, magnesia, and most of the alumina, with a little silica. On evaporating to dryness, and digesting in water, all the silica will remain in an insoluble state. If the solution somewhat acidulated be treated with oxalate of ammonia, the lime will fall down in the form of an oxalate; ammonia will now precipitate the alumina and the oxyde of iron together, while the manganese and magnesia will continue dissolved in the state of triple salts (ammoniamuriates). The alumina may be separated from the ferric oxyde by potash-ley. The manganese may be thrown down by hydrosulphuret of potash; and, finally, the magnesia may be precipitated by carbonate of soda. 100 parts of the red oxyde of iron contain 69-34 of metal, and 30-66 of oxygen. If phosphorus be present in the ore, the nitro-muriatic solution, being rendered nearly neutral, will afford with muriate of lime a precipitate of phosphate of lime, soluble in an excess of muriatic acid. When the sole object is to learn readily the per-centage of iron, the ore may be treated with hot nitro-muriatic, the acid solution filtered and supersaturated with ammonia, which will throw down only the iron oxyde and alumina; because the lime is not precipitable by that alkali, nor is magnesia and manganese, when in the state of ammonia. 1066 IRON. muriates. The red precipitate, being digested with sonie potash-ley, will lose its alumina, and will leave the ferric oxyde nearly pure. The presence of sulphur, phosphorus, of arsenic, in iron ores, may always be detected by the blowpipe, or ustulation in the assay muffle, as described under FURNACE. Of the smelting of iron ores.-We shall describe, in the first place, the methods practised in Great Britain, and shall afterwards consider those pursued in other countries, in the treatment of their peculiar ores. Iron is divided into three kinds, according to the different metallic states in which it may be obtained; and these are called crude or cast iron; steel; and bar or malleable iron. These states are determined essentially by the different proportions of charcoal or carbon held in chemical combination; cast iron containing more than steel, and steel more than malleable iron; which last, indeed, ought to be the pure metal, a point of perfection, however, rarely if ever attained. It is impossible to assign the limits between these three forms of iron, or their relative proportions of carbon, with ultimate precision; for bar iron passes into steel by insensible gradations, and steel and cast iron make such mutual transitions as to render it difficult to define where the former commences, and the latter ceases, to exist. In fact, some steels may be called crude iron, and some cast irons may be reckoned among steels. Towards the conclusion of the last century the manu acture of iron underwent a very important revolution in Great Britain, by thfe substitution of pitcoal for charcoal of wood, the only combustible previously used in smelting the ores of this metal. This improvement served not merely to diminish the cost of reduction, but it furnished a softer cast iron, fit for many new purposes in the arts. From this era, iron works have assumed an immense importance in our national industry, and have given birth to many ingenious and powerful machines for fashioning the metal into bars of every form, with almost incredible economy and expedition. The profusion of excellent coal, and its association in many localities with iron-stone, have procured hitherto for our country a marked superiority over all others in the iron trade:; though now every possible effort is making by foreign policy to rival or to limit our fiture operations. In 1802, M. de Bonnard, now divisionary inspector in the royal corps of mines of France, and secretary of the general council, made a tour in England, in order to study our new processes of manufacturing iron, and published, on his return, in the Journal des Mines, tom. 17, a memoir descriptive of them. Since the peace, many French engineers and iron-masters have exerted themselves in naturalizing in France this species of industry; and M. de Gallois, in particular, after a long residence in Great Britain, where he was admitted to see deliberately and minutely every department of the iron trade, returned with ample details, and erected at Saint-Etienne a large establish. ment entirely on the English model. More recently, MM. Dufrdnoy and Elie de Beaumont, and MM. Coste and Perdonnet, have published two very copious accounts of their -espective metallurgic tours in Great Britain, illustrated with plans and sections of our furnaces, for the instruction of the French nation. The argillaceous carbonate of iron, or clay iron-stone of the coal measures, is the chief ore smelted in England. Some red hematite is used as an auxiliary in certain works in Cumberland and Lancashire; but nowhere is the iron-sand, or other ferruginous maiters of the secondary strata, employed at present for procuring the metal. Among the numerous coal-basins of England there are two, in particular, which furnish more than three fourths of the whole cast iron produced in the kingdom; namely, the coal field of Dudley, in the south of Staffordshire; and the coal fields of Monmouthshire, in South Wales, along with those of Gloucestershire and Somersetshire. Dudley is peculiarly favored by nature. There are found associated the coal, the iron ore, the limestone for flux, and the refractory fire-clay for constructing the interior brick-work of the furnaces. This famous clay is mined at Stourbridge, and exported to every part of the kingdom for making cast steel crucibles and glass-house melting pots. At Merthyr-Tydvil, the centre of the iron-works of Wales, the iron-stone is extremely plentiful, forming 16 beds, or rather constituting an integrant portion of 16 beds of slate-clay. Sometimes it occurs in pretty long tables adjoining each other, so as to resemble a continuous stratum; but more frequently it forms nodules of various size and abundance, placed in planes both above and below the coal seam. Eight varieties of ore, belonging to different beds, have been distinguished by the following barbarous names: black balls, black pins, six-inch-wide vein, six-inch jack, blue vein, blue pins, gray pins, seven pins. The bed containing the first quality of iron-stone is analogous to the black ore of Staffordshire, called gubbin; it is often cleft within like septaria, and its cavities are sometimes besprinkled with crystals of carbonate of lime or quartz. In the superior beds there are nodules decomposing into concentric coats, of which the middle is clay. Crystals of oxyde of titanium are occasionally found in the middle of IRON, 1067 the balls of clay iron-stone; to which the metallic titanium observed in the inside of the dome of blast furnaces, may be traced. Both at Dudley and South Wales, casts of shells belonging to the genus unio, are observed on the iron-stone. The average richness of the iron-stones of South Wales is somewhat greater than that oi those of Staffordshire. The former is estimated at 33 parts of cast iron, while the latter rarely exceeds 30 parts in 100 of ore; and this richness, joined to the superior quality o0 cheapness of the coals, and the proximity of the sea, gives South Wales a decided advantage as a manufacturing district. The number of blast furnaces in the parish of Merthyr-Tydvil amounts to upwards of 30. The cast iron produced is, however, seldom brought into the market, but is almost entirely converted into bar iron, of which, at Mr. Crawshay's works, 600 tons are manuactured in a week. Numerous iron railways, extending through a length of 220 miles, acilitate the transport of the materials and the exportation of the products. That concurrence of favorable circumstances, which we have noticed as occurring at Dudley, prevails in an equal degree in South Wales. The same economy which thle use of coal has introduced into the smelting of cast iron from the ore, also extends to its refinery into bars. And this process would supersede in every iron work the use of wood charcoal, were not the iron produced by the latter combustible better for many purposes, particularly the manufacture of steel. In some English smelting works, indeed, where sheet iron is prepared for making tin plate, a mixed refining process is employed, where the cat iron is made into bar iron by wood charcoal, and laminated by the aid of a coal fire. Till 1740, the smelting of iron ores in England was executed entirely with wood charcoal; and the ores employed were principally brown and red hematites. Earthy iron ores were also smelted; but it does not appear that the clay iron-stones of the coal-basins were then used, though they constitute almost the sole smelting material at the present day. At that era, there were 59 blast furnaces, whose annual product was 17,350 ton, of cast iron; that is, for each furnace, 294 tons per annum, and 58 tons per week. By the year 1788, several attempts had been made to reduce iron ore with coked coal; and there remained only 24 charcoal blast furnaces, which produced altogether 13,000 tons of cast iron in the year; being at the rate of 546 tons for each per annum, or nearly 11 tons per week. This remarkable increase of 11 tons for 5X, was due chiefly to the substitution of cylinder blowing machines worked with pistons, for the common wooden bellows. Already 53 blast furnaces fired with coke were in activity; which furnished in toto 48,800 tons of iron in a year; which raises the annual product of each furnace to 907 tons, and the weekly'product to about 17- tons. The quantity of cast iron produced that year (1788) by means of coal, was 48,800 tons, and that by wood charcoal, was 13,100 Constituting a total quantity of 61,900 tons. In 1796, the wood charcoal process was almost entirely given up; when the returns of the iron trade made by desire of Mr. Pitt, for establishing taxes on the manufacture afforded the following results:121 blast furnaces, furnishing in whole per annum 124,879 tons, constituting an average amount for each furnace of 1032 tons. In 1802, Great Britain possessed 168 blast furnaces, yielding a product of about 170,000 tons; and this product amounted, in 1806, to 250,000 tons, derived from 227 coke fur. naces, of which only 159 were in activity at once. These blast firnaces were distributed a. follows. In the principality of WIles - -. 52 In Staffordshire - - - - -42 In Shropshire - - - - -42 In Derbyshire ------.. 17 In Yorkshire - - - - - 28 In the counties of Gloucester, -Monmouth, Leicester, Lancaster, Cumberland, and Northumberland - 18 in Scotland - -... 28 227 In -820, the iron trade had risen to the amount shown in the following table:Tons. Wales manufactured, per annum - - -- 150,000 Shropshire and Staffordshire - -- 180,000 Yorkshire and Derbyshire - -- 50,000 Scotland, with some places in England - - - - 20,000 Total -... 400 000 1068 IRON. In a statistical view given by M. de Villefosse, of the French and English iron works be assigns to the latter, in 1826, 305 blast furnaces, distributed as follows:In the principality of Wales 87 In Staffordshire - - - - - 78 In Shropshire, Derbyshire, Yorkshire, &c. - - 84 In Scotland - - -.. 56 305 Out of these, 280 were in activity at the same time; and if we suppose their meatr product to have been 50 tons a week, the total product would have been, in 1826, 728,000 tons. But this estimate seems to be somewhat above the truth; for, from the informatior communicated by Mr.' Philip Taylor toM. Achille Chaper, a considerable French iron master, who, in the summer of 1826, inspected two thirds of the blast furnaces of Great Britain, their product during this year was about 600,000 tons. The preceding details show the successive increments which the manufacture of cast iron has received; and a similar progression has taken place in its refinery into wrought iron. This operation was formerly effected ty the agency of wood charcoal in refinerie, analogous to those still made use of in France. But when that kind of fuel began to be scarce in this island, it came to be mixed with coke in various proportions. The bar iron thus produced was usually hard, and required much time to convert, so that an establishment which could produce 20 tons of bar iron in a week, was deemed considerable. At that time, England imported annually from Sweden and Russia the enormous quantity of 70,000 tons of iron. Mr. Cort, to whom Great Britain is indebted for the methods now pursued in this country, succeeded about that time, after many unsuccessful experiments, in converting cast iron into bar iron, by exposing it on the hearth of a reverberatory furnace to the flame of pitcoal. This method, which possessed the advantage of employing this species of combustible alone, likewise simplified the treatment, because it required no blast apparatus. But this mode of refinery, consisting in the use of a reverberatory furnace alone, did not produce altogether the desired result. It was irregular; sometimes the loss of iron was small, but at others it was very considerable; and there were great variations in the quality of the iron, as well as in the quantity of fuel consumed. Mr. Cort succeeded in removing this uncertainty of result, by causing the puddling in the reverberatory furnace to be preceded by a kind of refinery with coke. The intent of this operation was to decarburate the iron, and to prepare it for becoming malleable. The metal took in that case the name of finery metal, called, for the sake of brevity, fine-metal. He also substituted the drawing cylinders for the extension under the hammer, an improvement which accelerated greatly the manufacture of bar iron. The iron then yielded by the operation of puddling was of a very inferior quality, and could not be directly employed in the arts. In order to give it more consistence, it was subjected to a second heating in a reverberatory furnace; and whenever this method had arrived at a high enough degree of perfection to afford products fit for the market, it became exclusively employed in Great Britain. This new method of transforming cast iron into malleable iron speedily gained such an extension, that of late years, a single iron-work, Cyfartha in Wales, manufactured annually more than twice as much as was made annually from 1740 to 1750, in the whole kingdom. In surveying the improvements which the iron manufacture has received in England in the space of the last 60 years, they are seen to be resolvable into two; the first set relating to the smelting of the ores; the other, to the conversion of the pigs into bar iron; hence naturally arise two heads under which the subject of iron must be treated. 1. Manufacture of cast-iron by coke and coal.-The cast-iron produced by the English and Scotch blast furnaces is in general black and very soft; but yet may be distinguished into several qualities, of which three are particularly noticed. No. 1. Very black cast-iron, in large rounded grains, obtained commonly near the commencement of the casting, when an excess of carbon is present; in flowing, it appears pasty, and throws out blue scintillations. It exhibits a surface where crystalline vegetations develop themselves rapidly in very fine branches; it congeals or fixes very slowly; its surface when cold is smooth, concave, and often charged with plumbago; it has but a moderate tenacity, is tender under the file, and susceptible of a dull polish. When melted ovel again, it passes into No. 2, and forms the best castings. No. 2. Black cast-iron has a somewhat lighter shade than the preceding, and may therefore on comparison be called blackish-gray. It presents less large granulations than No. 1; is tenacious, easily turned, filed, and polished; excellent for casting when it approaches to No. 1, and for the manufacture of bar iron when it has on the contrary a ihade somewhat lighter. If repeatedly melted, it passes into the next quality, or No. 3. White cist iron; this is brittle, and indicates always some derangement in the IRON. 1069 working of the furnace; it flows imperfectly,.and darts out, in casting, abundance of brilliant white scintillations; it fixes very quickly; and on cooling, exhibits on its surface irregular asperities, which make it extremely rough. It is easily broken, and presents s, lamellar and radiated fracture; and is so hard that tempered steel cannot act upon it. It is cast only into weights, bullets, or bombs, but never into pieces of machinery. When exposed to the refinery processes, it affords a bad bar iron. It is owing probably to the different nature of the cast iron obtained in different counties in England, that Staffordshire and Shropshire furnish the greater part of the great iron castings, while Wales manufactures almost exclusively malleable iron. The lower price of coals in Wales is perhaps the cause to a certain extent of this difference in the results of these two iron districts. It will be interesting, at any rate, to describe separately the processes employed in Staffordshire and Wales. The blast furnaces of Staffordshire, in the neighborhood of Dudley, Bilston, and Wednesbury, are constructed almost wholly of bricks. Their outer form is frequently a cone, often also a pyramid with a square base. They are bound about with a great many iron hoops, or with iron bars placed at different heigh't. This powerful armor allows the furnaces to be built much less massively than they formerly were; and admits lighter and more elegant external forms. They are seldom insulated; but are usually associated to the number of two or three in the same line. A narrow passage is left between them, which leads to the lateral openings where the tuyeres are placed. At the;93 front of the furnace, a large shed is always raised. The roofs of these sheds present in general circular profiles, and being made of cast or bar iron, they display a remarkable lightness of construction. The cast iron columns likewise, which support the joists anil girders, give additional elegance. In the Dudley field, the furnaces are almost always in the middle of the plain, and an inclined rail-way must be'formed to reach their platform. These inclined planes, composed of beams or rails placed alongside of each other, and sustained by props and crossbars, as indicated in fig. 793, are set up mostly against the posterior face of the furnace. Two chains or ropes, passing over the drums of gins, moved by a steam engine (commonly the same that drives the bellows), draw up the wagons of wood or sheet iron a a, which contain the various materials for supplying the furnace. To facilitate this service, the platform round the furnace is sometimes enlarged behind by a floor; while a balustrade, which opens when the wagons. arrive at the platform, prevents accidents. This projectibn is occasionally covered by a roof. For a furnace of the largest size, the force expended by this lifting apparatus is not more than a two-horse power. Fig. 793 is a vertical section through the f-rnace from front to rear, or at right angles to the line of the lateral tuyeres. The erection of a pair of blast firnaces, of 40 feet high each, costs, in the Dudley district, 1800 pounds sterling; and requires for building each, 160,000 common bricks for the outside work, 3900 fire-bricks for the lining or shirt of the furnace, and 825 for the boshes. The dimensions of the fire-bricks are various; 5 kinds are employed for the lining, and 9 kinds for the boshes. They are all 6 inches thick, and are curved to suit the voussoirs. The number of charges given in 12 hours is different in different furnaces; being sometimes 20, 25, and even so high as 40; but'0 is a fair average. Each charge is I-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1070 iRON. composed of from 5 to 6 cwts. of coke, (or now of 3 to 4 cwts. of coal with the hot blast) 1 3, 4, and sometimes 6 cwts. of the roasted mine, according to its richness and the quality of cast iron wanted; the limestone flux is usually one third of the weight of the roaster iron stone. There are 2 casts in 24 hours; one at 6 in the morning, and another at 6 ir the evening. The height of the blast furnaces is veiy variable; some being only 36 feet high including the chimney, while others have an elevation of 60 feet. These extreme limits are very rare: so that the greater part of the furnaces are from 45 to 50 feet high. They are all terminated by a cylindrical chimney of from 8 to 12 feet long; being about one fifth of the total height of the furnace. The inside diameter of this chimney is the same as that of the throat or mouth; and varies from 4 to 6 feet. The chimney is fira quently formed of a single course of bricks, and acquires solidity from its hoops of iron, so thickly placed that one half of the surface is often covered with them. At its lower end, the mouth presents one or two rectangular openings, through which the charge is given. It is built on a basement circle of cast-iron, which forms the circumference of the throat; and a sloping plate of cast-iron b is so placed as to make the materials slide ov-r into the furnace, as shown in the figure. The inside of the blast furnaces of Staffordshire is most frequently of a circular form, except the hearth and working area. The inner space is divided into four portions, different in their forms, and the functions which they fulfil in the smelting of the ore. The undermost, called the hearth, or crucible, in which the cast-iron collects, is a right rectangular prism, elongated in a line prependicular to the axes of the tuyeres. The sides of the hearth consist in general of refractory sandstone (fire-stone), obtained mostly.rom the bed of the coal basin, called millstone grit; and the bottom of the hearth is formed of a large block of the same nature, laid on a cast-iron plate. The second portion is also made of the same refractory grit stone. It has the form of quadrangular pyramidal, approaching considerably to a prism, from the smallness of the Ingle included between the sides and the asiis. The third portion or lower body of the furnace is conical, but here the interior space suddenly expands; the slope outwards at this part seems to have a great influence on the quality of the cast-iron obtained from the furnace. When No. 2 of the blackest kind is wanted for castings, the inclination of this cavity of the furnace is in general less considerable than when No. 2 cast iron for conversion into bar iron is required. The inclination of this conical chamber, called the boshes, varies from 55 to 60 degrees with the iorizon. The diameter of this part is equal to that of the belly, and is from 11 to 13 feet. Ihe boshes are built of masonry, as shown in figs. 194, 195. 794 Y' the fourth part, which constitutes about two thirds of the height of the furnace frora the base of the hearth up to the throat, presents the figure of a surface of revolution, generated by a curve whose concavity is turned towards the axis of the furnace, and, vhose last tangent towards the bottom is almost vertical. This surface is sloped off with that of the boshes (etalages in French), so that no sharp angle may exist at the belly. In some furnaces of considerable dimensions, as in that with three tuyeres, this portion of the /urnace is cylindrical for a certain height. IRON. 1071 The following measurements represent the interior structure of two well-going farnaces. No.,. No. 2. Feet. Feet. Height from the hearth to the throat or mouth -. 45 49 Height of the crucible or hearth -. 6 of the boshes. — 8 7 of the cone - - - 30 36 - of the chimney or mouth - -. 8 12j Width of the bottom of the hearth - 2 2 Ditto at its upper end - - - 3 24 Ditto of the boshes - - - 12 13; Ditto at one third of the belly - - - 12 112 Ditto at two thirds of ditto - - - - 84 94 Ditto at the mouth - - - 41 3 Inclination of the boshes - - - - 59~ 52~ 1 The conical orifice called the tuyere, in which the tapered pipes are placed, for impart ing the blast, is seen near the bottom of the furnace, fig. 794, at A. Nose tubes of various sizes, from 2 to 4 inches in diameter, are applied to the extremity of the main blast-pipe. Under A is the bottom of the hearth, which, in large furnaces, may be two feet square. B is the top of the hearth, about two feet six inches square. A B is the height of the hearth, about six feet six inches. s shows the round bottom of the conical or funnel part, called in this country the boshes, standing upon the square area of the hearth. c is the top of the boshes, which may be about 12 feet in diameter, and 8 feet in perpendicular height. D is the furnace top or mouth (gueulard in French), at which the materials are charged. It may be 41 feet in diameter. The line between c, D, is the height of the internal cavity of the furnace, from the top of the boshes upwards, supposed to be 30 feet. A, D, is the total height of the interior of the furnace, reckoned at 444 feet. E E is the lining, which is built in the nicest manner with the best fire-bricks, from 12 to 14 inches long, 3 inches thick, and curved to suit the circle of the cone. A vacancy of 3 inches wide is left all round the outside of the first lining by the builder; which is sometimes filled with coke dust, but more generally with sand firmly rammed. This void space in the brick-work is for the purpose of allowing for any expansion which might occur, either by an increase in the bulk of the building, or by the pressure and weight of the materials when descending to the bottom of the furnace. Exterior to E E is a second lining of fire-bricks similar to the first. At F, on either side, is a cast-iron lintel, 8- feet long, by 10 inches square, upon which the bottom of the arches is supported. F, G, is the rise of the tuyere arch, which may be 14 feet high upon the outside, and 18 feet wide. The extreme size of the bottom or sole of the hearth, upon each side of A, may be 10 feet square. This part and the boshing stones are preferably made fiom a coarse sandstone grit, containing large rounded grains of quartz, united by a sili. ceo-argillaceous cement. The bottom of the hearth consists, first, of a course of the said gritstone; beneatn [ i....../ which is a layer of bedding sand, having, in its under \ P ~/795!/ part, passages for the escape of the vapors generated by damps; the whole being supported upon pillars of brick. Fig. 795 represents the hearth and boshes, in a vertical side section. a is the tymp stone, and b the tymp plate for confining the liquid metal in the hearth. \ / jThe latter is wedged firmly into the side-walls of the hearth; c is the dam-stone, which occupies the whole L# \\ |i, | breadth at the bottom of the hearth, excepting about 6 inches, which space, when the furnace is at work, is filled, before every cast, with a strong binding sand. d S^ i ~ I This stone is faced outside by a cast-iron plate d, called the dam-plate, of considerable thickness, and peculiar " -~ _ 1 X shape. The top of the dam-stone, or rather the notch -v__ As'i __ I | of the dam-plate, lies from 4 to 8 inches under the level of the tuyere hole. The space under the tymp plate, for 5 or 6 inches down, is rammed full, fo.every cast, with strong loamy earth, or even fine clay; a process called the tymp stopping. The area of the base of this furnace being 38 feet, its extreme height is 55 feet. The blast furnaces of Staffordshire have always two tuyeres, at least, placed on oppo 1072 IRON. site sides, but so pointed that the blast may not pursue directly opposite lines. In a furnace acting well in the neighborhood of Dudley, the one of the tuyeres was 10 inches distant from the posterior wall of the hearth, and the other only four inches. In other furnaces with 3 tuyeres, the side ones are placed, the one 16- inches, and the other 6k inches from the back. Three tuyeres are seldom made to blow simultaneously. The third is brought into action only when the furnace seems to be choked up, and when it becomes necessary to clear it up by a powerful concussion. Too much pains cannot be bestowed on the masonry and brickwork of a blast furnace, and on the solidity of its foundation. In akoft ground it should rest on piles, so driven that the channel left beneath for'the drainage of the building may be above any water level. Small passages should likewise be left throughout the body of the work, for the transpiration of moisture. The blowing machines employed in Staffordshire are generally cast-iron cylinders, in which a metallic piston is exactly fitted as for a steam engine, and made in the same way. Towards the top and bottom of the blowing cylinders orifices are left covered with valves, which open inside when the vacuum is made with the cylinders, and afterwards shut by their own weight. Adjutages conduct into the iron globe or chest, the air expelled by the piston, both in its ascent and descent; because these blowing machines have always a double stroke. The pressure of the air is made to vary through a very considerable range, according to the nature of the fuel and season of the year; for as in summer the atmosphere is more rarefied, it must be expelled with a compensating force. The limits are from 1k pounds to 3} pounds on the inch; but these numbers represent extreme proportions, the average amount in Staffordshire being 3 pounds. With this pressure a furnace usually works, which affords 60 tons of cast-iron in the week; and the pressure may be 2k'pounds on an average. The orifices, or nose-pipes, through which the air issues, also vary with the nature of the coke and the ore. In Staffordshire they are generally from 2 inches and 5 tenths to 2 inches and 8 tenths in diameter. The blowing machines of Staffordshire are always impelled by steam engines. At Mr. Bagnall's works, two blast furnaces, 40 feet high, exclusive of the chimney or top, and two finery furnaces, are worked by a steam engine of 40 horses power; and therefore the power of one horse corresponds to the production of 22 tons of cast iron per week, independently of the finery. In South Wales, especially at Pontypool, there are slighter blast furnaces, whose upper portion is composed of a single range of bricks, each of which is 20 inches long, 4 thick, and 9 broad. The interior of the chimney represents an inverted cone.' These furnaces derive solidity, and power to resist the expansions and contractions from change of temperature, by being cased, as it were, in horizontal hoops, placed 3 feet, or, even in some cases, only 6 inches asunder. These flat rings consist of four pieces, which are joined by means of vertical bars, that carry a species of ears or rings, into which the hoops enter, and are retained by bolts or keys. Instead of these ears, screw nuts are also employed for the junction. Each hoop is alternately connected to each of the eight vertical bars. The interior of these furnaces is the same as of the others; being generally from 12 to 14 feet diameter at the belly, and from 50 to 55 feet high. Though slight, they last as long as those composed of an outer body of masonry and a double lining of bricks; and have continued constantly at work for three years. In Wales also the blast furnaces are generally somewhat larger than in Staffordshire; because there the object being to refine the cast iron, they wish to procure as large a smelting product as possible. But in Staffordshire, a fine quality of casting iron is chiefly sought after, and hence their furnaces have less height, but nearly the same width. In a blast apparatus employed at the Cyfartha works, moved by a 90 horse steam power, the piston rod of the blowing cylinder is connected by a parallelogram mechanism with the opposite end of the working beam of the steam engine. The cylinder is 9 feet 4 inches diameter, and 8 feet 4 inches high. The piston has a stroke 8 feet long, and it'rises 13 times in the minute. By calculating the sum of the spaces percurred by the piston in a minute, and supposing that the volume of the air expelled is equal to only 96 per cent. of that sum, which must be admitted to hold with machines executed with so maich precision, we find that 12,588 cubic feet of air are propelled every minute. Hence a horse power applied to blowing machines of this nature gives, on an average, 137 cubic feet of air per minute. The pressure on the air, as it issues, rarely exceeds two pounds on the square inch in the Welsh works. At the establishment of Cyfartha, for blowing seven smelting furnaces, and the seven corresponding fineries, three steam engines are employed, one of 90 horse power, another of 80, and a third of 40; which constitutes in the whole a force of 210 horses, or 26 horses and X1 per furnace supposing the fineries to consume one eighth of the blast. In the whole of the works of Messrs. Crawshay, the proprietors of Cyfartha, the power of about 350 horses is expended in blowing 12 smelting furnaces, and their subordinate fineries; which gives frbm 25 to 26 horses for each, allowing as before one eighth for the fineries. As'hese furnaces produce each about 60 tons of cast iron weekly, we find IRON. 1073 ihat a horse power corresponds to 2 tons and a tenth in that time. Each of the furnaces consumes about 3567 cubic feet of air per minute. These works have been greatly increased of late years. The following analyses of the English coal ironstones have been made by M. Berthier, at the school of mines in Paris. Rich Welsh Ore. Poor Welsh Ore. Rich Ore of Dudley, or gubbin. Loss by ignition - - - 30-00 27-00 21-00 Insoluble residuum - - 8-40 22-03 7-66 Lime - - - 0'0 6-00 2-66 Peroxyde of iron - - - 60-00 42-66 58-33 On calculating the quantities of carbonate of iron, and metallic iron, to which the above peroxyde corresponds, we have:- Carbonate of iron - - 88-77 65-09 8520 Metallic iron - - 42-15 31-38 40-45 l The mean richness of the ores of carbonate of iron of these coal basins is not far from 33 per cent. About 28 per cent. is dissipated on an average, in the roasting of the ores. Every ferruginous clay-stone is regarded as an iron ore, when it contains more than 20 per cent. of metal; and it is paid for according to its quality, being on an average at 12 shillings per ton in Staffordshire. The gubbin, however, fetches so high a price as 16 w. 17 shillings. The ore must be roasted before it is fit for the blast furnace, a process caInled on in the open air. A heap of ore mingled with small coal (if necessary) is piled up over a stratum of larger pieces of coal; and this heap may be 6 or 7 feet high, by 15 or 20 broad. The fire is applied at the windward end, and after it has burned a certain way, the heap is prolonged at the other extremity, as far as the nature of the ground or convenience of the work requires. The quantity of coal requisite for roasting the ore varies from one to four hundred weight per ton, according to the proportion of bituminous matter associated with the iron-stone. The ore loses in this operation from 25 to 30 per cent. of its weight. Three and a quarter tons of crude ore, or two and a quarter tons of roasted ore, are required to produce a ton of cast-iron; that is to say, the crude material yields on an average 30-7 per cent., and the roasted ore 44-4 of pig metal. In most smelting works in Staffordshire, about equal weights of the rich ore in round nodules called gubbin, and the poorer ore in cakes called blue flat, are employed together in their roasted state; but the proportions are varied, in order to have a uniform mixture, capable of yielding from 30 to 33 per cent. of metal. The transition or carboniferous limrestone of Dudley is used as the flux; it is compact and contains little clay. The bulk of the flux is made nearly equal to that of the ore. To treat two tons and a quarter of roasted ore, which furnish one ton of pig iron, 19 hundred weight of limestone are employed; constituting nearly 1 of limestone for 3 of unroasted ore. The limestone costs 6 shillings the ton. Carbonized pitcoal or coke was, till within these few years, the sole combustible used in the blast furnaces of Staffordshire. The coal is distributed in circular heaps, about 5 feet diameter, by 4 feet high; and the middle is occupied by a low brick chimney, piled with loose bricks, so open as to leave interstices between them, especially near the ground. The larger lumps of coal are arranged round this chimney, and the smaller towards the circumference of the heap. When every thing is adjusted, a kindling of coals is introduced into the bottom of the brick chimney; and to render the combustion slow, the whole is covered over with a coat of coal dross, the chimney being loosely closed with a slab of any kind. Openings are occasionally made in the crust and afterwards shut up, to quicken and retard the ignition at pleasure, during its continuance of 24 hours. Whenever the carbonization has reached the proper point for forming good coke, the covering of coal dross is removed, and water is thrown on the heap to extinguish the combustion; a circumstance deemed useful to the q'ality of the coke. In this operation the Staffordshire coal loses the half of its weight, or two tons of coal produce one ot coke. As soon as the blast furnace gets into a regular heat, which happens about 15 days or three weeks after fires have been put in it, the working consists simply in charging it, at the opening in the throat, whenever there is a sufficient empty space; the only rule being to keep the furnace always full. The coke is measured in a basket, thirteen of which go to the ton. The ore and the flux (limestone) are brought forwards in wheelbarrows of sheet iron. In 24 hours, there are thrown into a furnace such as fig. 582, 141 tons of coke, 16 tons of roasted ore, and 6{ tons of limestone; from which about 7 tons of pig iron are procured. This is run off ezery 12 hours; in some works the blast is suspended during the discharge. The metal intended to be converted into 10'74 -IRON bar iron, or to be cast again into moulds, is ran into small pigs 3 feet long, and 4 inches diameter; weighing each about 2 hundred weight and a half. The disorders to which blast furnaces are liable have a tendency always to produce white cast-iron. The color of the slag or scoriae is the surest test of these derangements, as it indicates the quality of the products. If the furnace is yielding an iron proper for casting into moulds, the slag has a uniform vitrification, and is slightly translucid. When the dose of ore is increased in order to obtain a gray pig iron, fit for fabrication into bars, the slag is opaque, dull, and of a greenish-yellow tint, with blue enamelled zones. Lastly, when the furnace is producing a white metal, the slags are black, glassy, full of bubbles, and emit an odor of sulphureted hydrogen. The scoriae from a coke are much more loaded with lime than those from a charcoal blast furnace. This excess of lime appears adapted to absorb and carry off the sulphur, which would otherwise injure the quality of the iron. The slags, when breathed on, emit an argillaceous odor. A blast furnace of 50 or 60 feet in height gives commonly from 60 to 70 tons of castiron per week; one from 50 to 55 feet high,.gives 60 tons; two united of 45 feet produce together 100 tons; and one of 36 feet furnishes from 30 to 40. A blast furnace should go for four or five years without needing restoration. From 3- to 4 tons of coal, inclusive of the coal of calcination, are required in Staffordshire to obtain one ton of chst-iron and the expense in workmen's wages is about 15 shillings on that quantity. At the Cyfartha works of Messrs. Crawshay in South Wales, the average price of the lithoid carbonate of iron, ready for roasting, is only 7s. 6d. a ton, and its richness is about 33 per cent. The furnaces for roasting the ore in that country are made in the form of cylinders, placed above an inverted cone. The cylindrical part is 6 feet high and wide, and the cone is about 4 feet high, with a base equal to that of the cylinder; towards the bottom or narrowest part of the inverted cone, there is an aperture which terminates in an outlet on a level with the bottom of the terrace in which the furnace is built. Sometimes, however, all the roasting furnaces are in a manner combined into one, which resembles a long pit about 6 feet in width and depth, and whose bottom presents a series of inverted ho-low quadrangular pyramids, 6 feet in each side, and 4 deep. The bottom or apex of each of these pyramids communicates with a mouth or door-way that opens on a lower terrace, through which the ore falls in proportion as it is roasted; and whence it is wheeled and tumbled into the throat of an adjoining blast furnace, on the same level with the terrace; for in Wales the blast furnace is generally built up against the face of a hill, which makes one of its fronts. The above roasting furnaces, which closely resemble lime-kilns, after being filled with alternate strata of small coal aid ore, are set on fire; and the roasted ore is progressively withdrawn below, as already mentioned. The product of coke from a certain weight of coal is greater in Wales than in Staffordshire, though the mode of manufacture is the same. At Pen-y-Darran, for example, 5 of coal furnish 3- o:f coke; or 100 give 70; at Dowlais 100 of coal afford 71 of coke, and the product would be still greater if more pains were bestowed upon the process. At Dowlais, coal costs only 2 shillings a ton; at Cyfartha, it is worth fiom 2s. 6d. to 5 shillings. About 2 tons of coke are employed in obtaining 1 ton of cast-iron. According to M. Berthier's analysis, the slag or cinder of Dowlais consists of silica, 40-4; lime, 38'4; magnesia, 5'2; alumina, 11'2; protoxyde of iron, 3.8; and a trace of sllphur. He says that the silica contains as much oxygen as all the other bases united; or is equivalent to them in satur;ning power; and to the excess of lime he ascribes the freedom from sulphur, and the good quality of the iron produced. The specimen examined was from a furnace at Merthyr-Tydvil. Other slags from the same furnace, and one from Dudley, furnished upwards of 2 per cent. of manganese. Tkose which he analyzed from Saint Etienne, in France, afforded about 1 per cent. of sulphur. The consumption of coal in the Welsh smelting furnaces may be estimated, on an average, at 3 tons per ton of cast-iron; corresponding to 2-1 of their coke. From this economy in the quantity of fuel, as well as from its cheapness and that of the iron ore, the iron of South Wales can be brought into the market at a much lower rate than that of'any other district. These blast furnaces remain in action from 5.to 10 years; at the end of which time, only their interior surface, has to be repaired. The lining of the -pper part lasts much longer; for examples are not wanting of its holding good for nearly 40' years. One of the greatest improvements ever made by simple means in any manufacture is the employment of hot air, instead of the ordinary cold air of the atmosphere, in supplying the blast of furnaces for smelting and founding iron. The discovery of the superior power of a hot over a cold blast in fusing refractory lumps of cast-iron was accidentally observed by my pupil, Mr. James Beaumont Neilson, engineer to the Glasgow gas works, about the year 1827, at a smith's forge in that city, and it was made the subject of a patent in the month of September of the following year. No particular construction of apparatus was described by the inventor by which the a:r was to bp IRON. 1075 heated, and conveyed to the furnace; but it was merely stated tnat the air may bc neated in a chamber or closed vessel, having a fire under it, or in a vessel connected in any convenient manner with the forge or furnace. From this vessel the air is to be forced oy means of bellows into the furnace. The quantity of surface which a heating furnace is required to have for a forge, is about 1260 cubic inches; for a cupola furnace, about 10,000 cubic inches. The vessel may be enclosed in brickwork, or fixed in any other manner that may be found desirable, the application of heated air in any way to furnaces or forges, for the purposes of working iron, being the subject c-aimed as constituting the invention. Wherever a forced stream of air is employed for combustion, the resulting temperature must evidently be impaired by the coldness of the air injected upon the fuel. The heat developed in combustion is distributed into three portions; one is communicated to the remaining fuel, another is communicated to the azote of the atmosphere, and to the volatile products of combustion, and a third to the iron and fluxes, or other surrounding matter to be afterwards dissipated by wider diffusion. This inevitable distribution takes place in such a way, that there is a nearly equal temperature over the whole extent of a fire-place, in which an equal degree of combustion exists. We thus perceive that if the air and the coal be very cold, the portions of heat absorbed by them might be very considerable, and sufficient to prevea the resulting temperature from rising to a proper pitch; but if they were very hot lhey would absorb less caloric, and would leave more to elevate the common temperature. Let us suppose two furnaces charged with burning fuel, into one of which cold air is blown, and into the other hot air, in the same quantity. In the same time, nearly equal quantities of fuel w' be consumed with a nearly equal production of heat; but notwithstanding of this, there will not be the same degree of heat in the two furnaces, for the one which receives the hot air will be hotter by all the excess of heat in its air above that of the other, since the former air adds to the heat while the latter abstracts from it. Nor are we to imagine that by injecting a little more cold air into the one furnace, we can raise its temperature to that of the other. With more air indeed we should burn more coals in the same time, and we should produce a greater quantity of heat, but this heat being diffused proportionally among more considerable masses of matter, would not produce a greater temperature; we should have a larger space heated, but not a greater intensity of heat in the same space. Thus, according to the physical principles of the production and distribution of heat, fires fed with hot air should, with the same fuel, rise to a higher pitch of temperature than fires fed with common cold air. This consequence is independent of the masses, being as true for a small stove which burns only an ounce of charcoal in a minute, as for a furnace which burns a hundred weight; but the excess of temperature produced by hot air cannot be the same in small fires as in great; because the waste of heat is usually less the more fuel is burned. This principle may be rendered still more evident by a numerical illustration. Let us take, for example, a blast furnace, into which 600 cubic feet of air are blown per minute; suppose it to contain no ore, but merely coal or coke, and that it has been burn; ing long enough to have arrived at the equilibrium of temperature, and let us see what excess of temperature it would have if blown with air of 300~ C. (572~ F.), instead of being blown with air at 0~ C. 600 cubic feet of air under the mean temperature and pressure, weigh a little more than 45 pounds avoirdupois; they contain 10'4 pounds of oxygen, which would burn very nearly 4 pounds of carbon, and disengage 16,000 times as much heat as would raise by one degree Cent. the temperature of two pounds of water. These 16,000 portions of heat, produced every minute, will replace 16,000 other portions of heat, dissipated by the sides of the furnace, and employed in heating the gases which escape fiom its mouth. This must take place in order to establish the assumed equilibrium of caloric. If the 45 pounds of air be heated beforehand up to 300~ C., they will contain about the eighth part of the heat of the 16,000 disengaged by the combustion, and there will be therefore in the same space one eighth of heat more, which will be ready to operate upon hny bodies within its range, and to heat them one eighth more. Thus the blast of 300~ C. gives a temperature which is nine eighths of the blast at zero C., or at even the ordinary atmospheric temperature; and as we may reckon-at from 2200~ to 27000 F. (from 1200~ to 1500~ C.), the temperature of blast furnaces worked in the common way we perceive that the hot air blast produces an increase of temperature equal to from 270~ to 3603 F. Now in order to appreciate the immense effects which this excess of temperature may produce in metallurgic operations, we must consider that often only a few degrees more temperature are required to modify the state of a fusible body, or to determine the play of affinities dormant at lower degrees of heat. Water is solid at 1~ under 32~ F.; it is liquid at 1~ above. Every fusible body has a determinate melting point, a very few 69 i076 IRON. degrees above which it is quite fluid, though it may be pasty below it. The same or, servation applies to ordinary chemical affinities; charcoal, for example, which reduces the greater part of metallic oxydes, begins to do so only at a determinate pitch of tern perature, under which it is inoperative, but a few degrees above, it is in general lively and complete. It is unnecessary, in this article, to enter into any more details to show% the influence of a few degrees of heat, more or less, in a furnace, upon chemical opera. tions, or merely upon physical changes of state. These consequences might have been deduced long ago, and industry might thus have been enriched with a new application of science; but philosophers have been and still 796 n are too much estranged from the study of the useful arts, and content themselves too much with the minutive of the laboratory or theoretic abstractions. Within the space of 7 years, the use of the hot blast has been so much extended in Great Britain, as to have enabled many proprietors of iron works to add 50 per cent. to their weekly production of metal, to diminish the expenses of smelting by 50 per cent., and, in many cases, to produce a better'sort of cast iron from indifferean; materials. 797 798 n n E 799 The figures here given represent the blast furnace, and all the details of the air heating, 800 at one view. Fig. 794 is a vertical section of the furnace and the apparatus; fig. 796 represents the plan at the height of the line 1, 2, of fig.'794. The blowing machine, which is not shown in this view, injects the air through the pipe A, into the regulator chamber R, fig. 796; m the air thence issues by the pipe B, proceeds to a e s in i c, where it is subdivided into two portions; the I VI n O one passes along the pipe c D to get to the T I PI _ ~Th U tuyere T, the other passes behind the furnace, Jn II H \\.^ 1M and arrives at the tuyere T' by the pipe c E F. i i o These pipes are distributed in a long furnace t f na? or flue, whose bottom, sides, and top are formed t i'-I\ "i'J;) I1 rwith fire-brick, where they are exposed to the action of the flame of the three fires x, Y, z. The flame of the fire x plays round the pipe n at its entrance into the flue, and quits it only to go into the chimney H; that of the fire Y acts from the point D to the same chimney, passing by the elbow c; that of the fire z acts equally upon F and, in passing by the elbow E. /7 ^ /t,7 t e Disposition of the fires and furnace.-Fig. g797 represents, upon a scale three times larger than fig. 796, the section of the ---- — act___on ____x________name______________three____fires____x,___Y.____$ IRON. 1077 fire x, of which the plan is seen infig. 796, and the elevation in fig. 794; as also in the outside view of the blast furnace, fig. 800. The grate is at L; the fuel is introduced by the door r, fig. 794; the flame rises above the bridge I K, and proceeds along the vaulted flue towards the chimney H. Through a length of about 13 feet, including the grate, the furnace is on each side supported by oblong plates of cast-iron, which are bound together by 4 upright ribbed or feathered bars, also on each side; these bars, n, being bound together by iron rods furnished with screw nuts at their ends (figs. 794, 796, 797). Beyond this distance, the outside of the' furnace is mere brickwork. The fires Y and z have exactly a like disposition with the above. Fig. 797 indicates the dimensions and the curvature of the arch above the grate, near the bridge; fig. 798 represents the section of the furnace and of the pipe beyond the castiron casing. I find that the furnace is only about 3 feet wide at the bottom, and that the elevation of the arch above the bottom is no more than 30 inches. Perhaps it might be made a little wider with advantage; the combustion would be more vigorous and effective; and if the sides also were a little thicker, the heat would be better confined. The distance from the fire-place x to the chimney H, is 431 feet. _~- - av to;he point c, is 13 - _ ~- ~ - z to the chimney, is 29 - including the turn of the elbow E. Distribution of the pipes.-At B the pipe is 18 inches diameter outside, and one inch thick of metal, and it tapers to c; from c to D and from D to c the pipes are only 11 inches in external diameter, and three fourths of an inch thick; they are 5 feet long, and are united by two kinds of joints; the ordinary ones, and those of compensation, to give play for the expansion and contraction. One of these is seen between B and c, one between c and D, one between c and E, and a fourth between E and r. These pipes and their adjustment are seen more at large in fig. 799; u v is one of these pipes, its widened mouth receives the extremity M of the preceding pipe. These pieces are truly bored and turned to fit each other, and slide out and in like telescope tubes, by the effect of dilatation and contraction of the pipes with changes of temperature. At certain distances castors or friction-rollers of cast-iron are placed to carry the pipes, which roll upon oblong plates of cast-iron laid upon the floor of the flues. These castors are shown at a, b, c, d, e, f, g, fig. 796; one of them is shown separate upon a larger scale at G, in fig. 798, as also the plate or rail s, on which it runs. The tuyeres T T' are adjusted into the pipe behind them; this is truly bored, so as to allow the thick end of the tuyere to slide tightly backwards and forwards in it, like a piston in the barrel of a pump; a diaphragm moreover prevents the tuyere from being drawn or forced entirely out of its tube. At the side of this tube there is a small orifice, which may be shut or opened at pleasure with a stopcock or screw-plug: it serves to try the degree of heat of the air-blast; if a lead wire does not melt when held at this hole, the temperature is reckoned too low; being under the 612th degree of Fahrenheit. The nozzles are 2 inches in diameter. Near the fire-places of the air-heating furnaces the pipes are at a cherry-red heat; and lest they should be burned, they are there coated with a lute of fire-clay, as shown near K, in fig. 797. By this means the air is kept up at the heat of 3530 C., or 662~ F., a little above the boiling point of quicksilver. Quantity of air and pressure.-The blowing-machine belonging to the above blastfurnace is moved by a water wheel of 22 horse power; the pistons are 4 feet in diameter, have a 32-feet stroke, work double, and expel 1200 cubic feet of air in the minute; or 600 cubic feet for each nozzle. The pressure of the air is equivalent to no more than 2 or 24 inches of mercury; formerly with cold air it amounted to 3- inches. This filrnace yields, upon an average, 5- tons of cast-iron daily, and consumes 1 cwt. of coke for each cwt. of cast-iron produced; being 7 tons of coke per diem. The consumption of the three flue fires is 30 pounds of small coal, for 100 pounds of east-iron produced, which may be reckoned equivalent to 15 pounds of coke; hence altogether, each ton of cast-iron requires for its production 11 tons of coke. The same furnace worked with the cold blast, the same pressure, and the same ores, produced only 34 tons of cast-iron daily, with an expenditure of 2-55 of coke for 1 of cast-iron; in which case the coke amounted to 9 tons daily. The returns by the hot blast compared with those by the cold, are therefore as the numbers 3 and 2, which shows an advantage by the former plan of 50 per cent. The consumption of fuel in the two cases is as 8 to 9, being a saving in this article of about 11 per cent. Coke is used on account of sulphur in the coal. Hot-blast heated by the flame of the furnace mouth.-This system is mounted in Staffordshire. The heating apparatus is there set immediately upon the mouth of the fur. nace; and is composed of two large cast-iron cylinders of the same length, the one withir 1078 IRON. the other, leaving a space between them. This annular interval amounts to 16 inches and it is closed at top and bottom: but the innermost cylinder is open at both ends, and forms, indeed, the vent of the chimney or furnace. It carries nine rows of pipes, three in each row, which cross its interior, and open into the annular space. The flame of the furnace passes between the intervals of the cross pipes, heating them, and also the two upright cylinders with which they are connected. The air of the blowing machine arrives by a vertical pipe, which is placed at the back of the fur nace; it enters into the above annular space, and thence circulates, with more or less velocity, through the 27 cross tubes, upon which the flame is continually playing; lastly, it is drawn through to the bottom of the annular space; the two tubes which conduct it to the two tuyeres, pass down within the brickwork of the furnace, and thus prevent the dissipation of its heat. Below this heating apparatus there is a door for putting the charges into the furnace. The above arrangement does not seem to be the best for obtaining the greatest possible heat for the blast, nor for favoring the free action of the furnace; but it illustrates perfectly well the principle of this application. A serpentine movement in a long bent hot channel would be much better adapted for communicating heat to so bad a conductor as air is known to be. In the month of July, 1836, I paid a visit to Codner Park and Butterly works, in Derbyshire, belonging to the eminent iron-masters, Messrs. Jessop & Co., where I was kindly permitted not only to study the various processes of the manufacture of cast and wrought iron, but to inspect the registers of the products of cast iron in their blast furnaces for several years back. It appeared that in the year 1829, only 29 tons of cast-iron were made weekly in each of the blast furnaces at Codner Park. They were then worked with coke, and blown with cold air. Each ton of iron required for its production, at that time, 6-82 tons of coals, made into coke for smelting; with 2'64 of roasted iron ore (carbonate), called mine; and 0-87 of limestone, the castine of the French. In 1835 and 1836, the same furnaces turned out weekly 49 tons of cast-iron each; ann every ton of iron required for its production only 3 tons of coal (not made into coke); 2-72 tons of mine; and 0-77 of lime. In 1829, and for many years before, as well as one or two after, each ton of coals is said to have cost for coking the sum of 6s., whence the 6-82 tons of coals then converted into coke for smelting one ton of iron, cost fully 40s. ih coking alone, in addition to their prime cost. The saving in this respect, therefore, is 40s. upon each ton of iron, besides the saving of fully half the coal, and the increased produce of nearly 60 per cent. of metal per week. The iron-master pays the patentee Is. upon every ton of iron which he makes, and, at the prices of 1836, he lessened his expenses by at least 30s. or 40s. per ton by the patent improvement. The following tabular view of the progression in the management and results of the hot blast, is given by M. Dufrdnoy, afte4 visiting the various iron works in this country where it had been introduced. " At the Clyde iron works, near Glasgow; in 1829, when the combustion was effected by the cold air blast,- Coal. Tons. cwt. lbs There were consumed, for smelting, 3 tons of coke, equivalent to - 6 13 0 - for the blowing engine - - - 1 0 7 Total coal per ton of iron - 7 13 7 Limestone - - - 0 10 0 In 1831, with the hot blast at 450c F., coke being still used ia smelting,There were consumed, for smelting, 1 ton, 18 cwt. of coke, equivalent to - - - - - - - - 4 6 0 -~- for heating the air, 5 cwt. 12 4 -~- ~ for the blowing engine, 7 cwt. 4 ibs. Total coal per ton of iron - 4 18 4 Limestone - - - 0 9 0 In July, 1833, with the hot blast at 612~ F., raw coal alone being used for smelting,There were consumed: for smelting - - - - 2 0 0 -for heating the air - - - - 0 8 0 - for the blowing engine - - - 0 11 2 Total coal per ton of iron 2 19 2 Limestone - - 7 0 IRON. 1079 "At the last period the use of hot air had increased the make c( the furnaces by more than one third, and had consequently produced a great saving of expense in the article of labor. The quantity of blast necessary for the furnaces was also sensibly diminished for a blowing engine of seventy-horse power, which, in 1829, served only for three blast furnaces, was now sufficient for the supply of four. " On comparing these several results, we find that the economy of fuel is in proportion to the temperature to which the air is raised. As for the actual saving, it varies in every work, according to the nature of the coal, and the care with which the operation is conducted. "This process, though it has been four years in use in the works near Glasgow (which it has rescued from certain ruin), has scarcely passed the borders of Scotland; the marvellous advantages, however, which it has produced, are beginning to triumph over prejudice, and gradually to extend its use into the different English iron districts. There are one-and-twenty works, containing altogether sixty-seven blast furnaces, in which hot air is used. The pig iron run out of these furnaces is generally No. 1, and is fit for making the most delicate castings. This process is equally applicable to forge pigs for the manufacture of bar iron; since in order to obtain this quality of iron, it is only necessary to alter the proportion of fuel and mineral. In the forges of the Tyne ironworks, near Newcastle, and of Codner Park, near Derby, pigs made in furnaces blown by hot air, are alone used in the manufacture of bar iron? " In the side of the tuyere pipe a small hole is made, by means of which the heat of the air may be ascertained at any moment. This precaution is indispensable, it being of importance to the beneficial use of hot air, that it be kept st a uniformly high temperature. With a proper apparatus the air is raised to 612 degrees Fahr., which is a greater heat, by several degrees, than is necessary for the fusion of lead." "At Calder works the consumption of fuel has diminished in the proportion of 7 tons 17 cwts. to 2 tons 2 cwts. There has also been a great diminution of expense in limestone, of which only 5- cwts. are now used, instead of 13 cwts., which were used in 1828. This decrease results, as I have already said, from the high temperature which the furnace has acquired since the introduction of hot air. " The quantity of blast has been reduced from 3500 cubic feet per minu e, to 2627 cubic feet; the pressure also has been reduced from 3 to 2- lbs." Of the refinery of cast-iron, or its conversion into bar-iron, in England.-This,peration is naturally divisible into three distinct parts. The first, or the finery properly sneaking, is executed in peculiar furnaces called running out fires; the second operation ccmpletes the first, and is called puddling; and the third consists in welding several iron tars together, and working them under forge hammers, and between rolls. 1. The finery furnaces are composed of a body of brickwork, about 9 feet square; rising but little above the surface of the ground. The hearth, placed in the middle, is two feet and a half deep; it is rectangular, being in general, 3 feet by 2, with its greatest side parallel to the face of the tuyeres; and it is made of cast iron in four plates. On the side of the tuyeres there is a single brick wall. On the three other sides, sheet iron doors are placed, to prevent the external air from cooling the metal, which is almost always worked under an open shed, or in the open air, but never in a space surrounded by walls. The chimney, from 15 to 18 feet high, is supported upon four columns of cast iron; its lintel is four feet above the level of the hearth, in order that the laborers may work without restraint. The number of tuyeres is from two to three; they are placed at the height of the lip of the crucible or hearth, and distributed so as to divide its length into equal parts; their axes being inclined towards the bottom, at an angle of from 25~ to 30%, so as to point upon the bath of melted metal as it flows. The cast-iron nose-pipe is incased, and water is made to circulate in the hollow space by means of cylindrical tubes; being introduced by one tube, and let off by another, so as to prevent the tuyeres from getting burned in the process. Two nozzles are usually placed in each tuyere, to render the blast constant and uniform; and for the same end, the air impelled by the bellows, is sometimes received at first in a regulator. The quantity of air blown into the fineries is considerable; being nearlyt 400 cubic feet per minute for each finery; or about the eighth part of the consump. tion of a blast furnace. The finery furnace, or running out fire, is represented in figs. 801 and 802. It is a smelting hearth, in which by first fusing and then cooling gray cast iron in a peculiar way, it is converted into white cast iron, called fine iron, or fine metal, of the quality of forge pig, for making malleable iron by the puddling process. The furnace resembles the forge hearth employed in Germany and France for converting forge pig into wrought iron; but it differs, particularly in this, that the fused iron is run out into an oblong iron trough, for sudden congelation. a is the air-chest, in communication with the ictwing cylinder, or bellows; the ail 1080 IROIN. Deing conducted through at least two blast pipes to the fire, and sometimes through even 4 or 6 pipes. b is the side of the furnace, corresponding to the tuy6re platen. is 802 ---------- 801 f/ a i e which are the openings for the blast pipes. All the sides of the furnace are hollow, and are kept cool by the circulation of water through the cavity between them. c is the front wall of the furnace, having a strong cast iron plate containing the tap holes for running off the melted metal. d d is the exterior wall of the furnace, which corresponds to the contre-vent and ash-hearth of the French refining forge. e, is the top plate upon which the coke is piled up in store. ff,.ff, iron props of the chimney, (not shown in this view). g, cast iron trough into which the fine iron is run off in fusion; which is sometimes made in one piece, but more usually in separate plates joined together. Beneath this mould a stream of water is made to flow. h is the bottom of the hearth, covered with sand. In the finery process, the hearth or crucible of the furnace is filled with coke; then'six pigs of cast iron are laid horizontally on the hearth, namely, four of them parallel to the four sides, and two in the middle above; and the whole is covered up in a dome. form, with a heap of coke. The fire is now lighted, and in a quarter of an hour the blast is applied. The cast iron flows down gradually, and collects in the crucible; more coke being added as the first quantity burns away. This operation proceeds by itself; the melted metal is not stirred about, as in some modes of refinery, and the temperature is always kept high enough to preserve the metal liquid. During this stage the coals are observed continually heaving up, a movement due in part to the action of the blast, and in part to an expansion caused in the metal by the discharge of gaseous oxyde of carbon. When all the pig iron is collected at the bottom of the hearth, which happens commonly at the end of two hours, or two and a half, the tap hole is opened, and the fine metal flows out with the slag, into the loam-coated pit, on a plate 10 feet long, 3 broad, and from 2 inches to 2k thick. A portion of the slag forms a small crust on the surface of the metal; but most part of it collects in a basin scooped out at the bottom of the pit, into which the fine metal is run. A large quantity of water is thrown on the fine metal, with the view of rendering it brittle, and perhaps of partially oxydizing it. This metal'suddenly cooled, is very white, and possesses in general a fibrous radiated texture; or sometimes a cellular, including a considerable number of small spherical cavities, like a decomposed amygdaloid rock. If the cast iron be of bad quality, a little limestone is occasionally used in the above operation. Three samples of cinder, analyzed by Berthier, gave. Silica 0-276; protox. of iron, 0-612; alumina, 0'040; phosp. acid, 0'072, Dudley. - 0368 - 0*610 - 0*015; puddling of Dowlais. - 0424 - 0'520 - 0033; ditto. The remarkable fact of the presence of phosphoric acid, shows how important this operation is to the purification of the iron. The charge varies from a ton and a quarter to a ton and a half of pigs; and the loss by the process varies from 12 to 17 per cent. The fine metal is -broken into fragments, and sent to the puddling furnace after the product of each operation has been weighed. The coal consumed in the fine metal process is from 4 to 5 hundred weight for the ton of cast iron. About 10 tons may be refined per diem, a quantity somewhat greater than the supply from a blast furnace; but the fineries are not worked on the Sundays; and therefore a smelting furnace just keeps one of them in play. Whatever care be taken in this process, the bar iron finally'resulting is never so good as if wood charcoal had been used in the refinery; and hence in making sheet iron for the tin plate manufacture, wood charcoal is substituted for coke in one Welsh establishment. The cast iron treated with charcoal, gets into clots IRON. 1081 or lumps in the finer3 furnace, which are lifted out, set under the harrmer, and flatteneo into thin cakes. The main effect., of the finery process, is probably the separation of the plumbaginous part of the charcoal, which is disseminated through the gray cast iron in a state of imperfect chemical combination. When that is removed the metal becomes more homogeneous, having no crystalline carbon present to counteract its transition into pure iron; much of the silica and manganese are also vitrified together, and run off in the finery cinder. 2. The puddling furnace is of the reverberatory form. It is bound generally with iron, as represented in the side view, fig. 803, by means of horizontal and vertical bars, whici 803 r'' a'-a — i a are joined together and fixed by wedges, to prevent them from starting asunder. Very frequently, indeed, the reverberatory furnaces are armed with cast-iron plates over the whole surface. These are retained by upright bars of cast iron applied to the side wall and by horizontal bars of iron, placed across the arch or roof. The furnace itself is divided interiorly into three parts; the fire-place, the hearth, and theflue. The fire-place varies from 3x to 41 feet long, by from 2 feet 8 inches to 3 feet 4 inches wide. The door way by which the coke is charged, is 8 inches square, and is bevelled off towards the outside of the furnace. This opening consists entirely of cast iron, and has a quantity of coal gathered round it. The bars of the fire grate are moveable, to admit of more readily clearing them from ashes. Fig. 804 is a longitudinal section referring to the elevation, fig. 803; and fig. 805, 804 805 r id l D is a ground plan. When the furnace is a single one, a square hole is left in the side of the fire-place opposite to the door, through which the rakes are introduced, in order to be heated. a is the fire door; b, the grate; c, the fire bridge; d d, cast-iron hearth plates, resting npon cast-iron beams e e, which are bolted upon both sides to the cast-iron binding plates of the furnace. f is the hearth covered with cinders or sand; g, is the main working door, which may be opened and shut by means of a lever g', and chain to move it up and down. In this large door there is a hole 5 inches square, through which the iron may be worked with the paddles or rakes; it may also be closed air, 1082 IRON. tight. There is a second working door h, near the flue, for introaucing the cast iron so that it may soften slowly, till it be ready for drawing towards the bridge. i, is the chimney, from 30 to 50 feet high, which receives commonly the flues of two furnaces, each 806 provided with a damper plate or register. Fig. 806, shows the main damper for the top of the common chimney, which may be opened or shut to any degree by means of the lever and chain. k, fig. 804, is the tap or Lb/ j gr 2 floss hole for running off the slag or cinder. The sole is sometimes made of bricks, sometimes of cast iron. In the first case it is composed of fire-bricks set on edge, forming a species of flat vault. It rests immediately on a body of brickwork either solid or arched below. When it is made of cast iron, which is now beginning to be the general practice, it may be made either of one piece or of several. It is commonly in a single piece, which, however, causes the inconvenience of reconstructing the furnace entirely when the sole is to be changed. In this case it is a little hollow, as is shown in the preceding vertical section; but if it consists or several pieces, it is usually made flat. The hearths of cast iron rest upon cast iron pillars, to the number of four or five; which are supported on pedestals of cast iron placed on large blocks of stone. Such an arrangement is shown ih the figure, where also the square hole a,fig. 803, for heating the rake irons, may be observed. The length of the hearth is usually six feet; and its breadth varies from one part to another. Its greatest breadth, which is opposite the door, is four feet. In the furnace, whose horizontal plan is given above, and which produces good results, the sole exhibits, in this part, a species of ear, which enters into the mouth of the door. At its origin towards the fireplace, it is 2 feet 10 inches wide; from the fire it is separated, moreover, by a low wall of bricks (the fire-bridge) 10 inches thick, and from 3 inches to 5 high. At the other extremity its breadth is 2 feet. The curvature presented by the sides of the sole or hearth is not symmetrical; for sometimes it makes an advancement, as is observable in the plan. At the extremity of the sole furthest from the fire, there is a low rising in the bricks of 2- inches, called the altar, for preventing the metal from running out at the floss-hole when it begins to fuse. Beyond this shelf the sole terminates in an inclined plane, which leads to the floss, or outlet of the slag from the furnace. This floss is a little below the level of the sole, and is hollowed out of the basement of the chimney. The slag is prevented from concreting here, by the flame being made to pass over it, in its way to the sunk entry of the chimney; and there is also a plate of cast iron near this opening, on which a moderate fire is kept up to preserve the fluidity of the scoriae, and to burn the gases that escape from the furnace, as also to quicken the draught, and to keep the remote end of the furnace warm. On the top of this iron plate, and at the bottom of the inclined plane, the cinder accumulates in a small cavity, whence it afterwards flows away; whenever it tends to congeal, the workman must clear it out with his rake. The door is a cast iron frame filled up inside with fire-bricks; through a small hole in its bottom the workmen can observe the state of the furnace. This hole is at other times shut with a stopper. The chimney has an area of from 14 to 16 inches. The hearth stands 3 feet above the ground. Its arched roof, only one brick thick, is raised 2 feet above the fire-bridge, and above the level of the sole, taken at the middle of the furnace. At its extreme point near the chimney, its elevation is only 8 inches; and the same height is given to the opening of the chimney. In most iron weeks the sole is covered with a layer of refractory sand from 21 to 3 inches thick, which is lign'y beat down with a shovel. At each operation a portion of the sand is carried away; and is replaced before another. Within these few years, there has been substituted for the sand a body of pounded slags; a substitution which has occasioned, it is said, a great economy of iron and fuel. The fine metal obtained by the coke is puddled by a continuous operation, which calls Cor much care and skill on the part of the workmen. To charge the puddling furnace, pieces offine metal are successively introduced with a shovel, and laid one over another on the sides of the hearth, in the form of piles rising to the roof; the middle being left open for puddling the metal, as it is successively fused. Indeed, the whole are kept as far separate as possible, to give free circulation to the air round the piles. The working door of the furnace is now closed, fuel is laid on the grate, and the mouth of the fireplace, as well as the side opening of the grate, are both filled up with coal, at the same time that the damper is entirely opened. The fine metal in about twenty minutes comes to a white-red heat, and its thin-edged fragments begin to melt and fall in drops on the sole of the furnace. At this period the workman opens the small hole of the furnace door, detaches with a rake the pieces of fne metal that begin to melt, tries to expose new surfaces to the action of the heat, and IRON. 1083.n order to prevent the metal from running together as it softens, he removes it from the vicinity of the fire-bridge. When the whole of the fine metal has thus got reduced to a pasty condition, he must lower the temperature of the furnace, to prevent it from becoming more fluid. He closes the damper, takes out a portion of the fire, and the ribs of the grate, and also throws a little water sometimes on the semi-fused mass. He then works about with his paddle the clotty metal, which swells up, with the discharge of gaseous oxyde of carbon, burning with a blue flame, as if the bath were on fire. The metal becomes finer by degrees, and less fusible; or in the language of the workmen, it begins to get dry. The disengagement of the oxyde of carbon diminishes, and soon stops. The workmen continue meanwhile to puddle the metal till the whole charge be reduced to the state of incoherent sand; and at that time, the ribs of the grate are replaced, the fire is restored, and the register is progressively opened up. With the return of the heat, the particles of metal begin to agglutinate, the charge becomes more difficult to raise, or in the laborers' language, it works heavy. The refining is now finished, and nothing remains but to gather the iron into balls. The founder with his paddle takes now a little lump of metal, as a nucleus, and makes it roll about on the surface of the furnace, so as to collect more metal, and form a ball of about 60 or 70 pounds weight. With a kind of rake, called in England a dolly, and which he heats beforehand, the workman sets this ball on that side of the furnace most exposed to the action of the heat, in order to unite its different particles; which he then squeezes together to force out the scorie. When all the balls are fashioned, (they take about 20 minutes work,) the small opening of the working door is closed with a brick, to cause the heat to rise, and to facilitate the welding. Each ball is then lifted out, either with tongs, if roughing rollers are to be used, as in Wales, or with an iron rod welded to the Tump as a handle, if the hammer is to be employed, as in Staffordshire. Thus we see that the operation lasts in whole from 2 hours to 2-; in a quarter of an hour, the fine metal melts at its edges, when the puddling begins, in order to effect its division; at the end of an hour or an hour and a half, the metal is entirely reduced to a sand; a state that is kept up for half an hour by continual stirring; and finally, the balling operation takes nearly the same time. The charge for each operation is from 3- to 4 hundred weight; and sometimes the cuttings of bar-ends are introduced, which are puddled apart. The loss of iron is here very variable, according to the degree of skill in the workman, who by negligence may suffer a considerable body of iron to scorify or to flow into the hearth and raise the bottom. In good working, the loss is from 8 to 10 per cent. In Wales, the'consumption of coal is estimated at one ton for every ton of fine metal. About five puddling furnaces are required for the service of one smelting furnace and one finery. The hearth of the puddling furnace should be exposed to heat for 12 hours before the work begins on the Mondays; and on the Saturdays, the old sole must be cleared out, by melting it off, and running it out by the floss-hole. Mr. Schafthault obtained, in May, 1835, a patent for the conversion of cast into wrought iron, by adding a mixture of black oxyde of manganese, common salt, and potter's clay, in certain small portions, successively, to the melting iron in the puddling furnace. The reheating furnaces, balling furnaces, or mill furnaces, are analogous to the puddling furnaces, but only of larger dimensions. The wood charcoal forge hearth is employed for working up scrap iron into boiler plate, &c. Here 22 bushels of charcoal are consumed in making one ton of iron of that description, from boiler plate parings. Machines forforging and condensing the iron.-In England there are employed for the forging and drawing out of the iron, cast-iron hammers of great weight, and cylinders ol different dimensions, for beating out the balls, or extending the iron into bars, as also powerful shears. These several mechanisms are moved either by a steam engine, as in Staffordshire, and in almost all the other counties of England, or by water-wheels when the localities are favorable, as in many establishments in South Wales. We shall here offer some details concerning these machines. Thd main driving shaft usually carries at either end a large toothed wheel, which communicates motion to the different machines through smaller toothed wheels. Of these, there are commonly six, four of which drive four different systems of cylinders, and the two others work the hammer and the shears. The different cylinders of an iron work should never be placed on the same arbor, because they are not to move together, and they must have different velocities, according to their diameter. In order to economize time and facilitate labor, care is taken to associate on one'side of the motive machine the hammer, the shears, and the reducing cylinders; and on the other side to place the several systems of cylinders for drawing out the iron into bars. For the same reason the puddling furnaces ought to be grouped on the side of the hammer; and the reheating furnaces on the other side of the works. 1084 IRON, The hammers, fig. 807, are made entirely of cast iron; they are nearly 10 feet long and consist usually of two parts, the helve c, and the head or pane d. The latter entern 807 b with friction into the former, and is retained in its place by wedges of iron or wood The head consists of several faces or planes receding from each other; for the purpose of giving different forms to the ball lumps. A ring of cast-iron a, called the cam-ring bag, bearing moveable cams b b, drives the hammer d, by lifting it up round its fulcrum f, and then letting it fall alternately. In one iron work, this ring was found to be 3 feet in diameter, 18 inches thick, and to weigh 4 tons. The weight of the helve (handle) of the corresponding hammer was 3 tons and a half, and that of the head of the hammer, 8 hundred weight. The anvil e consists also of two parts; the one called the pane of the anvil, is the counterpart of the pane of the hammer; it likewise weighs 8 hundred weight. The second, g, named the stock of the anvil, weighs 4 tons. Its form is a parallelopiped, with the edges rounded. The bloom or rough ball, from the puddle furnace, is laid and turned about upon it, by means of a rod of iron welded to each of them, called a porter. Since the weight of these pieces is very great, and the shocks very considerable, the utmost precautions should be taken in setting the hammer and its anvil upon a substantial mass of masonry, as shown in the figure, over which is laid a double, or even quadruple flooring of wood, formed of beams placed in transverse layers close to each other. Such beams possess an elastic force, and thereby partially destroy the injurous reaction of the shock. In some works, a six-feet cube of cast iron is placed as a pedestal to the anvil. Forge hammers are very frequently mounted as levers of the first kind, with the centre of motion about one third or one fourth of the length of the helve from the cam wheel. The principle of this construction will be understood by inspection offig. 816. The short end of the lever which is struck down by the tappet c, is driven against the end of an elastic beam a, and immediately rebounds, causing the long end to strike a harder blow upon the anvil s. The shears are composed of two branches, the one fixed and the other moveable, each formed of two pieces. The fixed branch is a cast-iron plate, which forms one mass with a horizontal base fixed to a piece of wood or cast iron buried in the ground. A sharpened chisel is fastened to its upper part by screws and nuts. The moveable branch is likewise of cast iron; it bears an axis round which it turns, and this axis passes through the fixed part. It is also furnished with a cutting chisel, fixed on by nuts and screws. An eccentric or an ellipse, moved directly by a toothed wheel, lifts the moveable branch of the shears, and forces it to cut the iron bars presented to it. The pressure exerted by these scissors is such, that they can cut without difficulty, iron bars, one half or two thirds of an inch thick. Cylinders.-The compression between cylinders now effects, in a few seconds, that condensation and distribution of the fibres, which, 40 years ago, could not be accomplished till after many heats in the furnace, and many blows of the hammer. The cylinders may be distinguished into two kinds; 1. those which serve to draw out the ball, called puddling rolls, or roughing rolls, and which are, in fact, reducing cylinders; 2. the cylinders of extension, called rollers, for drawing into bars the massive iron after t has received a welding, to make it more malleable. This second kind of cylinders is IRON. 1085 subdivided into several varieties, according to the patterns of bar iron that are required. These may rary from 2 inches square to less than one sixth of an inch. Beneath the cylinders there is usually formed an oblong fosse, into which the scoria and the scales fall when the iron is compressed. The sides of this fosse, constructed of stone, are founded on a body of solid masonry, capable of supporting the enormous load of the cylinders. Beams of wood form in some measure the sides of this pit, to which cylinders may be made fast, by securing them with screws and bolts. Massive bars of cast iron are found, however, to answer still better, not only because the uprights and bearers may be more solidly fixed to them, but because the basement of heavy metal is more difficult to shatter or displace, an accident which happens frequently to the wooden beams. A rill of water is supplied by a pipe to each pair of cylinders, to hinder them from getting hot; as also to prevent the hot iron from adhering to the cylinder, by cooling its surface, and perhaps producing on it a slight degree of oxydizement. The shafts are one foot in diameter for the hammer and the roughing rolls; and six inches where they communicate motion to the cylinders destined to draw the iron into bars. The roughing rolls are employed either to work out the lump or ball immediately after it leaves the puddling furnace, as in the Welsh forges, or only to draw out the piece, after it has been shaped under the hammer, as is practised in most of the Staffordshire establishments. These roughing cylinders are generally 7 feet long, including the trunnions, or 5 feet between the bearers, and 18 inches diameter; and weigh in the whole from 4 to 41 tons. They contain from 5 to 7 grooves, commonly of an elliptical form, one smaller than another in regular progression, as is seen in fig. 808. The small axis of each ellipse, as formed by the union of the upper and under grooves, is always placed in the vertical direction, and is equal to the great axis, or horizontal axis of the succeeding groove; so that in transferring the bar from one groove to another, it must receive a quarter of a revolution, whereby the iron gets elongated in every direction. Sometimes the roughing rolls serve as preparatory cylinders, in which case they bear towards one extremity rectangular grooves, as the figure exhibits. Several of these large grooves are bestudded with small asperities analogous to the teeth of files, for biting the lump of iron, and preventing its sliding. On a level with the under side of the grooves of the lower cylinder, there is a plate of cast iron with notches in its edge adapted to the grooves. This piece, called the apron, rests on iron rods, and serves to support the balls and bars exposed to the action of the rollers, and to receive the fragments of ill-welded metal, which fall off during the drawing. The housiingframes in which the rollers are supported and revolve, are made of great strength. Their height is 5 feet; their thickness is 1 foot in the side perpendicular to the axis of the cylinders, and 10 inches in the other. Each pair of bearers is connected at their upper ends by two iron rods, on which the workmen rest their tongs or pincers for passing the lump or bar from one side of the cylinders to the other. The cods or bushes are each composed of two pieces; the one of hard brass, which presents a cylindrical notch, is framed into the other which is made of cast iron, as is clearly seen in fig. 808. The iron bar delivered from the square grooves, is cut by the shears into short lengths, which are collected in a bundle in order to be welded together. When this bundle of bars has become hot enough in the furnace, it is conveyed to the rollers; which differ in their arrangement according as they are meant to draw iron from a large or small piece. The first, fig. 808, possess both elliptical and rectangular grooves; are 1 foot in diameter and 3 feet long between the bearers. The bar is not finished under these cylinders, but is transferred to another pair, whose grooves have the dimensions proper for the bar, with a round, triangular, rectangular, or fillet form. The triangular grooves made use of for square iron, have for their profile an isosceles triangle, slightly obtuse, so that the space left by the two grooves together may be a rhombus, differing little from a square, and whose smaller diagonal is vertical. When the bar is to be passed successively through several grooves of this kind, the larger or horizontal diagonal of each'following groove is made equal to the smaller or upright of the preceding one, whereby the iron must be turned one fourth round at each successive draught, and thus receive pressure in opposite directions. Indeed, the bar is often turned in succession through the triangular and rectangular grooves, that its fibres may be more accurately worked together. The decrement in the capacity of the grooves follows the proportion of 15 to 11. When it is intended to reduce the iron to a small rod, the cylinders have such a diam. eter, that three may be set in the same housing frame. The lower and middle cylinders are employed as roughing rollers, while the upper and middle ones are made to draw out the rod. When a rod or bar is to be drawn with a channel or gutter in its face, the rooves of the rollers are suitably formed. I L 1086 IRON. To draw out square rods of a very small size, as nail-rods, a system of small rollers 15 employed, called slitters. Their ridges are sharp-edged, and enter into the opposite 808 grooves 21 inches deep; so that the flat bar in v4% passing between such rollers is instantaneously divided into several slips. For this purpose;-.-1 i - the rollers represented in fig. 809 may be.O ^.; J 809 put on and removed from the shaft at plea sure. The velocity of the cylinders varies with <-k/~~~ 11 -Etheir dimensions. In one work, cylinders for ^ drawing out iron of from one third to two * _. ^.. -thirds of an inch thick, make 140 revolutions. per minute; while those for iron of from two b^ II~ ~ thirds of an inch to 3 inches, make only 65. -. _.: In another work, the cylinders for two inch iron, make 95 revolutions per minute; those for iron from two thirds of an inch to an inch and a third, make 128; and those for bars,~ 1 _ from one third to two thirds of an inch, 150. - i. V The roughing rollers move with only one third ~C| *s rA II ^^ the velocity of the drawing cylinders. lr IT-t >in i \ The shingling and plate-rolling mill is repH I1~lll ll ll I I 1 resented in fig. 808. The shingling mill, for p:~'F converting the blooms from the balling fur* _' { 1 nace into bars, consists of two sets of grooved cylinders, the first being called puddling rolls or roughing rolls; the second are for reducing or drawing the iron into mill-bars, and are called simply rolls. a, a, a, a, are the powerful uprights or standI 1 i1 1 1:X\X~ards called housinlgframes, of cast iron, in which the gudgeons of the rolls are set to revolve;.. — o b, b, b, b, are bolt rods for binding these frames u^' isl jll~,1 together at top and bottom; c, are the roughing'.. ( e r f rolls, having each a series of triangular grooves, r ( 1X such that between those of the upper and __ = 2 2 53 under cylinder, rectangular concavities are 1 4 p $ 4formed in the circumference with slightly sloping sides. The end groove to the right of c, should be channelled like a rough file, in: {'X1 =order to take the better hold of the blooms, or to bite the metal, as the workmen say; and give it the preparatory elongation for entering into -(U, -r ^and passing through the remaining grooves till it comes to the square ones, where it ben " - 1 comes a mill-bar. d, d, are the smooth cylEJsL |< inders, hardened upon the surface, or chilled c' a as it is called, by being cast in iron moulds, for rolling iron into plates or hoops. e, e, e, e, are strong screws with rectangular threads.'which work by means of a wrench or key, into the nuts e' e' e' e', fixed in the standards; they serve to regulate the height of the plummer blocks or bearers of the gudgeons, and thereby the distance between the u)per and under cylinders, f is a junction shaft; g g, g, are solid coupling boxes, which embrace the two separate ends of the shafts, and make them turn together. h, h, are junction pinions, whereby motion is communicated from the driving shaft f, through the under pinion to the upper one, and thus to both upper and under rolls at once. i, i, are the pinion standards in which their shafts run; they are smaller than the uprights of the rolls. k, k, are screws for fastening the head pieces 1 to Jie top of the pinion standards. All the standards are provided with sole plates m, IRON. 1087 whereLy they arc screwed to the foundation beams n, of wood or preferably i:-n, as shown by dotted lines; o o are the binding screw bolts. Each pair of rolls at work is Kept cool by a small stream of water let down upon it from a pipe and stop-cock. In the cylinder drawing, the workman who holds the ball in tongs, passes it into the first of the elliptical grooves; and a second workman on the other side of the cylinders, receives this lump, and hands it over to the first, who re-passes it between the rollers, after bringing them somewhat closer to each other, by giving a turn to the adjusting pressure screws. After the lump has passed five or six times through the same groove, it has got an elliptical form, and is called in England a bloom. It is next passed through a second groove of less size, which stretches the iron bar. In this state it is subjected to a second pair of cylinders, by which the iron is drawn into flat bars, 4 inches broad and half an inch thick. Fragments of the ball or bloom fall round about the cylinders; which are afterwards added to the puddling charge. In a minute and a half, the rude lump is transformed into bars, with a neatness and rapidity which the inexperienced eye can hardly follow. A steam engine of thirty-horse power can rough down in a week, 200 tons of coarse iron. Thj. iron, called mill-bar iron, is however of too inferior a quality to be employed in any machinery; and it is subjected to another operation, which consists in welding several pieces together, and working them into a mass of the desired quality. The iron bars, while still hot, are cut by the shears into a length proportional to the size of iron bar that is wanted; and four rows of these are usually laid over each other into a heap or pile, which is placed in the re-heating furnace above described, and exposed to a free circulation of heat; one pile being set crosswise over another. In a half or three quarters of an hour, the iron is hot enough, and the pieces now sticking together, aie carried in successive piles to the bar-drawing cylinders, to be converted into strong bars, which are reckoned of middle quality. When a very wtagh iron is wanted, as for anchors, another welding and rolling must be given. In the re-heating ovens, the loss is from 8 to 10 per cent. on the large bar iron, and from 10 to 12 in smaller work. A ton of iron consumes in this process about 150 lbs. of coals. It is thought by many that a purer iron is obtained by subjecting the balls as they come out of the puddling furnace, to the action of the hammer at first, than to the roughing rollers; and that by the latter process vitrified specks remain in the metal, which the hammer expels. Hence, in some works, the balls are first worked under the forgehammer; and these stampings being afterwards heated in the form of pies or cakes pilcl over each other, are passed through the roughing rollers. Having given ample details concerning the manufacturing processes used in England for making cast iron, it may be proper to subjoin a few observations upon its chemical constitution. It has been generally believed and taught that the dark gray cast iron, No. 1 or No. 2, contains more carbon than the white cast iron; and that the superior quality of the former in tenacity and softness, is to be ascribed to that excess. But the distinguished German metallurgist, M. Karsten, in his instructive volume, "Handbuch der Eisenhiittenkunde," or manual of the art of smelting iron ores, has proved, on the contrary, that the white cast iron contains most charcoal; that this substance exists in it in a state of combination with the whole body of the iron; that the foliated or lamellar white cast iron contains as much carbon as iron can absorb in the liquid state; and that this constitutes a compound of 4 atoms of iron combined with 1 of charcoal, or 112+-6 or 5- per cent.; whereas the dark gray cast iron contains generally from 3 to 4 pel cent., in the state of plumbago merely dispersed through the metal. He has further confirmed his opinion, by causing the white variety to pass into the gray, and reciprocally. Thus, dark gray cast metal melted and suddenly cooled, gives a silvery white metal, hard and brittle. On the other hand, when the white cast iron is cooled very slowly after fusion, the condition of the carbon in it changes, and a dark gray cast iron is obtained. These phenomena show that the graphite or plumbago, which requires a high temperature for its formation, cannot be produced but by a slow cooling, which allows the carbon to agglomerate itself in the iron in the state ac graphite; while under a rapid congelation, the carbon remains dissolved in the mass, and produces a white metal. Hence we may understand how each successive fusion of dark gray iron hardens and whitens it, though in contact with coke, by completing that chemical dissolution of the carbon on which the white state depends. In the manufacture of the blackest No. 1 cast iron, it sometimes happens that a considerable quantity of a glistening carburet of iron appears, floating on the top of the metal as it is run out into the sand-moulds. This substance is called kzsh by the English workmen; and it affords a sure test of the good state of the furnace and quality of the iron. The most remarkable fact relative to the smelting of cast iron, is the difference of pro. duct between the workings of the summer and the winter season, though all the materia.. and machinery be the same. In fact, no cold-blast furnace will carry so great a burder 1088 IRON. in summer as in winter, that is, afford so great a product of metal, or bear so great a charge of ore with the same quantity of coke. This difference is undoubtedly due to the dilated and humid state of the atmosphere in the warm season. A very competent judge of this matter, states the diminution in summer at from one fifth to one seventh, indepen dently of deterioration of quality. Some of the foreign irons, particularly certain Swedish and Russian bars, are imported into Great Britain in large quantities, and at prices much greater than those of the English bars, and therefore the modes of manufacturing such excellent metal deserve examination. All the best English cast steel, indeed, is made from the hoop L iron from Dannemora, in Sweden. The processes pursued in the smelting works of the Continent have frequently in view to obtain from the ore malleable iron directly, in a pure or nearly pure state. The furnaces used for this purpose are of two kinds, called in French, 1. Feux de Loupes, or Forges Catalanes; and 2. Fourneaux a piece, or Forges Adllemadwles. In the Catalan, or French method, the ore previously roasted in a kiln is afterwards strongly torrefied in the forge before the smelting begins; operations which follow in immediate succession. Ores treated in this way should be very fusible and very rich; such as black oxyde of iron, hematites, and certain spathose iron ores. From 100 parts of ore, 50 of metallic iron have been procured, but the average product is 35. The furnaces employed are rectangular hearths, figs. 810, and 811, the water-blowing 810 811 i3 machine being employed to give the blast. See METALLURGY. There are three varieties of this forge; the Catalan, the Navarrese, and the Biscayan. The dimensions of the first, the one most generally employed, are as follows: 21 inches long, in the direction p ffig. 811; 181 broad, at the bottom of the hearth or creuset, in the line A B; and 17 inches deep,fig. 810. The tuyere, q p, is placed 9- inches above the bottom, so that its axis is directed towards the opposite side, about 2 inches above the bottom. But it must be moveable, as its inclination needs to be changed, according to the stage of the operation, or the quantity of the ores. It is often raised or lowered with pellets of clay; and even with a graduated circle, for the workmen make a great mystery of this matter. The hearth is lined with a layer of brasque (loam and charcoal dust worked together), and the ore after being roasted is sifted; the small powder being set aside to be used in the course of the operation. The ore is piled up on the side opposite to the blast in a sharp saddle ridge, and it occupies one third of the furnace. In the remaining space of two thirds, the charcoal is put. To solidify the small ore on the hearth, it is covered with moist cinders mixed with clay. The fire is urged with moderation during the first two hours, the workman being continually employed in pressing down more charcoal as the former supply burns away, so as to keep the space full, and prevent the ore from crumbling down. By a blast so tempered at the beginning, the ore gets well calcined, and partially reduced in the way of cementation. But after two hours, the full force of the air is given; at which period the fusion ought to commence. It is easy to see whether the torre. faction be sufficiently advanced, by the aspect of the flame, as well as of the ore, which becomes spongy or cavernous; and the workman now completes the fusion, by detaching the pieces of ore from the bottom, and placing them in front of the tuyere. When the fine siftings are afterwards thrown upon the top, they must be watered, to prevent their being blown away, and to keep them evenly spread over the whole surface of the light fuel. They increase the quantity of the products, and give a propel fusibility to the scoriae. When the scoriae are viscid, the quantity of siftings must be diminished; but if thin, they must be increased. The excess of slag is allowed to run off by the chio or floss hole. The process lasts from five to six hours, after which the pasty mass is taken out, and placed under a hammer to be cut into lumps, which are afterwards forged into bars. Each mass presents a mixed variety of iron and steel; in proportions which may bre modified at pleasure; for by using much of the siftings, and making the tuyere dip ow ards the sole of the hearth, iron is the chief product; but if the operation be cor IRON 1039 ucted slowly, with a small quantity of siftings, and an upraised tuyere, the quantity'A steel is more considerable. This primitive process is favorably spoken of by M. Brongniart. The weight of the lump of metal varies from 200 to 400 pounds. As the consumption of charcoal is very great, amounting in the Palatinate or Rheinkreis to seven times the weight of iron'obtained, though in the, Pyrenees it is only thrice, the Cataian forge can be profitably employed only where wood is exceedingly cheap and abundant. The Fourneaux a piece of the French, or Stuck-ofen of the Germans, resembbesfig. 885 (COPPER); the tuyere (not shown there) having a dip towards the bottom of the hearth, where the smelted matter collects. When the operation is finished, that is, at least once in every 24 hours, one of the sides of the hearth must be demolished, to take out the pasty mass of iron, more or less pure. This furnace holds a middle place in the treatment of iron, between the Catalan forge and the cast-ironfloss-ofen, or high-blast Furnaces. The stuck-ofen are from 10 to 15 feet high, and about 3 feet in diameter at.he hearth. Most usually there is only one aperture for the tuyere and for working; with a small one for the escape of the slag; on which account, the bellows are removed to make way for the lifting out of the lump of metal, which is done through an opening left on a level with the sole, temporarily closed with bricks and potters' clay, while the furnace is in action. This outlet being closed, and the furnace filled with charcoal, fire is kindled at the bottom. Whenever the whole is in combustion, the roasted ore is introduced at the top in alternate charges with charcoal, till the proper quantity has been introduced. The ore falls down; and whenever it comes opposite to the tuyere the slag begins to flow, and the iron drops down and collects at the bottom of the hearth into the mass or stuck; and in proportion as this mass increases, the floss-hole for the slag and the tuyere is raised higher. When the quantity of iron accumulated in the hearth is judged to be sufficier.., the bellows are stopped, the scorie are raked off, the little brick wall is taken down, and the mass of iron is removed by rakes and tongs. This mass is then flattened under the hammer, into a cake from 3 to 4 inches thick, and is cut into two lumps, which are submitted to a new operation; where it is treated in a peculiar refinery, lined with charcoal crasque, and exposed to a nearly horizontal blast. The above mass, seized in the jaws if a powerful tongs, is heated before the tuyere; a portion of the metal flows down to the bottom of the hearth, loses its carbon in a bath of rich slags or fused oxydes, and forms thereby a mass of iron thoroughly refined. The portion that remains in the tongs fur. nishes steel, which is drawn out into bars. This process is employed in Carniola for smelting a granular oxyde of iron. The mass or stuck amounts to from 15 to 20 hundred weight, after each operation of 24 hours. Eight strong men are required to lift it out, and to carry it under a large hammer, where t is cut into pieces of about 1 cwt. each. These are afterwards refined and drawn into tars as above described. These furnaces are now almost generally abandoned on the continent, in favor of charcoal high or blast furnaces. F1ig. 385 represents a shachtofen (but without the tuyere, which may be supposed to be m the usual place), and is, like all the continental Hauts Fourneaux, remarkable for the excessive thickness of its masonry. The charge is put in at the throat, near the summit of the octagonal or square concavity, for they are made of both forms. At the bottom of the hearth there is a dam-stone with its plate, for permitting the overflow of the slag, while it confines the subjacent fluid metal; as well as a tymp-stone with its plate, which forms the key to the front of the hearth; the boshes are a wide finnel, almost flat, to obstruct the easy descent of the charges, whereby the smelting with charcoal would proceed too rapidly. The bottom of the hearth is constructed of two large stones, and the hinder part of one great stone, called in German, riicksltein (black stone), which the French have corrupted into rustine. In other countries of the Continent, the boshes are frequently a good deal more tapered downwards, and the hearth is larger than here represented. The refractory nature of the Hartz iron ores is the reason assigned for this peculiarity. In Sweden there are blast-furnaces, schachtofeez, 35 fe?: in height, measured fiom the Doshes above the line of the hearth, or creuset. Their cavity has the form of an elonga tel ellipse, whose small diameter is 8 feet across, at a height of 14 feet above the bottom of the hearth; hence, at this part, the interior space constitutes a belly, corresponding with the upper part of the boshes. In other respects, the details of the construction of the Swedish furnaces resemble the one figured above. Marcher relates that a furnace of that kind, whose height was only 30 feet, in which brown hydrate of iron (hematite) was smelted, yielded 47 per cent. in cast-iron, at the rate of 5 hundred weight a day, or 36 hundred weight one week afteranother; and that in the production of 100. pounds of cast-iron, 130 pounds of charcoal were consumed. That furnace was worked with forge bellows, mounted with leather. 1090 IRON. The decaiburation of cast-iron is merely a restoration of the carbon to the surface, i tracing inversely the same progressive steps as had carried it into the interior during the smelting of the ore. The oxygen of the air, acting first at the surface of the cast metal, upon the carbon which it finds there, burns it: fresh charcoal, oozing from the interior comes then to occupy the place of what had been dissipated; till, finally, the whole carbon is transferred from the centre to the surface, and is there converted into either carbonic acid gas, or oxyde of carbon; for no direct experiment has hitherto proved which of these is the precise product of this combustion. This diffusibility of carbon through the whole mass of iron constitutes a movement by means of which cast-iron may be refined even without undergoing fusion, as is proved by a multitude of phenomena. Every workman has observed that steel loses a portion of its steely properties every time it is heated in contact with air. On the above principle, cast-iron may be refined at one operation. Three kinds of iron are susceptible of this continuous process:-1. The speckled cast-iron, which contains such a proportion of oxygen and carbon as with the oxygen of the air and the carbon of the fuel may produce sufficient and complete saturation, but nothing in excess 2. The dark gray cast-iron. 3. The white cast-iron. The nature of the crude metsL requires variations both in the forms of the furnaces, and in the manipulations. Indeed, malleable iron may be obtained directly from the ores by one fusion. This mode of working is practised in the Pyrenees to a considerable extent. All the ores of iron are not adapted for this operation. Those in which the metallic oxyde is mixed with much earthy matter, do not answer well; but those composed of the pure black oxiy, red oxyde, and carbonate, succeed much better. To extract the metal from such ores, it is sufficient to expose them to a high temperature, in contact either with charcoal, or with carbonaceous gases; the metallic oxyde is speedily reduced. But when several earths are present, these tend continually, during the vitrification which they suffer, to retain in their vitreous mass the unreduced oxyde of iron. Were such earthy ores, as our ironstones, to be put into the low furnaces called Catalan, through which the charges pass with great rapidity, and in which the contact with the fuel is merely momentary, there would be found in the crucible or hearth merely a rich metallic glass, instead of a lump of metal. In smelting and refining by a continuous operation, three different stages may be distinguished: 1. The roasting of the ore to expel the sulphur, which would be less easily separated afterwards. The roasting dissipates likewise the water, the carbonic acid, and any other volatile substances which the minerals may contain. 2. The deoxydizement and reduction to metal by exposure to charcoal or carbureted vapors. 3. The melting, agglutination, and refining of the metal to fit it for the heavy hammers where it gets nerve. There are several forges in which these three operations seem to be con founded into a single one, because, although still successive, they are practised at one single heating without interruption. In other forges, the processes are performed separately, or an interval elapses between each stage of the work. Three systems of this kind are known to exist:-1. The Corsican method; 2. The Catalan with wood charcoal; and 3. The Catalan with coke. The furnaces of Corsica are a kind of semicircular basins, 18 inches in diameter, and 6 inches deep. These are excavated in an area, or a small elevation of masonry, 8 or 10 feet long by 5 or 6 broad, and covered in with a chimney. This area is quite similar to that of the ordinary hearths of our blast-furnaces. The tuyere stands 5 or 6 inches above the basin, and has a slight inclination downwards. In Corsica, and the whole portion of Italy adjoining the Mediterranean shores, the iron ore is an oxyde similar to the specular ore of the Isle of Elba. This ore contains a little water, some carbonic acid, occasionally pyrites, but in small quantity. Before deoxydizing the ore, it is requisite to expel the water and carbonic acid combined with the oxyde, as well as the sulphur of the pyrites. The operations of roasting, reduction, fusion, and agglutination, are executed in the same furnace. These are indeed divided into two stages, but the one is a continuation of the other. In the first, the two primary operations are performed at once;-the reduction of a portion of the roasted ore is begun at the same time that a portion of the raw ore is roasted: these two substances are afterwards separated. In the second stage, the deoxydizement of the metal is continued, which had begun in the preceding stage; it is then melted and agglutinated, so as to form a ball to bm submitted to the forge-hammer. The roasted pieces are broken down to the size of nuts, to make the reduction of the metal easier. In executing the first step, the basin and area of the furnace must be lined with a brasque of charcoal dust, 3, 4, or even 5 inches thick: over this brasque a mound is raised with lumps of charcoal, very hard, and 4 or 5 inches high. A semicircle is formed round the tuyere, the inner radius of which is 5 or 6 inches. This mass of charcoal is next surrounded with another pile of the roasted and broken ores, which IRON. 1091 must be covt-ed with charcoal dust. The whole is sustained with large blocks of the raw ore, which form externally a third wall. These three piles of charcoal, with roasted and unroasted ore, are raised in three suc. cessive beds, each 7 inches thick: they are separated from each other by a layer of charcoal dust of about an inch, which makes the whole 24 inches high. This is afterwards covered over with a thick coat of pounded charcoal. The blocks of raw ore which compose the outward wall form a slope; the larger and stronger pieces are at the bottom, and the smaller in the upper part. The large blocks are sunk very firmly into the charcoal dust, to enable them better to resist the pressure from within. On the bottom of the semicircular well formed within the charcoal lumps, kindled pieces are thrown, and over these, pieces of black charcoal; after which the blast of a waterblowing machine (trompe) is given. The fire is kept up by constantly throwing charcoal into the central well. At the beginning of the operation it is thrust down with wooden rods, lest it should affect the building; but when the heat becomes too intense for the workmen to come so near the hearth, a long iron rake is employed for the purpose.'At the end of about 3 hours, the two processes of roasting and reduction are commonly finished: then the raw ore no longer exhales any fumes, and the roasted ore, being softened, unites into lumps more or less coherent. The workman now removes the blocks of roasted ore which form the outer casing, rolls them to the spot where they are to be broken into small pieces, and pulls down the brasque (small charcoal) which surrounds the mass of reduced ore. The second operation is executed by cleaning the basin, removing the slags, covering the basin anew with 2 or 3 brasques (coats of pounded charcoal), and piling up to the right and the left, two heaps of charcoal dust. Into the interval between these conical piles two or three baskets of charcoal are cast, and on its top some cakes of the reduced crude metal being laid, the blast is resumed. The cakes, as they heat, undergo a sort of liquation, or sweating, by the action of the earthy glasses on the unreduced black oxyde present. Very fusible slags flow down through the mass; and the iron, reduced and melted, passes finally through the coals, and falls into the slag basin below. To the first parcel of cakes, others are added in succession. In proportion as the slags proceeding from these run down, and the melted iron falls to the bottom, the thin slag is run off by an upper overflow or chio hole, and the reduced iron kept by the heat in the pasty condition, remains in the basin: all its parts get agglutinated, forming a soft mass, which is removed by means of a hooked pole in order to be forged. Each lump or bloom of malleable iron requires 3 hours and a half for its production. The iron obtained by this process is in general soft, very malleable, and but little steely. In Corsica four workmen are employed at one forge. The produce of their labor is only about 4 cwts. of iron from 10 cwts. of ore and 20 of charcoal, mingled with wood of beech and chestnut. Though their ore contains on an average 65 per cent. of iron, only about 40 parts are extracted; evincing a prodigious waste, which remains in the slags. The difference between the Corsican and the Catalonian methods consists in the latter roasting the ore at a distinct operation, and employing a second one in the reduction, agglutination, and refining of the metal. In the Catalonian forges, 100 pounds of iron are obtained from 300 pounds of ore and 310 pounds of charcoal; be'tng a produce of only 33 per cent. It may be concluded that there is a notable loss, since the sparry iron ores, which are those principally smelted, contain on an average from 54 to 56 per cent. of iron. The same ores, smelted in the ordinary blast furnace, produce about 45 per cent. of cast iron. On the Continent, iron is frequently refined from the cast metal of the blast furnaces by three operations, in three different ways. In one, the pig being melted, with aspersion of water, a cake is obtained, which is again melted in order to form a second cake. This being treated in the refinery fire, is then worked into a bloom. In another system, the pig iron is melted and cast into plates: these are melted anew in order to obtain crude balls, which are finally worked into blooms. In a third mode of manufacture, the pig-iron is melted and cast into plates, which are roasted, and then strongly heated, to form a bloom. The French fusible ores, such as the silicates of iron, are very apt to smelt into white cast iron. An excess of fluxes, light charcoals, too strong a blast, produce the same results. A surcharge of ores which deranges the furnace and affords impure slags mixed with much iron, too rapid a slope in the boshes, too low a degree of heat, and too great condensation of the materials in the upper part of the furnace; all tend also to produce a white cast iron. In its state of perfection, white cast iron has a silver color, and a bright metallic lustre. It is employed frequently in Germany for the manufacture of steel, and is then called steel floss, or lamellar floss, a title which it still retains, though it be hardly silver white, and have ceased to be foliated. When its color takes a bl'iish70 1092 IRON. gray tinge, and its fracture appears striated or splintery, or when it exhibits gray spots, it is then styled flowerfloss. In a third species of white cast iron we observe still much lustre, but its color verges upon gray, and its texture is variable. Its fracture has been sometimes compared to that of a broken cheese. This variety occurs very frequently. It is a white cast iron, made by a surcharge of ore in the furnace. If the white color becomes less clear and turns bluish, if its fracture be contorted, and cohtains a great many empty spaces or air-cells, the metal takes the name of cavernous-floss, or tender-floss. The whitest metal cannot be employed for casting. When the white is mixed with the gray cast iron, it becomes riband or trout cast iron. The German refining forge.-Figs. 812, 813 represent one of the numerous refinery 812 x~~~~A / furnaces so common in the Hartz. The example is taken from the Mandelholz works, in the neighborhood of Elbingerode. Fig. 813 is an elevation of this forge. D is the refinery hearth, provided with two pairs of bellows. Fig. 812 is a vertical section, showing particularly the construction of the crucible or hearth in the refinery forge D. c is an overshot water wheel, which gives an alternate impulsion to the two bellows a b by means of the revolving shaft c, and the cams or tappets df e g. D, the hearth, is lined with cast iron plates. Through the pipe 1, cold water may be introduced, under the bottom plate m, in order to keep down, when necessary, the temperature of the crucible, and facilitate the solidification of the loupe or bloom. An orifice n, figs. 812, 813, called the chio (floss hole), allows the melted slag or cinder to flow off from the surface of the melted metal. The copper pipe or nose piece p, fig. 811, conducts the blast of both bellows into the hearth, as shown at b x, fig. 813, and D g p, fig. 811. The substance subjected to this mode of refinery, is a gray carbonaceous cast iron, from the works of Rothehitte. The hearth D, being filled and heaped over with live charcoal, upon the side opposite to the tuyere x, figs. 812, 813, long pigs of cast iron are laid with their ends sloping downwards, and are drawn forwards successively into the hearth by a hooked poker, so that the extremity of each may be plunged into the middle of the fire, at a distance of 6 or 8 inches from the mouth of the tuyere. The workman proceeds in this way, till he has melted enough of metal to form a loupe. The cast iron, on melting, falls down in drops to the bottom of the hearth; being covered by the fused slags, or vitreous matters more or less ioaded with oxyde of iron. After running them off by the orifice n, he then works the cast iron by powerful stirring with an iron rake (ringard), till it is converted into a mass of a pasty consistence. During this operation, a portion of the carbon contained in the cast iron combines wsth the atmospherical oxygen supplied by the bellows, and passes off in the form of carbonic oxyde and carbonic acid. When the lump is coagulated sufficiently, the workman turns it over in the hearth, then increases the heat so as to melt it afresh, meanwhile exposing it all round to the blast, in order to consume the remainder of the carbon, that is, till the iron has become ductile, or refined. If one fusion should prove inadequate to this effect, two are given. Before the conclusion, the workman runs off a second stratum of vitreous slag, but at a higher level, so that some of it may remain upon the metal. The weight of such a loupe or bloom is about 2 cwts., being the product of 2 cwts. and 70 of pig iron; the loss of weight is therefore about 26 per cent. 149 pounds of charcoal are consumed for every 100 pounds of bar iron obtained. The whole operation lasts about 5 hours. The bellows are stopped as soon as the bloom is ready; this is immediately Transferred to a forge hammer, such as is represented fig. 816; the cast iron head of which weighs 8 o0 9 cwts. The bloom is greatly condensed thereby, and discharges a considerable q'lantitv of semi-fluid cinder. The lump is then divided by the hamme: IRON. 1093 ana a chisel into 4 or 6 pieces, which are reheated, one after another, in the same refinery fire, in order to be forged into bars, while another pig of cast iron is laid in its place, to prepare for the formation of a new bloom. The above process is called by the Germans klump-frischen, or lump-refining. It differs from the durch-brech-frischen, because in the latter, the lump is not turned over in mass, but is broken, and exposed in separate pieces successively to the refining power of the blast near the tuyere. The French call this afqinage par portions; it is much lighter work than the other. The quality of the iron is tried in various ways; as first, by raising a bar by one end, with the two hands over one's head, and bringing it forcibly down to strike across a nar. row anvil at its centre of percussion, or one third from the other extremity of the bar; aflel which it may be bent backwards and forwards at the place of percussion several times; 2. a heavy bar may be laid obliquely over props near its end, and struck strongly with a hammer with a narrow pane, so as to curve it in opposite directions; or while heated to redness, they may be kneed backwards and forwards at the same spot, on the edge of the anvil. This is a severe trial, which the hoop L, Swedish iron, bears surprisingly, emitting as it is hammered, a phosphoric odor, peculiar to it and to the bar iron ot Ulverstone, which also resembles it, in furnishing a good steel. The forging of a horseshoe is reckoned a good criterion of the quality of iron. Its freedom from flaws is detected by the above modes; and its linear strength may 7c- determined by suspending a scale to the lower end of a hard-drawn wire, of a given size, and adding weights till the wire breaks. The treatises of Barlow and Tredgold may be consulted with advantage on the methods of proving the strength of different kinds of iron, in a great variety of circumstances. Steel of cementation, or blistered steel and cast steel, are treated under the article STEEL. But since in the conversion of cast iron into wrought iron, by a very slight difference in the manipulations, a species of steel may be produced called natural steel, I shall describe this process here. Fig. 814 is a view of the celebrated steel iron works, called Konigshiitte, (king's-forge), in Upper Silesia, being one of the best arranged in Germany, for smelting iron ore by Ab >. 814 /n n Jn TI means of coke. The front shown here is about 400 English feet long. a a are two blast furnaces. A third blast furnace, all like the English, is situated to the left of one of the towers b. b b are the charging towers, into which the ore is raised by machinery from the level of the store-houses I I, up to the mouth of the furnaces a a; c c point to the positions of the boilers of the two steam engines, which drive two cylinder bellows at f. n n n n are arched cellars placed below the store-houses 11, for containing materials and tools necessary for the establishment. Figs. 810, 815, are vertical sections of the forge of K6nigshiitte, for making natural steel; fig. 810 being drawn in the line A B of A/m —. - J 815 the plan, fig. 811. a is the bottom of the hearth, consisting of a fire-proof gritstone; b is a space filled with small charcoal, damped with water, under which, at n, in fig. 815, is a bed of well. ^ IA ~ E Irammed clay; d is a plate of cast iron, which lines the side of the hearth called ruckstein (backstone) in German, and corrupted by the French into rustine; f is the plate of the counter-blast; g the plate of the side of the tuyere; behind, upon the face d, the fire-place or hearth is only 51 inches deep; in front as well as upon the lateral faces, it is 18 inches deep. By means of a mound made of dry charcoal, the posterior face d is raised to the height of the face f. i, fig. 811, is the floss-hole, by which the slags are run.off from the hearth during the working, and through which, by removing some bricks, the lump of steel is taken out when finished. k 1 m are pieces of cast iron, for confining the fire in front, that is, towards the side where the workman stands; o is the level of the floor of the works; p a copper tuyere; it is situated 41 inches above the bottom a, slopes 5 degrees towards it, and advances 4 inches into the hearth or fire-place. where it presents an orifice, one half inch in horizontal length, and one inch up and down; q the nose pipes of two bellows, like those represented 1094 IRON, infig. 813, and under SILVER; the round orifice of each of them within the tuyere being one inch in diameter. r is the lintel or top arch of the tuyere, beneath which is seen the cross section of the pig of cast iron under operation. *For the production of natural steel, a white cast iron is preferred, which contains little zarbon, which does not flow thin, and which: being cemented over or above the wind, fall, down at once through the blast to the bottom of the hearth in the state of steel. With this view, a very flat fire is used; and should the metal run too fluid, some malleable lumps are introduced to give the mass a thicker pasty consistence. If the natural steel be supposed to contain too little carbon, which is v very rare case, the metal bath covered with its cinder slag, is diligently stirred with a wooden pole, or it may receive a little of the more highly carbureted iron. If it contains the right dose of carbon, the earthy and other foreign matters are made progressively to sweat out, into the supernatant slag. When the mass is found by the trial of a sample to be completely converted, and has acquired the requisite stiffness, it is lifted out of the furnace, by the opening in front, subjected to the forge hammer, and drawn into bars. In Sweden, the cast iron pigs are heated to a cherry-red, and in this state broken to pieces under the hammer, before they are exposed in the steel furnace. These natural steels are much employed on the Continent in making agricultural implements, on account of their cheapness. The natural steel of Styria is regarded as a very good article. Wootz is a natural steel prepared from a black ore of iron in Hindostan, by a process analogous to that of the Catalan hearth, but still simpler. It seems to contain a minute portion of the combustible bases of alumina and silica, to which its peculiar hardness when tempered may possibly be ascribed. It is remarkable for the property of assuming a damask surface, by the action of dilute srulphuric acid, after it has been forged and polished. See DAMASCUS and STEEL. Fig. 816 is the German forge-hammer; to the left of 1, is the axis of the rotatory cam, 2, 3, consisting of 8 sides,...... each formed of a strong broad bar f816,..o. of cast iron, which are joined tog\ ether to make the octagon wheel.. 2r e n\ 4, 5, 6, are cast iron binding rings i/t^~ y ^ \ O or hoops, made fast by wooden.i j'Y r t y^^av \ 6 wedges. b, b, are standards of the 74 6^1 nl T 6 frame-work e, 1, m, in which the so-"? < t'<1<; Ad"^@ 6 j helve of the forge-hammer has its -- A II-^^^',' fulcrum near u. h, the sole part *1 l-s^i~,/// 0 1of the frame. Another cast iron >XX^ ^ ]n base or sole is seen at m. n is a f g n ~\ g n v* strong stay, to strengthen the _I~~.t - ^I.-* frame-work. At r two parallel y' hammers are placed, with cast. iron heads and wooden helves. s is the anvil, a very massive piece of cast iron. t is tho end of a vibrating beam, for throwing back the hammer from it forcibly by recoil.: x y is the outline of the water-wheel which drives the whole. The cams or tappets are shown mounted upon the wheel 6, g, 6. Analysis of irons.-Oxydized substances cannot exist in metallic iron and the foreign substances it does contain are present in such small quantities, that it is somewhat difficult to determine their amount. The most intricate point is, the proportion of carbon. The free carbon, which is present only in gray cast iron, may, indeed, be determined nearly, for most of it remains after solution of the metal in acids. The combined charcoal, however, changes by the action of muriatic acid into gas and oil; sulphuric acid also occasions a great loss of carbon, and nitric acid dissipates it almost entirely. Either nitre or chloride of silver may be employed to ascertain the amount of carbon; but when the iron contains chromium and much phosphorus, the determination of the carbon is attended with many difficulties. The quantity of sulphur is always so small, that it can scarcely be ascertained by the weight of the precipitate of sulphate of barytes from the solution of the iron in nitromuriatic acid. The iron should be dissolved in muriatic acid; and the hydrogen, as it escapes charged with the sulphur, should be passed through an acidulous solution of acetate of lead. The weight of the precipitated sulphuret shows the amount of sulphur, allowing 13-45 of the latter for 100-of the former. In this experiment the metal should be slowly acted upon by the acid. Cast iron takes from 10 to 15 days to dissolve, steel from 8 to 10, and malleable iron 4 days. The residuum of a black color does not contain a trace of sulphur. Phosphorus and chromium are determined in the following way. The iron must be dissolved in nitro-muriatic acid, to oxygenate those two bodies. The solution must be evaporated cautiously to dryness in porcelain capsules, and the saline residuum heated IRON. 1095 to redness. A little chloride of iron is volatilized, and the remainder resembles the red-brown oxyde. This must be mixed with thrice its weight of carbonate of potash, and fused in a platinum crucible the quantity of iron being from 40 to 50 grains at most. The mixture, after being acted upon by boiling water, is to be left to settle, to allow the oxyde to be deposited, for it is so fine as to pass through a filter. If the iron con. tained manganese, this would be found at first in the alkaline solution; but manganese spontaneously separates by exposure to the air. The alkaline liquor must be supersaturated with muriatic acid, and evaporated to dryness. The liquor acidulated, and deprived of its silica by filtration, is to be supersaturated with ammonia; when the alumina will precipitate in the state of a subphosphate. When the liquor is now supersaturated with acetic acid, and then treated with acetate of lead, a precipitate of phosphate of lead almost always falls. There is hardly a bit of iron to be found which does not contain phosphorus. The slightest trace of chrome is detected by the yellow color of the lead precipitate; if this be white there is none of the coloring metal present. 100 parts of the precipitated phosphate of lead contain, after calcination, 19'4 parts of phosphoric acid. The precipitate should be previously washed with acetic acid, and then with water. These 19.4 parts contain 8'525 parts of phosphorus. Cast iron sometimes contains calcium and barium, which may be detected by their well-known reagents, oxalate of ammonia. and sulphuric acid. In malleable iron they are seldom or never present. The charcoal found in the residuum of the nitro-muriatic solution is to be burned away under a muffle. The solution itself contains along with the oxyde of iron, protoxyde of manganese, and other oxydes, as well as the earths, and the phosphoric and arsenic acids. Tartaric acid is to be added to it, till no precipitate be formed by supersaturation with caustic ammonia. The ammoniacal liquor must be treated with hydrosulphuret of ammonia as long as it is clouded, then thrown upon a filter. The precipitate is usually very voluminous, and must be well washed. The liquor vwhich passes through is to be saturated with muriatic acid, to decompose all the sulphurets. The solution still contains all the earths and the oxyde of titanium, besides the phosphoric acid. It is to be evaporated to dryness, whereby the ammonia is expelled, and the carbonaceous residuum must be burned under a muffle. If the iron contains much phosphorus, the ashes are strongly agglutinated. They are to be fused as already described along with carbonate of potash, and the mass is to be treated with boiling water. The residuum may be examined for silica, lime, barytes, and oxyde of titanium. Muriatic acid being digested on it, then evaporated to dryness, and the residuum treated with water, will leave the silica. Caustic ammonia, poured into the solution, will separate the alumina, if any be present, and the oxyde of titanium; but the former almost never occurs. Manganese is best sought for by a distinct operation. The iron must be dissolved at the heat of boiling water, in nitro-muriatic acid; and the solution, when very cold, is to be treated with small successive doses of solution of carbonate of ammonia. If the iron has been oxydized to a maximum, and if the liquor has been sufficiently acid, and diluted with water, it will retain the whole of the manganese. This process is as good as that by succinate of ammonia, which requires many precautions. The liquor is often tinged yellow by carbon, after it has ceased to contain a single trace of iron oxyde. As soon as litmus paper begins to be blued by carbonate of ammonia, we should stop adding it; immediately throw the: whole upon a filter, and wash continuously with cold water. What passes through is to be neutralized with muriatic acid, and concentrated by evaporation. It may contain, besides manganese, some lime or barytes. It should therefore be precipitated with hydro-sulphuret of ammonia, the hydrosulphuret of manganese should be collected, dissolved in strong muriatic acid, filtered, and treated, at a boiling heat, with carbonate of potash. The precipitate, well washed and calcined, contains, in 100 parts, 72-75 parts of metallic manganese. The copper, arsenic, lead, tin, bismuth, antimony, or silver, are best separated by a stream of sulphureted hydrogen gas passed through the solution in nitro-muriatic acid, after it is largely diluted with water. The precipitate must be cautiously roasted in a porcelain test, to burn away the large quantity of sulphur which is deposited in consequence of the conversion of the peroxyde of iron into the protoxyde. If nothing remains upon the test, none of these metals is present. If a residuum be obtained, it must be dissolved in nitro-muriatic acid, and subjected to examination. But, in fact, carbon, sulphur, phosphorus, silicon, and manganese, are the chief contaminators of iron. Chloride of silver affords the means of determining the proportion of carbon contained in iron and of ascertaining the state in which that substance exists in thr metal. Fusea 1096 IRON. chloride of a pale yellow color must be employed. The operation is to be performed in close vessels, with the addition of a great deal of water, and a few drops of muriatie acid. The carbonaceous residuum is occasionally slightly acted upon. We ma} judge of this circumstance by the gases disengaged, as well as by tne appearance cf the charcoal. Ductile iron and soft steel, as well as white cast-iron which has been rendered gray by roasting, when decomposed by chloride of silver, afford a blackish-brown unmagnetic charcoal, and a plumbaginous substance perfectly similar to what is extracted from the same kinds of iron, by solution in acids. A portion of this plumbago is also converted into charcoal of a blackish brown color, by the action of the chloride. Hence this agent does not afford the means of obtaining what has been called the poly-carburet, till it has produced a previous decomposition. But we obtain it, in this manner, purer and in greater quantity than we could by dissolving the metal in the acids. The only subject of regret is, that we possess no good criterion for judging of the progress of this analytical operation. Gray cast iron leaves, besides the poly-carburet, a residuum of plumbago, and carbon which was not chemically combined with the iron; while tempered steel and white cast iron afford merely a blackish brown charcoal; but the operation is extremely slow with the latter two bodies, because a layer of charcoal forms upon the surface, which obstructs their oxydizement. For this reason the white cast iron ought to be previously changed into gray by fusion in a crucible lined with charcoal, before being subjected to the chloride of silver; if this process be emrloyed for tempered steel, the combined carbon becomes merely a poly-carburet. It wcl, l not be possible to operate upon more than 15 grains, which require from 60 to 80 tines that quantity of the chloride, and a period of 15 days for the experiment. The residuum, which is separable from the silver only by mechanical means, should be dried a long time at the heat of boiling water. It contains almost always iron and silica. After its weight is ascertained, it is to be burned in a crucible of platinum till the ashes no longer change their color, and are not attractable by the magnet. The difference be. tween the weights of the dried and calcined residuum is the weight of the charcoal. The oxyde of iron is afterwards separated from the silica by muriatic acid. In operating upon gray cast iron, we should ascertain separately the proportion of graphite or plumbago, and that of the combined charcoal. To determine the former, we dissolve a second quantity of the cast iron in nitric acid, with a little muriatic; the residuum, which is graphite, is separated from the silica and the combined carbon by the action of caustic potash. After being washed and dried, it must be weighed. The weight of the graphite obtained being deducted from the quantity of carbon resulting from the de composition effected by the chloride of silver, the remainder is the amount of the chemi caJy combined carbon. By employing muriatic acid, we could dissipate at once the combined carbon; but the method would be inexact, because the hydrogen disengaged would carry off a portion of the graphite. According to Karsten, Mushet's table of the quantities of carbon contained in differen; steels and cast irons is altogether erroneous. It gives no explanation why, with equa proportions of charcoal, cast iron constitutes at one time a gray, soft, granular metal, and at another, a white, hard, brittle metal in lamellar facets. The incorrectness of Mushet's statement becomes most manifest when we see the white lamellar cast iron melted in a crucible lined with charcoal, take no increase of weight, while the gray cast iron treated in the same way becomes considerably heavier. Analysis has never detected a trace of carbon unaltered or of graphite in white cast iron, if it did not proceed from small quantities of the gray mixed with it; while perfect gray cast iron affords always a much smaller quantity of carbon altered by combination, and a much greater quantity of graphite. Neither kind of cast iron, however, betrays the presence of any oxygen. Steel affords merely altered carbon, without graphite; the same thing holds true of malleable iron; while the iron obtained by fusion with 25 per cent. of scales of iron contains no carbon at all. Ihe graphite of cast iron is obtained in scales of a metallic aspect, whereas the com. bined carbon is obtained in a fine powder. When the white cast iron has been roasted, and become gray, and is as malleable as the softest gray cast iron, it still affords no gra. phite as the latter does, though in appearance both are alike. Yet in their properties they are still essentially dissimilar. With 44 per cent. of carbon, the white cast iron preserves its lamellar texture; but with less carbon, it becomes granular and of a gray color, growing paler as the dose of carbon is diminished, while the metal, after passing through an indefinite number of gradations, becomes steely cast iron, very hard steel, soft steel, and steely wrought iron. The steels of the forge and the cast steels examined by Karsten, afforded him frorr IRON. 1097 Gi to 1} per cent. of carbon; in the steel of cementation (blistered steel), he never found above 14 of carbon. Some wrought irons which ought to contain no charcoal, hold as much as I per cent. and they then approach to steel in nature. The softest and purest rons contain still 0-2 per cent. of carbon. The quantity of graphite which gray cast-iron contains, varies, according to Karsten's experiments, from 2-57 to 3-75 per cent.; but it contains, besides, some carbon in a state of alteration. The total contents in carbon varied from 3-15 to 4'65 per cent. When the congelation of melted iron is very slow, the carbon separates, probably in conse. quence of its crystallizing force, so as to form a gray cast-iron replete with plumbago. If the gray do not contain more charcoal than the white from which it has been formed, and if it contain the charcoal in the state of mechanical mixture, then it can have little or none in a state of combination, even much less than what some steels contain. Hence we can account for some of its peculiarities in reference to white cast-iron; such as its granular texture, its moderate hardness, the length of time it requires to receive annealing colors, the modifications it experiences by contact of air at elevated ten^eratuies, the high degree of heat requisite to fuse it, its liquidity, and finally its tendency to rust by porosity, much faster than the white cast-iron. We thus see that carbon may combine with iron in several manners; that the gray cast-iron is a mixture of steely iron and plumbago; that the white, rendered gray and soft by roasting, is a compound of steely iron and a carburet of iron, in which the carbon iredominates; and that untempered steel is in the same predicament. For the following analyses of cast-irons, we are indebted to MM. Gay Lussac and Wilson. TABLE.-In 100 parts. Cast-iron. Iron. Carbon. Silica. ho Manga- Remarks. White cast from Siegen 94-338 2-690 0-230 0-162 2-590 By wood charcoal. Do. Coblentz - 94-654 2-441 0-230 0-185 2-490 do. Do. a. d. Champ 96-133 2-324 0-840 0-703 a trace do. Do. Isere - - 94-687 2-636 0-260 0-280 2-137 do. Gray Nivernais - 95-673 2-254 1-030 1-043 a trace do. Do. Berry - - 95-573 2-319 1-920 0-188 do. Mixt'e of coke & do. Do. a. d. Champ 95-971 2-100 1-060 0-869 do. Charcoal. Do. Creusot - 93-385 2-021 3-490 0-604 do. Coke. Do. a. d. Franche Comt6 - 95-689 2-800 1-160 0-351 do. do. Do. Wales - - 94-842 1-666 3-000 0-492 do. do. Do. Do. - -- 95310 2-550 1-200 0-440 do. do. l Do. Do. - - - 95-150 2-450 1620 0*780 do. do. Karsten has given the following results as to carbon, in 100 parts of gray cast-iron. Combined Free Total. Gray cast-iron. carbon. carbon. carbon. Remarks. Siegen, from brown iron stone - 0-89 3-71 4-60 By wood charcoal. Siegen (Widderstein), from brown and sparry iron- -- 1-03 3*62 4-65 do. Malapane, from spherosiderite - 0-75 3-15 3-90 do. I Knigshiitte, from brown ore - 0-58 2-57 3-15 coke. IDo. at a lower smelting heat- - 0-95 2-70 3-65 do. IRON, Cast, Strength of.-In the following Table each bar is reduced to ex:;ct one square inch; and the transverse strength, which may be taken as a criterilon the value of each iron, is obtained from a mean between the experiments upl i (Memoirs of Brit. Ass.) first on bars 4 ft. 6 in. between the supports, and lexx, those of half the length, or 2 ft. 3 in. between the supports. All the other (csi li are deduced from the 4 ft. 6 in. bars. In all cases the weights were laid on the lmiddle of the bar. 1098 IRON. rable of Results obtained from Experiments on the Strengt' and other Properties of Cast Iron, from the principal Iron Works in the United Kingdom. By Mr. Wm. Fairbairn. I't'~:, " "'' a.'>..- 1 Names of Irons C ~Names of Irons 4. ~ ~( |. *1'1.d. Color.. Quality Potkey, No. 3.Cold Blast - -0. Bfrt, No. 3. Hot Blat 6- 20055 29 517159 07 llih gray Hard. e, No.. Cold Blast 0 706 151000 495 47 491 1704 872 Bluish gray Soft. iad Hill E d, No. 2. Cold Blast 4 7071 164900 43 495 409 1-581 765 Dark gay rd. 9 Old Park, No. 2. Cold Blast 0 7,040 1787000 441 529 485 1-621 718 Gray.W -. - Soft. 10 Beaufort, No. 2. Hot Blast - 4 7 108 16100 478 470 474 1512 729 Dull gray Hard. 11 Low or, No. 2. Cold Blast - - 4 7.055 15500 462 453 472 1'852 85589 Dark gray - So. 1 Buery, No. 1. Cold Blast - - 7079 15381263000 493 -5 487 491 1'7721 Gray.. Raer hard. 13Wind Mill Endo, No.. Cold Blast 5 7017 1491666 48366 453 459 1574881 5 Light gray - RalHl ard. 14 Apedale, No. 2. Hot Blast... 3 7017 14852000 457 455 456 1730 791 Light gray - Still. 1 Old Parr, No. 2. Cold Blast - 7'059 14307000 453 59 485 16811 822 Dark gray. Raer soft. 16 Beafort, No. 2. Hot Blast - 7108 1651000 48 73 455 1'51484 6729 0 Blulish gray Hard. 11 Low Mooraeteg, No. 2. Cold Blast - 7'05538 13959500 453 48355 472 1'857 855 Dark gray Rot.er soft. 18 Buffirkirky, No. 1. Cold Blast* - 7113 1003550 443 464 463 1734 770 Bright gray - - Rather hard. 19 Adeli, No. 2. Cold Blast - 5 70 14981500 441 457 449 1759 777 815Light gray - SofRather hard.. 20 Blansa, No. 3. CoBlast -159 14281466 433 464 448 1726 747 Bright gray Hard. 14 Apedale, No. 3. Hot Blast - 701785 22907700 45748 455 456148 1730 753 Light gray - tiff.Hard. 225 Oldberrie, No. 3. Cold Blast 701713894307500 4273 457 45547 1'811 8 LighDark gray. athersoft. 16 PentwynFrood, No. 2. Cold Blas 4 7038 151930006 438 473 447 1825 484 650Bluish gray Hard. 17 Maesten, No. 2. -..... 7'038 1359500 453 455 4 44 11'957 629 Dark gray - Rathersoft. 18 Muirkirk, No. 1. Cold Blast* 711314003550 444 464 443 17346 5770Bri3 Ght gray Fluid. 19 Adelphi, No. 3. Cold Blast 70807 13815500 44156 45730 449 1'79 7774 Dll htgray. Raer oft. 270 Bana, No. 3.arkold Blast 7'159038 1481 4 464 448 1'76 747 Brluish gray Hard. 28 Deron, No. 2.Cold Blast* 0 7'285 29077005 448 54 448'90 7053Light gray -. Hard. 29 Gartsherrie, No.. HotBlast 5 7'01780 13894000 42739 46741 447 1'557 998 Light gray. Raer soft. 30 F rood, No. 3. ColdBlast 5 7'031 131166 460 434 447 1'8443 625 Light gray - Open. 24 Lane End, No. 2. - - - 7'028 15787666 444 - {444 1'414 629 Dark gray Soft. 31 Carton, No. 3. Cold Blast* - -. 709451 16246966 44427 443 443 1'336 593 Gray - Ralier harSoft. 26 Dundivan, No. 3. Cold Blast 4 7087 16534000 46 430 4436 1-469 72174 Dull gray -Rather oft. 337 Maesteg, (MarkedNo. ed) 5 7038 13971500 44061 444 4432 1516887 830 Bluish gray Fluid. 28 Corbyns Hall, No... 7'007975 138458660900 430 454 442 1687 727Light gray - Ra- - erSo hardt. 29 Pontypool, No. 2. -.... H 7'080 131365000 419 44139 440 1-358 57 816Dull blue - ather soft. 30 Wallrook, No.. - - - 0- 6'979 15394766 432 449 440 1443 6254 Light gray Sofather hard. 31 Milton,Ndryo. 3. Hot Blast B- 4 705138 1584211500 4 4469 438 1512 368 Blu585 ish gray Sof Rater hard. 38 Buffery, No. 2. Hot Blast* - - 3 6'998 137305500 436 - 4 427 2-224 72 Gray Dull Soft. 39 Level, No. 2. Hot Blast - -..5 7080 154512500 461 403 432 1516 699 Lightray - Soft Hard. 34 Pant, No. 1. t Blast - 5 6'129758 15280900 408 38455 4324 15321 716 Whitisht gray Rather softard. 35 Level, No. 1. Hot Blast - 79031 132941000 41 419 429 1'358 570 6 BDull gray Soft. 43 BiereyW.S.S, No. 2.- 5 7 16156133 404 4632 429 1222339 494 DLightark gray - Soft. 37 EaleFoundry, No. 2. Hot Blast 4 7'038969 14211000 408 446 427 1512 77618 Bluish gray Soft. 38 Eld-Tcar, No. 2. Cold Blast - 695528 1435804000 446 408 413 14702'4 60992 Gray - - SRaer oft. 39 Varteg, No. 2. Hot Blast - - - 4 7'007 15012000 422 430 426 1'4,50 621{Gray... {Hard. 46 Coltham, No. 2. Hot Blast - 7'1286 15510066 464 385 424 176532 716 Whitish gray Raoft.er 41 Carroll, No. 2 Cold Blast - - - 4 7'069 17036000 430 [ 408 A19 1'231 530{Gray - - -Hard. 42 Muirkirk, No. 1. Hot Blast - - 69537 115394400333417 392 419 3418 1-89570 74656 Bluish gray Soft. 43 Bierley, No. 2........ - 7'185 16156133 404 432 418 1'-222 494{Dark gray - Soft. 44 Coed-Talon, No. 2. Hot Blast* - 4 6'969 14322500 409 424 416 1'882 [771{Bright gray Soft. 45 Coed-Talon, No. 2. Cold Blast* [ 6'955 14304000 408 418 413 1'470 600{Gray - - - IRather soft. 46 Monkland, No. 2. Hot Blast - 3 6'916 12259.500 402 404 403 1'762 709[Bluish gray Soft. 47 Ley's Works, No. 1. Hot Blast - 3 6'957 111539333 392 - 392 1'890 742[Bluish gray Soft. 48 Milton, No. 1. Hot Blast - - - 4 6976 11974500 353 386 369 1-525 638 Gray. -. Soft and ftitd. 49 Plaskynaston, No. 2. Hot Blast - 5 6916. 13341633 378 S37 357 1-366 517 Light gray Rather soft. Rule.-To find from the above table the breaking weight in rectangular bars, generally, calling b and d the breadth and depth in inches, and 1 the distance between the supports in feet, and putting 4-5 for 4 ft. 6 in., we have -- -- breaking weight in lbs., the value of S being taken from the table above. For example:-What weight would be necessary to break a bar of Low Moor iron, 2 inches broad, 3 inches deep, and 6 feet between the supports? Acoording to Analyses of Ten Specimens of Cast Iron made from South Staffordshire Iron Ore, Wets of Dudley. Iron from Hot Blast. I. 11. III. IlL IV. V. VI. Iron ----- 89.53 92-98 93-84 92-90 C(a)95-23 95-80 Carbon - - - C 327 7-93 C3-11 6-51 C 2-98 5-54 C O-S7 6-83 C(b) 1-7T 2-72 Catbon - - - -... 0-49 0-26 Silica, &c.-. -. -. 0.31 0.11 Manganese- -- 1-71 1-30 0-72 0-62 0-34 0-54 Calcium - - - 0'11 trace 0.34 0'06 0-10 0-06 Sodium - - - 0-41 0.37 0.39 0-30 0-19 0-14 Potassium -.- -... trace trace Sulphur - - 0'07 trace minute trace trace trace trace Phosphorus - - 054 lost 0-07 0-40 0-12 0-37 100-39 100-19 100'90 101.11 98-55 100-00 * The irons with asterisks are taken from the experiments on hot and cold blast iron, made by Mr Ilodgkinson and myself for the British Association for the Advancement of Science.-See Seventh ]Report, vol. vi. 1 The modulus of elasticity was usually taken from the deflection caused by 112 lbs. on the 4 ft. in. bars. IRON. 109S Iron from Cold Blast. I. III. IV. I V. Iron- --- - 94-10 96-57 945-6Y. - 94'42 Combined carbon (a) 1-87 0 95 Uncombined carbon (b) - 1-92 1-67 C 1-98 3-71 C 2'73 4.05 Silica -.- - 1 30 051 Manganese ----- 1-12 116 03 - - 094 Cobalt trace - - - -- - trace trace Chromium - - - - - - trace Calcium ------ 005 trace 0'25 - 016 Sodium - - - -- 015 trace 030 - 034 Potassium - trace 0-42 Sulphur a- - - -00 - trace11 05 trace Phosphorus - - - - 0'21 0-36 003 - 0-36 100-73 101-75 1 99-20 - - 100'27 the rule given above, we have b = 2 inches, d= 3 inches, = 6 feet, S =472 from the 4'5 X bd2S 4'5 X 2 X U X 472 table. Then I4 = - -- - 2 = 6372 lbs., the breaking weight. 1 6 A very small amount of phosphorus is found to impart to iron a great degree of brittleness, when bar iron contains but 0-5 per cent. Fig. 818. represents in section, andfig. 817. in plan, the famous cupola furnace for casting iron employed at the Royal Foundry in Berlin. It rests upon a foundation a, from 18 to 24 inches high, which supports the basement plate of cast iron, furnished with ledges, for binding the lower ends of the upright side plates or cylinder, e. Near the mouth there is a top-plate d, made in several pieces, which serves to bind the sides at their upper end, as also to cover in the walls of the shaft. These plates are most readily secured in their places by screws and bolts. Within this iron case, at a little distance from it, the proper furnace-shaft e, is built with fire-bricks, and the space between this and the iron is filled up with ashes. The sole of the hearth f, over the basement-plate, is composed of a mixture of fire-clay and quartz-sand firmly beat down to the thickness of 6 or 8 inches, with a slight slope towards the discharge-hole for running off the metal. g is the form or the tuyere (there are sometimes one on each side); h the nose pipe; the discharge aperture i is 12 inches wide and 15 inches high; across which the sole of the hearth is rammed- down. During the melting operation this opening is filled up with fire-clay; when it is completed, a small hole merely is pierced through it at the lowest point, for running off the liquid metal. The hollow shaft should a d 818 oe somewhat wider at bottom than at top. Its dimensions vary with the magnitude of the foundry. When 5 feet high, its width at the level of the tuyere or blast hole may be from 20 to 22 inches. From 250 to 300 cubic feet of air per minute are required for the working of such a cupola. For running down 100 pounds of iron, after the furnace has been brought to its heat, 48 pounds of ordinary coke are used; but with the hot blast much less will suffice. The furnace requires feeding with alternate charges of coke and iron every 8 or 10 minutes. The waste of iron by oxidation and slag amounts in most foundries to fully 5 per cent. For carrying off the burnt air, a chim ney-hood is commonly erected over the cupola. See FOUNDRY. 1100 IRON. The double-arched air or wind-furnace used in the foundries in Staffordshire for melting cast iron, has been found advantageous in saving fuel, and preventing waste by slag. It requires fire-bricks of great size and the best composition. The main central key-stone is constructed of large fire-bricks made on purpose; against that key-stone the two arches press, having their abutments at the sides against the wills. The highest point of the roof is only 8 inches above the melted metal. The sole of the hearth is composed of a layer of sand 8 inches thick, resting upon a bed of iron or of brickwork. The edge of the fire-bridge is only 3 inches above the fluid iron. In from 2 to 4 hours from 1 to 3 tons of metal may be founded in such a furnace, according to its size; but it ought always to be heated to whiteness before the iron is introduced. 100 pounds of cast iron require from 1 to 1~ cubic foot of coal to melt them. The waste varies from 5 to 9 per cent. I shall conclude the subject of iron with a few miscellaneous observations and statistical tables. Previously to the discovery by Mr. Cort, in 1785, of the methods of puddling and rolling or shingling iron, this country imported 70,000 tons of this metal from Russia and Sweden; an enormous quantity for the time, if we consider that the cotton and other automatic manufactures, which now consume so vast a quantity of iron, were then in their infancy. From the following table of the prices of bar iron in successive years, we may infer the successive rates of improvementuand economy, with slight vicissitudes. Years. Per Ton. Years. Per Ton. ~ s. ~ s. ~ 8. ~ 8. 1824 9 0 to 10 0 1830 5 5 to 6 0 1825 10 0-14 0 1831 5 5- 5 10 1826 8 10-10 0 1832 5 0 5 10 1827 8 0 9 0 1833 5 10 -6 0 1828 8 10- 8 0 1834 6 0 - 6 10 1829 5 10 - 0 1835 5 10 - 7 0 The export of iron in 1836, in bars, rods, pigs, castings, wire, anchors, hoops, nails, and old iron, amounted to 189,390 tons; in unwrought steel to 3,014, and in cutlery to 21,072; in whole to 213,478; leaving apparently for internal consumption 176,522 tons, from which however one-tenth should probably be deducted for waste, in the conversion of the bar iron. Hence 700,000 tons may be taken as the approximate quantity of iron made use of in the United Kingdom, in the year 1836. The years 1835 and 1836 being those of the railway mania over the world, produced a considerable temporary rise in the price of bar iron; but as this increased demand caused the construction of a great many more smelting and refining furnaces, it has tended eventually to lower the prices; an effect also to be ascribed to the more general use of the hot blast. The exports of foreign produce in 1850 amounted to 5,996 tons, in 1851 to 4,813 tons; of British produce of all kinds (except steel) in 1850, 772,830 tons, in 1851 908,955 tons; the declared value being respectively 4,956,3081. and 5,414,1211. The imports in bars unwrought amounted in 1850 to 34,066 tons, and in 1851 to 40,279. The relative cost of making cast iron at Merthyr Tydvil in South Wales, and at Glasgow, was as follows, eight or nine years ago. At Merthyr. s. Tons. Cwts. Qrs. ~ s. d. Raw mine at 10 per ton, 3 7 0 - -1 13 6 Coal at 6 2 16 0 -- 0 16 6 Limestone 1 5 2 - - - 0 1 4 Other charges - - - - - - - - 0 9 1 Total Cost - - - - - -3 0 5 At Glasgow. s. d. Tons. Cwts. ~ s. d. Raw mine at 4 6 3 10 - - - - 0 16 3 Splint coal at 2 5 5 15 - - - -0 14 0 Limestone at 0 3 0 14 - - -0 3 6 Coals for the engine 1 10 - - - - 8 0 Other charges - - -1 1 0 Total Cost - 2 17 9 IRON. 1101 The cost is still nearly the same at Merthyr, but it has been greatly decreased at Glasgow. The saving of fuel by the hot-blast is said to be in fact so great, that blowing cylinders, which were adequate merely to work three furnaces at the first period, were competent to work four furnaces at the last period. The saving of materials has moreover been accompanied by an increase of one-fourth in the quantity of iron, in the same time; as a furnace which turned out only 60 tons a week with the cold blast now turns out no less than 80 tons. That the iron so made is no worse, but probably better, when judiciously smelted, would appear from the following statement. A considerable order was not long since given to four iron-work companies in England, to supply pipes to one of the London water companies. Three of these supplied pipes made from the cold-blast iron; the fourth, it is said, supplied pipes made with the hot-blast iron. On subjecting these several sets of pipes to the requisite trials by hydraulic pressure, the last lot was found to stand the proof far better than any of the former three.-That iron was made with raw coal. I have been since told by eminent iron-masters of Merthyr, that this statement stands in need of confirmation, or it is probably altogether apocryphal, and that as they find the hot blast weakens the iron, they will not adopt it. Between the cast ironstnade in different parts of Great Britain, there are characteristic differences. The Staffordshire metal runs remarkably fluid, and makes fine sharp castings. The Welsh is strong, less fluent, but produces bar iron of superior quality. The Derbyshire iron also forms excellent castings, and may be worked with care into very good bar iron. The Scotch iron is very valuable for casting into hollow wares, as it affords a beautiful smooth skin from the moulds, so remarkable in the castings of the Carron company, in Stirlingshire, and of the Phoenix foundry, at Glasgow. The Shropshire iron resembles the Staffordshire in its good qualities. The average quantity of fine metal obtainable from the forge-pigs at Merthyr Tydvil, from the finery furnace, is one ton for 22j cwt. of cast iron, with a consumption of about 9J cwt. of coal per ton. Estimate of the average cost of erecting three blastfurnaces. BUILDING EXPENSES. Foundations -.. ~480 Masonry of hewn grit-stones - 60C Common bricklayers' work - - 1200 Lining of the furnace, hearth, &c., in fire-bricks - - - - - 1140 Fire-clay for building - - - - - - - 80 Lime and sand - - - - - - 800 CAST IRON. Cast-iron pieces, such as dar-plates, tymp-plates, beams, tuyere-plates, &c., weighing about 24 tons for each furnace;-in whole - - 1140 WROUGHT IRON. For the binding-hoops, keys, &c.; 5 tons for each - * 300 COST OF LABOUR. Bricklayers, masons, and labourers in building - - 1080 VARIOUS EXPENSES. Scaffolding.. - 48 Tools - - - - - - -- 160 Shed in front of each furnace 480 Terracing, cost of ground, &c. - - - - - - - 2400 Total cost of erecting the furnaces - - - - 9908 INCIDENTAL CHARGES. Blowing machinery, and steam engine of 80-horse power - * - 6400 Inclined railway for mounting the charges - - - - 120 Gallery for charging - - 160 Steam engine house - -... 400 Carried forward - 16,988 \___I___.......... I 1102 IRON. Brought forward - ~ - 16,988 Chimneys, boilers, &c...-.. 480 Roasting kilns - - 480 Coke kilns - -... 800 Dwelling houses for workmen - - - 800 Total cost of 3 furnaces complete -. - ~19,548 Estimate from the Neath-Abbey Works tin S. Wales, of the cost of machines requisite for a forge and shingling mill, capable of turning out 120 tons of bar iron per week. 1. Steam-engine upon Bolton and Watt's construction; of 40 inches diameter.r the cylinder, and 8-feet stroke; with boilers, pipes, grate, bars, firedoors, &c. &c., complete - - - ~1,600 2. System of.great-geering for transmitting the crank-motion of the engine to the mill-work, with fly-wheel, &c. - - - - - 1,090 8. A system of roughing rolls, with pinions, uprights, and every thing else necessary - - - - - 525 4. Two pails of finisher rolls, with all their accessories - 525 5. Two pairs of shear-machines, at 1701. a-piece - - - 340 6. One pair of rolls of 10 inches diameter, for making small bar iron, with all their accessories - - -.. -. 30 7. Forge hammer, including the anvil, the cam-shafts, and all the other requisites - - - - - - - - 185 8. A complete turning lathe -. - 200 ~4,695 9. To the above must be added, spare cylinders weighing about 60 tons - 960 10. Duplicate articles for the steam-engine - - - - - 11. 150 tons of cast-iron plates, to cover the floor of the mill - - - 900 12. Eight tons of cast-iron pieces for a reverberatory furnace - - - 52 13. Tools of malleable iron; rakes, oars, &c. - 28 14. Castings for mounting a cupola furnace - - - - - 50 15. Blowing machine for the cupola - - - - - - 80 16. Pieces of iron for a small forge, with two fires, two bellows, two anvils, iron tools faced with steel, and common iron tools, &c. - - 100 17. Eight tons of cast-iron pieces, and wrought-iron pieces for 14 puddling furnaces - - 983 18. Seven tons of cast-iron pieces, and wrought-iron for 4 re-heating furnaces 252 19. Tools for the puddlers and other workmen - - - - - 15 20. Iron mountings for two cranes, partly made of wood - - - 50 Total cost of machines, and pieces of iron - - - - 8165 To the above, the cost of the steam engine house is to be added, that of another forge hammer, and incidental expenses. In Staffordshire the following estimate has been given: A steam-engine of 60-horse power -- 2016 Rolls, with the iron-work of the furnaces, &c., to make 120 tons of bar iron weekly - - - - - - - - 2572 4588 The Neath-Abbey estimate is greater, but that company has a high character for making substantial well-finished machinery. Bar iron made entirely from ore without admixture of cinder, or vitrified oxide, is always reckoned worth 10s. a ton more than the average iron in the market, which is frequently made by smelting 25 per cent. of cinder with 75 of ore or mine, as it is called A.. Virlet's Statistical Table of the Produce of Iron in Europe Quintals. England (1827) - - 7,098,000 France (1834) - -- 2,200,000 Russia (1834) - - - -1,150,000 Austria (1829) - - - 850,000 Sweden (1825) - - - 850,000 Prussia. -. - 800,000 IRON 1103 The Hartz Mountains - - 600,000 Holland and Belgium - - - 600,000 Elba and Italy. - - 280,000 Piedmont. 200,000 Spain - --- 180,000 Norway... -150,000 Denmark - - - - - 135,000 Bavaria - - - - 130,000 Saxony 80,000 Poland -... 75,000 Switzerland - - - - 30,000 Savoy - - - - - 25,000 Total - 13,433,000 (equal to about 672,000 tons.) The gross annual production of iron in Great Britain is now upwards of 2,250,000 tons. Of this quantity South Wales furnishes 700,000, South Staffordshire, including Worcestershire, 600,000, and Scotland 600,000 tons. The remainder is divided among the several smaller districts. One of the principal causes of the advantages possessed by Great Britain in the manufacture of iron arises from the number and variety of the measures of argillaceous and black band ironstones which alternate with the beds of coal in almost all the coal fields; and in consequence of which, the same localities, and in many instances the same mineral workings, frequently furnish both the ore and the fuel to smelt it. So extensive are the ironstone beds of the coal measures that they furnish in themselves the greater part of the iron produced in Great Britain; but the iron-making resources of the kingdom are by no means confined to them. The carboniferous or mountain limestones of Lancashire, Cumberland, Durham, the Forest of Dean, Derbyshire, Somersetshire and South Wales, all furnish important beds and veins of laematite; those of Ulverstone, Whitehaven and the Forest of Dean, are the most extensively worked, and seem to be almost exhaustless. The brown hematites and white carbonates of Alston Moor and Weardale also exist in such large masses, that they must ultimately become of vast importance. In the older rocks of Devon and Cornwall are found important veins of black haematite, and in the granite of Dartmoor numerous veins of magnetic oxide and specular iron ore. The new red sandstone furnishes in its lowest measures beds of hemnatitic conglomerate. In the lias and oolites are important beds of argillaceous ironstones, now becoming extensively worked; and the iron ores of the green sand of Sussex, once the seat of a considerable manufacture of iron, will in all probability soon again become available by means of the facilities of railway communication. In the following classification the number of the blast furnaces in each district is given, and the ironstone of the coal measures are arranged in the definite order in which they occur in the different coal fields; so that their position in reference to tile beds of coal alternating with them is at once seen. The more important of the coal fields are also subdivided into districts showing the changes which occur in each, and thus giving a concise view of their general character. The produce of the iron manufacture in Great Britain in 1750 was only about 30,000 tons; in 1800 it had increased to 180,000 tons; in 1825 to 600,000 tons. Set METALLIC' STATISTICS. IRON, PRODUCTION OF. SoUTH WALES. (Eastern Outcrop.) Blast Furnaces. Principal Works:- In. Out. Cwm Bran - - - 0 1 Pontypool.. - 2 1 Abersychan - -- 2 4 Pentwyn - - - - 0 3 Vate - - - - 2 0 Gelynos - -. 3 0 Blaenavon - - 2 23 Furnces - -. - 12 11 1104 IRON. SOUTH WALES. (North Eastern Outcrop.) Blast Furnames. Principal Works:- In. Out. Clydach.. 4 0 Nant-y-glo... 1 Coalbrook Vale - - - 2 3 Blaina - - - - - 2 1 Cwm Celyn - - - - 2 1 Beaufort - - 7 0 Ebbw Vale - - - - 4 0 Victoria - 2 2 Sirhowey - - 5 0 Tredegar - - -7 0 50 Furnaces - - - - 42 8 The beds of coal in this division of the coal-field are all bituminous. The principal coals only are given in this section. The iron stones are principally argillaceous, although some important beds of blackband or carbonaceous ironstone exist locally. The total thickness of the coal measures, in this series, from the Soap Vein Mine to the bottom coal, is about 150 yards. SOUTH WALES. (Northern Outcrop.) Blast Furnaces. Principal Works:- In. Out. Rhymney.. 8 2 Dowlais - - 11 3 Ivor - - - - - - - 3 1 Penydarren - - 5 2 Cytharfa- - - 6 1 Hirwain -. 4 0 Duffryn and Furnace Ycha - - - 8 0 Ynysfach - - - 4 0 Aberdare - - - 6 0 Aberammon - - - - 2 1 Gadlys -.. 3 0 70 Furnaces - - - - 60 10 SOUTH WALES. (Central Anticlinal District.) Blast Furnaes. Principal Works:- In. Out. Cwm Avon - -- - 4 2 Oakwood - - - -2 0 Garth - 0 3 Maesteg - - - - 0 3 Llynvi - - - - 4 0 Neath Abbey - - - 0 2 20 Furnaces - -- 10 10 SOUTH WALES. (W estern or Anthracite District.) Blast Furnaces Principal Works:- In. Out. Venalt - - - 0 2 Ystalyfera - -. 5 6 Yniscedwin -. 3 4 Banwen - - - -0 2 Onlluyn or Brin - - - 2 0 Cwm Ammon -. -2 0 Trim Saren - 3 3 Gwendrarth - -. 0 3 Branere - - - 0 2 84 Furnaces - - - 2 22 IRON. 1105 SOUTH WALES. (SowtJhern Outcrop.) Blast Furnaces. Principal Works:- In. Out. Pentyrch - - 2 0 Toudu 1 1 Cefn Cusc - -1 2 Cefn Cribbur - - - - - - 0 1 Dinas - -3 0 11 Furnaces - - - - -7 4 The iron ore principally used at the Pentyrch works is haematite, from the carboniferous limestone on the south of the South Welsh coal-field. The annual production of iron on the south outcrop is about 25,000 tons. NORTH WALES. Blast Furnaces. Principal Works:- In. Out. Rhuabon- - - - - -2 1 Brymbo - 1 1 5 Furnaces - - 3 2 SHROPSHIRE. Blast Furnaces. Principal Works:- In. Out. Madeley Wood - - - - - 3 0 Madeley Court - - - - 2 1 The Castle - 1- 1 Light Moor - -- 2 0 Horse-hay - - - - 2 1 Lawley - - - - - 1 0 Hinkshay - - - 0 2 Stirchley -.. -4 0 Dark Lane - - - - 0 2 New Lodge - - - - - 1 1 Donnington - - - - - 3 0 Sneds Hill -.... 0 Langley- -- - 1 1 Ketley. - - - 1 33 Furnaces - - - 23 10 SOUTH STAFFORDSHIRE. Blast Furnaces In. Out. 148 Furnaces 105 43 NORTH STAFFORDSHIRE. Blast Furnaces Principal Works:- In. Out. Silverdale -. 1 4 Apedale- -. -. 2 2 Kidsgrove -. 3 0 Goldendale - - - 2 1 Etruria. -.. 3 0 Lcngton -. - 2 1 21 Furnaces - - 13 8 YORKSHIRE. (Northern District.) Blast Furnaces In. Out. Bowling - 3 2 Low Moor - - - 1 2 New Begin. - 2 0 Shelfe - -.. 0 1 Bierley - - - - 1 Farnley - - - - - 1 0 16 Furnaces - - - - 10 e 1106 IRON. Annual production of iron about 25,000 tons. The quality of iron made is very superior. The:Low Moor and Bowling marks are-especially celebrated... The beds of coal in this district are exceedingly thin. The Better Bed coal is the only one used for;ron making purposes. The White Bed and Black Bed mines of this district probably correspond with the Thorncliffe White mine and the Clay Wood mine of the southern division of this field. YORKSHIRE. (Southern District.) Blast Furnaces. Principal Works:- In. Out, Worsbro' Dale -. 0 1 Elsecar - -. 0 3 Milton - - - 1 1 Thorncliffe - 1 1 Chapeltown - - -. - 1 1 Holmes - -. - 1 Parkgate - - -.1 0 13 Furnaces -.- - - 5 8 Annual production of iron about 20,000 tons, Thickness of measures from the Hobbimer to Mirtomley beds of coal about 430 yards. The entire thickness of the coal series is however much more. The measures thin out rapidly towards the north. DERBYSHIRE. Blast Furnaces. Principal Works:- In. Out. Unston - - 1 0 Reinshaw - - -1 1 Staveley- - - 2 2 Duckmanton - - - - 0 1 Birmington Moor - - -1 0 Newbold - - - 1 0 Wingerworth - - - 1 1 Clay Cross - -1 1 Morley Park - - 2 0 Alfreton - - - - - 2 1 Butterley - - - 2 1 Codnor Park - - 2 0 West Hallam.- - 1 1 Stanton - - - 2 1 29 Furnaces 19 10 Annual production of iron about 60,000 tons; average thickness of coal measures, from magnesian limestone to Kilburne or lowest worked coal, 600 yards. Many of the beds of ironstone lie in such a thickness of measure as only to be workable to advantage by open work or bell pits. Where these means of working can be adopted the produce per acre is oftentimes very large; in the Honeycroft Rake it is 6,000 tons per acre; in the black shale 8,000 tons. NORTHUMBERLAND, CUMBERLAND, AND DURHAM. Blast Furnaces. Principal Works:- In. Out. Walker - - 2 0 Tyne - - - 2 0 Wylam - - 1 0 Hareshaw -. 0 3 Redesdale - - - 0 3 Birtley.. - -. 2 Witton Park -. - 1 Taw Law -- -. 2 3 Consett and Crookhead - - 7 7 Stanhope -.. 1 0 38 Furnaces - - - - 19 19 IRON. 110' Annual production of iron about 90,000 tons. The iron works of this district are gradually increasing in importance, the cost of fuel being so low as to permit ores to be brought from many different localities. The bands of Scotland and of Haydon Bridge the brown haematites and white carbonates of Alston and Weardale, and the argillaceous ironstones of the lias of Whitby and Middlesborough, are all used for the supply of the iror works of this district. The brown haematites deserve especial attention. They are found associated in very large masses with the lead veins of this district, and occasionally they occur as distinct and regular beds. They contain from 20 to 40 per cent. of iron. Sometimes they exist as "riders".to the vein, sometimes they form its entire mass, and in this case they occasionally attain a thickness of 20, 30, and even 50 yards. Their employment for iron making purposes is only recent, but the supply of ore which they can furnish is almost unlimited, and when some better means of separating the zinc and lead associated with them shall have been discovered, they will doubtless be found to be of great importance Remarkable changes sometimes occur in the character of the metalliferous veins of this district; the same vein which at one point bears principally lead-ore changing to a calamine vein, and then again to brown hematites. LANCASHIRE AND WEST CUMBERLAND. Blast Furnaces. Principal Works:- In. Out, Cleator Iron Company - - 3 0 3 Furnaces. The production of iron in this district is very limited, being confined to the Cleator works and one or two small charcoal works in the Ulverstone district. The quality of the latter, charcoal being used for fuel, is very superior, and the produce commands the highest prices, as it combines with the fluidity of cast-iron a certain malleability, especially after careful annealing. The iron of the Cleator works is smelted with coal, and though in consequence not equal to the other, is yet superior in quality. The ore both of the Whitehaven and the Ulverstone and Furness districts is raised most extensively for shipment to the iron works of Yorkshire, Staffordshire, and North and South Wales. In quality these ores may be considered as the finest in this kingdom, and the supplies which these districts are calculated to produce are very great. The large percentage of iron which they contain, from 60 to 65 per cent., and their superior quality, also enable them to bear the cost of transport, and they are becoming every day of greater importance. They are found both as beds traversing the beds of mountain limestone formation transversely to the lines of stratification, and also as beds more or less regular. The former is the general character of the Ulverstone and Furness ores, no clearly defined bed being as yet known in that district, whilst at Whitehaven there are two, if not more, beds of irregular thickness, but with clearly defined floors and roofs, and oftentimes subdivided by regular partings. These beds attain a considerable thickness, occasionally 20 or 30 feet. The area over which they extend is not as yet well known;but they have been worked extensively for many years, and the workings upon them are rapidly increasing. They lie beneath and close to the coal measures, which both furnishes the necessary fuel, and also important beds of argillaceous ironstones for admixture. FOREST OF DEAN. Blast Furnaces. Principal Works:- In. Out. Cinderford - - - 2 0 Forest of Dean Company - 3 0 5 Furnaces 5 0 Annual production of iron about 30,000 tons. The ores of the Forest of Dean are carboniferous, or mountain limestone ores lying beneath the coal measures, which are not here productive in argillaceous ironstones, as in other principal coal fields of the kingdom. Besides the limestone ore there is a bed in the millstone grit measures; but which is only worked very locally. The limestone ore occupies a regular position in the limestone measures, although in itself exceedingly irregular, assuming rather the character of a series of chambers than a regular bed. These chambers are sometimes of great extent and contain many thousand tons of ore, which is generally raised at an exceedingly low cost, no timbering or other supports for the roof being required. The supply of ore producible in the Forest of Dean is almost unlimited. The iron made from it is of a red short nature, and especially celebrated for the manufacture of tin 71{I LF. 1108 IRON. plates. Its superior quality always commands a high price. This ore is raised exten sively for shipment to the iron works of South Wales. It was worked at a very ancient date, either by the Romans or the Britons, as is evident from the remains of old workings along the outcrop of the ore bed. This ore averages from 30 to 40 per cent. For certain new processes for making malleable iron, Mr. W. N. Clay has obtained two successive patents. Under the first, of December, 1837, he mixed bruised heematite witl one-fifth of its weight of clean carbonaceous matter in coarse powder, and subjected the mixture in a a shaped retort to a bright red heat for twelve or more hours, till the ore be reduced to the metallic state, as is easily ascertained by applying a file to one of the fragments. When discharged, the metal is to be transferred into a balling or puddling furnace, along with about five per cent. of ground coke or anthracite, and worked therein in the usual way. He also proposes to use a conical kiln, like that for burning lime, instead of the retorts. In his second patent, dated March, 1840, Mr. Clay prescribes above 28 per cent. (from 30 to 40) of carbonaceous matter to be mixed with the ground-iron ore, containing at least 45 per cent. of metal, which mixture is to be directly treated in a puddling furnace. He also proposes to use a mixture of pig or scrap iron and ore, in equal quantities. The application, of the waste gases (carbonic oxide chiefly) of the blast furnace to the purpose of heating the puddling or balling furnace, was made the subject of a patent in June, 1841, by a foreigner not named. The process had been previously practised in Germany, and was fully described in the Annales des Mines some years ago. In fig. 819. the manner of conveying the waste carbonic oxide from a blast furnace is fhown. a, a, a, are openings leading into the vertical channels or passages b, and from thence into the chamber c. There is a top to this chamber, with openings corresponding to the pas^819 IKIIM II 1ull sages b. These openings are closed with cast-iron plates that can be taken off for the purpose of clearing out the passages b, and the chamber c. From the chamber c, the gas may be conducted in any direction, and to a distance of several hundred feet. In some localities, and in cases where it is required to take the gas from a blast furnace in |X~a la Al operation, a metal cylinder, of a smaller diameter than the top of the furnace, and of a depth equal to ma a lt g its diameter, is suspended vertically within the top of the blast furnace the whole of its length. The 1 z^ -- -Ipill ~ space between the cylinder and the furnace at the -i- | - I.....' top or mouth is to be hermetically sealed, and the furnace is to be charged through the cylinder which | - |i [ must be kept full of minerals and combustibles. Thus the space between the cylinder and the interior of the furnace remains vacant, but the gas may be conducted out of that part laterally, I. I I ___ if required. The gases led off from the blast J -I l A ~ \ furnace may, if need be, pass through heated and- - E- * ] pipes, as for the hot blast Figs. 820. and 821. represent a refining furnace for iron, with the necessary apparatus for working it with the gases, without the use of other fuel; fig. 820. being a vertical section, and fig. 821. a sectional plan view. 820 821 ed id d e The gas from the blast furnace is brought into the chamber a a, and, passing through an opening i b, it enters the furnace. c, are a series of blow pipes, through which the heated air is forced into the furnace. In the space between the part marked b and the tubes c, the gas becomes mixed with the heated atmospherical air. This combustible gas from the blast furnace, mixed with the heated air, produces an.ntense heat in the furnace, adequate to the refining of iron. The warm air for burning:he gas is usually obtained from the blowing machine and hot blast pipes. IRON. 110S For giving a still greater heat, the air may be carried through the tube f, into the iron chambers g g, or a system of pipes, whence it is led through the tube h into the semi-circular chamber i, and then through the small pipes c, c, c, into the furnace. The metal to be refined is placed in the space d d, in a liquid state, if the arrangement of the furnaces will admit of its being so taken from the blast furnace; if not, it may be nearly melted by the waste heat in the chamber e e. In order to decarbonize the metal, a quantity of warm air, from the pipe h, is conducted through the pipe k, which is divided into two nozzles or tuyeres 11, and blown upon the fluid metal in the space d d. After having been thus exposed for an hour or two, it is run off through the opening m, and will be found in a refined state. Figs. 823, 824, show the application to a puddling furnace. The openings n is admil a stream of cold water to flow through the cast-iron piece e i, to preserve it from injure by the fire. 824 823 e: d Fig.824is a welding furnace; the interior dimensions and the casing of the hearth teing different, as well as the fire bridge, from those of the puddling furnace. The pipes for conducting the gases are made of cast-iron, and must have at least a sectional area of one foot for every furnace that is to be heated. Figs. 825, 826, 827, 828, 829. show the application of this invention to the generation of steam. A chimney is here employed only at the commencement of the operation. Tba 822 N L 829 825 828 826 827 air is forced into the furnace by any sort of blowing machine, or in any other con venient way. The fuel is introduced into the fireplace, upon the grate n n, through the door a, which can be closed. The fireplace must contain as much fuel as will lasi for several hours. When the fire is first lighted, the combustion takes place in the ordinary way, on opening the door d, and the slide-valve b, and carrying through them a current of air by the chimney draught. This is continued till the steam-engine furnace, or any working (power) engine is in operation, after which a blowing apparatus is employed to force the air through the tube c, as shown in fig. 826. The openings d 1110 IRON. and b aIe then closed; the air forced in now passes through the flues f, f,, placed round and beneath the boiler. The air, on arriving at the point g, is divided, one portion passes through the opening h, regulated by a valve, into the open space beneath the grate n n, to assist in the slow combustion of the fuel. The other part of the air passes through g, into h h, round the fire-place, in order to heat the air to an intense degree. After the second portion of the air has passed into the chamber h h, it enters another i i, thence through a series of blowpipes, or through o, into p p, beneath the boiler. The burnt air goes off through p p, into a small chimney, through the opening b b, which is regulated by a valve. IRON. Hot Blast. To the account of this interesting innovation in the smelting of iron ores, given in the dictionary, I have now the pleasure of representing in accurate plans, the complete system mounted at the Codner Park Works belonging to William Jessop, Esq. For the drawings, from which the woodcuts are faithfully copied, I am indebted to Mr. Joseph Glynn, F.R.S., the distinguished engineer of the Butterly Iron Works. Figs. 830, 831, 832, exhibit the apparatus of the hot blast in every requisite detail. The smelting furnaces have now generally three tuveres, and three sets of air heating 830 ///: 1 1 f7 A I HSU lurnaces. The figures show twosets built together; the third set being detached on account of peculiar local circumstances. The air enters the horizontal pipe A, in the ground plan, fig. 830, on one side of the arched or syphon pipes, shown in upright section infig. 831, and passes through these pipes to the horizontal pipe, B, on the other side; whence it proceeds to the blast furnace. These syphon pipes are flattened laterally, their section being a parallelogram, to give more heating surface, and also more depth of pipe (in the vertical plane), so as to make it stronger, and less liable to X 1________________X__________________m_ IRON. 1111 bend by its own weight when softened by the red heat. This system of arched pipe apparatus is set in a kind of oven, from which the flue is taken out at the top of it; but it thence again descends, before it reaches the chimney, entering it nearly at the level of the fire grate (as with coal gas retorts). By this contrivance, the pipes are kept in a bath of ignited air, and not exposed to the corroding influence of a current of flame. The places and directions of these oven flues are plainly marked in the drawing. Fig. 832 is a plan of the blast furnace, crawn to a smaller tcate than that of the oreceding figures. 1 5 1o; I,' I t -- - The three sets of hot-blast apparatus, all communicate with one line of conducting pipes, A, which leads to the furnace. Thus in case of repairs being required in one set, the other two may be kept in full activity, capable of supplying abundance of hot air to the blast, though of a somewhat lower temperature. See SMELTING for con. structions of different blast furnaces; also PUDDLING. During a visit which I have recently made to Mr. Jessop, at Butterley, I found this 1112 IRON. 832 5 10 15 20 l-4 - ~ _ —I 1 --- _ \p-t eminent and very ingenious iron-master had made several improvements upon ms hot. blast arrangements, whereby he prevented the alteration of form to which the arched pipes were subject at a high temperature, as also that he was about to employ five tuyeres instead of three. For a drawing and explanation of his furnace-feeding apparatus, see SMELTING. IRON CAST, improved by combination with wrought iron. This improvement, invented and patented by Mr. Morries Stirling, has been reported upon by the Government Commissioners on the application of iron to railway purposes. It is applicable to both cast and wrought iron. A mixture of the two in certain proportions has the effect of giving a fibrous nature to the cast metal, and thereby greatly increasing its strength and tenacity. For all kinds of beams, girders, and other castings where strength is required, its use is found very advantageous and economical. Beams cast of such toughened iron may be made of less dimensions to support the same load; and they have the advantage of deflecting to a greater extent, and are therefore not so liable to sudden failure. At page 101. of the Commissioners' Report, an abstract is given of a series of trials, from which it will be seen that Mr. Stirling's alloy is nearly 50 per cent. superior to 16 other soots of iron experimented upon. Various other experiments have been made by Mr. Owen for the Admiralty, and by Messrs. Rennie and others, all with the same results, showing the increase of strength in the patent iron. Common Scotch pig iron thus toughened can be had now (1851) for about 21. 10s. per ton; and it is at least 50 per zent. stronger than the best Blaenavon iron, which costs 31. 3s. per ton. The improvements in the manufacture of wrought iron are, first, the admixture of a certain alloy in the puddling furnace, by which all malleable iron is rendered much more fibrous and tougher than common wrought iron, so much so that common or merchant bar becomes equal to best bar, thus saving one process to the manufacturer. Also very ordinary iron, which can scarcely be used at all, is made equal to the best. The'llowing abstracts of experiments are given in the Report of Commissioners (p 417. IRON ORES. 111d Breaking Strali in Tons per Square Inch. Average of Mr. Jesse Hartley's experiments at Liverpool on many sorts of malleable iron - - 232 Average of S. C. Crown Iron from numerous trials at Woolwich Dockyard - - - - -- 24-47 Average of best Dundyvan bar - -. 24-33 Average of Mr. Sterling's best quality - - - 2781 Do. another quality - 27-70 The cost of the process is only a few shillings per ton. When Mr. Stirling's toughened pig is used in the puddling furnace instead of common pig, and the alloy added, an iron is produced of a very superior quality, of a very fibrous nature, and much finer in the fibre than the iron mentioned above; this will be found very advantageous in the manufacture of thin plates and sheets. Second, the admixture of a different alloy in the puddling furnace, whereby a quantity of iron is produced quite opposite in its character to the last; instead of being fibrous, it becomes hard and crystalline, approaching to the nature of steel. The average strength of common round bars, 1 inch diameter, is about 3 inches per foot; whereas the average of Mr. Stirling's hardened iron is from one-eighth to three-eighths of an inch per foot. This shows the great stiffness obtained by this method. The crystalline nature of this description of iron causes it to resist compression, lamination, and abrasion. Thus for the top portions of wrought iron girders, it is precisely what is required to resist the compression force, the fibrous iron being used for the bottom portion, to resist the tension. For rails and tyres for wheels this sort of iron is peculiarly adapted; the top of the rails and the outside of the tyres being made with it, will resist the wear and tear and lamination so universally complained of; and rails made of the patent iron are found to answer remarkably well. They have been used on the East Lancashire, Caledonian, Edinburgh and Glasgow, and other railways, with great success; the extra cost of rails made of this iron being only from 7s. 6d. to 10s. per ton. The first of these improvements in the manufacture of metallic sheets is the use of polished rolls to such sheets as are either intended for being coated with other metals, or after such sheets have been so coated; and this improvement is more particularly applicable to iron plate either coated or to be coated with tin, zinc, or other of the more fusible metals. After the plates or sheets of iron have been cleaned by pickling or otherwise in the usual way, they are to be passed between polished rollers, using sufficient pressure to smooth the surface without injuring the quality by producing brittleness; and as iron is of such different qualities as regards its ductility, both when hot and cold (according to the district from whence the ore is produced, and peculiarities of make,) no absolute rule respecting the amount of pressure can be given, but a little practice will enable a workman to judge, and care is to be taken that the rolls are clean. The plates so.polished are then to be dipped in the usual manner into the metal or alloy intended for the coating. After the plates or sheets have been coated with any metal or alloy, they are, where a high degree of smoothness is desired, again passed between polished rolls, the degree of pressure being carefully regulated so as to avoid producing brittleness. It is not essential that the sheets of metal should be passed between the smooth rolls before coating, but it is preferred that such should be the case. IRON CAST, ENAMELLED. The Great Exhibition contained the following examples. Model of an enamelled tank or cistern composed of cast iron plates, screwed together with gutta percha joint. Model of enamelled water or gas pipes and watercloset pan, with trap pipe; dry trough, poultry trough, and spittoon. The application of enamel for the protection of water cistern pipes, &c. from oxidation and for the lining of cooking utensils is of comparatively recent date. The various materials of which the coating is composed (silex being the principal) are reduced to a fluid state; the article to be coated is dipped in the mass; a portion of the fluid adheres; it is then subjected to the heat of a muffle, and the whole becomes vitrified or reduced into a glossy covering, affording an excellent defence against oxidation, and a substitute for the protection afforded by tinning. IRON, ZINKING OF. See ZINKING. IRON ORES (Analysis of, by Bichromate of Potash). A convenient quantity of the specimen is reduced to coarse powder, and one-half at least of this still further pulverized, until it is no longer gritty between the fingers. The test solution of bichromate of potash is next prepared. 44'4 gr. of the salt in fine powder are weighed out, and put into an alkalimeter (graduated into 100 divisions), and tepid distilled water afterwards poured in until the instrument is filled to 0. The palm of the hand is then securely placed on the top, and the contents agitated by repeatedly inverting the in 1114 IRON ORES. strument until the salt is dissolved, and the solution rendered of uniform density throughout. It is obvious that each division of the solution thus prepared contains 0-444 gr. of bichromate, which corresponds to i a grain of metallic iron. The bichro. mate of potash used in this process must of course be purchased pure, or made so by repeated crystallization, and it should be thoroughly dried by being heated to incipient infusion. 100 grains of the pulverized ironstone are now introduced into a Florence flask, with 1U oz. by measure of strong hydrochloric acid, and ~ an ounce of distilled water. Heat is cautiously applied, and the mixture occasionally agitated, until the effervescence caused by the escape of the carbonic acid ceases; the heat is then increased and the mixture made to boil, and kept at moderate ebullition for ten minutes or a quarter of an hour. During these operations it will be advisable to incline the flask, in order to avoid the projection and consequent loss of any portion of the liquid by spirting. About 6 oz. of water are next added, and mixed with the contents of the flask, and the whole rapidly transferred to an evaporating basin. The flask is rinsed several times with water to remove all adhering solution. Several small portions of a weak solution of pure red prussiate of potash (containing 1 part of the salt to 40 of water) are now dropped upon a white porcelain slab, which is conveniently placed for testing the solution in the basin during the next operation. The prepared solution of bichromate of potash in the alkalimeter is then added very cautiously to the solution of iron, which must be repeatedly stirred, and as soon as it assumes a dark greenish shade, it should be occasionally tested with the red prussiate of potash. This may be easily done by taking out a small quantity on the end of a glass rod, and mixing it with a drop of the solution on the porcelain slab. When it is noticed that the last drop communicates a distinct red tinge, the operation is terminated. The alkalimeter is allowed to drain for a few minutes, and the number of divisions of the test liquor consumed read off. This number multiplied by 2 gives the amount of iron per cent. in the specimen of ironstone, assuming that, as directed, 100 grs. have been used for the experiment. The necessary calculation for ascertaining the corresponding quantity of protoxide is obvious. When black-band ironstone is the subject of analysis, or when the ore affords indications by its appearance, or during the treatment with hydrochloric acid, that it contains an appreciable quantity of carbonaceous matter, then the hydrochloric acid solution must be filtered before being transferred to the basin, and the filter, with the insoluble ingredients, must be washed in the usual way with warm distilled water, slightly acidulated with hydrochloric acid, until the filtrate ceases to give a blue colour with red prussiate of potash. In those cases, also, where the presence of iron pyrites in the ironstone is suspected, it will be necessary to remove the insoluble matter by filtering before using the bichromate solution; but with ironstones in which the insoluble ingredients are merely clay and silica, filtration is not essential. Now it is evident that the foregoing process, so far as I have described it, serves for the determination of that portion of iron only which exists in the ore in the state of protoxide. But many specimens of the common ironstone of this country contain appreciable quantities of peroxide of iron, which, being unacted upon by the bichromate of potash, would escape estimation by the present method. By an additional and easy operation, however, the amount of metallic iron in this ingredient may be likewise determined. It is only necessary to reduce it to the minimum state of oxidation, and then to add the bichromate, as previously directed. The best and most convenient agent for effecting the reduction of the persalts of iron, is sulphite of soda. The only precaution to be observed is to use it in sufficient quantity, and at the same time to take care that the iron solution contains excess of acid. When the reduction is complete, a few minutes' ebullition suffices to decompose the excess of sulphite of soda, and effectually to expel every trace of sulphurous acid. In order to test the exactness of this mode of estimating the iron in the peroxide, I made several experiments with peroxide prepared from known quantities of pure iron wire. The peroxide was thoroughly washed, dissolved in hydrochloric acid, reduced with sulphite of soda, and after complete expulsion of the excess of sulphurous acid, the solution was diluted with water and treated with bichromate of potash. I select three of the experiments:Exp. I. 10 grs. of iron consumed 8-87 of bichromate. Exp. II. 18 do. do. 15-94 do. Exp. III. 25 do. do. 22-15 do. The mean of all my experiments on this point gives the ratio of 100 of iron to 88-6 of bichromate, which is in close accordance with the former results. Whenever, therefore, the ore of iron contains peroxide, it will be necessary to add sulphite of soda to the hydrochloric acid solution before the addition of the test liquor ISINGLASS. 111. from the alkalimeter. The sulphite should be dissolved in distilled water, and added to the solution of iron in small successive portions, until a drop of the liquor gives merely a rose pink colour with sulpho-cyanide of potassium, which indicates that the reduction of the persalt of iron is sufficiently perfect. The liquid is now heated till the odour of sulphurous acid.s no longer perceptible These operations should be performed while the solution is in the flask, and before it is filtered or transferred to the basin. I will here mention, for the guidance of those who may not be fully aware of the reactions of the oxides of iron, that the existence of an appreciable quantity of peroxide in the ironstone may be readily discovered by dissolving (as directed in the process) 30 or 40 grs. of the ore in hydrochloric acid, diluting with about 8 oz. of water, filtering and testing a portion of the solution with sulpho-cyanide of potassium. If a decided dark blood-red colour is produced, the quantity of peroxide in the stone must be determined; but if the colour is only light red or rose pink, the proportion is exceedingly small, and for practical purposes not worth estimating. Of course, when the specimen of ironstone has an ochrey or a reddish appearance on the surface or in the fracture, the presence of a large proportion of peroxide is indicated, and its exact quantity must be determined. In conclusion, I must not omit to notice one or two circumstances which appear at first to militate against the accuracy of this process. It may be questioned whether solutions of the protosalts of iron do not absorb oxygen so rapidly from the air as to influence the results obtained by this method. Marguerite has shown, and my own observations completely confirm his statement, that protosalts of iron, in an acid solution, become peroxydized very slowly; and, in a particular experiment, I found that contact with the air during several hours caused no diminution in the quantity of bichromate of potash required. As the process may be completed in a few minutes, it is certain that no inaccuracy can arise from this cause. It is also important to inquire whether the chromic acid in the chromates of potash may not be partially deoxydized by hydrochloric acid alone without the presence of a protosalt of iron. Such a reaction would obviously give rise to a serious error. It is well known that concentrated hydrochloric acid rapidly decomposes the chromic acid of the chromates when aided by the application of heat. But I have satisfied myself by numerous experiments, that this acid exerts very little appreciable action upon dilute solutions of the chromates of potash, either cold or warm, and that the action is only partial even after continued ebullition; so that the present method is free from inaccuracy on this account.-Dr. Penney. Bronzing of polished iron.-The barrels of fowling-pieces and rifles are occasionally bronzed and varnished, to relieve the eye of the sportsman from the glare of a polished metal, and to protect the surface from rusting. The liquid used for browning the barrels is made by mixing nitric acid of specific gravity 1.2, with its own weight of spirit of nitric ether, of alcohol, and tincture of muriate of iron; and adding to that mixture a quantity of sulphate of copper equal in weight to the nitric acid and ethereous spirit taken together. The sulphate must be dissolved in water before being added; and the whole being diluted with about 10 times its weight of water, is to be bottled up for use. This liquid must be applied by friction with a rag to the clear barrel, which must then be rubbed with a hard brush; processes to be alternated two or three times. The barrel should be afterwards dipped in boiling water, rendered feebly alkaline with carbonate of potash or soda, well dried, burnished, and heated slightly for receiving several coats of tin-smith's lacquer, consisting of a solution of shellac in alcohol, coloured with dragon's blood. ISINGLASS, or Fish glue, called in Latin ichthyocolla, is a whitish, dry, tough, semi transparent substance, twisted into different shapes, often in the form of a lyre, ana consisting of membranes rolled together. Good isinglass is unchangeable in the air, has a leathery aspect, and a mawkish taste, nearly insipid; when steeped in cold water it swells, softens, and separates in membranous laminie. At the boiling heat it dissolves in water, and the solution, on cooling, forms a white jelly, which is semi-transparent, soluble in weak acids, but is precipitated from them by alkalis. It is gelatine nearly pure; and if not brittle, like other glue, this depends on its fibrous and elastic texture. The whitest and finest is preferred in commerce. Isinglass is prepared from the airbladders of sturgeons, and especially the great sturgeon, the accipenser huso; which is fished on the shores of the Caspian Sea, and in the rivers flowing into it, for the sake chiefly of its swim bladder. The preparations of isinglass in this part of Russia, and particularly at Astracan, consists in steeping these bladders in water, removing carefully their external coat, and the blood which often covers them, putting them into a hempen bag, squeezing them, softening them between the hands, and twisting them into small cylinders, which are afterwards bent into the shape of a lyre. They are ready for the market immediately after being dried in the sun, and whitened with the fumes of burning sulohur. 1116 ISLAND MOSS. In some districts of Moldavia, another process is followed. The skin, the stomachs the intestines, and the swim bladder of the sturgeon are cut in small pieces, steeped in cold water, and then gently boiled. The jelly thus obtained is spread in thin layers te dry, when it assumes the appearance of parchment. This being softened in a little water then rolled into cylinders, or extended into plates, constitutes an inferior article. The swim bladder of the cod and many other fishes also furnishes a species of isinglass, but it is much more membranous, and less soluble, than that of the sturgeon. The properties of isinglass are the same as those of gelatine or pure glue; and its uses are very numerous. It is employed in considerable quantities to clarify ale, wine, liqueurs, and coffee. As an article of food to the luxurious in the preparation of creams and jellies, it is in great request. Four parts of it convert 100 of water into a tremulous jelly, which is employed to enrich many soups and sauces. It is used along with gum as a dressing to give lustre to ribands and other silk articles. The makers of artificial pearls employ it to fix the essence d'Orient on the glass globules which form these pearls, and the Turks set their precious stones or jewellery by means of isinglass dissolved in alcohol along with gum ammoniac; a combination which is also employed in this country to join broken pieces of China and glass, under the name of diamond cement. That setting preserves its transparency after it solidifies, if it be well made. It is by covering taffety or thin silk with a coat of isinglass that court plaster is made. A solution of isinglass colored with carmine forms an excellent injection liquor to the anatomist. M. Rochen has made another pretty application of isinglass. He plunges into a limpid solution of it, made by means of a water bath, sheets of wire gauze set in window or lamp frames, which, when cold, have the appearance of glass, and answer instead of it for shades and other purposes. If one dip be not sufficient to make a proper transparent plate of isinglass, several may be given in succession, allowing each film to harden in the interval between the dips. The outer surface should be varnished to protect it from damp air. These panes of gelatine are now generally used for lamps instead of horn, in the maritime arsenals of France. Isinglass imported for home consumption, and duties paid, in 1835. 1836. 1835. 1836. 1,814 cwts. 1,735 cwts. ~4,290! ~4,125 ISLAND MOSS (Lichen d'Islande, Fr.; Flechte Isl., Germ.) is a lichen, the Cetraria islandica, which contains a substance soluble in hot water, but forming a jelly when it cools, styled lichenine by M. Guerin. Lichenine has a yellowish tint in the dry state, is transparent in thin plates, insipid, inodorous, and difficult to pulverize. Cold water makes it swell, but does not dissolve it. It is precipitated in white flocks by alcohol and ether. Iodine tinges'it of a brownish-green. Sulphuric acid converts it into sugar; and the nitric into oxalic acid. Lichenine is prepared by extracting first of all from the plant a bitter coloring matter, by digesting 1 pound of it in 16 pounds of cold water, containing 1 ounce of pearlash; then draining the lichen, edulcorating with cold water, and boiling it in 9 pounds of boiling water till 3 pounds be evaporated. The jelly which forms, upon cooling the filtered solution, is dark colored, but, being dried and redissolved in hot water, it becomes clear and colorless. Lichenine consists of 39'33 carbon, 7'24 hydrogen, and 55-43 oxygen. With potash, lime, oxyde of lead, and tincture of galls, the habitudes of lichenine and starch are the same. The mucilage of island moss is preferred in Germany to common paste for dressing the warp of webs in the loom, because it remains soft, from its hygrometric quality. It is also mixed with the pulp for sizing paper in the vat. IVORY (Ivoire, Fr.; Elfenbein, Germ.) is the osseous matter of the tusks and teeth of the elephant, the hippopotamus, or morse, wild boar, several species ot phooe, as well as the horn or tooth of the narwhal. Ivory is a white, fine-grained, dense substance, of considerable elasticity, in thin plates, and more transparent than paper of equal thickness. The outside of the tusk is covered by the cortical part, which is softer and less compact than the interior substance, with the exception of the brown plate that sometimes lines the interior cavity. The hardest, toughest, whitest, and most translucent ivory, has the preference in the market; and the tusks of the sea-horse are considered to afford the best. In these, a rough glassy enamel covers the cortical part, of such hardness, as to strike sparks with steel. The horn of the narwhal is sometimes ten feet long, and consists of an ivory of the finest description, as hard as that of the elephant, and susceptible of a better polish; but it is not in general so much esteemed as the latter. Ivory has the same constituents as the teeth of animals: three fourths being phosphate, with a little carbonate of lime; one fourth cartilage. See BONES. It is extensively employed by miniature painters for their tablets; by turners, in making numberless useful and ornamental objects; by cutlers, for the handles of knives nd forks; by comb-makers; as also by philosophical instrument makers, for constructing -. 1I IVORY. 1117 tle scales of thermometers, &c. The ivory of the sea-horse is preferred by aentists foi making artificial teeth; that of the East India elephant is better than of the African. When it shows cracks or fissures in its substance, and when a splinter bioken off has a dull aspect, it is reckoned of inferior value. Ivory is distinguishable from bone by its peculiar semi-transparent rhombohedral net-work, which may be readily seen in slips of ivory cut transversely. Ivory is very apt to take a yellow-brown tint by exposure to air. It may be whitened or bleached, by rubbing it first with pounded pumice-stone and water, then placing it moist under a glass shade luted to the sole at the bottom, and exposing it to sunshine. The sunbeams without the shade would be apt to occasion fissures in the ivory The moist rubbing and exposure may be repeated several times. For etching ivory, a ground made by the following recipe is to be applied tu the polish. ed surface:-Take of pure white wax, and transparent tears of mastic, each one ounce; asphalt, half an ounce. The mastic and asphalt having been separately reduced to fine powder, and the wax being melted in an earthenware vessel over the fire, the mastic is to be first slowly strewed in and dissolved by stirring; and then the asphalt in like manner. This compound is to be poured out into lukewarm water, well kneaded, as it cools, by the hand, into rolls or balls about one inch in diameter. These should be kept wrapned round with taffety. If white rosin be substituted for the mastic, a cheaper composition will be obtained, which answers nearly as well; 2 oz. asphalt, 1 oz. rosin, 2 oz. white wax, being good proportions. Callot's etching ground for copper plates, is made by dissolving with heat 4 oz. of mastic in 4 oz. of very fine linseed oil; filtering the varnish through a rag, and bottling it for use. Either of the two first grounds being applied to the ivory, the figured design is to be traced through it in the usual way, a ledge of wax is to be applied, and the surface is to be then covered with strong sulphuric acid. The effect comes better out with the aid of a little heat; and by replacing the acid, as it becomes dilute by absorption of moisture, with concentrated oil of vitriol. Simple wax may be employed instead of the copperplate engraver's ground; and strong muriatic acid instead of sulphuric. If an acid solution of silver or gold be used for etching, the design will become purple or black, on exposure to sunshine. The wax may be washed away with oil of turpentine. Acid nitrate of silver affords the easiest means of tracing permanent black lines upon ivory. Ivory may be dyed by using the following prescriptions:1. Black dye.-If the ivory be laid for several hours m a dilute solution of neutral nitrate of pure silver, with access of light, it will assume a black color, having a slightly green cast. A still finer and deeper black may be obtained by boiling the ivory for some time in a strained decoction of logwood, and then steeping it in a solution of red sulphate or rea acetate of iron. 2. Blue dye.-When ivory is kept immersed for a longer or shorter time in a dilute solution of sulphate of indigo (partly saturated with potash), it assumes a blue tint of greater or less intensity. 3. Green dye.-This is given by dipping blued ivory for a little while in solution of nitro-muriate of tin, and then in a hot decoction of fustic. 4. Yellow dye is given by impregnating the ivory first with the above tin mordant, and then digesting it with heat in a strained decoction of fustic. The color passes into orange, if some Brazil wood has been mixed with the fustic. A very fine unchangeable yellow may be communicated to ivory by steeping it 18 or 24 hours in a strong solution of the neutral chromate of potash, and then plunging it for some time in a becling hot solution of acetate of lead. 5. Red dye-may be given by imbuing the ivory first with the tin mordant, then plunging it in a bath of brazil wood, cochineal, or a mixture of the two. Lac-dye may be used with still more advantage, to produce a scarlet tint. If the scarlet ivory be plunged for a little in a solution of potash, it will become cherry red. 6. Violet dye-is given in the logwood bath, to ivory previously mordanted for a short time with solution of tin. When the bath becomes exhausted, it imparts a lilac hue, Violet ivory is changed to purple-red by steeping it a little while in water containing a few drops of nitro-muriatic acid. With regard to dyeing ivory, it may in general be observed, that the colours penetrate better before the surface is polished than aferwards. Should any dark spots appear, they may be cleared up by rubbing them with chalk; after which the ivory should be dyed once more to produce perfect uniformity of shade. On taking it out of the boiling hot dye bath, it ought to be immediately plunged into cold water, to prevent the chance of fissures being caused by the heat. If the borings and chips of the ivory-turner, caled ivory dust, be boiled in water, a hind of fine size is obtained. ________________________________________________________________ 1118 IVORY BLACK. The importation of elephants' teeth amounts to about 5000 cwts. per annum. Ivory made flexible. Ivory articles may be made flexible and semi-transparent, by immersing them in a solution of pure phosphoric acid of sp. gr. 1,130, and leaving them there till they lose their opacity; they are then to be taken out, washed with water, and dried with a soft cloth; it thus becomes as flexible as leather. It hardens on exposure to dry air, but resumes its pliancy when immersed in hot water. Necks of children's sucking bottles are thus made. IVORY BLACK (Noir d'ivoire, Fr.; Kohle von.Elfenbein, Germ.) is prepared from ivory dust, by calcination in the very same way as is described under BONE BLACK. The calcined matter being ground and levigated on a porphyry slab affords a beautiful velvety black, much used in copperplate printing. Ivory black may be prepared upon the small scale by a well regulated ignition of the ivory dust in a covered crucible. END OF THE FIRST VOLUME.